MULE DEER DECLINE IN THE WEST A SYMPOSIUM and Settings/37/Site... · 2015-05-28 · MULE DEER...

MULE DEER DECLINE IN THE WEST A SYMPOSIUM

utah state university college of natural resources

utah agricultural experiment station logan, utah 84322

MULE DEER DECLINE I N THE WEST

A SYMPOSIUM

Edi to rs and Symposium Directors:

Gar N. Workman Jessop B. Low

Sponsored by :

College of Natural Resources, Utah S t a t e Universi ty Natural Resources Alumni Associat ion, Utah S t a t e Universi ty

Extension Services, Utah S t a t e Universi ty Utah Chapter of The Wi ld l i fe Society

Bonneville Chapter of t h e American F i sher ies Society Intermountain Sect ion of the Society of American Fores te r s Utah Chapter of the S o i l Conservation Society of America

ACKNOWLEDGMENTS

The sess ion chairmen f o r t h i s symposium were: Norman V. Hancock, Chief4ame Management, Utah Divis ion of Wi ld l i fe Resources; Paul W. Sh ie lds , Utah Regional Wi ld l i fe Bio log i s t , U. S. Forest Service; Ronald S. Trogstad, Utah Wi ld l i fe Management Bio log i s t , Bureau of Land Management.

The following s e c r e t a r i e s a l s o a s s i s t e d i n preparat ion of the program, typing, and providing ass i s t ance t o speakers and guests : Karen Mi tche l l , Lonna Beth Bowles, and Marcie Egbert .

FOREWORD

Mule deer numbers i n the Western United S t a t e s experienced a general dec l ine in nmbers from t h e e a r l y 1950's u n t i l t h e present mid-1970's. At l e a s t a p a r t of t h i s dec l ine was a r e s u l t of a planned reduct ion by game managers t o a d j u s t deer numbers t o the carrying capaci ty of overused deer winter ranges. I n add i t ion t o the planned reduct ion of deer numbers, i t became apparent by 1970 t h a t the reduct ion i n nun- be r of deer on western ranges was the r e s u l t of something beyond the planned reduct ion programs. The cause, or causes, f o r t h e reduct ion was not c l e a r l y understood or even defined i n many cases. Such in- f luences as predat ion, canpe t i t ion , weather, d i sease , h a b i t a t changes, and n u t r i t i o n were suspected causes. Perhaps the main cause of the dec l ine has no t been discussed and w i l l need t o wa i t f o r f u r t h e r research.

This symposium was designed t o help n a t u r a l resource managers become b e t t e r informed about t h e reduct ion and t h e various reasons f o r t h e mule deer dec l ine i n the West. The speakers a t t h i s conference a r e considered t o be a u t h o r i t i e s on the various aspec t s of mule deer populations. Subsequently, the information presented i n these proceedings represents some of the important cur ren t knowledge per ta in ing t o present-day mule deer populat ions, research, and management.

Gar W . Workman and Jessop B. Low

Table of Contents

Page

Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction to Conference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A Historical Account and Present Status of the Mule Deer in the West . . . . . . . . . . . . Mule Deer Habitat Changes Resulting from Livestock Practices . . . . . . . . . . . . . . . . Alteration of Mule Deer Habitat by Wildfire. Logging. Highways. Agriculture. and

HousingDevelopments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Interspecific Competition Between Mule Deer. Other Game Animals. and Livestock . . . . . . . Deer Range Improvement and Mule Deer Management . . . . . . . . . . . . . . . . . . . . . . . An Overview of Big Game Management . . . . . . . . . . . . . . . . . . . . . . . . . . Mule Deer Nutrition and Plant Utilization . . . . . . . . . . . . . . . . . . . . . . . . . . Mule Deer Productivity.. Past and Present . . . . . . . . . . . . . . . . . . . . . . . . . . Regulations and the Mule Deer Harvest.. Political and Biological Management . . . . . . . . . Reliability of Mule Deer Population Measurements . . . . . . . . . . . . . . . . . . . . . a

Mule Deer Management Myths and the Mule Deer Population Decline . . . . . . . . . . . . . a .

The Possible Influences of the Mountain Lion on Mule Deer Populations . . . . . . . . . . . . Potential Influence of Coyotes on Mule Deer Populations . . . . . . . . . . . . . . . . . . . Mule Deer Disease Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mule Deer Mortality from Various Causes . . . . . . . . . . . . . . . . . . . . . . . . . . . Probable Causes of the Recent Decline of Mule Deer in the Western U.S...A StmmarY . . . . . .

INTRODUCTION TO CONFERENCE

John E. Phelps , Di rec to r Utah Divis ion of W i l d l i f e Resources

Since pioneer days, t h e Western mule dee r has been of g r e a t value and concern t o t h e populace. E a r l i e r s e t t l e r s were alarmed about s c a r c i t y of t h e animals. A t t h e tu rn of t h e cen tu ry , grandfather and f a t h e r t a l k e d f o r days about t h e event i f by chance they saw a deer .

Things changed, however, and populat ions of dee r inc reased . I n t h e l a t e 1940 's and e a r l y 1950's landowners and l i v e s t o c k people complained b i t t e r l y about dee r on t h e i r land o r on f e d e r a l lands. A t t h a t t ime, game managers recognized t h e need f o r reduc- t i o n of t h e s i z e of dee r herds . A program t o reduce dee r populat ions was g e n e r a l l y c a r r i e d on u n t i l t h e middle 1960 's . However, hun te r s genera l ly f e l t t h a t the game departments were going t o o f a r . Unfortun- a t e l y , we f a i l e d t o persuade many people t h i s was a c a l c u l a t e d management p lan , and a s a r e s u l t , many voca l c r i t i c s emerged.

I n my opinion, s i n c e t h e e a r l y 1970 's t h e r e has been a genera l dec l ine i n t h e populat ion of t h e West- e r n mule dee r .

Big game t echn ic ians i n t h e Western Associa t ion of S t a t e Game and Fish Commissioners held two meet- i n g s , one i n 1964 and t h e o t h e r i n 1968, t o d i scuss t h e genera l dec l ine of some of the d e s e r t herds i n t h e Southwest.

I n 1970, an annual western mule dee r workshop was inaugurated because of a d e c l i n e o r f l u c t u a t i o n i n most mule dee r herds throughout t h e West. During t h e f i r s t few workshops, emphasis was on product iv- i t y and fawn su rv iva l . Technicians now recognize t h a t t h e r e i s probably no s i n g l e f a c t o r t o which a de- c l i n e can be a t t r i b u t e d .

E r r a t i c fawn product ion occurred i n t h e d e s e r t herds of t h e West i n t h e l a t e 1960 ' s . It was t h e e a r l y 1970 ' s when more s i g n i f i c a n t , widespread, and abrupt drops i n fawn product ion occurred throughout most of t h e Western S t a t e s . General causes f o r t h e d e c l i n e i n Utah were noted. Undoubtedly, most of t h e s e f a c t o r s were opera t ive i n o t h e r Western S t a t e s .

Following a r e some of t h e causes of t h e d e c l i n e i n Utah dee r herd numbers. They a r e arranged i n o rde r of t h e i r importance.

1 ) The win te r l o s s of 1972-1973. This i s t h e p r i n c i p a l f a c t o r f o r a s t a t ewide d e c l i n e i n Utah.

2 ) Does were i n poor shape i n t h e s p r i n g of 1973 following t h i s bad win te r . As a r e s u l t , fawn product ion was down. This va r i ed con- s i d e r a b l y from u n i t t o u n i t .

5 ) The excep t iona l ly long, co ld s p r i n g of 1975 extended i n t o June and caused s i g n i - f i c a n t fawn l o s s e s dur ing t h e peak of t h e fawn drop i n southern and sou th -cen t ra l Utah.

6 ) Another cause is t h e p reda to r . P r i n c i p a l p reda to r s a r e dogs (domestic and f e r a l ) , coyotes , and mountain l i o n s .

7 ) Other genera l f a c t o r s a r e ope ra t ing a l so . These a r e highway m o r t a l i t y , d i sease , acc iden t s , and poaching. Undoubtedly, t h e r e a r e o t h e r th ings involved which a t t h i s time we do no t understand.

8 ) F i n a l l y , t h e r e is another concern which i n importance would be w e l l up on t h i s l i s t , b u t , f o r t h e sake of t reatment only , I have reserved f o r t h e l a s t . This i s h a b i t a t lo s s . Th i s l o s s is a slow, creeping a c t i v i t y which sometimes i s s o g radua l t h a t we do not recognize i t u n t i l we begin t o s e e i t s combined cumulative e f f e c t s .

Chief h a b i t a t l o s s e s t h a t we s e e a r e caused by u rban iza t ion , land specu la t ion , t h e second-home movement, and adverse p l a n t success ion away from browse spec ies . This l a t t e r has been i n t e n s i f i e d by t h e t o t a l e l imina t ion of l i v e s t o c k grazing on many dee r win te r ranges. The ph i losoph ica l b a s i s f o r e l imina t ing l i v e s t o c k grazing emerged from a p o i n t of view t h a t management of t h e watershed should be c a r r i e d out wi th the u l t i m a t e goa l of e s t a b l i s h i n g and mainta ining a climax vege ta t ion o f grasses .

P r i o r t o t h e smokey-the-e ear syndrome and modern f i r e f i g h t i n g techniques , n a t u r e and t h e Indian provided f o r a d i v e r s i f i c a t i o n of a climax vege ta t ion by f i r e . U n t i l very r ecen t t imes, our co lon iza t ion f u r t h e r extended s e v e r a l v e g e t a t i v e s t a g e s through widespread use of domestic l i v e - s tock. Unfor tunate ly , now t h e r e is developing an a n t a g o n i s t i c a t t i t u d e towards l i v e s t o c k g raz ing on p u b l i c lands .

It is necessary t o have this graz ing a s a l e - g i t i m a t e range management t o o l t o mainta in vege- t a t i v e types f o r m u l t i p l e uses. We should b e think- i n g of i t i n terms of proper l i v e s t o c k grazing and c o r r e c t season of use.

I n t h e course of t h e nex t day and a h a l f , we a r e going t o have t h e oppor tun i ty of exp lo r ing some of these f a c t o r s and undoubtedly o the r s . By tomorrow a f t e rnoon , I hope we a r e a b l e t o s e e where they f i t i n t o t h e o v e r a l l s t a t u s of our p a s t and p resen t mule dee r herds throughout t h e West.

3 ) I n t h e e a s t e r n and sou th -cen t ra l p a r t s For t h e peace of mind of t h e d i r e c t o r s of t h e of t h e s t a t e , 1972 fawn crops were down a s a w i l d l i f e agencies of t h e Western S t a t e s , an r e s u l t of drought cond i t ions i n 1971-1972. o p t i m i s t i c f u t u r e is predicated--we are going t o look

a t t h e f u t u r e , no t j u s t t h e p a s t and p resen t . 4 ) High a n t l e r l e s s removal occurred i n t h e

c e n t r a l and sou th -cen t ra l p a r t s of Utah dur ing 1971, 1972, 1973, and 1974.

1 Introduction t o Conference

A HISTORICAL ACCOUNT AND PRESENT STATUS

OF T m MULE DEER I N THE WEST

Ode11 Julander Professor Emeritus

Brigham Young Univers i ty , Provo, Utah 84601

Jessop B. Low Professor

Department of Wi ld l i fe Science Utah S t a t e Universi ty , Logan, Utah 84322

Abstract

The dec l ine of mule deer (Odocoileus hemionus) has been documented by most western s t a t e s during t h e pas t severa l years . I n t h e main, t h e dec l ine has been a t t r i b u t e d t o a number of causes, p r i n c i p a l l y , however, t o overhagvesting, range reduct ion, h a b i t a t change from l ives tock and deer pressure, poor deer reproduct ion, urbanizat ion, f i r e c o n t r o l , and management e f f o r t s t o reduce herds nearer range carrying capaci ty. The h i s t o r y of the mule deer herds noted s c a r c i t y during prepioneer days and the e a r l y pioneer set t lement period t o a l a r g e bu i ldup of herds during the second quar te r of the twentieth century. The bu i ldup was Concurrent with conversion of ranges from grass t o browse, con t ro l of pre- d a t a t o r s and p ro tec t ion of herds through l imi ted and manipulated harvests . Large herds i n t h e l a t e 1930s through the 1960s were reduced through con t ro l permits above the regu la r ha rves t . Documented d a t a on a number of ind iv idua l herds i n Utah and Arizona i n d i c a t e a genera l dec l ine i n numbers a s a r e s u l t of management t o br ing deer numbers wi th in carrying capac i ty of the range.

The dec l ine of the mule deer i n t h e West has been of major concern t o most s t a t e conservat ion agencies during recent years . Many s t a t e s have documented t h i s dec l ine i n populat ion and harvest t r ends , a s w e l l a s hunter success. Following periods of r e l a t i v e l y few deer i n p rep ioneer days, then dep le t ion of the pop- u la t ions by t h e e a r l y pioneers and t h e inc reas ing numbers i n the f i r s t h a l f of t h e century, t h e herds have now decreased and appear t o be dec l in ing even f u r t h e r .

The decl ining populations of mule deer was recognized and documented by many workers, a s pointed ou t by Longhurst e t a l . (1976):

For t h a t matter , t h e dec l ine of deer has by no means been confined t o Ca l i fo rn ia , bu t seems t o have been a genera l phenomenon i n a number of western s t a t e s . By 1964 a number of s t a t e s recognized t h a t Rocky Mountain mule deer populat ions had s t a r t e d t o dec l ine (Macgregor, 1964)-California; (Mohler, 1964)-Idaho; (McKean and Luman, 1964)-Oregon; (Greenly and Humphreys, 1964)- Nevada; and (Hancock, 1964)-Utah. By 1968

even more s t a t e s were documenting t h e de- c l i n e (Russo, 1968) -Arizona; (Macgregor , 1968)-Nevada; (Nielson and Williams, 1968)- Idaho; (Snyder, 1968)-New Mexico; (S te in , 1968)-0regon; (Lauchart, 1968)-Washington; (Corsi, 1968)-Wyoming; and (Hancock, 1968)-

Utah.

Many people have blamed t h e dec l ine t o over- shooting, predators , range reduct ion or d e t e r i o r a t i o n from too many l ives tock , and the presence of too many deer , which l i t e r a l l y "a te themselves out of house and home." Urbanizat ion, f i r e con t ro l , and the causes and reasons a r e legend, depending upon who asks and answers the question--sportsman, b i o l o g i s t , admin i s t ra to r , o r housewife. Perhaps our quest ion should not be, "Has the re been an unexplained de- c l ine?" , but r a t h e r , "Has t h e dec l ine o r reduct ion been the response of d e l i b e r a t e programs designed t o manage watersheds o r reduce over populat ions of deer t h a t had previously responded t o favorable management p r a c t i c e s o r favorable h a b i t a t condit ions and thus b u i l t up beyond t h e normal carrying capaci ty of t h e i r ranges?"

3 A HistoricaZ Accomt and Present Status of the Mule Deers i n the West

We acknowledge the f i n e response from a l l f i s h and game organizat ions i n the western s t a t e s regarding t h e h i s t o r y of mule deer i n t h e i r s t a t e . We must, of course, i n the i n t e r e s t of time, pa in t with a broad brush the h i s t o r y and present s t a t u s of mule deer i n the West. To do otherwise would e n t a i l too much space and time. Since we a r e most acquainted with Utah, our emphasis w i l l undoubtedly be on the h i s t o r y of the deer i n t h i s s t a t e . However, the same general p i c t u r e p reva i l s i n most western s t a t e s .

Re la t ive Nunbers Pr io r t o Early Pioneer Days

Relat ively l i t t l e i s known concerning the t rue numbers of mule deer p r i o r t o the e a r l y pioneers . Trappers and e a r l y explorers r a r e l y reported deer , except inc iden t t o o ther observations.

Father Esca lan te ' s pa r ty i n September and October, 1776, explored the Utah a rea and o ther western t e r r i - t o r i e s . Although Escalante t r ave led through and along the borders of some of Utah's bes t present-day big game hunting grounds, he made no mention of e i t h e r deer o r e l k , both of which he noted i n southwestern Colo- rado. Further , Escalante reported t h a t while t r ave l - ing south from Utah Lake the party ran out of food and experienced g rea t d i f f i c u l t y i n obtaining g ra in , seeds and nuts from the Indians and found i t necessary t o k i l l severa l of t h e i r horses f o r food. I n o ther a reas they reportedly kill .ed buf fa lo , t raded wi th Indians f o r bighorn sheep meat, but made no mention of deer .

In the 1820-1834 period of explorat ion and in- t ens ive f u r t rapping, s t a l w a r t mountain men, such a s J.S. Smith, 1826-1827; W.A. F e r r i s , 1830-1834; J.R. Walker, 1833-1834; and o thers , recorded i n d i a r i e s and journals only i n d i c e n t a l mule deer , although buf fa lo , antelope, e l k , and beaver were regu la r ly recorded.

Osborn Russe l l recorded mule deer i n h i s d ia ry during the period 1834-1843, while t rapping beaver i n northern Utah i n 1837, he speaks of having a Christmas par ty with h i s family and f r i e n d s i n which "The next d i sh was s i m i l a r t o the f i r s t (e lk) heaped up wi th boi led deer meat (or as t h e whites c a l l i t , venison, a term not used i n the mountains.)" (Haines, 1955, p. 115). La te r , i n what was probably Utah County, he speaks of the Indians: "If a Eutaw has 8 o r 10 good horses , a r i f l e , and ammunition, he is contented i f he fe tches a deer a t night from t h e hunt. . ." (Haines, 1955, p. 121).

Essen t ia l ly the same s t o r y i s t o l d i n a l l western s t a t e s i n prepioneer days--that of r e l a t i v e l y few deer , apparent ly i n harmony with t h e i r environment and h a b i t a t . Montana records t h a t :

Mule deer (Odocoileus hemoinus) have been an important b ig game animal i n Montana a s f a r back as records e x i s t . The popula r i ty of t h i s na t ive deer among the Indians might be ascr ibed t o the f a c t the meat, f r e s h o r cured, i s very pa la tab le ; the hide was used t o make buckskin, and even the bones and a n t l e r s made use fu l implements.

The e a r l y exp lore r s , f u r t r appers , and s e t t l e r s a l s o used and depended on the mule deer as a source of food and clothing. The

hides were even used as l e g a l tender ( 5 0 ~ per hide) i n p a r t s of Montana j u s t before the tu rn of t h e century.

Lewis and Clark can be c red i ted with w r i t i n g t h e f i r s t d e t a i l e d account of mule deer h a b i t a t requirements. There i s evidence t h a t Lewis coined t h e name, "Mule Deer," when he s t a t e d , "We have r a r e l y found the mule deer i n any except rough country. They pre fe r the oDen grounds and a r e seldom found i n woodlands or r i v e r bottom." (Egan, 1971)

P r a c t i c a l l y a l l s t a t e s with mule deer have records, d i a r i e s , and h i s t o r i e s point ing out the s c a r c i t y of deer i n the e a r l y prepioneer days, but i n d i c a t i n g t h a t deer were known t o occur i n about a l l the s t a t e s now having mule deer. Deer was not the choice food of the beaver t r appers o r exp lore r s , who chose bighorn sheep and e l k when possible . Deer was, however, taken when poss ib le as food by ex- p lo re r s and t rappers a l i k e . The Lewis and Clark ex- ped i t ion of the e a r l y 1800's d e t a i l e d the w i l d l i f e , including deer , i n the northwest. Such t rappers and explorers a s Pe te r Skene Ogden, Townsend, and Alexander Ross a l s o recorded i n t h e i r journals about the r e l a t i v e s c a r c i t y of deer i n comparison t o other w i l d l i f e .

Depletion of Mule Deer i n Pioneer Days

When the pioneers entered t h e Great S a l t Lake Valley on Ju ly 24, 1847, b i g game animals were sca rce , a s reported bv the t r appers and explorers . The hear ty pioneers su f fe red acute food shortages during the f i r s t winter . Indians and whites a l i k e vigorously hunted the few deer f o r t h e i r meat and hides.

Captain Stansbury reported t h a t during t h e winter and spr ing of 1847-1848, Mormon pioneers i n t h e Great S a l t Lake Valley were forced t o d ig roo t s and t e a r h ides from t h e i r roofs i n order t o survive. He frequently mentioned t h a t game was sca rce t h i s f i r s t winter i n the val ley. Thus, although we have no h i s t o r i c a l record upon which numerical est imates of deer numbers i n ZTtah can be based a t the time of t h e f i r s t se t t l ements , i t i s apparent t h a t t h e r e were r e l a t i v e l y few deer.

During the period between the advent of the pioneers and t h e end of t h e century, severe dep le t ion of Utah's grasslands occurred as a r e s u l t of excess- i v e grazing by domestic l ives tock gave r i s e t o the spread and abundance of browse spec ies , many of which were choice deer foods, which s e t the s t a g e f o r the deer populat ion booms to come not too many years l a t e r . The unres t r i c ted hunting and unres t r i c ted grazing by domestic s tock over the e n t i r e s t a t e had, by the tu rn of the century, depleted much of t h e n a t i v e forage and b i g game numbers t o t h e ex ten t t h a t ac t ion was necessary t o save both of these resources (Utah Biennial Report, 1946).

One o ld timer t h a t I interviewed about 1950 re- c a l l s t h a t i n about 1900, he, a s a youth l i v i n g near the h i l l s d i r e c t l y above Providence i n Cache Valley, Utah, found deer t r acks scarce. On one occasion, he reportedly followed a deer t rack f o r four consecutive

A Historical Accomt and Present Status of t h e 4 Mule Deer i n the West

days before g e t t i n g a f l e e t i n g glimpse of t h e animal (Low, personal f i l e s ) .

The s i g n i f i c a n t events and condit ions a f f e c t i n g Utah's mule deer populations from e a r l y h i s t o r i c times t o the present a r e b r i e f l y given i n Table 1 and fur- t h e r i l l u s t r a t e d i n Figure l.

Other S t a t e s

Populations of mule deer i n most, i f not a l l , western s t a t e s su f fe red a t the hands of t h e pioneers and e a r l y s e t t l e r s . No game laws o r thought of pro- t e c t i o n made the mule deer, a s w e l l a s other w i l d l i f e , t a r g e t s of the pioneers f o r a r t i c l e s of food and clothing. A few excerpts from some of the western s t a t e s i l l u s t r a t e , although incompletely given, t h e mule deer s i t u a t i o n i n pioneer days:

Arizona No records a r e a v a i l a b l e , but from

some pioneer documents t h e r e was an indica- t i o n t h a t deer populations were very low. Many of the pioneers had t o depend on rabbibs, e t c . f o r protein. (Russo, 1976, personal comunica t ion) .

Ca l i fo rn ia rhere were fewer mule deer i n e a r l y

pioneer days than a t present . . . Herds were depleted primari ly during the gold rush by hunting f o r hides and meat. (Macgregor, 1976, personal communication).

Idaho - The Lewis and Clark expedit ion of t h e

e a r l y 1800's r epor t s deer as we l l a s o ther wild animals:

"On June 3, 1806, two members of t h e i r pa r ty k i l l e d f i v e deer. . ."

Pete r Skene Ogden repor t s : When t h e pa r ty f i n a l l y s t rugg led

through deep snav over the s-mit t o camp on t h e Birch Creek s i d e , they m o t e of many buf fa lo , e l k , deer , and goats i n t h e country. Ogden s a i d , 5 wretched country, we had hopes of f ind ing deer , but we a l l know (now) t h a t the re a r e none t o be seen from River Malade (Magic a rea ) t o Burnt River.

Townsend's n a r r a t i v e reported: La te r , a s t h e party moved ac ross the

dese r t t o Lost River and over t o Big Wood River , they were t roubled by lack of game and s a i d they only k i l l e d th ree buf fa lo i n severa lweeks , but did f ind deer i n good numbers on t h e Malade (Big Wood) River.

The Alexander Ross Journals : l'he Big Wood River a rea was ' a

beaver hunter 's paradise. ' As the p a r t y moved along the lower Boise River i n l a t e June, they k i l l e d 17 deer and 6 e lk . (Edison, 1963).

Nevada Deer were considered abundant i n

Nevada only s i n c e the 1930's. Scat tered repor t s of e a r l y explorers and hunters mention few o r no deer . (McColm, 1976).

New Xexico In 1880, the f i r s t conservat ion

law was passed i n New Mexico because of the continued dec l ine i n game numbers. . . Two years l a t e r , i n 1899, a bag l i m i t of one buck deer was imposed by the T e r r i t o r i a l Legislature. Because t h e pub l ic refused t o accept the law, decimation of game continued; the re fore , the t e r r i t o r i a l law- makers placed a five-year closure on the hunting of deer , e l k , antelope, and mountain sheep. I n 1903, the deer season was again opened f o r deer. The s t a t e ' s deer herd continued i t s apparent dec l ine , reaching its lowest ebb about 1924 when the popu- l a t i o n f o r a l l deer on n a t i o n a l f o r e s t s within t h e s t a t e was est imated t o be 19,488. By 1926, the s tatewide deer popu- l a t i o n was est imated a t 41,000. (Stewart, 1967, p. 42.)

Montana Population peaks reportedlv occurred

i n the l a t e 18801s, t h e e a r l y 1900's, and t h e l a t e 1920's i n southeastern Montana. The reported peak of the l a t e 1920's was of small magnitude and was preceded by a period when many res iden t s considered the deer e x t i n c t . (Egan, 1971).

Oregon 1899 -1912 Scarce deer populations.

Deer genera l ly sca rce , b u t l i t t l e hunting pressure. Lack of roads and t ranspor ta t ion l imi ted harves t and the re was l i t t l e hunting pressure. . .

1913-1922. . .deer continued t o be scarce. (Anonymous 1971, p. 1 . )

Washington No e a r l y records, b u t mule were

uncommon u n t i l about 1935. (L. D. Parsons, 1976, personal communication.)

pew deer i n pioneer days. "In t h e e a r l y 1800's wh& the white man f i r s t entered what is now Wyoming, he found w i l d l i f e i n abundance, e spec ia l ly bison, antelope, e l k , and bighorn sheep. Deer were a l s o abundant, but apparent ly not i n such no t iceab le numbers as t h e o ther animals.

Populations of big game animals reached a low about the tu rn of the century." (Corsi, Wyoming Wildl i fe , Aug. 1974, p. 3.)

Build Up of the Herds and Management Measures

Utah - I n recognit ion of the s c a r c i t y of mule deer ,

the Utah l e g i s l a t u r e ended the " f ree r ide" f o r hunters i n Utah i n 1908. The season on deer then was closed and remained closed f o r f i v e years . I n 1913, t h e l e g i s l a t u r e declared a season t o take buck deer only with a n t l e r s 5 inches o r longer. Tine k i l l of deer during the f i r s t buck season (1914) was recorded when "approximately 600 of these magnificent

A Historical Acco~mt and Present Status o f the Mule Deer i n the West

MULE DEER HARVEST IN UTAH IN THOUSANDS

? - + + - +

+ N W C V I O I U W a O r N w p 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

a m a n n ~ m

,-. 0 m r+ a cl

m m n 1 1

er die off (1936-1937) P 2 1 w S 1 m b, rt r,

\Interagency comnittee established (1942)

avy winter mortality (1948-1949)

the state (1973)

animals were taken, and these mostly i n the eas te rn p a r t s of t h e s t a t e . " (Utah Biennial Report, 1946).

This indeed was the turning po in t , a s deer continued t o increase i n numbers each year from 1913. Mule deer populations i n Utah were given from time t o time from the e a r l i e s t es t imate of 8,500 i n 1916, t o and including the est imated he igh t of t h e population i n the 1945-55 period a t about 375,000. These e s t i mated f igures by the western s t a t e conservation departments were compiled by t h e U.S. F i sh and Wi ld l i fe Service (1937 t o 1970) i n a s e r i e s of w i l d l i f e l ea f - l e t s issued each year (Table 2). No claim was made by any s t a t e o r the Service f o r t h e accuracy of the f igures . Most s t a t e s stopped publishing estimated populat ions i n t h e 1 9 4 0 ' s because of t h e inaccuracies of pas t est imations and s t a r t e d using hasvest f i g u r e s and o ther measurements a s more accura te i n d i c i e s t o populat ion changes (Tables 3 and 4). The Utah S t a t e l e g i s l a t u r e i n 1917 es tab l i shed a s e r i e s of l a r g e game preserves, which by 1923 consis ted of near ly a mi l l ion ac res of the s t a t e ' s bes t deer and e l k range, t o provide p ro tec t ion f o r these game animals.

Recognition of t h e damage caused t o farmlands and the competitive na tu re of e l k with l ives tock r e s u l t e d i n the establishment of the Board of Elk Control in 1927; l a t e r , i n 1933, t h i s organizat ion was changed t o the Board of Big Game Control , with the a u t h o r i t y t o e s t a b l i s h regu la t ions f o r a l l b ig game animals i n t h e s t a t e . I t s funct ion and r e s p o n s i b i l i t i e s have been inc reas ing ly important s i n c e i t s establ ishment . This board, composed of members of land managing agencies , has membership represent ing f e d e r a l lands, Utah Wild- l i f e and Recreation Federat ion, Cat t leman's Associa- t i o n , Wool Grower's Associat ion, and t h e Divis ion Wi ld l i fe Resources. This Board was instrumental i n taking ac t ion on rap id ly r i s i n g deer herds and t o manage them on an ava i l ab le game and range b a s i s .

Severe winter weather, accompanied by deep snows over much of t h e winter season, has had a devas ta t ing e f f e c t upon deer populations i n Utah, beginning as e a r l y a s 1936- 37, again i n 1939-40, 1948-49, and 1951- 52, and of l a t e i n 1972-73. During some of these win- t e r s , more deer have died from malnu t r i t ion i n loca l - i zed a reas of t h e s t a t e than were k i l l e d by hunters (Low, e t a l . , 1949; Hancock, 1976, personal communi- ca t ion) .

Undoubtedly many f a c t o r s had an e f f e c t upon t h e bui ld up of deer herds i n Utah, and o ther western s t a t e s , during t h e 1920- 40 period. Predator c o n t r o l , which had its beginnings i n t h e 1880's by stockmen,

was se r ious ly i n i t i a t e d i n 1916, when the f e d e r a l government entered t h e con t ro l p ic tu re . Livestock numbers, which soared t o 275,000 range c a t t l e and 2,742,000 range sheep i n the 1 8 9 0 ' ~ ~ undoubtedly brought a s i g n i f i c a n t change from g r a s s t o browse ranges, which permit ted deer populat ions t o inc rease (Utah Biennial Report, 1946). Habitat l o s s e s , e a r l y recognized as r e s u l t s of urban sprawl, highway development, f a m i n g p r a c t i c e s , and others , concentrated or el iminated deer. Buck hunting i n t h e f i r s t one- t h i r d of t h e 20th century undoubtedly contr ibuted t o population inc reases .

Pending problems were recognized e a r l y i n Utah by Fish and Game administrators . I n the 1926-28 Utah Biennial Report we read:

"The inc rease i n deer i n Utah during t h e pas t 10 years has been phenomenal ... . This inc rease has been due t o s e v e r a l sources: the enforcement of the buck law ..., t h e establishment of game refuges, the reduct ion i n the number of predatory animals, and the more systematic regu la t ion of grazing on the National Forests." (p. 10.)

Fur the r , the next Utah Biennial Report (1928-30) s t a t e d :

"Big game problems have, within t h e pas t few years , become very acu te u n t i l now i t is imperative t h a t remedial laws be enacted f o r t h e cor rec t ion of some of these unfavorable condit ions. For ins tance , the deer have increased i n some l o c a l i t i e s u n t i l they a r e a menace t o f o o t h i l l farmers and f r u i t growers and a r e i n severe com- p e t i t i o n with domestic l ives tock f o r range forage, while the Fish and Game Department is without au thor i ty t o remove these offending animals." (p. 9.)

However, r es i s t ance t o ei ther-sex hunting was e a r l y expressed by the d i r e c t o r of the Utah Department of F i sh and Game. I n the Utah Biennial Report of 1934-36, when populat ions were beginning t o s o a r , we f ind the d i r e c t o r opposed t o the suggestion t h a t e i ther-sex hunting be i n i t i a t e d :

"I recommend t o t h e l e g i s l a t u r e of t h i s s t a t e t h a t they do not enac t a law t h a t would permit the k i l l i n g of deer of e i t h e r sex. It i s our b e l i e f t h a t 20,000 deer were k i l l e d l a s t year. Under t h e present set-up, and should l e g i s l a t i o n be passed, we a r e su re our deer herds would be ann ih i l a ted a t the end of the t h i r d season." (p. 5.)

The f i r s t ind ica t ion i n Utah of the need f o r a balanced herd of deer wi th in t h e range carrying capaci ty was given i n 1939 (Utah Biennial Report, 1936-38) :

"The game animals, a s w e l l a s t h e l ives tock , should be reduced t o t h e carrying capaci ty of t h e ind iv idua l ranges, giving the forage an opportuni ty t o reproduce i n kind, something t h a t has been neglected i n t h e past ." (p. 6 . )

Ant le r l ess permits were f i r s t issued i n 1934. Of the 1600 permits then i s sued , 825 a n t l e r l e s s deer were k i l l e d . I n 1935, an a d d i t i o n a l 2,008 does were k i l l e d on s p e c i a l permits.

Ant le r l ess deer permits were suspended i n 1936 and 1937 because of severe winter losses ; but the following year (1938), 4,500 permits were i s sued , followed by 10,700 permits i n 1939 (Utah Biennial Re- p o r t , 1938-40).

The numbers of spec ia l con t ro l permits were con- t inuously increased, u n t i l i n 1961 the re were approximately 40,000 con t ro l permits issued (Table 3). The ob jec t ive of management was t o b r ing t h e deer herds c lose r t o t h e carrying capaci ty of t h e i r ranges. The peak of Utah's mule deer numbers occurred during t h e 1945-50 period (with a second peak from 1964-71).

A HistoricaZ Account and Present Status o f the Mule Deer i n the West

T h i s s p e c i a l c o n t r o l permit program had s t a r t e d t o have i t s e f f e c t on t he popu la t i on and was r e f l e c t e d i n t h e numbers of s p e c i a l c o n t r o l pe rmi t s i s s u e d :

"By 1966 t h i s number had been reduced s y s t e m a t i c a l l y t o l e s s t han 4,000 and has exceeded t h a t number on ly once s i n c e t hen . I n 1972, 4,106 were s o l d , b u t this number dropped t o 1 ,260 i n 1973. I n 1974, t h e r e were no pe rmi t s i s s u e d which would a l l ow t h e t ak ing of more than one d e e r p e r hun te r . " (Utah B i e n n i a l Repor t , 1972-74).

F u r t h e r r e a c t i o n t o t h e needs of t h e growing he rds was e v i d e n t a s e a r l y a s 1939 when 4,078 a c r e s of game w i n t e r range were purchased by t h e Department (Utah B i e n n i a l Repor t , 1938-40, p. 15 ) . S ince t h e n , t h e Utah D i v i s i o n has been ded i ca t ed t o a program of w i n t e r range a c q u i s i t i o n , w i t h a g o a l of 577,000 a c r e s of w i n t e r range under t h e i r management program. To d a t e , about 225,000 a c r e s have been acqu i r ed (Hancock, 1976, p e r s o n a l communication).

The bounty sys tem was i n i t i a t e d i n Utah i n 1938 t o f u r t h e r reduce p r e d a t o r s . L ions were boun t i ed a t $10, and bobca t s and coyo te s a t $2.50. At t h i s t i m e , t h e Department e n t e r e d i n t o an agreement w i t h t h e Bureau of Biologj.ca1 Survey f o r more e f f e c t i v e preda- t o r c o n t r o l .

F u r t h e r p r e s s u r e s were e x e r t e d f o r e i t h e r - s e x hun t ing a s e a r l y a s 1938:

There i s y e t some a g i t a t i o n f o r a g e n e r a l open sea son on d e e r of e i t h e r s ex . We b e l i e v e t h i s would prove d i s a s t r o u s and i s e n t i r e l y unnecessary f o r p rope r c o n t r o l . (Utah B i e n n i a l Repor t , 1936-38, p. 44.)

I n 1943, t h e In t e r agency Big Game Committee was organized. It c o n s i s t e d of one r e p r e s e n t a t i v e each from t h e U.S. F o r e s t S e r v i c e , t h e Bureau of Land Management, and t h e Department of F i s h and Game, whose d u t i e s a s l and managers was t o determine b i g game con- d i t i o n s i n t h e s t a t e and g i v e recommendations t o t h e Board of Big Game Con t ro l f o r t h e e s t ab l i shmen t of s e a s o n s , l i m i t s , and o t h e r ma t t e r s p e r t a i n i n g t o b i g game.

The r e c o g n i t i o n of t h e need f o r e i t he r - s ex hunt- i n g s ea sons was now exp re s sed by t h e d i r e c t o r i n 1946 (Utah B i e n n i a l Repor t , 1944-46):

There i s a growing f e e l i n g toward a l i c e n s e t o k i l l a dee r r e g a r d l e s s of s e x t o s u b s t i t u t e t h e p r e s e n t "buck law", b u t t h i s might p rove d i s a s t r o u s t o some of ou r d e e r he rds , un l e s s a method of c o n t r o l of t h e number of h u n t e r s pe rmi t t ed on a g iven a r e a were a l s o t o be provided. (p. 33 ) .

Supplementa l f eed ing of b i g game had been spo- r a d i c a l l y p r a c t i c e d i n Utah i n t h e l a t e 19301s , b u t t he s e v e r e w i n t e r of 1948-49 brought an emergency f eed ing program f o r b i g game n o t only i n Utah, b u t i n many n o r t h e r n Rocky Mountain s t a t e s (Law, 1950).

A 54 pe rcen t hun te r s u c c e s s i n Utah i n t h e decade of t h e 4 0 ' s jumped t o 84 pe rcen t under t h e f i r s t " E i t h e r ex" law season , 1951, f o r a t o t a l h a r v e s t of 101,000 dee r .

"Many prophesied a f t e r t h e hunt t h a t '

t h e d e e r h e r d s a d j a c e n t t o t h e l a r g e c i t i e s were 'wiped o u t ' d u r i n g t h e f i r s t e i t h e r - s e x h u n t , bu t t h e s e v e r e w i n t e r of 1951-52 brought many dee r down from t h e s e same r anges t o d i e , i n some c a s e s numbers exceeding t h e l e g a l h a r v e s t . " (Utah B i e n n i a l Repor t , 1950-52, p . 8)

Management of Utah cont inued t o cope w i t h t h e l a r g e numbers of dee r :

Hunter p r e s s u r e i n c r e a s e d s t e a d i l y over t h e yea r s . T h i s s t e a d y i n c r e a s e i n h u n t e r s and l i b e r a l h u n t i n g r e g u l a t i o n s had , by t h e e a r l y 1960 's brought d e e r h e r d s i n t o b e t t e r ba l ance w i t h fo rage r e sou rces .

The Board of Big Game C o n t r o l , a c t i n g on t h e recommendations of t h e D i v i s i o n of W i l d l i f e Rescurces and o t h e r r e s o u r c e management agenc i e s , began a s y s t e m a t i c cutback i n c o n t r o l pe rmi t s and l i b e r a l i z e d s ea sons a t about t h i s t ime. (Utah B i e n n i a l Repor t , 1972-74)

The r e d u c t i o n i n t h e number of s p e c i a l pe rmi t s a v a i l a b l e was a d i r e c t r e s u l t of t h e dee r be ing more c l o s e l y balanced w i t h p rope r w i n t e r range con- d i t i o n s and hence a l e s s e r need f o r a d d i t i o n a l dee r removal. (Utah B i e n n i a l Repor" 1964-66, p. 10)

Fu r the r :

Deer management p l a n i n Utah has l a r g e l y achieved i t s o b j e c t i v e . As judged by t h e h a r v e s t , r ange t r e n d s , and o t h e r f a c t o r s , t h e p o p u l a t i o n i s g e n e r a l l y s t a b l e and i n ba l ance w i t h t h e h a b i t a t . (Utah B i e n n i a l Repor t , 1970-72, p. 13)

And f i n a l l y :

Deer management con t inued t o fo l l ow t h e cou r se e s t a b l i s h e d i n t h e 1960 's . The o b j e c t i v e of b r i n g i n g h e r d s i n t o ba l ance w i t h t h e i r range had l a r g e l y been ach i eved a t t h a t t ime and c u t backs i n c o n t r o l pe rmi t s and l i b e r a l i z e d s ea sons were i n d i c a t e d . (Utah B i e n n i a l Repor t , 1972-74, p. 40)

Recent changes i n t h e r e g u l a t i o n s f u r t h e r r e f l e c t s a d e c l i n e o r lower numbers t aken former ly i n he rd popu la t i ons :

Concurrent w i t h t h e r e d u c t i o n i n c o n t r o l pe rmi t s , t h e number of herd u n i t s w i t h l i b e r a l i z e d s ea sons a l s o began a g e n e r a l d e c l i n e . I n 1961 and 1962, t h e number of he rd u n i t s w i t h s ea sons more l i b e r a l than t h e 11-day e i t he r - s ex s ea son was 28. By 1966 t h i s had dropped t o 4. I n 1974, t h e r e were no s ea sons more l i b e r a l t han t h e 11-day e i t h e r - s e x s ea son ; i n f a c t , t h e most l i b e r a l s ea sons i n t h e s t a t e i n 1974 were t hose a l l owing t h e hun t ing of a n t l e r l e s s dee r f o r t h e l a s t seven days and t h o s e a l l owing a n t l e r l e s s

A tiistorica2 Account and Present Stutus o f t h e 8 Mu?ulc iiecr i n the West

hunting the f i r s t th ree days of the season. In 1961 the re had been no u n i t s wi th regu la t ions more r e s t r i c t i v e than t h e general 11-day ei ther-sex season. These more r e s t r i c t i v e hunts increased s t e a d i l y from 1961 t o 1969, then sharply t o 1973 when 31 herd u n i t s had seasons more re- s t r i c t i v e than the 11-day ei ther-sex season. Types of r e s t r i c t i v e seasons have included hunts shortened t o 5 days, a combination of 3 days ei ther-sex hunting f o l l m e d by 8 days of buck-only hunting, 4 days of buck-only hunting follwed by 7 days of ei ther-sex hunting, and a f u l l season of buck-only hunting. (Utah Big Game Harvest Handbook, 1974, p. 7.)

The dec l ine i n the herds, however, may not have been a l l a r e s u l t of management t o g e t herds wi th in t h e i r carrying capaci ty, p a r t i c u l a r l y during the pas t few years . During t h e pas t s e v e r a l years , more evidence i s a t hand t h a t adverse weather--abnormally cold and long win te r s and prolonged cold and wet springs--has had an e f f e c t upon t h e p roduc t iv i ty of some of t h e herds, e spec ia l ly i n c e n t r a l and south- e m Utah. The hard winter of 1972-73 took a t o l l of fawns, which reduced fawn s u r v i v a l i n some u n i t s t o 31 fawns per 100 does. Further , drought condit ions i n 1971-72 and i n 1972-73 i n southern and e a s t e r n Utah adversely e f fec ted t h e growth of vegetat ion upon which l a c t a t i n g does and weened fawns depended, which r e s u l t e d i n lower fawn surv iva l . Adverse weather condit ions, coupled with an inc rease i n a n t l e r l e s s removal i n 1971-72-73 i n t h e c e n t r a l p a r t of the s t a t e , undoubtedly had an adverse e f f e c t upon the present dec l in ing population of mule deer i n Utah (Hancock, 1976, personal communication).

I n summary, t h e present s t a t u s of mule deer i n Utah appears t o be one of dec l in ing populat ions undoubtedly inf luenced by many f a c t o r s such as depleted ranges t h a t have not y e t recovered from pas t overuse, drought, cold hard win te r s , h a b i t a t l o s s from highway cons t ruc t ion , summer homes, and p lan t succession as fewer c a t t l e a r e grazed. Coupled with these f a c t o r s may be the inf luence of predat ion from f e r a l dogs, coyotes, and o ther predators , a s w e l l a s poaching.

Other S t a t e s

To d e t a i l the build-up i n numbers of mule deer i n most western s t a t e s would be t o dup l ica te i n a l a r g e measure the p i c t u r e i n Utah. Most s t a t e s have shown exploding populat ions during t h e f i r s t ha l f of t h e century, accompanied by e f f o r t s t o reduce herds by g r e a t e r hunter ha rves t s of one kind o r another. Habitat improvement, win te r range acqu is i t ion , and o ther management p r a c t i c e s have been followed.

Populations i n most western s t a t e s peaked i n t h e 1940fs , 5 0 t s , and 60 's , a s i n Utah, and populat ions now appear t o be dec l in ing even f u r t h e r . I n a recent paper by Longhurst e t a l . (1976), t h e Ca l i fo rn ia mule deer dec l ine is d e t a i l e d and poss ib le remedial measures given.

A few excerp t s from some of the game managers i n the western s t a t e s i n d i c a t e the populat ion changes, ha rves t s , and measures used t o manage t h e herds:

Arizona

If we can use the Kaibab a s an example, what happened the re happened s tatewide. A tremendous herd build-up i n the e a r l y 1900's and then a sharp die- off about the mid-20's. However, i n our more recent h i s t o r y , t h e da te would be 1952-58. (Russo, 1976, personal communication)

Records showing t h e year ly deer harves t s and t h e number of hunters i t took t o b r ing them about a r e p r e t t y sketchy f o r t h e years p r i o r t o 1946. Since then, though, accurate records have been kep t , and they show a s teady inc rease i n t h e annual ha rves t t o a high point i n 1961, followed by a gradual dec l ine t o a low i n 1968. Buck-only harves t , which a l s o topped out i n 1961 a t 26,627 animals, h i t i ts modern-day low point of 17,094 i n 1965 and has climbed slowly s i n c e then.

During t h e l a t e 50's and e a r l y 60 's , Arizona was experiencing a boom i n i t s deer population. Range condit ions were c r i t i c a l and win te r die-offs were common. The seasonal r egu la t ions during t h i s period r e f l e c t e d t h e Departments' concern through l a r g e numbers of any- deer permits , and many a reas where does were l e g a l with no s p e c i a l permit. By about 1963 t h e peak i n populat ions had subsided, and while ranges were s t i l l i n poor condit ion, the any-deer hunting again became more r e s t r i c t e d . This po l icy has continued t o t h e point where i n recent years , only a very smal l number of any-deer permits has been authorized. (Anonymous, 1970)

C a l i f o r n i a

Longhurst e t a l . 's (1976) recen t summary documents t h e dec l ine and gives management suggest ions t o r e s t o r e deer numbers.

Idaho - Population of deer increased from post-pioneer

days t o t h e p resen t time: Estimates given i n t h e l i t e r a t u r e show t h e following deer population increases and subsequent decreases t o present numbers:

45,000 75,000

137,717 315,000 down 30 -+ X 215,000 (Thiessen, 1976, personal communication)

Montana

There a r e many ind ica t ions t h a t t h e peak mule deer populat ions which began i n t h e l a t e 40's and extended i n t o the l a t e 50's and e a r l y 60's were g r e a t e r than has occurred i n t h e pas t hundred years . How- ever , the re apparent ly has been considerable

9 A Historical Account and Present Status of' the Mute Deer i n the West

change o r f luc tua t ion i n numbers of deer during t h e pas t hundred years i n various a reas throughout the s t a t e .

Thus, during the period 1941-69, mule deer not only increased i n number, bu t a l s o expanded i n d i s t r i b u t i o n over the e n t i r e s t a t e , wi th peak numbers and d i s t r i b u t i o n being reached around 1950- 55. There has been l i t t l e change s ince .

The "Buck Law" of the 30 's and 40's r esu l t ed i n few deer harvested and i n s t i l l e d i n t h e minds of many t h a t shooting does and fawns was s i n f u l .

Montana has even employed l a t e win- t e r hunts i n an e f f o r t t o b r ing deer i n t o balance wi th t h e i r range. Such seasons were o f ten met by much pub l ic c r i t i c i s m . The mule deer management program i n Mon- tana has reached an "hour of decision". We must i n some manner reduce deer t o t h e ex- t e n t t h e ranges can recover.

The re-establishment of doe seasons i n 1950 and 1951 gave more people an opportunity t o hunt and take deer. ( J . Egan, 1971)

Since 1970, ~ o n t a n a ' s mule deer herds have continued t o dec l ine . (Allen, 1976, personal communication)

Nevada

Since t h e ea r ly 1960ts , a l l deer herds i n e a s t e r n Nevada have shown the same populat ion t rend; populations decl ined during the e a r l y 19601s, bottomed out i n 1965 and 1966, expanded u n t i l 1971, and have decl ined s i n c e then. (McColm, 1976)

A t t he present time, we f e e l we a r e experiencing a decided and very d r a s t i c c rash i n t h e populations of eas te rn Nevada.. . (Chris t ianson, 1976, personal communication)

Oregon

Build up of herds peaked i n 1953 and 1967. L ibera l season 1955 s t a b i l i z e d herds i n 1967. Fawn r a t i o s and fawn sur- v i v a l decl ined and s o did population.

1945 150,000 est imated populations p r i o r 1967 575,000 est imated populat ions

1975 400,000 est imated populat ions Fawn surv iva l was the most important

f ac to r i n population decl ine. (Ebert, 1976, personal communication)

Washington

The winter of 1889 se r ious ly depleted o r reduced herds. Build-up of l a rge herds occurred between 1935 and 1950 with l a r g e s t herds believed present i n 1947-50, 1955, 1963, and 1968. Mule deer h i t bottom i n 1969, 1971, and 1972 and have slowly in-

creased s i n c e then. (L.D. Parson, 1976, personal communication)

Wyoming

What has happened t o our deer herd? This i s a quest ion game managers encounter f requently today and c e r t a i n l y it is a proper one. Mule deer populat ions a r e not as they were i n the l a t e 1950's and 1960's. (Corsi , 1974, p. 3)

Trends i n Mule Deer Populations on Spec i f i c Units

Well-documented da ta shaving long time t rends i n deer populat ions a r e d i f f i c u l t t o f ind . Except f o r the f i r s t example, we have se lec ted a reas where p e l l e t group counts formed t h e b a s i s f o r est imating r e l a t i v e i n t e n s i t y of deer use of the range.

Information from the Kaibab (North) National Fores t , although based on es t imates , i s t h e c lass - i c a l example of what has happened t o many of our mule deer herds (Figure 2 ) . The h i s t o r y of t h e Kaibab i s the s t o r y of many of the deer herds of the West. The boom was apparent ly from 1918 (Forest Ranger repor t s of heavy over -u t i l i za t ion) t o 1923-24 followed by t h e d r a s t i c s t a r v a t i o n during the next few years . Est imates , by our most experienced men of the time, went from 100,000 i n 1924 t o l e s s than 30,000 i n 1930. Numbers were s t i l l high f o r t h i s de- p le ted range as indicated by the f a c t t h a t u n t i l 1935, Supervisor Walter Mann had a s tanding o f f e r of $1 f o r every aspen shoot over 12 inches high t h a t could be found on the Kaibab. I n 1936, however, a t i s o l a t e d spo t s , a few aspen sprou t s began t o "get- away" from deer.

A personal visit i n 1942 (Julander personal f i l e s ) shaved r a t h e r extensive a reas of good aspen reproduction developing over much, but not a l l , of the f o r e s t ; agreeing with the est imates t h a t deer numbers were a t a low i n t h e l a t e 1930's and e a r l y 1940's.

Estimates of deer numbers could no t be found between 1947 and 1969, but another v i s i t i n 1954 (Julander personal f i l e s ) showed a sharp deer high- l i n e on t h e newly es tab l i shed drop of aspen, ind ica t - ing a higher deer population. During the winter of 1954-55, t h e Arizona S t a t e Game and Fish Department (Swank, 1958, p. 78) est imated a l o s s of 18,000 deer . In the f a l l , 1954, a t o t a l of 8,058 deer were harvested. This i s t h e l a r g e s t annual k i l l on the Kaibab (North) t o d a t e , but i t was too l i t t l e and too l a t e .

Clay McCullough's e s t imates of deer dens i ty from 1969 t o 1975 inc lus ive , based on p e l l e t group counts , on the higher port ion of t h e Kaibab s u m e r range (575 mi les ) , gives a r e l i a b l e p i c t u r e of t rend i n numbers f o r t h a t period (Figure 3 ) . The Kaibab herd again appears t o be on a s l i g h t upward t rend s ince 1971.

Data from Robinette (personal l e t t e r s ) on the Oak Creek deer range i n Utah on est imated deer herd numbers over an 11-year period a r e well documented. Deer numbers were est imated by p e l l e t group counts over the e n t i r e winter range.

A Histor-icaZ Account and Present Status of tne Mule Deer i n the West

0 - 4 N C ? . j Y 1 \ 9 h m r n N

NNgz.,,3ma,.mm03Nn3Y1\9,. n m m n m z 2 8 g 2 8 2 m m m m m m m m m m m m m m n m * u ~ 3 * 3 u u m m m m m

3 3 3 4 3 3 3 3 ~ 3 3 - 4 3 4 3 3 4 3 4 d 3 3 r ( 3 3 3 3 3

YEAR

Figure 2. Estimated mule deer numbers on the Kaibab (north) National Forest (From D. 1. Rasmussen, 1941, and U . S . Forest Service Unpublished Reports.)

YEAR

Figure 3 . Estimated mule deer numbers on the Kaibab (north) National Forest summer range (from p e l l e t group counts); (Data from Arizona Game and Fish Department).

The deer populat ion of t h i s u n i t reached peak numbers i n about 1942 and decl ined some by 1946 when s t u d i e s began. Over t h e 11-year per iod, 1946-1955 i n c l u s i v e , es t imated numbers d id no t vary g r e a t l y and no d e f i n i t e t r end , up o r down, is ind ica ted (Figure 4). E f f o r t s were made through l i b e r a l doe permits , t o reduce t h i s herd t o proper ca r ry ing capac i ty w i t h no success .

During t h e per iod 1958-1975, w i t h less i n t e n s i v e samplings, e s t ima tes of deer use a t Oak Creek was determined by deer days use and percent u t i l i z a t i o n of key s p e c i e s (Figure 51, Utah 1952-1975. (Data from Utah Divis ion of Wi ld l i f e Resources.) Both es t ima tes i n d i c a t e a reduct ion i n herd numbers from 1958 t o 1966 w i t h a d e f i n i t e lower populat ion i n 1966, '67, and '68. This was followed by a r a t h e r r ap id upward t r end from 1969 t o 1975 t o a populat ion apparen t ly nea r ing ca r ry ing capaci ty . His tory of this herd d i f f e r e d from t h e Kaibab s i n c e t h e decrease from peak numbers were no t s o d r a s t i c and t h e range, a l though damaged, was f a r l e s s severe than t h e Kaibab. This herd had only a l i t t l e above average win te r l o s s e s i n 1948-49. However, summer range i s somewhat l i m i t e d and of low q u a l i t y .

On two neighboring, r a t h e r i s o l a t e d mountain ranges i n sou theas te rn Utah, t h e Henry and t h e LaSal, dee r days use pe r a c r e was determined by p e l l e t group counts (Utah, 1952-75). Here, a s a t Oak Creek, t h e peak i n dee r numbers were bel ieved reached and some d e c l i n e made be fore d a t a c o l l e c t i n g began i n 1945-46. The Henry mountain herd shows a sharp de- c l i n e , reaching a low po in t i n 1956 (Figure 6 ) . From t h a t low po in t , a slow recovery is ind ica ted . This range was badly depleted by both deer and l i v e s t o c k and was low i n forb product ion on summer range.

Average deer days use pe r a c r e on t h e LaSal mountain reached a low po in t i n 1949 followed by a r a t h e r vigorous rise from 1953 t o 1955 i n d i c a t i n g a f a i r l y - p r o d u c t i v e herd. From 1955 t o 1975, a slow

damward t r end is ind ica ted . However, a high pop- u l a t i o n was s t i l l evident during t h i s per iod (Fig- ure 6 ) . Summer range is of h igher q u a l i t y than on t h e Henry Mountains. (Pat terson and Harper, unpublished data) .

Data from t h e Arizona Game and Fish Department show t h e t r end i n r e l a t i v e dens i ty of mule dee r , a s determined by p e l l e t group counts , on t h e Three Bar W i l d l i f e a rea i n Arizona from 1959 t o 1975 (Arizona Game and Fish Department, pe r sona l correspondence). (Figure 7). A genera l dec l ine , from a h igher deer dens i ty i n 1959-60 t o a much lwer dens i ty i n 1969, is ind ica ted . From 1969 t o 1975 t h e d e n s i t y appears t o be s t a b i l i z e d a t a r a t h e r low l e v e l .

On a l l of t h e above a r e a s , t h e o b j e c t i v e of management has been t o b r ing mule deer numbers wi th in ca r ry ing capaci ty of t h e range. The d i f f e r e n t r e s u l t s shown i n d i c a t e varying degrees of success and poss ib ly d i f f e r e n t causes and d i f f e r e n t management.

From genera l informat ion obtained from most of t h e western s t a t e s , t h e r e i s no doubt t h a t mule dee r populat ions a r e down a s of 1975. However, i n v e s t i - ga t ions of i n d i v i d u a l herd u n i t s (with i n t e n s i t y of dee r use documented by p e l l e t group counts) i n d i c a t e t h a t , although deer numbers a r e much below an extremely high peak, populat ions s i n c e then, and par- t i c u l a r l y during t h e l a s t s i x o r seven years , seem t o be l e v e l i n g o f f , o r i n some cases , inc reas ing . Based on t h e o v e r a l l p i c t u r e , we ask: " W i l l t h e t r end cont inue down? Can management of herds and h a b i t a t r everse t h e downward t r end and s t a b i l i z e o r inc rease t h e he rds? What a r e the causes of t h e de- c l i n e and p o s s i b l e s o l u t i o n s ?

Based on i n d i v i d u a l herd d a t a , we ask: "Are our mule deer he rds , i n genera l , dec l in ing below d e s i r a b l e l e v e l s which w i l l permit recovery of de- p l e t e d ranges, o r a r e they a d j u s t i n g i n s i z e t o t h e a c t u a l impared ca r ry ing capac i ty of t h e i r h a b i t a t ?

W e hope t h e above ques t ions w i l l be answered, o r a t l e a s t en l igh tened , i n t h e fol lowing papers of t h i s symposium.

1 3 A Historical Account and Present Status of the Mule Deer i n the West

YEAR

Figure 4. Mule deer population for the Oak Creek herd uni t , Utah, 1946- 1956. (Data from W . L . Robinette and 0. Julander and Utah Division of Wildl i fe Resources).

o o m o r r w m " I m a a a a ~ m a ~ . o o m o ~ w m m m I.

O \ m m m a a a a a L a I . I . r . I . 2 - d 4 4 4 4 4

m m m m m m m m m m m c n 4 4 4 4 4 4 4 4 + 4 4 +

YEAR

Figure 5 . Measure of mule deer use on Oak Creek winter range, Utah, 1957-1975. (Data from Utah Division of Wildl ife Resources).

- LaSal Mountain deer herd ------ Henry Mountain deer herd

Figure 6 . LaSal and Henry Mountains, Utah, deer days use per acre estimated from pel le t group counts. Data col lected i n early spring of each year by Utah Division of Wildlife Resources.

YEAR

Figure 7. Mule deer population for the Three Bar Wildlife Area, Arizona. Population density based on p e l l e t group counts (November and December data) by Arizona Game and Fish Department.

LITERATURE CITED

Anonymous. 1928. B i e n n i a l Repor t of t h e S t a t e F i s h and Game Commisioner of t h e S t a t e of Utah , June 30 , 1926, t o June 30 , 1928, 22 pp.

Anonymous. 1930. B i e n n i a l Repor t of t h e S t a t e F i s h and Game Commissioner of t h e S t a t e of Utah, J u l y 1, 1928, t o June 30 , 1930, 21 pp.

Anonymous. 1936. B i e n n i a l Repor t o f t h e S t a t e F i s h and Game Commissioner of t h e S t a t e of Utah , J u l y 1, 1934, t o June 30 , 1936, 6 3 pp.

C o r s i , R. M . 1968. Deer and p u b l i c management. Proc . West. Assoc. S t a t e Game and F i s h Corn . , 48:255-257.

C o r s i , R. M. 1974. A p o t p o u r r i of d e e r f a c t s . Wyoming Wild- l i f e , Aug. p . 3.

Edison, M. 1963. Idaho w i l d l i f e i n e a r l y days . I daho Wild- l i f e Review. J u l y - Aug. 1963, p. 8-13, and Sept . - Oct. 1963, p. 8-12.

Egan, J . 1971. Game management i n Montana. Chap t e r 6 on mule d e e r , p. 53-79.

Anonymous. 1938. B i e n n i a l Repor t of t h e S t a t e F i s h and Green l ey , J . C. and M. Humphreys.

Game Commissioner o f t h e S t a t e of Utah , 1964. The d e c l i n e i n t h e 1962 mule d e e r h a r v e s t

J u l y 1, 1936, t o June 30, 1938, 45 pp. i n Nevada. Proc . West. Assoc. S t a t e Game and F i s h Comm., 44:173-176.

Anonymous. 1940. B i e n n i a l Repor t o f t h e S t a t e F i s h and Ha ine s , A. L.

Game Commission of t h e S t a t e o f Utah , 1955. J o u r n a l of a t r a p p e r . (1834-1843) by

J u l y 1, 1938, t o June 30, 1940. Osborn R u s s e l l . E d i t e d by Aubrey L. Ha ine s , 1 9 1 pp.

Anonymous. 1946. Twenty-s ix th B i e n n i a l Repor t of t h e Hancock, N . V . S t a t e F i s h and Game Commission of t h e S t a t e 1964. Mule d e e r h a r v e s t d e c l i n e i n Utah. Proc .

of Utah , J u l y 1, 1944, t o June 30 , 1946, 78 pp. E s t . Assoc. S t a t e Game and F i s h C m . , 44: 181- 188.

Anonymous. 1952. T h i r t i e t h B i e n n i a l Repor t of t h e S t a t e Hancock, N . V .

F i s h and Game Commission of t h e S t a t e of 1968. Major f a c t o r s i n f l u e n c i n g mule d e e r pop-

Utah , J u l y 1, 1950, t o June 30, 1952, 78 pp. u l a t i o n and h a r v e s t t r e n d s i n Utah s i n c e 1962. Proc . West. Assoc. S t a t e Game and F i s h Comm.. - -

Anonymous. 48:245-252. 1966. Th i r t y - s even th B i e n n i a l Repo r t , Utah S t a t e ~ e ~ a r t i e n t of F i s h and ~ a m e ; J u l y 1, 1964, Lauchart, J . B.

t o June 30, 1966, 44 pp. 1968. Mule d e e r management i n t h e s t a t e o f Wash- i n a t o n . Proc . West. Assoc. S t a t e Game and F i s h

Anonymous. 1970. F o r t y y e a r s o f p r o g r e s s , Game Management, Ar izona W i l d l i f e Views, p. 19-20.

Anonymous. 1970. Game Management, Fo r ty y e a r s o f p r o g r e s s , Ar izona W i l d l i f e Views, p. 16-22.

Anonymous. 1971. H i s t o r y of b i g game r e g u l a t i o n s , 1899- 1970. Deer s e c t i o n Oregon Dept. o f F i s h and W i l d l i f e , 7 pp.

Anonymous. 1974. F o r t y - f i r s t B i e n n i a l Repo r t , S t a t e of Utah , D i v i s i o n of N a t u r a l Resources , J u l y 1, 1972, t o June 30, 1974, 52 pp.

Anonymous. 1974. Big game h a r v e s t r e p o r t . Utah S t a t e D i v i s i o n of W i l d l i f e Resources . Completion r e - p o r t f o r F e d e r a l Aid P r o j e c t W-65-R-D-23. Pub- l i c a t i o n No. 75-2. March 31, 9 4 pp.

Anonymous. 1952-1975. Utah b i g game i n v e s t i g a t i o n s and management recommendations. I s s u e d a n n u a l l y by t h e S t a t e of Utah, Department of N a t u r a l Re- s o u r c e s , D i v i s i o n of W i l d l i f e Resources .

Comm., 48:253-254.

Longhu r s t , W. M . , E . 0. Ga r ton , J . F. Heady, and G. E. Connolly.

1976. C a l i f o r n i a d e e r d e c l i n e and p o s s i b i l i t i e s f o r r e s t o r a t i o n . Western S e c t i o n of t h e W i l d l i f e S o c i e t y and t h e Cal i fornia-Nevada Chap t e r of t h e American F i s h e r i e s S o c i e t y . F r e sno , C a l i f o r n i a , J anua ry 30-31. 16 pp. + t a b l e s , f i g u r e s , and l i t e r a t u r e c i t e d .

Low, J. B. and W . B. Low. 1949. Deer l o s s e s on t h e =he d e e r h e r d , win- t e r , 1948-49. S p e c i a l Repor t of t h e Utah Co- o p e r a t i v e W i l d l i f e Resea r ch U n i t . Oct. 1, 1 8 pp.

Low, J . B. 1950. An a n a l y s i s o f t h e 1948-49 emergency f e e d i n g programs f o r w i l d l i f e i n t h e Nor the rn Rocky Mountain Region. Nor the rn Rocky Mountain W i l d l i f e S o c i e t y , J ackson , Wyoming. March 29- A p r i l , 20 pp.

Macgregor, W. G. 1964. A n a l y s i s of Grea t Bas in d e e r d e c l i n e - C a l i f . Proc . West. Assoc. S t a t e Game and F i sh Comm., 44:167-169.

A HistoricaZ Account and Present Status of the 18 Mule ileer in the West

Macgregor, W. G . 1968. Major fac to rs inf luencing mule deer pop- u la t ions and harvest t rends i n Ca l i fo rn ia s i n c e 1962. Proc. West. Assoc. S t a t e Game and Fish Comm., 48:215-218.

McColm, M. A. 1976. Mule deer population t rends i n north- eas te rn Nevada and inf luencing fac to rs . The Nevada Sect ion of the Society f o r Range Manage- ment and t h e Nevada Chapter of the Wi ld l i fe Society, Elko, Jan. 10, 16 pp.

McKean, J . W. and I. D. Luman. 1964. Oregon's 1962 dec l ine i n mule deer harves t . Proc. West. Assoc. S t a t e Game and Fish Comm., 44:177-180.

Mohler, L. L. 1964. Deer ha rves t f luc tua t ions i n Idaho. Proc. West. Assoc. S t a t e Game and Fish Comm., 44:170-172.

Nielson, A. E. and R. M. Williams. 1968. Major f a c t o r s inf luencing mule deer pop- u l a t i o n and harves t t r ends s i n c e 1962 - Idaho. Proc. West. Assoc. S t a t e Game and Fish Comm., 48:232-236.

Rasmussen, D. I. 1941. Bio t i c communities of Kaibab P la teau , Arizona. Ecological Monographs 3:229-275.

Reynolds, T. A. 1960. The mule deer , i t s h i s t o r y , l i f e h i s t o r y , and management i n Utah. Utah S t a t e Department Fish and Game. Dept. Informative Bul le t in No. 60-4, 32 pp.

Russo, J . P. 1968. Major f a c t o r s inf luencing mule deer pop- u la t ion and harvest t rends i n Arizona s i n c e 1962. Proc. West. Assoc. S t a t e Game and Fish Corn., 48:209-214.

S t e i n , R. H. 1968. Oregon's mule deer populat ion and management program s i n c e 1962. Proc. West. Assoc. S t a t e Game and Fish Corn., 48:241-244.

Stewart. R. H. 1967. New Mexico w i l d l i f e management. New Mexico Department of Game and Fish. Chapter 8 , Mule Deer, March, p. 42-51.

Snyder, W. A. 1968. Major f a c t o r s inf luencing mule deer pop- u la t ions and harves t t r ends i n New Mexico. Proc. West. Assoc. S t a t e Game and Fish Comm., 48:237-240.

Swank. W. G . 1958. The mule deer i n Arizona Chapparal, S t a t e of Arizona Game and F i sh Department, Wi ld l i fe Bul le t in No. 3, February, 109 pp.

19 A HistoricaZ Account and Present Status of the Mule Deer i n the West

MULE DEER HABITAT CHANGES RESULTING FROM

LIVESTOCK PRACTICES

P h i l i p J. Urness

Assnciate Professor and Pro jec t Leader Utah S t a t e Universi ty

Range Science Department and Utah Divis ion of Wi ld l i fe Resources

Abstract

Livestock grazing has had g r e a t inf luence on mule deer h a b i t a t s s ince in tens ive set t lement i n t h e l a t t e r ha l f of the 19th century. Pos i t ive and adverse e f f e c t s have resu l t ed from vas t successional change, land preemption f o r cu l t iva ted crops and hab i ta t ions , and a c t i v i t i e s associated with l ives tock production. Explo i t a t ive grazing during the "open range" e r a and widespread burning of montane f o r e s t s s e t i n motion sweeping h a b i t a t changes. Deer then increased g rea t ly a f t e r conservat ion programs and i n t e n s i v e predator con t ro l i n the ea r ly 1900's reduced mor ta l i ty below recruitment. Although these h a b i t a t changes were l a rge ly unplanned, they must be considered i n present- day management s ince adjustments i n pas t p r a c t i c e s can be expected t o a l t e r deer ca r ry ing c a p a c i t i e s and populations.

Mule deer (Odocoileus hemionus) a r e a western North American form t h a t , considering a l l subspecies , have broad ~ . c c l o g i c a l amplitude. They occur, a t l e a s t seasonal ly, from hot and cold d e s e r t s t o montane f o r e s t s and a lp ine tundra (Figure 1 ) . The major commonality i n t h i s broad geographic v a r i a t i o n is mountairs, including importantly the f o o t h i l l s o r bajadas. Rather few mule deer occupied f l a t l a n d s and these were quickly supplanted by modem man's agr i - c u l t u r e and o ther developments. Consequently, a considerat ion of l ives tock p r a c t i c e s , a s they impact mule deer , e s s e n t i a l l y deals with ecology and management of f o o t h i l l and mountain vegetat ion.

Complicating elements immediately emerge when at tempting t o cover a general t o p i c such a s t h i s . These elements include (1) migratory populat ions occupying d i s t i n c t winter:summer ranges i n northern and high e leva t ion southern a reas vs. nonmigratory populat ions occupying dese r t , chaparral , and c o a s t a l zones, (2) very d i f f e r e n t responses of d iverse vege- t a t i o n types to s p e c i f i c management p r a c t i c e s such a s c l a s s of l ives tock , season and i n t e n s i t y of use by l ives tock , and f i r e use o r suppression, (3) varying periods and causes of s t r e s s a f f e c t i n g s u r v i v a l and p roduc t iv i ty of deer (i.e. win te r forage s c a r c i t y and deep snow i n northern l a t i t u d e s o r high e leva t ions ; summer drought and forage q u a l i t y r e s t r i c t i o n s i n southern l a t i t u d e s ) .

H i s t o r i c a l Perspect ives

Any discussion of how the l ives tock industry might inf luence an apparent dec l ine i n mule deer populat ions must be viewed i n developmental a s w e l l a s cur ren t perspect ive. That a general dec l ine has occurred s ince the mid-1960's i s not a point of debate , thus the impetus f o r our symposium. However, t h e dec l ine may be of l e s s e r magnitude than some would have us be l i eve , a t l e a s t i n the c e n t r a l por t ion of mule deer d i s t r i b u t i o n (Figure 2) . While we a r e p resen t ly below the peak harvest years i n Utah, much of the drop i s accounted f o r i n near-elimination of a n t l e r l e s s animals i n the harvest . Examination of the buck-only harvest curve suggests much l e s s change, although t h e dow~lward t rend acce le ra ted during t h e p a s t th ree years .

Trends i n range l ives tock numbers i n Utah show some s i g n i f i c a n t changes t h a t r e f l e c t s i m i l a r p a t t e r n s over much of the Intermountain West (Figure 3). One of my professors , a prominent zoo log i s t , occasional ly would lament the presence of domestic sheep on mounrain ranges. It was h i s b e l i e f t h a t e l iminat ion of "mountain maggots" from the range would usher i n a new dea l f o r mule deer based on a narrow concept of s t rong d i e t a r y overlap. The s teady dec l ine i n the range sheep industry has not borne out h i s prophecy.

21 Pule Deer Habitat flanges Resulting from Livestock Practices

An e x t e n s i v e l i t e r a t u r e a t t e s t s t o g e n e r a l abus ive rangeland use by l i v e s t o c k o v e r most o f wes tern North America from rerid-19th c e n t u r y s e t t l e - ment, up t o t h e p r e s e n t i n some c a s e s . The p e r i o d of major abuse was g e n e r a l l y from 1880 t o 1930, w i th f o o t h i l l s a round v a l l e y s e t t l e m e n t s a f f e c t e d e a r l i e s t .

U n r e s t r i c t e d s e l e c t i v e g r a z i n g by l i v e s t o c k , e s p e c i a l l y i n s p r i n g , on t h e p a l a t a b l e g r a s s e s and f o r b s l e d , i n p a r t , t o widespread s u c c e s s i o n a l change f a v o r i n g sh rubs t h a t were f r e q u e n t l y s u b o r d i n a t e s i n p r e s e t t l e m e n t v e g e t a t i o n ( E l l i s o n e t a l . 1951, H u l l and H u l l 1974, Leopold 1950, McConnell and Dalke 1960) . On many a r e a s o u t r i g h t i n v a s i o n of g r a s s l a n d s by woody p l a n t s and s u c c u l e n t s occu r r ed (Blackburn and T u e l l e r 1970, Glendening 1952, Humphrey 1953, Reynolds and Elart in 1968). Causes f o r i n c r e a s e s i n woody p l a n t s have been v a r i o u s l y a s c r i b e d t o e x c e s s i v e g r a z i n g , f i r e supp re s s ion , promiscuous bu rn ing , c l i - m a t i c change, b i o t i c f a c t o r s b e s i d e s g r a z i n g , and combinat ions of t h e s e f a c t o r s , depending upon vege- t a t i o n type .

Succes s iona l R e l a t i o n s

Although much f o o t h i l l h a b i t a t was pre-empted by a g r i c u l t u r e , a d d i t i o n a l c a r r y i n g c a p a c i t y on remaining h a b i t a t was c r e a t e d through p r o g r e s s i v e and r e t r o g r e s s i v e s u c c e s s i o n a l change r e s u l t i n g from e x c e s s i v e g r a z i n g , a l t e r e d f i r e p a t t e r n s , and logging. These changes were s u f f i c i e n t l y widespread t o permi t mule d e e r i n c r e a s e s t o unprecedented numbers from about t h e 1930 's t o 1950 ' s (Leopold 1950, Leopold e t a l . 1947, Longhurs t e t a l . 1952) .

I n f l u e n c e of e a r l y l i v e s t o c k g r a z i n g was imposed on a l l v e g e t a t i o n t ypes a f f e c t i n g mule d e e r , b u t impacts d i f f e r e d s u f f i c i e n t l y t o r e q u i r e s e p a r a t e d i s c u s s i o n . I n g e n e r a l , f i r e e x c l u s i o n i n a r i d o r semi-ar id t ypes and widespread u n c o n t r o l l e d bu rn ing i n montane f o r e s t t y p e s accompanied g r a z i n g and p o s i t i v e l y a f f e c t e d h a b i t a t v a l u e s f o r mule d e e r . Major t y p e s a r e d e s e r t g r a s s l a n d , sagebrush:bunchgrass, c h a p a r r a l , j un ipe r :p inyon , and montane f o r e s t .

Dese r t g r a s s l a n d : Ex tens ive g r a s s l a n d a r e a s i n t h e Southwest and Mexico were h e a v i l y s t ocked w i t h c a t t l e a f t e r 1800 (Humphrey 1958) . Although Spanish s e t t l e m e n t had i n t roduced c a t t l e , sheep , and h o r s e s i n t h e 1 5 0 0 t s , u s e was g e n e r a l l y r e s t r i c t e d t o a r e a s immedia te ly around wide ly s c a t t e r e d towns a s a r e s u l t of I nd i an r a i d s . Woody p l a n t s occu r r ed s p a r s e l y throughout t h e grass-dominated uplands and i n bosques a l o n g s t r e a m cou r se s . With heavy use a f t e r 1880, t h e p a l a t a b l e g r a s s e s , mos t ly gramas (Boutaloua s p p . ) , three-awns ( A r i s t i d a spp . ) , and h i l a r i e s ( H i l a r i a s p p . ) , were q u i c k l y reduced under heavy yearlong use . Nesqu i t e (P rosop i s spp . ) , o t h e r leguminous and non-leguminous d e s e r t sh rubs , and c a c t i i n c r e a s e d ( F i g u r e 4) and assumed dominance on ve ry g r e a t a r e a s (Ben t l ey 1898, Branscomb 1958, Brown 1950, Glendening 1952, Humphrey 1953) .

C o n f l i c t i n g r e p o r t s v a r i o u s l y a s c r i b e vegeta- t i o n a l change t o c l i m a t i c s h i f t toward i n c r e a s i n g a r i d i t y (Schulman 1956, Branscomb 1958) , heavy g r a z i n g r educ ing compe t i t i on from herbaceous s p e c i e s (Buechner 1944, W h i t f i e l d and Anderson 1938, Glendening 1952) , and f u e l r e d u c t i o n p r e v e n t i n g p e r i o d i c f i r e s ( G r i f f i t h s 1910, Humphrey 1958, Reynolds and Bohning 1956, Thornber 1910, Wooten

Mule Deer Habitat Changes Resulting from Livestock Practices

1915) . Longterm p r o t e c t i o n from g r a z i n g o r l i g h t g r a z i n g d i d n o t m a t e r i a l l y a f f e c t growth of woody p l a n t s n o r p r e v e n t t h e i r expans ion (B lydens t e in e t a l . 1957, Glendening 1952) . Once s t a r t e d t h e p r o c e s s was p robab ly a c c e l e r a t e d through p ropagu le d i s p e r s a l by b i r d s , r o d e n t s , and o t h e r b i o t i c f a c t o r s (Arnold 1942, Reynolds 1950, Reynolds and Glendening 1949, Timmons 1942) .

A combinat ion of some o r a l l of t h e s e f a c t o r s is probably t h e most a ccep t ed e x p l a n a t i o n of woody p l a n t i n v a s i o n i n d e s e r t g r a s s l a n d s . Rega rd l e s s of c a u s a l f a c t o r s , t h e e f f e c t i n te rms of mule d e e r was a c o n s i d e r a b l e expans ion of y e a r l o n g h a b i t a t which t h e c a c t i and sh rub f r u i t s , browse, and cover provided.

Sagebrush:bunchgrass: Sagebrush ( ~ r t e m i s i a spp. ) was a ~ ~ a r e n t l v dominant i n t h e c l imax community on . . t h e d r i e r a r e a s and on c e r t a i n s o i l s of t h i s t y p e w i t h bunchgrasses--wheatgrasses (Agropyron spp. ) , b l u e g r a s s e s (Pod spp . ) , and n e e d l e g r a s s e s ( S t i p a spp.)--and f o r b s prominent i n t h e unde r s to ry . With heavy, s e l e c t i v e g r a z i n g , e s p e c i a l l y i n s p r i n g , t h e g r a s s e s d e c l i n e d and s ageb rush and o t h e r s h r u b s i n c r e a s e d i n d e n s i t y (Robertson 1971, S t o d d a r t 1941, T u e l l e r 1973, T u e l l e r and Blackburn 1974). Where f i r e s occu r r ed , r e t r o g r e s s i o n proceeded t o weedy annua l s , e s p e c i a l l y c h e a t g r a s s (Bromus t ec to rum) , and s p r o u t i n g sh rubs ( r a b b i t b r u s h Chrys thamnus spp. , and ho r seb rush Tetradymia spp.) . A c t i v e f i r e s u p p r e s s i o n l i m i t e d a r e a s burned s o b i g sagebrush dominated ve ry l a r g e t r a c t s and, b e s i d e s , i t r e e s t a b l i s h e s r a t h e r q u i c k l y on such s i t e s f o l l o w i n g f i r e ( B l a i s d e l l 1953).

The more mesic f o o t h i l l s a p p a r e n t l y e x h i b i t e d a grass : forb-dominated c l imax wi th s h r u b s more w ide ly spaced ( H u l l and H u l l 1974, P i c k f o r d 1931, S todda r t 1941) . I n t e n s e u s e i n s p r i n g reduced t h e herbaceous unde r s to ry fo l lowed by g r e a t i n c r e a s e i n s ageb rush , r a b b i t b r u s h (Chrysothamnus spp . ) , and some more p a l a t a b l e sh rubs such a s b i t t e r b r u s h , P u r s h i a t r i d e n t a t a ( P i c k f o r d 1931) . S o i l e r o s i o n and s i t e v e r i f i c a t i o n appea r t o have p layed prom- i n e n t r o l e s i n t h i s p r o c e s s ( E l l i s o n 1954, 1960, Leopold 1950). I n c r e a s e i n p a l a t a b l e sh rubs Were more l i k e l y t o occu r where c a t t l e g r azed , l e s s s o w i th sheep (Cottam and Evans 1945) . F a l l u se a l o n e was n o t n e a r l y s o l i k e l y t o e f f e c t composi t ion s h i f t s f a v o r i n g sh rubs (Mueggler 1950) .

Gene ra l l y , t h e c a r r y i n g c a p a c i t y f o r d e e r on f o o t h i l l w i n t e r r anges was i n c r e a s e d w i t h g r e a t e r s h r u b d e n s i t y where f i r e was excluded ( J u l a n d e r 1962) . L a t e r , r e g u l a t e d s p r i n g l i v e s t o c k u s e ma in t a ined t h i s c o n d i t i o n bu t l a t e summer and f a l l u s e removed a c o n s i d e r a b l e amount of t h e p a l a t a b l e browse upon which d e e r depended f o r w in t e r r ange .

Chaparra l : Graz ing and f i r e have been i n e x t r i c a b l y in terwoven i n t h e development of most , i f n o t a t a l l , c h a p a r r a l t ypes occupied by mule dee r . Zn Ar izona , t h e p r e s e t t l e m e n t t ype a p p a r e n t l y p r e s e n t e d an open, grass-dominated a s p e c t w i th sh rubs p r e s e n t b u t h e a v i l y supp re s sed by f r e q u e n t f i r e s c a r r i e d ove r l a r g e a r e a s w i t h heavy amounts of herbaceous f u e l s (Leopold 1924, Croxen 1926). The bimodal p r e c i p i t a t i o n p a t t e r n favored g r a s s : f o r b growth when f i r e s k,,pt sh rub compe t i t i on down. Heavy pos t - s e t t l emen t g r a z i n g , most ly by c a t t l e , q u i c k l y

reduced herbaceous f u e l s and f i r e frequency. Shrubs and woodland t r e e s increased dramatically. The present-day aspect i s one of dense t a l l shrubs, t y p i c a l l y sclerophyllous and evergreen, with l i t t l e herbaceous understory unless recen t ly burned. A l - though the type o f f e r s g rea t cover value, the quan t i ty of high-quality forages i s l imi ted during droughty periods before and a f t e r summer monsoons (Swank 1958).

Ca l i fo rn ia chaparral had a somewhat d i f f e r e n t h i s t o r y a s well a s a d i s t i n c t l y d i f f e r e n t climate. Long hot , dry s u m e r s favored brush spec ies dominance. Purposeful burning was more prevalent a f t e r 1850 than during Indian o r Spanish domination (Taber and Dasmann 1958, Sampson 1944). A major expansion of b rushf ie lds upslope i n t o previously fo res ted a r e a s occurred with e a r l y logging and burning, e spec ia l ly i n the S i e r r a Nevada (Longhurst e t a l . 1952, Sampson and Jesperson 1963). Frequent burning was done primari ly t o inc rease l i v e s t o c k fo rage qua l i ty and p a l a t a b i l i t y . Expansion of chaparral i n t o va l l ey grasslands and oak-woodlands was ascr ibed t o overgrazing, reduced competition from grasses , and reduced f i r e frequency (Leopold 1950, Shantz 1947).

Carrying capac i t i e s f o r mule deer were (and a r e ) g r e a t e s t on a r e a s i n continuous cycles of secondary succession where a mix of g rass , forb, and shrub forages was ava i l ab le . Moderate l e v e l s of l ives tock use and frequent small f i r e s of varying age, from newly burned t o mature b rushf ie lds i n close juxta- pos i t ion , provided productive yearlong o r winter deer h a b i t a t (Biswell e t a l . 1952, Cronemiller and Bartholomew 1950).

Juniper-pinyon: As i n the case of o ther a r i d o r semi-arid types, woody p l a n t s i n the juniper- pinyon zone have expanded i n t o t a l a r e a during the pas t century. Extension of t r e e s i n t o grassland and shrub s teppe occurred both upslope and down (West e t a l . 1975). The causes were no doubt complex bu t overgrazing and f i r e suppression appeared prom- inen t a s i n i t i a t i n g mechanisms (Blackburn and Tue l le r 1970). Climatic change and b i o t i c in f luences have a l s o been implicated (Frischknecht 1975, LaMarche 1974, P h i l l i p s 1910, Schulman 1956).

Cover values, pr imari ly, and browse forage provision accompanying shrub and t r e e invasion of g rass lands increased mule deer winter range ( T e r r i l l and S p i l l e t t 1975, Reynolds 1964). I n the absence of renewal by f i r e o r mechanical means, however, the t r e e s become dense and p r a c t i c a l l y e l imina te the understory, including many shrubs, e spec ia l ly i n t h e Great Basin (Julander 1962, Tausch 1973). Consequently, t h e increased h a b i t a t values wrought by t r e e invasion have been somewhat ephemeral, with e a r l y ga ins dec l in ing i n l a t e succession. This has been the b a s i s f o r widespread t r e e con t ro l p ro jec t s , namely, t o s e t succession back t o a phase more product ive f o r l ives tock and deer (Dwyer 1975, Plummer e t a l . 1968).

Montane f o r e s t and uplands: Higher e leva t ion , fo res ted and non-forested a reas provided summer range f o r l a r g e l o c a l l ives tock herds, e spec ia l ly sheep a f t e r 1870. These were usua l ly i n f l a t e d by i t i n e r a n t herds t r a i l e d o r shipped i n from long d i s tances t o graze the "open range." Unt i l the f o r e s t reserves were es tab l i shed around 1900 and t h e Forest Service

created i n 1905, an increasingly abusive pressure was placed on mountain summer ranges. Grazing on Forest Service lands was placed on a con t ro l l ed l e a s e system which became increasingly more e f f e c t i v e i n reducing abuses a f t e r 1910. A number of r e p o r t s emanating from the Bureau of P lan t Industry, s t a t e a g r i c u l t u r a l experiment s t a t i o n s and other U.S.D.A. pub l ica t ions appeared about t h i s time documenting the "tragedy of t h e commons" ( G r i f f i t h s 1902, 1903. Kennedy 1901, 1903, Wooten 1908).

Some l a t e r papers ind ica te improvement with grazing con t ro l but a t t e s t t o the slow recovery and s e v e r i t y of damage sustained (Darlington 1915, Forsl ing 1931. Humphrey 1943, Pickford 1931, Sampson and Weyl 1918, and many o thers ) . In add i t ion t o overgra-ing, purposeful burning occurred on many mountain ranges t o s t imula te forage and make dense b rushf ie lds and fo res ted a r e a s more access ib le t o l ives tock , e s p e c i a l l y sheep (Reynolds 1911, E l l i son 1954). S o i l erosion and denudation of vege ta t ion from grasslands and f o r e s t s l e d t o invasion or thickening of xerophytic shrubs (E l l i son 1960, E l i i son e t a l . 1951).

Slash f i r e s on logged a r e a s and w i l d f i r e s swept over s taggering acreages of f o r e s t throughout t h e West from the l a t e 1800's t o about 1940, c rea t ing l a r g e b rushf ie lds t h a t were grazed heavi ly by l ive - s tock and provided exce l l en t h a b i t a t f o r deer , a l b e i t a t g rea t cost (Sampson and Jesperson 1963, Leopold 1950). The rapid cycl ing of accumulated s o i l n u t r i e n t s t o deer forage was probably responsible , t o a considerable ex ten t , f o r tremendous populat ion inc reases during t h i s period along with concomitant con t ro l of l ives tock grazing, predator populat ions, and deer exp lo i t a t ion (Julander 1962, Longhurst e t a l . 1952).

Secondary succession t o closed canopy f o r e s t on many of the burned a r e a s is rap id ly reducing carrying capaci ty of deer summer range (Hines 1973, Leege 1959, Loope and Gruel1 1973, Lyon 1966, 1971). Prescr ibed burning and o ther f o r e s t r y and range management p r a c t i c e s t h a t i n t e g r a t e forage and timber production w i l l be necessary on many montane f o r e s t a reas i n f u t u r e i f important summer range values a f f e c t i n g deer product ivi ty a r e t o be maintained.

Successional change: Mule deer a r e adapted to mid-successional communities t h a t contain a good mix of g rass , fo rb , and shrub species , but e spec ia l ly browse communities in winter. Changes leading away from such condit ions usua l ly adversely a f f e c t deer ca r ry ing capaci ty where they occur over extensive a reas . Management of succession, then, is the business we a r e i n i f opt imizat ion of harvestable game i s our goal (Leopold 1950).

Unless s i t e p o t e n t i a l has been se r ious ly a l t e r e d , processes of pas t change can be reversed and t h i s i n no way excludes those wrought by grazing. Indeed, on many a r e a s determined t o be b e s t managed without l ives tock use, municipal and other watersheds come t o mind, we can observe secondary succession toward the climax community. A good example is the Wasatch Front i n Utah, a t l e a s t port ions of i t . Removal of growing season l ives tock grazing has been followed by surpr i s ing ly rapid recovery of bunchgrasses and fo rbs with a coro l l a ry reduct ion of

23 Mute Deer Hahi to t Changes desesutting from Livestock Prac t i ces

shrub cover (Smith 1949, S todda r t and Smith 1955).

F i r e i n s u s c e p t i b l e types such a s sagebrush: g r a s s can h a s t e n p rog res s ion through heavy r educ t ion of shrubs . Where d i sc l imaxes a r e t h e d e s i r e d o b j e c t i v e , a s i n juniper-pinyon, f i r e o r mechanical c o n t r o l i s a neces sa ry element t o avoid canopy c l o s u r e and l o s s of unders tory (Plummer e t a l . 1968). General ly , succes s ion proceeds s lowly and t h e r e is p r e s e n t l y l i t t l e evidence, o u t s i d e of some montane f o r e s t t ypes , t h a t i t i s r e spons ib l e f o r shor t - term d e c l i n e s of mule deer . However, ex t ens ive change toward a g ra s s l and , woodland, o r f o r e s t c l imax can b e expected t o reduce dee r c a r r y i n g capac i ty over t h e long term. This should b e a n t i c i p a t e d i n any r e source p l ans and a c t i o n ( o r i n a c t i o n ) programs t h a t l e a d t o s i g n i f i c a n t s h i f t s i n p l a n t communities. We have been remiss i n no t moni tor ing change more c l o s e l y .

Current Management S t a t u s

My assignment unavoidably p a r a l l e l s l a t e r symposium papers i n s e v e r a l a r eas ; namely, p reda to r c o n t r o l , vege ta t ion manipula t ion, and compet i t ion. As much a s p o s s i b l e , an a t tempt h a s been made t o avoid s p e c i f i c c o n s i d e r a t i o n of t hese and r e l a t e d t o p i c s , b u t they cannot be completely ignored s i n c e they a r e an i n t e g r a l p a r t of l i v e s t o c k product ion on most rangelands . L ives tock p r a c t i c e s f r e q u e n t l y a f f e c t food: space r e l a t i o n s ( n u t r i t i o n and behavior) of mule dee r and t h e e lements o f compe t i t i on and h a b i t a t d e s t r u c t i o n a r e p o t e n t i a l l y s t rong .

Adjustments of l i v e s t o c k numbers t o a c a r r y i n g c a p a c i t y t h a t recognizes a l l o c a t i o n of r e sou rces t o d i v e r s e uses has come a long way (Smith 1958, 1959) , y e t t h e r e is s t i l l need f o r much improvement on p u b l i c rangelands (Bureau of Land Management 1974). Our t a s k i s t o i d e n t i f y t h e f o r c e s o f e c o l o g i c a l change put i n t o motion by n e a r l y a century of exploi- t a t i v e use , and t o u t i l i z e t hose a s p e c t s t h a t a c c i d e n t a l l y produced b e n e f i t s and t o con t inue t o combat nega t ive a spec t s .

Vege ta t iona l management: Manipula t ive t r ea tmen t s f o r i n c r e a s i n g l i v e s t o c k fo rage have been condemned i n many w i l d l i f e c i r c l e s a s made a t t h e expense of dee r h a b i t a t . I n f a c t , e a r l i e r programs d i d tend t o b e over-sized and s ingle-purpose wi th t h e r e s u l t t h a t very l a r g e acreages were changed from one form of monotony t o another . Thus, huge expanses of mature juniper-pinyon were chained and seeded t o c r e s t e d wheatgrass (A-gropyron c r i s t a twn , A. d e s e r t o m ) from about 1940 t o 1970 (Aro 1975). S i m i l a r l y , l a r g e blocks of sagebrush were plowed o r sprayed wi th h e r b i c i d e s i n a l l western s t a t e s .

Assessments of deer h a b i t a t va lues on p r o j e c t s t h a t were planned with t h i s a s an o b j e c t i v e a r e p r a c t i c a l l y n i l . The few s t u d i e s e x t a n t a r e u s u a l l y examinat ions of o l d e r , s ingle-purpose p r o j e c t s and these s t u d i e s have o f t e n shown c o n f l i c t i n g r e s u l t s . For example, dee r response t o juniper-pinyon cha in ings has been both p o s i t i v e (Minnich 1969, Reynolds 1964) and nega t ive ( T e r r i l l and S p i l l e t t 1975, McCulloch 1971), depending upon c r i t e r i a used i n e v a l u a t i o n and l o c a t i o n .

Pase r t a l . 1967, Taber and Dasmann 1958, Urness 1975). Creat ion of v e g e t a t i o n a l d i v e r s i t y o f t e n has provided h igh -qua l i t y fo rage r e sources , unava i l ab l e on una l t e r ed s t a n d s , which can b e seasona l ly important t o mule dee r (Plummer e t a l . 1968). Thus green c r e s t e d wheatgrass i s sought by dee r from f a l l t o e a r l y s p r i n g when o t h e r a v a i l a b l e fo rages , most ly browse and i n d i s p e n s i b l e , a r e much lower i n va lue (Koehler and Leckenby 1970).

S h i f t s toward management o b j e c t i v e s t h a t emphasized c r e a t e d mosaics t o provide t reatment b e n e f i t s wh i l e r e t a i n i n g va lues inna te t o t h e u n t r e a t e d community have been very r e c e n t . They came wi th the growth of environmental concerns a f t e r t h e mid-1960's. Planned d i v e r s i t y of cover t ypes through sma l l p r o j e c t s t h a t b lend n a t u r a l l y i n t o t h e landscape became accepted manager ia l p o l i c y (Fores t Se rv i ce 1973, Tausch 1973). However, by then s o c i a l , p o l i t i c a l , and economic p r e s s u r e s were s o g r e a t t h a t a nea r abandonment of such programs has ensued. We have, i n e f f e c t , thrown ou t t h e baby wi th t h e ba th .

While t he d e c l i n e of d e e r is coincident w i th a winding down of v e g e t a t i o n a l c o n t r o l programs on p u b l i c l a n d s , t h e r e is no sugges t ion of a cause: e f f e c t r e l a t i o n s h i p . Conversely, t h e r e is l i t t l e ca se f o r argument t h a t a " c r i t i c a l mass" of t r e a t e d land f i n a l l y exceeded an upper t h re sho ld which was followed by a c r a sh i n dee r numbers. Most t r ea tmen t s were accomplished we l l b e f o r e a d e c l i n e i n d e e r numbers. To my knowledge, no one has demonstrated a p a t t e r n i n popu la t ion l e v e l s t h a t p a r a l l e l s d i f f e r e n c e s i n amount of t r e a t e d a rea .

Grazing systems: Grazing systems t h a t provide some r o t a t i o n o r deferment of l i v e s t o c k use a r e i n c r e a s i n g l y adopted on p u b l i c l ands a s c a p i t a l improvements, p a r t i c u l a r l y f enc ing and b e t t e r water d i s t r i b u t i o n , permit animal c o n t r o l . The concepts and terminology vary b u t t h e b a s i c t e n e t is p e r i o d i c heavy use on p a r t of a range u n i t wi th r e s t o r deferment on the remainder (Herbel 1974, S todda r t e t a l . 1975).

Impacts on dee r o f a c h a n g e from l e s s heavy and l e s s uniform bu t cont inuous l i v e s t o c k use t o a d e f e r r e d system could be profound.1 Within-year compet i t ion between l i v e s t o c k and dee r could be eased where p o r t i o n s of t h e range a r e r e s t e d bu t a v a i l a b l e t o dee r . However, t h e major impact could be a l t e r a t i o n of compet i t ive r e l a t i o n s among p l a n t s p e c i e s a f f e c t i n g composition. Indeed, t h i s i s t h e o b j e c t i v e of any g raz ing system over cont inuous o r season-long use , namely, t o improve range c o n d i t i o n ( u s u a l l y i n t e r p r e t e d a s an i n c r e a s e i n dec rease r g r a s s e s and f o r b s , r educ t ion of i n c r e a s e r of i nvade r shrubs) .

' ~ e s e a r c h p roposa l on "Impacts of s p e c i a l i z e d g raz ing systems on mul t ip le-use a s p e c t s i n t h e Intermountain Region" on f i l e a t Utah S t a t e Univers icy, Range Science Department, Logan. Utah.

The s t o r y has been much t h e same i n sagebrush: g r a s s (Anderson 1969, Koehler 1970, Lechenby 1969, Urness 1966) and chapa r ra l types (Biswel l e t a l . 1952,

Mule Deer. H a b i t a t L'lzan~es Resu l t i ng from Livcs t o c ~ Practices

Depending upon vegetat ion type and season, the opposi te e f f e c t is possible . Heavy e a r l y summer l ive - s tock use can e f f e c t i v e l y increase vigor and production of browse p l a n t s valuable a s winter forage f o r mule deer (Jensen e t a l . 1972, Smith and Doell 1968). Midsummer t o f a l l u s e i n t h e same a r e a can negate the b e n e f i t s when l ives tock s h i f t heavi ly t o browse a s fo rbs and g rasses mature. Importance of l ives tock a s too l s t o con t ro l succession on game winter ranges has only recen t ly been invest igated. Utah has purchased extensive lands a s c r i t i c a l winter range t o help o f f s e t losses t o housing and o ther developments. Livestock grazing programs t o enhance t h e i r value f o r deer a r e cur ren t ly ac t ive .

Despite some change, grazing systems have not , i n my opinion, imposed a con t ro l l ing inf luence on near-term deer numbers over e n t i r e regions. Reduc- t ions i n permitted l ives tock numbers and seasons of use have been slow b u t continuous on many grazing u n i t s i n the Intermountain Region. Trucking of l ives tock from summer t o winter range has reduced f a l l use of deer winter range i n some areas. E f f o r t s t o secure more uniform and proper use have proceeded during the pas t severa l decades. A l l of these f a c t o r s tend t o suggest an improved range s i t u a t i o n f o r deer r e l a t i v e t o l ives tock grazing o r , a t the l e a s t , only s l i g h t l y changed s t a t u s .

Other l ives tock p rac t i ces : Development and b e t t e r d i s t r i b u t i o n of water sources on a r i d rangelands have permitted yearlong use of ranges t o deer t h a t otherwise would be seasonal ly unusable (Wright 1959). Deer access to l ives tock water developments should be assured on public lands. Wherever possible . these should be dependable sources, not j u s t ava i l ab le when l ives tock a r e present . The tendency t o use access t o water a s a means of c o n t r o l l i n g l ives tock use i n l i e u of fencing can have adverse e f f e c t s on deer h a b i t a t use. I t is not a widespread p r a c t i c e on pub l ic lands and i t should be discouraged. In general , a r i d lands where water l i m i t s seasonal deer use seldom a r e highly productive h a b i t a t s . Such a reas a r e not extensive and the water supply s i t u a t i o n has no t changed mate r ia l ly i n recent years o r i t has improved.

Fencing f o r l ives tock con t ro l , i f improperly constructed, can i n t e r f e r e with deer migrat ions and access t o hab i ta t . Except f o r major highway fences, these s i t u a t i o n s a r e usual ly l o c a l i n nature and normally do not c o n s t i t u t e a se r ious t h r e a t t o deer a s they have with antelope.

Greater use of veh ic les i n l ives tock management has expanded access roads i n t o more a reas i n recent years. This , p lus the acce le ra ted rec rea t iona l use of rangelands has probably a f fec ted seasonal deer use

of h a b i t a t somewhat although i t s importance has not been assessed. Harassment, general ly, has increased in i n t e n s i t y on a broad f r o n t and should receive g r e a t e r a t t e n t i o n a s p o t e n t i a l f a c t o r s a f f e c t i n g herd p roduc t iv i ty and mortal i ty .

Probably more than any o t h e r aspect a ssoc ia ted with l ives tock management, predator con t ro l has changed during the period of immediate concern. I w i l l de fe r t o l a t e r papers on t h e o v e r a l l quest ion, except t o r e i t e r a t e t h e ubiqui ty and e f fec t iveness of control programs over much of t h e t o t a l mule deer range through t h e mid-1960's. Public a s well a s p r i v a t e lands were sys temat ica l ly t r e a t e d over huge a reas p r i o r t o the toxicant ban i n 1972. With- drawal of tox ic compounds, e s p e c i a l l y 1080, and o ther r e s t r i c t i o n s on con t ro l methods, have created a storm of controversy within the l ives tock indus t ry espec ia l ly from sheep producers (Bowns 1976, Howard 1974, Davenport e t a l . 1973, Wagner 1972). The b e n e f i t s derived from the controversy a r e numerous s t u d i e s attempting, f i n a l l y , t o quant ify predator impacts on l ives tock and deer populations.

Disease transmission between l ives tock and mule deer , with a few exceptions, has seldom been more than a l o c a l problem. However, such cases a r e d i f f i c u l t t o diagnose on rangelands unless l o s s e s a r e heavy. Die-offs i n mule deer a r e r a r e as ide from l a t e winter losses where concentrat ions on poor condit ion ranges occur. The d i sease ind ica ted i n such s i t u a t i o n s i s usual ly "hollow-belly." A sparse l i t e r a t u r e r e l a t e d t o mule deer e i t h e r means d i seases a r e much l e s s common than i n wiiite-tailed and black-tai led deer , or t h a t l e s s research e f f o r t has been expended (Hunter and Yeager 1956, Neiland and Dukeminier 1972). In e i t h e r case, no apparent increases i n d i sease incidence have been reported over e n t i r e regions i n recent years . Furthermore, i t is unl ikely t h a t d i seases would se r ious ly a f f e c t deer while e lk , on the same ranges, have increased.

Conclusions

Factors assoc ia ted with l ives tock production on western rangelands t h a t a l s o serve a s mule deer h a b i t a t s have, with the possible exception of predator con t ro l and increased human a c t i v i t y , changed comparatively l i t t l e i n the past decade. Indeed, some aspec t s such a s reduced l ives tock use on many key a reas , changes i n c l a s s of l ives tock , and more c a r e f u l l y executed vegetat ion con t ro l p r o j e c t s , should have a f fec ted deer pos i t ive ly . Therefore, while it cannot be s t a t e d with absolute c e r t a i n t y , I w i l l go on record a s bel ieving t h a t l i v e s t o c k grazing p r a c t i c e s have had l i t t l e in f luence on the general decl ine i n mule deer numbers s ince the mid-1960's.

Mute Deer Habitat Changes Resulting from Livestock Practices

Figure 1. Approximate distribution of deer (Odocoileus hemionus) in North America after K.D. Taber (1966) and E. Beltran (1953).

125 - UTAH: Mule Deer Harvest

1000's

100

75

50 -

25

1935 1945 1955 1965 1975

Figure 2. Harvest curves for mule deer in Utah averaged for the preceding five years. Actual harvests are plotted for 1971-75.

UTAH: range stock

- sheep - r W I I I .

1,000,000'8

Figure 3. Range cattle and sheep numbers in Utah, January 1 inventories (ARS, Reporting Service).

Figure 4. Woody plant increases on desert grassland range at Santa Rita Experimental Range, Arizona (A. taken in 1903, B. retaken in 1948, courtesy of S.C. Martin).

Figure 5. Downslope invasion of grassland by pinyon and juniper provides cover value for mule deer in early and mid-succes~ional phases (Photo supplied by R.J. Tauech).

Figure 6 . "We constantly change the world, even by our inaction; therefore, l e t us change i t responsibly. " B . Franklin.

Figure 7. Removal of growing season livestock use can result in successional change affecting deer carrying capacity on sagebrush: bunchgrass winter range (Right of fence grazed by cattle in spring, left area ungrazed by livestock for approximately 30 years, photograph supplied by A.D. Smith).

LITERATURE CITED

Anderson, E. A. 1969. 2,4-D, s ageb rush , and mule d e e r - c a t t l e u s e of upper w i n t e r r ange . Colo. Game, F i s h and Pa rks Spec. Repor t . 21. 21 pp.

Arnold , L. N. 1942. Notes on t h e l i f e h i s t o r y of t h e sand pocket mouse. Jour . Mamm. 23(3) : 339-341.

Aro, R. S. 1975. P inyon- juniper woodland mani- p u l a t i o n w i t h mechanica l methods. Proc . Symp. on t h e Pinyon-Juniper Ecosystem, Logan, Utah. pp. 67-75.

B e l t r a n , Enr ique . 1953. Vida s i l v e s t r e y r e c u r s o s n a t u r a l e s a l o l a r g o d e l a c a r r e t e r a panamericana. I n s t i t u t o Mexicano De Recursos N a t u r a l e s Renovables , A. C., Mexico, D.F. 228 pp.

Ben t l ey , H. L . 1898. C a t t l e r anges o f t h e Southwest , a h i s t o r y of t h e e x h a u s t i o n o f t h e p a s t u r a g e and s u g g e s t i o n s f o r i t s r e s t o r a t i o n . U.S.D.A. Fanne r ' s B u l l . 72:l-32.

B i swe l l , H. H., R . D. Tabe r , D. W. Hedr ick , and A. M. S chu l t z . 1952. Management of chamise b ru sh l and f o r game i n t h e n o r t h c o a s t r eg ion o f C a l i f o r n i a . C a l i f . F. & G. 38:453-484.

Blackburn , W. H., and P. T. T u e l l e r . 1970. Pinyon and j u n i p e r i n v a s i o n i n b l a c k s ageb rush communities i n e a s t - c e n t r a l Nevada. Ecol . 51(5):841-848.

B l a i s d e l l , J. P. 1953. E c o l o g i c a l e f f e c t s o f p lanned bu rn ing o f s ageb rush :g r a s s r ange on t h e Upper Snake R i v e r P l a i n s . U.S.D.A. Tech. B u l l . 1075. 39 pp.

B lydens t e in , J., C. R. Hungerford , G. I. Day, and R. R. Humphrey. 1957. E f f e c t o f domes t i c l i v e s t o c k e x c l u s i o n on v e g e t a t i o n i n t h e Sonoran Dese r t . Ecol . 38(3) :522-526.

Bowns, J. E. 1976. F i e l d c r i t e r i a f o r p r e d a t o r damage assessment . Utah Sc i ence 37(1):26-30.

Branscomb, B. L. 1958. Shrub i n v a s i o n o f a s o u t h e r n New Mexico d e s e r t g r a s s l a n d range . J. Range Manage. 11(3) :129-133.

Brown, A. L. 1950. Shrub i n v a s i o n o f s o u t h e r n Ar izona d e s e r t g r a s s l and . J. Range Manage. 3(3) :172-177.

Buechner, H. K. 1944. The r ange v e g e t a t i o n o f Kerr County, Texas, i n r e l a t i o n t o l i v e s t o c k and w h i t e - t a i l e d dee r . Amer. Midl. Nat. 31:697-743.

Bureau of Land Management. 1974. E f f e c t s of l i v e s t o c k g r a z i n g on w i l d l i f e , wa t e r shed , r e c r e a t i o n , and o t h e r r e s o u r c e v a l u e s i n Nevada. Mimeo.

Cottam, W. P . , and F. R. Evans. 1945. A composi t ion s t u d y o f t h e v e g e t a t i o n of g r azed and ungrazed

Cronemi l l e r , F. P . , and P. S. Bartholomew. 1950. The C a l i f o r n i a mule d e e r i n c h a p a r r a l f o r e s t . C a l i f . F. & G. 3(4):343-365.

Croxen, F. W. 1926. H i s t o r y of g r a z i n g on Tonto. Tonto Grazing Conf. , Phoenix , Ar izona . 19 pp.

Da r l i ng ton , H. T. 1915. A s t u d y o f g r a z i n g c o n d i t i o n s i n t h e Wenaha Na t i ona l F o r e s t . Wash. S t a t e Agr. Exp. S tn . Bu l l . 122:l-18.

Davenport, J. W . , J. E. Bowns, and J . P. Workman. 1973. Assessment of sheep l o s s e s t o coyotes-a problem t o Utah sheepmen-a concern of Utah r e s e a r c h e r s . Utah S t a t e Univ., Agr. Exp. S tn . Res. Report . 7. 17 pp.

Dwyer, D. D. 1975. Response of l i v e s t o c k f o r a g e t o man ipu l a t i on o f t h e p inyon- juntper ecosys tem. Proc . Symp. of t h e Pinyon-Juniper Ecosystem, Logan, Utah. pp. 97-103.

E l l i s o n , L. 1954. Suba lp ine v e g e t a t i o n of t h e Wasatch P l a t e a u , Utah. Ecol . Monogr. 24:89-184.

E l l i s o n , L. 1960. I n f l u e n c e of g r a z i n g on p l a n t s u c c e s s i o n on r ange l ands . Bot. Rev. 26(1):1-78.

E l l i s o n , L., A . R. C r o f t , and R. W. Ba i l ey . 1951.

I n d i c a t o r s o f c o n d i t i o n and t r e n d on h igh range-watersheds o f t h e In t e rmoun ta in Region. U.S.D.A., Agr. Handb. 19. 66 pp.

F o r e s t S e r v i c e . 1973. P inyon- juniper c h a i n i n g program on N a t i o n a l F o r e s t l a n d s i n t h e s t a t e of Utah. U.S.D.A. For. Se rv . , In term. Region, F i n a l Environmenta l S t a t emen t . 60 pp ( p l u s appended m a t e r i a l s ) .

F o r s l i n g , C. L. 1931. A s t u d y of t h e i n f l u e n c e o f herbaceous p l a n t cove r on s u r f a c e runo f f and s o i l e r o s i o n i n r e l a t i o n t o g r a z i n g on t h e Wasatch P l a t e a u i n Utah. U.S.D.A. Tech. Bu l l . 220. 71 pp.

F r i s c h k n e c h t , N. C. 1975. N a t i v e f a u n a l r e l a t i o n - s h i p s w i t h i n t h e P-J ecosystem. Proc . Symp. o f t h e Pinyon-Juniper Ecosystem, Logan, Utah. pp. 55-65.

Glendening, G. E. 1952. Some q u a n t i a t i v e d a t a on t h e i n c r e a s e s of mesqu i t e and c a c t u s on a d e s e r t g r a s s l a n d r ange i n s o u t h e r n Ar izona . Ecol.

33(3):319-328.

G r i f f i t h s , D. 1902. Forage c o n d i t i o n s i n t h e n o r t h e r n bo rde r o f t h e Grea t Bas in . U.S.D.A.

Bur. P l a n t Ind . Bu l l . 15. 60 pp.

G r i f f i t h s , D. 1903. Forage c o n d i t i o n s and problems i n e a s t e r n Washington, e a s t e r n Oregon, nor th- e a s t e r n C a l i f o r n i a , and n o r t h e r n Nevada. Bur. P l a n t Ind . Bu l l . 38. 52 pp.

G r i f f i t h s , D. 1910. A p r o t e c t e d s t o c k r ange i n Ar izona . U.S.D.A. Bur. P l a n t Ind . Bu l l . 177. 28 PP.

canyons of t h e Wasatch r ange , Utah. ~ c o i . 26(2):171-181.

MuZe Deer H a b i t a t Changes R e s u l t i n g from Lives tock P r a c t i c e s

Herbe l , C. H. 1974. A review of r e s e a r c h r e l a t e d t o development o f g r a z i n g sy s t ems on n a t i v e r anges o f t h e wes t e rn Uni ted S t a t e s : In : P l a n t morphogenesis a s t h e b a s i s f o r s c i e n t i f i c management of r ange r e s o u r c e s . Proc . Workshop o f U.S.-Austral. Rangelands Panc l , Berkeley , C a l i f . U.S.D.A. Misc. Publ . 1271. pp. 138-149.

Hines , W. W. 1973. B l a c k - t a i l e d d e e r popu l a t i ons and Douglas- f i r r e f o r e s t a t i o n i n t h e Ti l lamook Burn, Oregon. Oregon Game Comm. Res. Repor t 3. 5 9 p p .

Howard, N. E. 1974. The b i o l o g y o f p r e d a t o r c o n t r o l . Addison-Wesley Module i n Biology 11. 48 PP.

H u l l , A. C., Jr. and M. K. Hu l l . 1974. P r e s e t t l e m e n t v e g e t a t i o n of Cache Va l l ey , Utah , and Idaho. J . Range Manage. 27(1):27-29.

Humphrey, R. R. 1943. A h i s t o r y of r ange u se and i ts r e l a t i o n t o s o i l and w a t e r l o s s e s on t h e Wal la Wal la R ive r Watershed. N . W. S c i . 17 (4) : 82-87.

Humphrey, R. R. 1953. The d e s e r t g r a s s l a n d , p a s t and p r e s e n t . J. Range Manage. 6(3):159-164.

Humphrey, R. R. 1958. The d e s e r t g r a s s l a n d , a h i s t o r y o f v e g e t a t i o n a l change and an a n a l y s i s o f causes . Bot. Rev. 24:193-252.

Hunter , G. N . , and L. E. Yeager. 1956. Management o f t h e mule dee r . In : The d e e r of Nor th America, W. P. ~ a ~ l z , ed. The S t ackpo l e Co., Ha r r i s bu rg , PA. pp. 449-482.

Jensen, C. H., A. D. Smith, and G. W. S c o t t e r . 1972. Gu ide l i ne s f o r g r a z i n g sheep on r ange l ands used by b i g game i n w in t e r . J. Range Manage. 25(5): 346-352.

J u l a n d e r , 0 . 1962. Range management i n r e l a t i o n t o mule d e e r h a b i t a t and d e e r p r o d u c t i v i t y i n Utah. J. Range Manage. 15(5):278-281.

Kennedy, P. B. 1901. A p r e l i m i n a r y r e p o r t on t h e summer r anges o f wes t e rn Nevada sheep. Nev. Agr. Exp. S tn . Bu l l . 51. 64 pp.

Kennedy, P. B. 1903. Summer r anges of e a s t e r n Nevada sheep. Nev. Agr. Exp. S tan . Bu l l . 55. 55 PP.

Koehler , 9. A. 1970. A review o f l i t e r a t u r e on re- s e e d i n g sagebrush-bunchgrass r a n g e s i n t h e semi- a r i d wes t e rn Un i t ed S t a t e s . Oregon Game Corn., Fed. Aid P r o j e c t W-53-R-12, Job . 1. 1 0 3 pp.

Koehler , D. A., and D. A. Lechenby. 1970. Economics o f r ange r e s e e d i n g vs . f e e d i n g o f mule d e e r . Oregon Game Corn., Fed. Aid P r o j e c t W-53-R-12, Job. 1. 14 pp. ( S p e c i a l r e p o r t ) .

LeMarch, V. C. 1974. P a l e o - c l i m a t i c i n f e r e n c e s from l o n g t r e e - r i n g r e c o r d s . Sc i ence 183:1043- 1048.

Lechenby, D. A. 1969. E c o l o g i c a l s t u d y o f mule dee r . Oregon S t a t e Game Comm., Fed. Aid P r o j . W-53-R-11. J o b 1. 5 1 pp.

Leege, T. A. 1969. Burning s e r a 1 b r u s h r anges f o r b i g game i n n o r t h e r n Idaho. Trans . N. h e r . Wild l . Conf. 34:429-438.

Leopold, A. 1924. Grass , b ru sh , t imbe r , and f i r e i n s o u t h e r n Ar izona . J. For . 22(6):1-10.

Leopold , A., L. K. Sowls, and D. L. Spencer . 1947. A su rvey o f over-popula ted d e e r r anges i n t h e Un i t ed S t a t e s . J. Wild l . Manage. 11(2):162-177.

Leopold, A. S. 1950. Deer i n r e l a t i o n t o p l a n t succe s s ions . J. For. 48(10):675-678.

Loope, L. L . , and G. E. G r u e l l . 1973. The e c o l o g i c a l r o l e o f f i r e i n t h e Jackson Hole a r e a , no r th - wes t e rn Wyoming. Qua t e rna ry Res. 3(3):423-443.

Longhurs t . W. M . , A. S. Leopold, and R. F. Dasnann. 1952. A su rvey o f C a l i f o r n i a d e e r he rd s . t h e i r r anges and management problems. C a l i f . F. & G. Bu l l . 6. 136 pp.

Lyon, L. J. 1966. Problems of h a b i t a t management f o r d e e r and e l k i n t h e n o r t h e r n f o r e s t s . U.S.D.A., For . Serv . , In term. For . 6 Range Exp. S tn . Res. Paper INT-24. 1 5 pp.

Lyon, L. J. 1971. Vege t a l development f o l l o w i n g p r e s c r i b e d hu rn ing of Douglas f i r i n south- c e n t r a l Idaho. U.S.D.A., For Serv . , In term. For . & Range Exp. S tn . Res. Paper INT-105. 30 PP.

McConnell, B. R., and P. D. Dalke. 1960. The C a s s i a d e e r he rd o f s o u t h e r n Idaho. J . Wild l . Manage. 24(3) : 265-271.

McCulloch, C. Y . 1973. C o n t r o l o f p inyon- juniper a s a d e e r management measure i n Arizona. Ar i z . Game & F i s h Dept . , Fed. Aid P r o j e c t W-78-R, WP 4 , J o b s 2 and 7. 32 pp.

Minnich, D. W. 1969. Vege t a t i ve r e sponse and p a t t e r n o f d e e r u se f o l l o w i n g c h a i n i n g of p inyon and j u n i p e r f o r e s t . Colo. Game, F i sb , & Pa rks . Mimeo.

Mueggler, W. F. 1950. E f f e c t s of s p r i n g and f a l l sheep g r a z i n g on v e g e t a t i o n o f t h e Upper Snake R i v e r P l a i n s . 3. Range Manage. 3(4):308- 315.

Nei land, K. A., and C. Tlukeminier. 1972. A b i b l i o - graphy o f t h e p a r a s i t e s , d i s e a s e s , and d i s o r d e r s of s e v e r a l impor t an t w i l d ruminants o f t h e n o r t h e r n hemisphere. Alaska Dept. F i s b & Game Wildl . Tech. Bu l l . 3. 1 5 1 pp.

Pa se , C. P., P. A. Ingebo, E. A. Davis , and C. Y. McCulloch. 1967. Improving wa t e r y i e l d and game h a b i t a t by chemical c o n t r o l of c h a p a r r a l . I n t e r n . Union o f F o r e s t r y Res. Org. Congress , Munich, Germany. 14:463-486. (Pape r s S e c t i o n 01-02-11).

P h i l l i p s , F. J . 1910. The d i s s e m i n a t i o n o f j u n i p e r s by b i r d s . For . Qua r t . pp. 60-73.

3 3 Mule Deer Habitat Changes ResuZting from Livestock Practices

P i c k f o r d , G. D. 1931. The i n ' l uence o f con t i nued heavy g r a z i n g and of promiscuous bu rn ing on s p r i n g - f a l l r anges i n Utah. Ecol . 13 (2 ) : 159-171.

Plummer, A. P . , D. R. C h r i s t e n s e n , and S. B. Monson. 1968. R e s t o r i n g big-game r a n g e i n Utah. Utah Div. F i sh & Game Publ . 68-3. 183 pp.

Reynolds, H. G. 1950. R e l a t i o n of kangaroo r a t s t o r ange v e g e t a t i o n i n s o u t h e r n Arizona. Ecol . 31(3):456-463.

Reynolds , H. G. 1964. E lk and d e e r h a b i t a t u se o f p inyon- juniper woodlands i n s o u t h e r n New Mexico. Trans . N. Amer. Wild l . Conf. 29:438-445.

Reynolds , H. G., and J. W. Bohning. 1956. E f f e c t s o f bu rn ing on a d e s e r t g r a s s - sh rub r ange i n s o u t h e r n Ar izona . Ecol . 37(4):769-777.

Reynolds, H. G. and G. E. Glendening. 1949. Merriam kangaroo r a t , a f a c t o r i n mesqu i t e p ropaga t i on on s o u t h e r n Ar izona r ange l ands . J. Range Manage. 2(4) :193-197.

Reynolds , 11. G . , and S. C. Mar t in . 1968. Managing g r a s s - sh rub c a t t l e r anges i n t he Southwest. U.S.D.A., Agr. Handb. 162. 44 pp.

Reynolds , R. V. R. 1911. Grazing and f l o o d s : a s t u d y o f c o n d i t i o n s i n t h e Mant i N a t i o n a l F o r e s t , Utah. U.S.D.A., For . Serv . B u l l . 91. 16 PP .

Rober tson, J . H. 1971. Changes on a s ageb rush -g ra s s r ange i n Nevada ungrazed f o r 30 y e a r s . J. Range Manage. 24(5):397-400.

Sampson, A. W. 1944. P l a n t s u c c e s s i o n on burned c h a p a r r a l l a n d s i n n o r t h e r n C a l i f o r n i a . Univ. C a l i f . Agr. Exp. S tn . B u l l . 685. 1 4 3 pp.

Sampson, A. W . , and B. S. J e spe r son . 1963. C a l i f o r n i a r ange b ru sh l ands and browse p l a n t s . Univ. C a l i f . Agr. Exp. S tn . Manual 33. 162 pp.

Sampson, A. W . , and L. H. Neyl. 1918. Range p r e s e r v a t i o n and i ts r e l a t i o n t o e r o s i o n c o n t r o l on wes t e rn g r a z i n g l ands . U.S.D.A. Bu l l . 675. 35 PP.

Schulman, E. 1956. Dend roc l ima t i c changes i n semi- a r i d America. Univ. Ar i z . P r e s s , Tucson. 142 pp.

Shan t z , H. L. 1947. F i r e a s a t o o l i n t h e management o f t h e b ru sh r anges i n C a l i f o r n i a . C a l i f . Dept. Nat. Resources , Div. o f Fo r . , Sacramento. 156 pp.

Smith , A. D. 1949. E f f e c t s of mule d e e r and l i v e s t o c k upon a f o o t h i l l r ange i n n o r t h e r n Utah. J. Wild l . Manage. 13(4):421-423.

Smith , A. D . 1958. C o n s i d e r a t i o n s a f f e c t i n g t h e p l a c e of b i g game on w e s t e r n ranges . Proc . Soc. Amer. Fo r . , S a l t Lake C i t y , Utah. pp. 188-192.

Smith , A. D., and D. D. Doe l l . 1968. Guides t o a l l o c a t i n g f o r a g e between c a t t l e and b i g game on b i g game w i n t e r r ange . Utah Div. F i s h & Game Pub l . 68-11. 32 pp.

S t o d d a r t , L. A. 1941. The Pa louse g r a s s l a n d a s s o c i a t i o n i n n o r t h e r n Utah. Ecol . 22 (2 ) : 158- 163.

S t o d d a r t , L. A . , and A . D. Smith. 1955. L ive s tock g r a z i n g i n t h e In t e rmoun ta in Region. Agr. and Food Chem. 3(4) : 303-305.

S t o d d a r t , L. A., A. D. Smith , and T. W. Box. 1975. Range Management. McGraw-Hill, I nc . 532 pp.

Swank, W . G . 1958. The mule d e e r i n Ar i zona c h a p a r r a l . A r i z . G . & F. Dept. Wild l . B u l l . 3. 109 pp.

Taber , R. D. 1966. Land u se and n a t i v e c e r v i d p o p u l a t i o n s i n America n o r t h of Mexico. Univ. Montana For. and Cons. Exp. S t n . Bu l l . 29, pp. 201-225. (Rep r in t from I n t e r n . Union o f Game B i o l . , Trans . VI Congress , Bournemouth, England, Oct . 7-12, 1963) .

Taber , R. D., and R. F. Dasman. 1958. The b l ack - t a i l e d d e e r of t h e c h a p a r r a l . C a l i f . F. & G. Dept. Game B u l l . 8. 1 6 3 pp.

Tausch, R . J. 1973. P l a n t s u c c e s s i o n and mule d e e r u t i l i z a t i o n on p inyon- juniper c h a i n i n g s i n Nevada. Univ. Nevada M.S. t h e s i s , Reno. 150 pp.

T e r r i l l , T. L., and J. J. S p i l l e t t . 1975. Pinyon- j u n i p e r convers ion: i t s impac t s on mule d e e r and o t h e r w i l d l i f e . Proc . Symp. of t h e Pinyon- J u n i p e r Ecosystem, Logan, Utah . pp. 105-119.

Thornber , J . J . 1910. The g r a z i n g r anges of Ar izona . Univ. A r i z . , Agr. Exp. S t n . B u l l . 65 . pp. 245-360.

Timmons, F. L. 1942. The d i s s emina t i on o f p r i c k l y - p e a r s e e d by j a c k r a b b i t s . J o u r . Am. Soc. Agron. 34(6):513-520.

T u e l l e r , P. T. 1973. Secondary s u c c e s s i o n , d i s c l imax , and r ange c o n d i t i o n s t a n d a r d s i n d e s e r t s h r u b v e g e t a t i o n . In: Ar id Shrublands , Proc . Workshop o f t h e U.S.-Austra. Rangelands Pane l 3: 57-65.

T u e l l e r , P. T.,and W. H. Blackburn . 1974. Cond i t i on and t r e n d o f t h e b i g sagebrushlneedle-and-thread g r a s s h a b i t a t - t y p e i n Nevada. J. Range Manage. 27(1) : 36-40.

U m e s s , P. J. 1966. I n f l u e n c e o f range improvement p r a c t i c e s on composi t ion , p roduc t i on , and u t i l i z a t i o n of Ar t emi s i a dee r w i n t e r r ange i n c e n t r a l Oregon. Oregon S t a t e Univ. Ph.D. d i s s e r t a t i o n . 1 8 3 pp.

Umess , P. J. 1975. Deer u se changes a f t e r r o o t p lowing i n Ar izona c h a p a r r a l . U.S.D.A. For. S e r v . , Rocky Mt. For. & Range Exp. S tn . Res. Note RM-255. 8 pp.

Smith, A. D. 1959. Whose space and f o r what? Trans. N . Amer. Wild l . Conf. 24:449-456.

MuLe Deer Habitat Changes Resulting from Livestock Practices

Wagner, F. H. 1972. Coyotes and sheep, some thoughts on ecology, economics, and e th ics . Utah S t a t e Univ.. Honor Lecture 44:l-59.

West, N. E . , K. H. Rea, and R. J. Tausch. 1975. Basic synecological r e la t ionsh ips i n pinyon- juniper woodlands. Proc. Symp. on the Pinyon-Juniper Ecosystem, Logan, Utah. pp. 41-53.

Whitf ie ld, C. J . , and H. L. Anderson. 1938. Secondary succession i n the d e s e r t p l a i n s grassland. Ecol. 19(2) :171-180.

Wooten, E. 0. 1908. The range problem i n New Mexico N. Mex. Agr. Exp. Stn. Bull. 66. 46 pp.

Wooten, E. 0. 1915. Factors a f f e c t i n g range management i n New Mexico. U.S.D.A. Bull. 211. 39 pp.

Wright, J. T. 1959. Desert Wildl i fe . Ariz. Game 6 Fish Dept. Wildl. Bull. 6. 78 pp.

35 MuZe Deer Habitat Chmges Resulting frm Livestock Practices

ALTERATION OF IRnE DEER HABITAT BY WILDFIRE,

LOGGING, HIGHWAYS, AGRICULTURE, AND HOUSING DEVELOPMENTS

Olof C. Wallmo Pr inc ipa l Wi ld l i fe Biologist

Rocky Mountain Forest and Range Experiment S t a t i o n U.S.D.A. Forest Service

For t Coll ins , Colorado 80521

Dale F. Reed V i l d l i f e Researcher

Colorado Division of Wi ld l i fe Glenwood Springs, Colorado 81601

Len H. Carpenter Ass i s tan t Wi ld l i fe Researcher Colorado Division of Wildl i fe

Kremling, Colorado 80459

Abstract

The meager da ta ava i l ab le f a i l t o support the hypothesis t h a t f o r e s t f i r e s , logging, highways, housing developments, o r agr icu l - tu re , s ing ly o r i n combination, can be held responsible f o r a dec l ine i n the populat ion of mule deer (OdocoiZeus h e m i o m hemionus) throughout the western United S ta tes . I f posed, i t would be a vacu- ous hypothesis i n the absence of documentation of such a decl ine. A uniform resource inventory system c l e a r l y is needed. The Fores t and Rangeland Renewable Resources Planning Act may provide the opportuni ty t o develop such a systen.

The geographic range of the Rocky Mountain mule deer (OdocoiZeus hemionus hemionus) covers more than 1 mi l l ion square miles of the United S t a t e s . Con- s ide r ing the enormous ecological amplitude of the spec ies , it can be presumed t h a t a t one time o r another i n h i s t o r y most of t h i s range was hab i tab le t o some extent . That is, it was poor, mediocre, o r good mule deer h a b i t a t , but probably never s t a t i c . During t h e time s ince the spec ies appeared and d i f - f e r e n t i a t e d i n t o 11 recognized subspecies , t h e contin- e n t has undergone g r e a t changes i n cl imates and f l o r a s .

A dynamic system would be necessary t o c l a s s i f y mule deer h a b i t a t over time. It would d e t e c t the inf luences of epochal changes, l e s s e r c l imat ic f luc - tua t ions r e s u l t i n g from i r r e g u l a r behavior of the sun, and, on a s t i l l smaller sca le , the unpredictable droughts, p luv ia l s , and prolonged winters t h a t a r e superimposed on l a r g e r c l imat ic t rends. With t h a t capab i l i ty , perhaps i t would a l s o be ab le t o d i s t i n - guish from "natural" h a b i t a t t rends those e f f e c t s t h a t a r e imposed by man. Without such a system, we can only say f o r su re t h a t h a b i t a t condit ions a r e i n a t r a n s i t i o n s t a t e t h a t we may o r may not be modifying s i g n i f i c a n t l y . To maintain them i n some constant s t a t e presumes t h a t we understand t h a t s t a t e and the fo rces changing it.

Commonly, the evidence f o r h a b i t a t change i s taken t o be the increase o r decrease i n the popula- t i o n s of the spec ies i n question. Observed changes i n the environment t h a t c o r r e l a t e with the population

change a r e assumed t o be causat ive, and the casual mechanisms can only be postulated. They might be proven with acceptable l e v e l s of confidence a f t e r the hypothesis i s posed, but not i n the process of hypothesizing.

Today we a r e i n the p o s i t i o n of posing hypo- theses. Managers a r e concerned over the content ions t h a t mule deer populations a r e dec l in ing over the e n t i r e range and t h a t some common cause o r combin- a t i o n of causes i s behind it . To venture i n t o t h i s pos i t ion it is necessary f i r s t t o document the pop- u l a t i o n change i n magnitude and locat ion. Unfortun- a t e l y our knowledge of the h i s to ry of mule deer populat ions on a con t inen ta l s c a l e is based only on guesses derived, commonly second- o r third-hand, from sub jec t ive impressions. By t h a t means Seton (1937) guessed t h a t the re were about 10 mi l l ion mule deer i n North America a t the time of the a r r i v a l of white men and about one-half mi l l ion i n 1908. Two decades l a t e r there were supposed, on equal ly poor evidence, t o be 100,000 mule deer on the Kaibab National Fores t a lone (Caughley 1970), an a rea com- p r i s i n g l e s s than 0.1 percent of the range of the species .

The only cons i s ten t r e p o r t s of deer numbers on a nation-wide b a s i s a r e provided by the U.S. Forest Service. I f these est imates a r e t o be bel ieved, there were about 750,000 deer ( a l l spec ies ) on the western National Fores t s i n 1930, over 3 mi l l ion i n 1965, and nearly two and one-half mi l l ion i n 1972.

37 Alteration of MuZe Deer Habitat

Unfortunately, these f igures a r e not derived from systematic inventories . Nor have the s t a t e s and provinces of the U.S. and Canada provided a c red ib le body of da ta from which to i n f e r populat ion t rends. Conse- quent ly, we a r e on flimsy ground i n t r ac ing events t h a t may have had l a rge e f f e c t s on mule deer populations.

We do not suggest t h a t the phenomena discussed below a r e casual ly re la ted to changes i n deer numbers on a region-wide bas i s . I t may be productive t o consider them, though, i f f o r no other reason than t o emphasize the need f o r b e t t e r information. Five types of h a b i t a t a l t e r a t i o n a r e discussed: f i r e , logging, roads and highways, a g r i c u l t u r a l development, and housing development.

FIRE

It is widely accepted t h a t f o r e s t f i r e s general ly improve the qua l i ty of mule deer h a b i t a t . Lyon and Stickney (1966) s t a t e d t h a t "most of the big-game ranges of western Montana and northern Idaho were c rea ted by uncontrolled f o r e s t f i r e s " -- pr inc ipa l ly between 1910 and 1934. The term c rea t ion might be too s t rong , inasmuch a s the deer l i v e d there p r i o r t o the f i r e s , but the h a b i t a t s t i l l may have been improved. Pos t - f i r e increase i n the biomass of vegetat ion access ib le a s deer forage i s a r a t i o n a l b a s i s f o r assuming h a b i t a t improvement. A chain of reasoning can be constructed to support the hypothesis t h a t l a r g e r deer populat ions would r e s u l t . But none of the information ava i l ab le to da te demonstrates t h a t i t has occurred.

While some authors (Pengelly 1963; Lyon and Stickney 1966) contend t h a t f o r e s t f i r e s have had a dominant inf luence on deer populations i n the Rocky Mountains, o the rs (Edwards 1956; Picton and Knight 1969; Robinette e t a l . 1952; Wallmo and G i l l 1971) suggest t h a t snow depth and durat ion on winter range a r e a major determinant of population l e v e l s . A t the same time we a r e l e d t o be l i eve t h a t changes i n hunting pressure s ince white man s e t t l e d the West may have e f fec ted major changes i n deer numbers. Whatever c o r r e l a t i o n s we might discover between the h i s t o r i e s of f o r e s t f i r e s and deer populat ions, they must be considered i n the l i g h t of o the r f a c t o r s .

The U.S. Forest Service has maintained a thor- ough f i r e repor t ing system s ince 1909. Data on a r e a burned within the National Forest boundaries i n Region 1, the northern Rocky Mountains, and Region 2 , c e n t r a l Rocky Mountains, a r e presented i n Table 1. In the 3 decades from 1910 t o 1940 over 7 mi l l ion ac res were a f fec ted by f o r e s t f i r e . In the 3 decades from 1940 to 1970 l e s s than 1 mi l l ion ac res were burned.

The h a b i t a t improvement t h a t may r e s u l t from f i r e r e s u l t s from disclimax ecological succession. Though the l i t e r a t u r e on pos t - f i r e development of vegetat ion i s extensive, the durat ion of condit ions more favorable to deer is not well documented. Lyon (1971) suggests t h a t the b e n e f i t s would continue f o r up to 60 years i n the Douglas f i r (Pseudotsuga spp.) type i n sou thcen t ra l Idaho. In Wyoming, the advan- tages may be l o s t i n 10-20 years i n lodgepole pine (Pinus eontorta) s t ands , 20-50 years i n aspen (PopuZus tremui-oides), 50 years i n Douglas f i r , and 80 years i n subalpine f i r (Abies Zasioearpa) (U.S. Department of the I n t e r i o r 1974). Pat ton and Avant (1970) est imate t h a t burning aspen s tands i n New Mexico w i l l improve the h a b i t a t f o r big game f o r 8 t o 10 years .

Whatever the period of e f f e c t , i t must be con- s idered i n est imating the a rea p o t e n t i a l l y influencing deer h a b i t a t over time. I f an average period of 20 years i s r e a l i s t i c , i n the National Fores t s of the c e n t r a l Rocky Mountain Region (Region 2) there were some 450,000 ac res i n "improved" condit ion i n 1929 and 150,000 i n 1970 (Fig. 1 ) . I f the improved condit ion l a s t e d an average of 40 years t h e peak a rea enhanced would have been about 7.4 mi l l ion ac res i n 1950, dwindling to about 1.2 i n 1975; a maximum of about 2 percent and a minimum of about 0.4 percent of the t o t a l a rea which the f i r e r e p o r t s cover. It seems quest ionable, a t l e a s t , t h a t the d i f fe rence between these f r a c t i o n s of the t o t a l a rea could have influenced reg iona l deer populat ions t o a de tec tab le degree, p a r t i c u l a r l y i n view of t h e f a c t t h a t we have l i t t l e evidence to support the b e l i e f t h a t fo res ted summer range is d e f i c i e n t i n i t s unburned s t a t e .

Table 1. Acres burned by decades within p ro tec t ive boundaries of I ia t ional Fores t s and Grasslands of Regions 1 and 2 of the U.S. Fores t Service.

Years - Region 1 Region 2 Total

I' Data incomplete.

2' Data not ava i l ab le .

Al te ra t ion of M u l e Deer Habi ta t 38

Fig. 1. Acres presumably in "improved" condition for deer range as a result of fire in National Forests of the central Rocky Mountain Region (relative to a base status in 1910).

LOGGING ROADS AND HIGHWAYS i

In f o r e s t environments understory vegetat ion biomass i s inversely r e l a t e d t o overstory. This i s an acceptable genera l i za t ion f o r most f o r e s t types in Noith America ( F f o l l i o t t and Clary 1972). Thus, v i r - t u a l l y a l l timber removal operat ions could, t h e o r e t i c a l l y , b e n e f i t deer h a b i t a t , the maximum bene- f i t p o t e n t i a l l y coming from c l e a r c u t t i n g (Wallmo e t a l . 1972). Pengelly (1963) in fe r red , ambiguously, tha t logging i n the northern Rocky Mountains was a major f a c t o r inf luencing the increase i n deer populations i n t h a t region i n the f i r s t half of t h i s century. Increases in deer populat ions i n the region, spec i f i - c a l l y as a r e s u l t of logging have y e t t o be Jocumented, however.

Research on the sub jec t ind ica tes t h a t use by deer commonly increases a f t e r logging (Edgerton 1972; Pat ton 1974; Pearson 1968; Wallmo 1969). But Regelin e t a] . (1974) postulated t h a t o the r f a c t o r s kept mule deer populat ions i n the c e n t r a l Rocky Mountains well below t h e d e n s i t i e s t h a t could be supported by unlogged f o r e s t . Nevertheless, the c i rcumstan t ia l evidence t h a t logging can be b e n e f i c i a l to mule deer h a b i t a t j u s t i f i e s considerat ion of i t s p o t e n t i a l e f f e c t on a reg iona l bas i s . Wallmo e t a l . (1972) est imated t h a t c lea rcu t t ing i n subalpine f o r e s t s of the c e n t r a l Rocky Mountains increased deer forage supplies nearly 50 percent 15 years and 20 years ( the l a t t e r unpublished) a f t e r logging.

Data on timber removals f o r the e n t i r e Rocky Moun- t a i n a r e a were not obtained, but complete records from the National Forests of the Central Rocky Mountain Region (Region 2) were examined. Over the period of record, 1911 to da te , there has been a progressive inc rease i n the timber ha rves t , reaching a peak i n 1969. A s l i g h t decrease s ince then i s a t t r i b u t a b l e t o the public opposi t ion to c l e a r c u t t i n g and the development of environmentally p re fe rab le harvest ing systems by Forest Service s i l v i c u l t u r i s t s .

In Region 2 the t o t a l area logged by a l l harvesting methods has averaged over 65,000 ac res per year over the pas t decade, compared with an average of about 6,000 ac res burned. I n Region 1 (northern Rocky Moun- t a ins ) over 100,000 ac res per year a r e logged (Lyon 1969), compared with an average of about 20,000 ac res burned.

As with f i r e , the b e n e f i c i a l e f f e c t s of logging t o deer h a b i t a t can be presumed t o l a s t over a period of years (Wallmo e t a l . 1972). I f we assumed an inf luence l a s t i n g 20 years , we could e s t i n a t e the region-wide cumulative e f f e c t of logging (Fig. 2) a s we d id with f i r e . The r e s u l t s suggest t h a t the decreasing amount of f i re- inf luenced h a b i t a t i n the c e n t r a l Kocky Moun- t a i n s in the pas t 40 years is more than compensated f o r by logging-influenced h a b i t a t . Together they remain a very small f r a c t i o n of the t o t a l a r e a considered.

Assuming t h a t f i r e and logging have s i m i l a r e f f e c t s on deer h a b i t a t , the record does no t subs tan t i - a t e t h a t t h e i r combined e f f e c t could account f o r decreasing deer populat ions i n the c e n t r a l and northern Rocky Mountains.

AZteration of Mule Deer Habitat

It is indisputable tha t deer a r e k i l l e d i n col- l i s i o n s with high-speed motor veh ic les . Beyond t h a t ,

the impacts of roads and highways on western-wide mule deer numbers a r e not we l l understood. Ind i rec t

impacts would include, f i r s t , the physical l o s s of some na tu ra l hab i ta t including forage, water, and cover ( L e o ~ o l d 1951), r equ i r ing adjustments by wintering and migrat ing deer. Secondly, t r a f f i c and roadways present audi tory and v i s u a l b a r r i e r s which can conceivably adversely a f f e c t deer behavior.

Loss of h a b i t a t - Reasonably accurate est imates of the number of ac res of h a b i t a t d i r e c t l y replaced by roads and highway sur faces o r l o s t through removal of na t ive vegetat ion i n rights-of-way a r e not r ead i ly ava i l ab le . Thus, we made p ro jec t ions f o r Colorado t o serve a s an example of the p o t e n t i a l magnitude of mule deer h a b i t a t losses from roads and highways (Table 2) . I n t e r s t a t e , r u r a l , and county highways usurp about 45, 12, and 7 ac res of land per mile , r espec t ive ly . To ta l p ro jec ted a c r e s encompassed by i n t e r s t a t e , r u r a l , and county highways increased 42.7, 7.5, and 4.8 percent , r e spec t ive ly , between 1960 and 1974. Consequently, i n t e r s t a t e highways represent the type of roadway with the g r e a t e s t poten- t i a l impact on mule deer h a b i t a t . I n mountainous a reas of western Colorado most highways a r e al igned along va l l eys and water courses , f requently on south- fac ing s lopes f o r ease of winter na in tenance These

a r e s p e c i f i c cases where important ac res of deer win te r range a r e modified and migrat ion routes severed o r impacted.

In most cases , highway rights-of-way a r e revege- t a t e d with g rass o r grass-legume mixtures , with c res ted wheatgrass (Agropyron spp.) being one of the more popular spec ies (Reynolds and Spr ingf ie ld 1953). I t i s highly pa la tab le i n the "early green-up" period (Narch-April) and is implicated i n much of the sp r ing deer mor ta l i ty on highways. These acc iden t s , p ius those occurr ing during winter and migrat ion periods, account f o r most of the mule and black-tai led deer (C. hemionus) k i l l e d from c o l l i s i o n s with veh ic les i n the western s t a t e s (Table 3).

Most of the s t a t e s do no t have accurate f igures on road k i l l s because i t i s d i f f i c u l t t o rou t ine ly monitor a l l f e d e r a l , s t a t e , and county roads and because animals which escape the rights-of-way before dying usua l ly a r e no t found. I r r e s p e c t i v e of t h e i r accuracy, the es t imates i n Table 3 represent d e f i n i t e l o s s e s of deer . We s p e c i f i c a l l y avoid drawing i n f e r - ences from the sums of 16,896 i n 1967 and 18,822 i n 1974. They might represent increased mor ta l i ty from smaller populat ions, o r decreased mor ta l i ty from l a r g e r populations.

The number of deer k i l l e d on any given sec t ion of highway i s r e l a t e d c lose ly t o two parameters, the number of deer coming onto o r crossing t h e t raveled por t ion of highway and the t r a f f i c volume. High num- b e r s of deer c ross ings combined with high t r a f f i c volume r e s u l t i n " c r i t i c a l " deer k i l l areas . For example, Colorado Highway 82, a 4-lane, high t r a f f i c volume (Fig. 3) highway, had an annual t r a f f i c volume of over 2 mi l l ion veh ic les (5,628 vehicles per day) i n 1975, an inc rease of 79.7 percent s ince 1968. Three " c r i t i c a l " k i l l a reas ex i s ted in a 15-mile l eng th of Highway 82 where methods (Reed and Woodard

Y E A R S

Fig. 2. Acres presumably in "improved" condition for deer range as a result of logging in National Forests of the central Rocky Mountain Region (relative to a base status in 1910).

YEAR

Fig. 3. Annual traffic volume on Colorado Highway 82 from 1968 through 1975.

i07fr; Pojar e t a l . 1975) have been used t o reduce deer-vehicle accidents . Since some of these methods r e s t r i c t deer movements, they a l s o reduce the amount of ava i l ab le hab i ta t .

T r a f f i c and road-way b a r r i e r s -- The behavioral response of ungulates t o t r a f f i c s t i m u l i may be e i t h e r a su rv iva l advantage o r disadvantage. Habituation (Thorpe 1963; Geist 1971) enables most ungulates t o use ranges within v i s u a l and aud i to ry range of roads and highways. Klein (1971) reported t h a t t r a f f i c along highways d id not appear t o d i s t u r b reindeer (Rangifer tarandus) feeding or moving nearby. Grenier (1974) reported on moose (AZces a l c e s ) movement and mor ta l i ty on roads where hab i tua t ion t o t r a f f i c s t i m u l i apparent ly occurred. Altmann (1952) indicated t h a t e l k (Cervus canadensis nelson$) became conditioned t o t h e s i g h t and sound of passing ca rs . She observed a cow e l k move her c a l f off a paved road by walking back and f o r t h , around i t , and eventual ly pushing i t sideways. More recen t ly , Ward e t a l . (1973) reported t h a t e l k showed l i t t l e aversion t o t r a f f i c within 300 yards of an i n t e r s t a t e highway, where no i se reached 58 decibels . Carbaugh e t a l . (1975) found t h a t grazing, ly ing , walking, or running were exhibi ted extensively by white- tai led deer (0. v i rg in ianus ) along I n t e r s t a t e 80 i n Pennsylvania. Reed e t a l . (1975) reported on Rocky Mountain mule deer behavioral responses t o a concrete-box underpass under I n t e r s t a t e 70 i n western Colorado. When ind i - v idua l s o r groups of deer were observed near t h e underpass entrance, 50 t o 100 f e e t from t h e west- bound highway lanes , the passing of only 7.3 percent of 449 veh ic les t r ave l ing west caused some f l i g h t r eac t ion or escape behavior (as defined by Hediger 1950; Scot t 1958). These observat ions support a hypothesis t h a t ungulates , p a r t i c u l a r l y mule deer , hab i tua te t o t h e s i g h t and sound of t r a f f i c .

Others have reported some re luc tance i n ungu- l a t e s t o approach o r c ross highways. I n Glacier National Park mountain goa t s (Oreamnos americanus) o f ten hes i t a ted i n cover o r on t h e pavement edge, and walked s t i f f - l egged o r ran ac ross t h e highway (Singer 1975). Ward e t a l . (1973) indicated t h a t a highway acted a s a b a r r i e r t o e l k movement. Behrend and Lubeck (1968) provided evidence t h a t white- tai led deer a r e more s e n s i t i v e t o dis turbance along roads than they a r e i n more removed areas. Villmo (1975) suggested t h a t r e indeer , which have habi tuated t o roadsides, may s t i l l be adversely a f fec ted by t h e i r proximity. tie hypothesized t h a t r e indeer fo r - age u t i l i z a t i o n is decreased along roadways because they i n t e r r u p t feeding and r e s t i n g a c t i v i t i e s each time an automobile passes. I n a study by Rost (1975), d e n s i t i e s of Rocky Mountain mule deer f e c a l p e l l e t - groups increased wi th d i s tance from roads i n two of t h r e e vegetat ion types. However, t h e assumption t h a t pellet-group d e n s i t i e s a r e v a l i d measures of h a b i t a t use is questionable. The r a t e of f e c a l depos i t ion might be a f fec ted by many f a c t o r s (Neff 1968), such a s psychological s t r e s s caused by t ra f f i c -assoc ia ted s t imul i .

The combined r e s u l t of h a b i t a t l o s s and road k i l l s may be of s ign i f i cance t o deer populat ions but we can c i t e no quan t i f i ed examples of t h e e f f e c t . We can only consider i t t o be one of t h e inimical fo rces working on mule deer , and one which we a r e un l ike ly t o reverse but only modify with more in tens ive management.

AGRICULTURAL DEVELOPMENTS

Linsdale and Tomich (1957:287) s t a t e d "Mule deer a r e more s t r i c t l y mountain animals than they were i n p r imi t ive condit ions, mainly because of t h e removal of woody vegetat ion from t h e f l a t lowlands by human c u l t i v a t i o n and o ther use of the s o i l . " This may be a quest ionable genera l i za t ion i n face of t h e eastward expansion of mule deer i n t h e p r a i r i e s , but i t is reasonable t o be l i eve t h a t a g r i c u l t u r e grossly a l t e r s t h e character of mule deer hab i ta t . The ne t r e s u l t probably v a r i e s with t h e ex ten t of c u l t i v a t i o n , the loca t ion , and t h e crops. Conse- quently, attempting t o c o r r e l a t e changes i n mule deer numbers with t h e h i s t o r y of a g r i c u l t u r a l development is hazardous a t bes t .

The a v a i l a b l e h i s t o r i c a l records of agr icu l - t u r a l development o f f e r l i t t l e information r e l a t i v e t o mule deer h a b i t a t . Certain na t iona l and reg iona l d a t a a r e reviewed here along with d a t a from Colorado t h a t can be r e l a t e d more s p e c i f i c a l l y t o mule deer .

Ava i lab i l i ty of i r r i g a t i o n water has made crop production poss ib le on many s o i l s of t h e western U.S. t h a t were previously unsu i tab le f o r agr icu l - t u r a l development. I r r i g a t e d land on farms throughout t h e U.S. to ta led more than 37 mi l l ion ac res i n 1964 (National Academy of Sciences 1970). The 17 western s t a t e s accounted f o r more than 33 mi l l ion acres . Nationwide, land under i r r i g a t i o n i n 1970 was increasing a t t h e r a t e of 780,000 ac res annually. and during t h e period 1949 t o 1964, western s t a t e s accounted f o r 80 percent of t h e inc rease (National Academy of Sciences 1970). I f t h i s t rend continued, by 1976 t h e r e would have been over 40 mi l l ion ac res of i r r i g a t e d land i n t h e western U.S.

Although t h e r e has been a s teady inc rease i n i r r i g a t i o n , much of t h e land was already i n crop production, p a r t i c u l a r l y i n t h e more humid eas te rn U.S. However, much of t h e inc rease i n land i r r i - gated between 1950 and 1965 i n t h e 17 western s t a t e s a l s o comprised land previously cu l t iva ted under dry- land condit ions. I n t h e most a r i d s t a t e s (New Mexico, Arizona, Utah, and Nevada) t h e i r r i g a t e d a rea increased from 2.7 t o 3.0 mi l l ion a c r e s between 1950 and 1965 and most of t h i s represented "new" cropland (National Academy of Sciences 1970).

It is important t o note from t h e s tandpoint of mule deer h a b i t a t t h a t 51 percent of t h e i r r i g a t e d cropland i n t h e West was used f o r t h e production of l ives tock feed (National Academy of Sciences 1970). Much of t h i s land was pasture, hay lands, o r other nonharvested crops and may have had a d i f f e r e n t e f f e c t than would the same amount of land i r r i g a t e d f o r corn production.

Using Colorado a s an example of the western s t a t e s , it is poss ib le t o ob ta in values t h a t r e l a t e more s p e c i f i c a l l y t o t h e magnitude of t h e encroachment of a g r i c u l t u r a l development on mule deer hab i ta t . By overlaying maps of mule deer range (Colorado Divis ion of Wildl i fe) on Colorado's land use maps prepared by the Colorado Land Use Cormnis- s ion , ac res of mule deer range encompassed by i r r i - gated and non i r r iga ted cropland were determined. The land use map was prepared i n 1973 but more rea l - i s t i c a l l y r e f l e c t e d land use i n 1971 o r 1972. Since most of the mule deer i n Colorado a r e found from t h e

43 Al te ra t ion of Mule Deer Habi ta t

- - - -- - - - - - - - -

Table 2. H ~ l e s of I n t e r s t a t e , r u r a l , and county h~ghways and p r o j e c t e d a r e a s of rlght-of-way I n Colorado.

I n t e r s t a t e Rura l County Est imated P r o j e c t e d Est imated P ro j ec t ed Est imated P r o j e c t e d T o t a l

Year Mileage 11 Acres 21 Mileave Acres 21 Mileage 1/ Acres 4/ Acres

L' Colorado Div i s ion of Highways. 1936-1975. Colorado S t a t e Highway System r o u t e d e s c r i p t i o n s and mi leage

. , s t a t i s t i c s . P lanning and Research Rep(s) . Denver.

L' Based on 44.6 a c r e s pe r m i l e p lanimetered from a e r i a l photography of I n t e r s t a t e 70 (4-lane d iv ided highway) e a s t of Avon, Colorado.

2! Based on a c a l c u l a t e d 12.1 a c r e s per m i l e , assuming a right-of-way wid th of 100 f e e t .

Based on a c a l c u l a t e d 7 .3 a c r e s pe r mi l e , assuming a right-of-way wid th of 60 f e e t .

The d e c l i n e i n mi leage was caused by road r e c l a s s i f i c a t i o n and by a d e c l i n i n g r u r a l popu la t i on which l e d t o dec rea sed r u r a l road u s e and a d e c l i n e i n t h e number of m i l e s of road mainta ined.

Table 3 . Est imated number of mule and b l ack - t a i l ed d e e r (OdocoiZeus hemionus) k i l l e d from c o l l i s i o n s w i t h v e h i c l e s i n t h e wes t e rn U.S.

S t a t e - Arizona C a l i f o r n i a Colorado ldaho Montana Nevada New Mexico Oregon Utah Washington Wyoming

-----

T o t a l s 16,896 11,047 12,098 12,647 12,992 14,323 13,350 18,822

L' Thompson, F. A . 1968. Deer on highways. 1967 supplement. New Mexico Dept. Game and F i sh . San t e Fe. 6 PP.

2/ Arizona Game and F i sh Department. 1969. W i l d l i f e News le t t e r 3(50) :1 . (Mule d e e r only)

31 Garland, L. E. (No d a t e ) . Number of d e e r l o s t t o causes o t h e r t han hun t ing - 1969. Vermont Dept. F i s h and Game, Roxbury. 1 p.

Es t ima te s based on f i s c a l yea r (1 Jul-30 Jun) t a b u l a t i o n s (Per . corn . G . Ga t e s , New Mexico Dept. F i s h and Game, San t a Fe) .

Pe r . comm. R. Drobnick, Utah Div. Wildl . Resour. , S a l t Lake C i ty .

6/ Per . co rn . D. S t r i c k l a n d , Wyoming Game and F i s h Dept . , Cheyenne.

AZteration of MuZe Deer Habitat

front range of the Rocky Mountains westward, the mule deer range in the eastern plains of Colorado was not included in the comparison.

Of 64,192 mi2 of mule deer range, 3,706 mi2 (5.8 percent) were in irrigated cropland. An additional 685 nt2 (1.1 percent) were in nonirrigated cropland. Much of the irrigated cropland is native and alfalfa hay lands, but considerable acreage is also involved in orchards and other human food crops. Considering the relatively small areas involved, in relation to total mule deer range, it is difficult to believe that agricultural development has materially influenced numbers of mule deer either on local or regional levels.

HOUSING DEVELOPMENTS

Available records of acreage involved in housing developments are practically nonexistent. County governments are generally the only source of information but summaries of the records are rarely obtainable. The situation may be improved by the increasing activity of county and state land use planning commissions.

The land use maps prepared by Colorado's Land Use Commission (1973) indicate that 1,079 square miles (1.7 percent) of mule deer range in that State were in housing developments. This represented only those areas that had been platted and offered for sale and did not include areas under consideration for development. In the western U.S. in general, and in Colorado specifically, many of these developments have occurred on wintering areas that are most critical to mule deer. This is mostly due to property ownerships, general topography, and previously located transpor- tation and utility corridors. These developments, with their accompanying increases in automobiles, snowmobiles, other motorized vehicles, dogs, and human activity, affect large areas beyond the actual boun- dary of the specific housing development. As a result, the overall effect of housing developments on mule deer habitat is greater than indicated by analysis of only the actual land area impacted.

However, if the values obtained for Colorado on extent of housing development are realistic for the whole of mule deer range, it seems improbable that the small amount of deer habitat involved would result in a regional decline in numbers of mule deer. Local developments may essentially eliminate deer from limited areas. Unfortunately, we are unable to assess the sum of such influence.

DISCUSSION

Each of the factors discussed -- fire, logging, roads, agricultural aod housing development -- alters the habitat for mule deer in some manner. The effect of these factors, taken either singly or in combination, on numbers of mule deer remains unknown. It is difficult to relate cause and effect when neither has been carefully defined and quantified. If we are genuinely interested, we must develop uniform data gathering procedures applicable to the entire range of mule deer. When we can describe the magnitude of

habitat change over time, we will be in a better position to assess the impacts on deer populations.

Perhaps the most important message of this paper is that man keeps poor records of the vicis- situdes of his environment. We have no systems for inventorying quantitative changes in the habitats on earth, and only rudimentary concepts of their qualitative significance. It is important that this deficiency be overcome, that we employ reliable information rather than crude speculation in our assessment of wildlife habitat on a national scale.

There is a common interest in this matter, and it will be best served through a common effort. A potential vehicle for this purpose is the Forest and Rangeland Renewable Resources Planning Act of 1974 (PL 93-378). It assigns to the U.S. Department of Agriculture, Forest Service, in cooperation with other agencies, the responsibility for a continuing assessment of the renewable natural resources of the U.S. in the following systems: wildlife and fish habitat; outdoor recreation and wilderness; rangeland grazing; timber; land and water; human and community development. A first order of business is the determination of information needs and the methodology for fulfilling these. A multidisciplin- ary group with this assignment has been assembled in the Rocky Mountain Forest and Range Experiment Station, headquartered in Fort Collins, Colorado. The Colorado Division of Wildlife is cooperating in the development of techniques for monitoring land and vegetation attributes related to the quantitative and qualitative adequacy of mule deer habitat. This program will link data from air- and satellite- borne surveillance systems to on-the-ground evaluation. The results will be built into the national inventory system for all resources, which, hopefully, will take us a respectably large step toward more en- lightened habitat evolution.

LITERATURE CITED

Altmann, M. 1952. Social behavior of elk. Cervus canadensis netsoni, in the Jackson Hole Area of Wyoming. Behavior 4:116-143.

Behrend, D. F. and R. A. Lubeck. 1968. Summer flight behavior of white-tailed deer in two Adirondack forests. J. Wildl. Manage. 32(3): 615-618.

Carbaugh, B., 'J. P. Vaughan, E. D. Bellis, and H. B. Graves. 1975. Distribution and activity of white-tailed deer along an interstate highway. J. Wildl. Manage. 39(3):570-581.

Caughley, G. 1970. Eruption of ungulate populations, with emphasis on Himalayan thar in New Zealand. Ecology 51(1):53-72.

Edgerton, P. J. 1972. Big game use and habitat changes in a recently logged mixed conifer forest in northeastern Oregon. Proc. Annu. Conf. W. Assn. State Game and Fish Comm. 52: 239-267.

Edwards, R. Y. 1956. Snow depths and ungulate abundance in western Canada. J. Wildl. Manage. 20(2) : 159-168.

45 AZteration of Mule Deer Habitat

F f o l l i o t t , P. F. and W. P. C l a ry . 1972. A s e l e c t e d and a n n o t a t e d b ib l i og raphy of unde r so t ry - o v e r s t o r y v e g e t a t i o n r e l a t i o n s h i p s . Tech. B u l l . 198, Agr i c . Exp. S t a . , U n i v e r s i t y of Ar izona , Tucson. 33 p .

G e i s t . V. 1971. A b e h a v i o r a l approach t o t h e management of w i l d ungu l a t e s . Pages 413-424 i n E . Duffey and A. S. Wat ts , eds . The s c i e n t i f i c management of an ima l and p l a n t communities f o r conse rva t i on . E l even th Symp. B r i t i s h Ecol . Soc., Blackwel l S c i e n t . Pub l s . , Oxford. 652 p.

G r e n i e r , P. A. 1974. Orignaux t u 4 s s u r l a r o u t e dans l e P a r c d e s L a u r e n t i d e s , Quebec, d e 1962 a 1972. N a t u r a l i s t e Can. 101(5):737-754.

Hediger , H. 1950. Wild an ima l s i n c a p t i v i t y . Bu t t e rwor th , London. 207 p.

K l e i n , D. R. 1971. Reac t i on o f r e i n d e e r t o obs t ruc - t i o n s and d i s t u r b a n c e s . Sc i ence 173(3995):393- 398.

Leopold, A. S . , T . Riney, R. McCain, and L. T e v i s , J r . 1951. The Jawbone d e e r he rd . C a l i f o r n i a Dept . F i s h and Game, Game B u l l . No. 4. 139 p.

L i n s d a l e , J . M. and P. Q. Tomich. 1953. A h e r d of mule dee r . U n i v e r s i t y of C a l i f o r n i a P r e s s , Berkeley and Los Angeles . 567 p.

Lyon, L. J. 1969. W i l d l i f e h a b i t a t r e s e a r c h and f i r e i n t h e n o r t h e r n Rock i e s . P roc . T a l l Timbers F i r e Ecology Conf. 9:213-227.

Lyon, L. J . 1971. Vege t a l development f o l l owing p r e s c r i b e d bu rn ing of Douglas f i r i n south- c e n t r a l Idaho. U.S.D.A. F o r e s t S e r v i c e Res. Paper INT-105. 30 p.

Lyon, L. J . and P . F. S t i ckney . 1966. Two f o r e s t f i r e s : and some s p e c i f i c i m p l i c a t i o n s i n b ig - game h a b i t a t management. Proc . W . Assn. S t a t e Game and F i s h Commissioners 46:187-193.

N a t i o n a l Academy o f Sc i ences -Na t i ona l Research Coun- c i l . 1970. Land u se and w i l d l i f e r e s o u r c e s . Washington, D.C. 262 p .

Ne f f , D. J. 1968. The pe l l e t - g roup co un t t e chn ique f o r b i g game t r e n d , c ensus , and d i s t r i b u t i o n : a review. J . Wild l . Manage. 32(3):597-614.

P a t t o n , D. R. 1974. Pa t ch c u t t i n g i n c r e a s e s dee r and e l k u se o f a p i n e f o r e s t i n Ar izona . J . F o r e s t r y 72(12):764-766.

P a t t o n , D. R. and H. D . Avant. 1970. F i r e s t i m u l a t e d aspen s p r o u t i n g i n a s p r u c e - f i r f o r e s t i n New Mexico. U.S.D.A. F o r e s t S e r v i c e Res. Note RM- 159. 4 p.

Pea r son , H. A. 1968. Th inn ing , c l e a r c u t t i n g , and r e seed ing a f f e c t d e e r and e l k u se o f ponderosa p i n e f o r e s t s i n Ar izona . U.S.D.A. F o r e s t Ser- v i c e Res. Note RM-119. 4 p.

P e n g e l l y , W. L. 1963. Timber lands and d e e r i n t h e n o r t h e r n Rockies . J. F o r e s t r y 61(10):734-740.

P i c t o n , H. D. and R. R . Knight . 1969. A numer i ca l i ndex of w i n t e r c o n d i t i o n s of u se i n b i g game management. Montana F i s h and Game Dept. Spec- i a l Repor t No. 3 , F e d e r a l Aid P r o j e c t s W-74-R and W-98-R. 8 p. (processed)

P o j a r , T. M., R. A. Presence, D . F. Reed, and T. N . Woodard. 1975. E f f e c t i v e n e s s of a l i g h t e d , animated d e e r c r o s s i n g s i g n . J . Wi ld l . Manage. 39(1) :87-91.

Reed, D. F. and T. N . Woodard. 1974. Deer-auto a c c i d e n t s t u d i e s i n Colorado. Univ. of Colo- r ado a t Denver, Proc . Annu. Highway Conf. 47: 66-77.

Reed, D. F . , T. N . Woodard, and T. M. P o j a r . 1975. Behav io r a l r e sponse of mule dee r t o a highway underpass . J. Wild l . Manage. 39(2):361-367.

Rege l i n , W. L . , 0 . C. Wallmo, J . Nagy, and D. R. D ie t z . 1974. E f f e c t o f l ogg ing on f o r a g e v a l u e s f o r d e e r i n Colorado. 3. Fo r . 72(5) : 282-285.

Reynolds , H. G. and H. W . S p r i n g f i e l d . 1953. Re- s eed ing sou thwes t e rn r ange l a n d s w i t h c r e s t e d whea tg r a s s . U.S. Dept. o f A g r i c u l t u r e , Farmers ' B u l l . 2056. 20 p .

R o b i n e t t e , W . L . , 0 . J u l a n d e r , J. S. Gashwiler , and J. G. Smith. 1952. Winter m o r t a l i t y of mule d e e r i n r e l a t i o n t o r ange c o n d i t i o n . J. Wild. Manage. 16 (3) :289-299.

Ros t , G. R. 1975. Response of d e e r and e l k t o r oads . M.S. T h e s i s , Colorado S t a t e Univ., F o r t C o l l i n s . 5 1 p .

S c o t t , J. P. 1958. Animal behav io r . 2nd ed . , Univ. of Chicago P r e s s , Chicago. 349 p.

Se ton , I?. T . 1937. L ive s o f game animals . Vol. 3. Hoofed Animals. L i t e r a r y Gui ld of Amer., New York. 780 p .

S i n g e r , F . J . 1975. Behavior o f mounta in g o a t s , e l k and o t h e r w i l d l i f e i n r e l a t i o n t o U.S. Highway 2 , G l a c i e r N a t i o n a l Park . N a t l . Pa rk Serv . 96 p .

Thorpe , W. H. 1963. The ontogeny of behav io r . Pages 483-518 i n John A. Moore, ed . , I d e a s i n modern b io logy . N a t u r a l H i s t o r y P r e s s , Garden C i t y , N.Y. 563 p.

U.S. Department of t h e I n t e r i o r . N a t i o n a l Pa rk Ser- v i c e . 1974. Environmenta l assessment : f i r e - v e g e t a t i o n management p l a n , Grand Te ton N a t i o n a l Park . 47 p . (Processed)

Vi l lmo, L. 1975. The Scandanavian v iewpoint . I n t e r n a t i o n a l Reindeer and Car ibou Symp., PKOC. 1:4-9.

Wallmo, 0. C. 1969. Response of d e e r t o a l t e r n a t e - s t r i p c l e a r c u t t i n g of l odgepo l e p i n e and sp ruce - f i r t imbe r i n Colorado. U.S.D.A. F o r e s t S e r v i c e Res. Note RM-141. 4 p .

AZteration o f Mule Deer Habitat

Wallmo, 0. C. and R. B. Gill. 1971. Snow, winter distribution, and population dynamics of mule deer in the central Rockies. Snow and Ice in Relation to Wildlife and Recreation Symp. ( h a , Iowa, Feb. 11-12, 1971) Proc.:l-15.

Wallmo, 0. C., W. L. Regelin, and D. W. Reichert. 1972. Forage use by mule deer relative to logging in Coloardo. J. Wildl. Manage. 36(4):1025- 1033.

Ward, A. L., J. J. Cupal, A. L. Lea, C. A. Oakley, and R. W. Weeks. 1973. Elk behavior in relation to cattle grazing, forest recreation, and traffic. Trans. N. Am. Wildl. Nat. Resour. Conf. 38: 327-337.

47 Alteration of Mule Deer Habitat

INTERSPECIFIC COMPETITION BETWEEN MULE DEER, OTHER GAME ANIMALS AND LIVESTOCK

Richard J. Mackie

Department of Biology Montana S t a t e Universi ty Bozeman, Montana 59715

Abstract

Comparisons of a v a i l a b l e d a t a on d i s t r i b u t i o n s , range use and food hab i t s , and behavior i n d i c a t e t h a t mule deer may i n t e r - a c t i n a competitive re la t ionsh ip with each of the o ther spec ies of wild and domestic ungulate with which they a s s o c i a t e on west- e rn rangelands. Exist ing s t u d i e s , however, have not produced substant ive evidence f o r the ex i s tence of competition general ly nor more than very general conclusions about i ts exact na tu re and importance; and most cur ren t thinking remains rooted i n inference and specu la t ion and i s con t rovers ia l a t bes t . This e s s e n t i a l l y precludes any f i rm conclusions a s to the poss ib le s ign i f i cance of in te r spec ies r e l a t i o n s and competition i n cur ren t t rends of mule deer populat ions i n western North America.

Mule deer (OdocoiZeus hemionus) r a r e l y , i f ever , e x i s t i n spec ies populations completely i so la ted from contact with o ther wild and domestic ungulates. Throughout t h e i r d i s t r i b u t i o n , they cohabit rangelands a t l e a s t seasonal ly with one o r more of t h e o ther wild ungulates na t ive t o western North America. Most of these rangelands a r e a l s o grazed by domestic l ives tock , including c a t t l e , sheep, horses , and, occasional ly, mules, burros, goats , and hogs. Local- ly , f e r a l o r "wild" populat ions of domestic animals a s well a s introduced wild ungulates a l s o occur. Because of t h i s , the p o s s i b i l i t y of competitive i n t e r - ac t ions has occupied t h e minds of w i l d l i f e , range, and l ives tock managers and s c i e n t i s t s f o r many years; and i t i s not su rpr i s ing t h a t in te r spec ies re la t ionsh ips of mule deer now loom a s a possibly s i g n i f i c a n t f a c t o r con t r ibu t ing t o recent dec l ines i n populat ions of t h i s spec ies over much of t h e western United S t a t e s and Canada. What i s su rpr i s ing , i n view of the widespread a t t e n t i o n given general ly t o i n t e r s p e c i f i c re la t ionsh ips of l a r g e herbivores and s p e c i f i c a l l y t o mule deer during the pas t half-century o r more, is t h a t remarkably few f irm conclusions of general app l ica t ion have emerged. Much of our cur ren t thinking remains rooted i n inference and speculat ion and is con t rovers ia l a t bes t . This apparent ly a p p l i e s a l s o t o almost a l l of our conclusions about the importance of competition i n n a t u r a l ecosystems genera l ly (Mil ler 1967).

INTERSPECIES RELATIONS AND COMPETITION

I n t e r s p e c i f i c re la t ionsh ips of l i v i n g organisms have been viewed i n many ways. Odum (1959) l i s t e d e i g h t important i n t e r a c t i o n s which may occur between two o r more spec ies populations: (1) neutral ism, i n which ne i the r populat ion is a f fec ted by assoc ia t ion with t h e other; (2) competition, i n which each popu- l a t i o n a f f e c t s the o ther ; (3) mutualism, i n which i n t e r a c t i o n is obl igatory f o r t h e growth and surv iva l of both populations; ( 4 ) protocooperation, i n which both populat ions benef i t from a non-obligatory asso-

c i a t i o n ; (5) commensalism, i n which one population i s benefi ted but t h e o ther unaffected; (6) amen- sal ism, i n which one population i s inh ib i t ed and t h e o ther unaffected; (7) pa ras i t i sm and (8) predat ion, wherein one population is dependent upon and adverse- l y a f f e c t s the other by d i r e c t a t t a c k .

I n the above context , competition is l imited t o those i n t e r a c t i o n s which adversely a f f e c t growth and surv iva l of both spec ies populat ions involved and u l t imate ly r e s u l t i n t h e el iminat ion of one a s defined by t h e competitive exclusion p r i n c i p l e (Hardin 1960). Others have defined i t a s a c t i v e demand by two o r more ind iv idua l s of t h e same spec ies populat ion ( in t raspec ies competition) o r members of two o r more spec ies a t the same trophic l e v e l ( in te r spec ies competition) f o r a comon resource o r requirement t h a t is a c t u a l l y o r p o t e n t i a l l y l imi t ing (Mil ler 1967). I n p r a c t i c a l usage, "competition" usual ly has been appl ied r a t h e r loosely t o include almost any i n t e r a c t i o n with an assumed o r r e a l , negat ive outcome, including those i n which t h e wel- f a r e of only one spec ies may be adversely a f fec ted (amensalism of Odum 1959).

Competition may involve elements of " in te r fe r - ence" a s we l l a s "exploitation" (Mil ler , 1967). In te r fe rence r e f e r s t o any a c t i v i t y which d i r e c t l y or i n d i r e c t l y l i m i t s a competitors access t o a necessary resource, usua l ly i n a s p a t i a l context . Exploi tat ion r e f e r s t o u t i l i z a t i o n of a resource once access has been achieved, usual ly i n the sense t h a t two ind iv idua l s o r spec ies with unlimited access t o a common source of food or n u t r i e n t s w i l l have d i f f e r e n t a b i l i t i e s o r opportuni ty t o exp lo i t the a v a i l a b l e supply.

The r o l e of in te r fe rence i n competition among l a r g e herbivores is l a r g e l y unknown. In te r spec ies

aggression approaching t e r r i t o r i a l i t y , a s required by M i l l e r ' s (1967) d e f i n i t i o n of in te r fe rence , i s not known among ungulates , a t l e a s t i n western North America. However, an element of in te r fe rence i s

i m p l i c i t i n Denniston's (1956) concept of "dis turbance" competition between moose (Alccs a l c e s ) and c a t t l e . Disturbance r e f e r s t o the movement of one animal from, and/or avoidance o f , a reas used by another , a t l e a s t t o the ex ten t t h a t a l t e r n a t e a reas or h a b i t a t s a r e ava i l ab le (Schladweiler 1974). Other wild ungulates, e spec ia l ly e l k (Cervus canadensis), may r e a c t s imi la r ly t o t h e presence of domestic l ive - s tock ( J e f f e r y 1963, Dzlke e t a l . 1965, Skovlin e t a l . 1968, Knowles 1975, Lonner 1975, Komberec 1976). Knowles (1975) indicated t h a t radio-marked mule deer jn r e s t - r o t a t i o n a l l y grazed pas tu res e i t h e r moved from the a rea or moved f u r t h e r and used a l l p a r t s of t h e i r home range more frequently a f t e r c a t t l e were turned i n t o t h e pastures i n which they occurred. Between wild ungulates , bighorn sheep (Ovis canadensis) may avoid e l k (Mair 1952) but dominate mule deer (Hunter and Kinghorn 1949), and mule deer may dominate over white- t a i l e d deer (Oducoileus virginianus) (Anthony 1972, Kramer 1973). Although the e f f e c t of dis turbance on t h e biology of wild ungulates has received l i t t l e study t o da te , Geist (1970) indicated t h a t repeated dis turbance could r e s u l t i n voluntary withdrawal from ava i lab le h a b i t a t and confinement of the population t o a smaller and l e s s favorable a rea .

Evaluations of in te r spec ies r e l a t i o n s and compe- t i t i o n among l a r g e r herbivores , including mule deer , have l a rge ly involved the e x p l o i t a t i o n a l aspect . Thus, t h e ex ten t t o which two spec ies graze the same a rea and p re fe r the same forage is genera l ly recognized a s t h e main f a c t o r i n i n t e r s p e c i f i c competition on western rangelands (Julander 1958). It might a l s o be important t h a t forage p l a n t s used i n common be an important source of food f o r e i t h e r or both animals, i n l imited supply, and over-ut i l ized or d e t e r i o r a t i n g a s a r e s u l t of the combined use (Cole 1958).

Smith and Julander d i f f e r e n t i a t e d two kinds or l e v e l s of competition among l a r g e herbivores: "forage" competition and "land use" competition. Though both involve t h e element of exp lo i t a t ion , the former r e f e r s t o common usage of preferred forage p l a n t s a t l e v e l s above those considered proper f o r sustained product ivi ty and y i e l d , while t h e l a t t e r is associated with comon use of a forage supply which i s adequate t o meet requirements of both animals but where removal of one would permit increased numbers of t h e o ther . I n e i t h e r case, i t i s not necessary t h a t competitors use the same a rea or forage p l a n t s a t the same time (Cole 1958). Use of a food by one animal during one season may preclude subsequent usage of t h a t area or food by another. Also, inten- s i v e usage of an a rea or forage source by one animal over a period of years may d i r e c t l y o r i n d i r e c t l y reduce forage y i e l d s or a l t e r p lan t spec ies composi- t i o n t o t h e eventual detriment of another animal.

INTERSPECIFIC RELATIONS OF MULE DEER AND OTHER UNGULATES

Mule Deer In te rac t ions With Other Wild Ungulates

White-tailed Deer.--The range of white- tai led deer overlaps t h a t of mule deer general ly across the north- e rn United S t a t e s from t h e western Dakotas t o eas te rn Washington, from western Manitoba westward t o Alberta and southeastern B r i t i s h Columbia i n Canada, i n north- eas te rn Wyoming, the western port ions of Nebraska, Kansas, Oklahoma, and Texas, and p a r t s of Colorado, New Mexico, and Arizona.

Kramer (1972) recen t ly evaluated ecological r e la t ionsh ips of these two spec ies i n d e t a i l . Within t h e i r zone of overlap, h a b i t a t preferences and some aspec t s of behavior were d i s t i n c t l y d i f f e r e n t , while food h a b i t s were f a i r l y s imi la r . The l a t t e r , p lus some overlap i n h a b i t a t usage where the two species occupied the same a rea suggested t h e p o s s i b i l i t y of competition i n l o c a l a reas ; however, competition did not appear t o be an important f a c t o r e i t h e r general ly o r i n recen t extensions of the range of white- tai led deer i n northern a reas where mule deer populat ions were decl ining.

EZk.--Elk occur genera l ly ac ross much of t h e range of mule deer. Wherever s t u d i e s have been conducted, p a t t e r n s of h a b i t a t usage of e l k appear q u i t e s imi la r t o those of mule deer ; though e l k appear t o be l e s s discr iminat ing i n t h e i r s e l e c t i o n of h a b i t a t types and move more widely. Foods u t i l i z e d by e l k f re - quent ly overlap preferences of mule deer; but both vary considerably by season and loca t ion and food h a b i t s of e lk genera l ly appear t o be broader and more f l e x i b l e than those of deer . On p r a i r i e - montane f o r e s t mountain ranges, both animals consume s i m i l a r grasses and fo rbs during spring and appear t o p re fe r s imi la r fo rbs during summer. Both may a l s o browse on the same spec ies during summer; though, i f fo rbs a r e not ava i l ab le , e l k o f t e n switch t o g rasses while mule deer browse more in tens ive ly . I n f a l l and win te r , where ava i l ab le , e l k t rend t o g rasses , but u t i l i z e some fo rbs and may browse in tens ive ly during periods of snow cover or when c rus t ing l i m i t s access t o grass . Though mule deer tend t o browse most extensively during winter i n most a reas , they may depend heavi ly on fo rbs and/or g rasses i n some a reas where ava i l ab le and shrubs a r e l imited. On heavi ly fo res ted ranges of western Montana and northern Idaho, both mule deer and e l k may browse extensively throughout the year and p r e f e r s i m i l a r species .

In general , a v a i l a b l e d a t a suggest considerable opportuni ty f o r i n t e r s p e c i f i c competition between mule deer and e l k where spec ies populations occupy t h e same range. Because e l k appear t o be more adaptable and flexib1.e i n t h e i r choice of h a b i t a t s and forage preferences, most a u t h o r i t i e s have concluded t h a t , i n the event of i n t e r a c t i o n , e l k would be the more e f f i c i e n t competitor and survive a t the expense of mule deer. However, the re i s a s ye t l i t t l e q u a n t i t a t i v e support of competition between the two spec ies being an important f a c t o r i n the population ecology of e i t h e r one. Among the few accounts of elk-mule deer i n t e r a c t i o n s i n the l i t e r - a t u r e , C l i f f (1939) ascr ibed heavy deer mor ta l i ty i n Idaho during t h e severe winter of 1931 t o heavy u t i l i z a t i o n of important mule deer forage p l a n t s by e lk .

Bighorn Sheep.--Although t h e d i s t r i b u t i o n of mule deer almost completely overlaps t h a t of bighorn sheep throughout t h e western United S t a t e s and Canada, bighorn ranges comprise only a very small proport ion of t h e t o t a l d i s t r i b u t i o n a l range of mule deer. Studies of l o c a l spec ies populations i n d i c a t e t h a t i n many a reas a t l e a s t they may u t i l i z e s i m i l a r h a b i t a t s and p re fe r much the same forage; while i n o t h e r s , h a b i t s diverged. I n genera l bighorns appear t o u t i l i z e grasses t o a much grea te r ex ten t and browse t o a l e s s e r extent than deer i n most a reas of comparative study, but s u f f i c i e n t overlap i n p lan t

I n t e r s p e c i f i c Competition

species utilized occurred to suggest competition at least locally.

Moose.--Moose occur within the range of mule deer in Canada from Saskatchewan west to British Columbia, in Montana, Idaho, and Wyoming, northeastern Utah. and possibly very locally in a few other areas, Prescott (1974) recently reviewed interrelationships with mule deer. Some similarities in habitat and forage selection were evident in most areas. In Montana, as elsewhere, they may share both summer and winter ranges and eat many of the same plants; and these overlaps probably result in competition in some areas. Overall, competition probably would affect mule deer more drastically than moose (Schladweiler 1974).

Pronghorn Antelope.--Pronghorn antelope (AntiZocapra americanal occur in association with mule deer on prairie and mountain valley or basin grass and shrublands in many areas of western North America. Although they may utilize much the same habitats and prefer many of the same forage plants throughout the year comparative studies are lacking. Opportunities for competition probably exist in many areas, especially where higher mule deer densities occur on extremely open prairie lands.

Mountain Goats.--Mountain goats ( O r e m s americana) occur locally within the range of mule deer in many areas of the northern Rocky Mountains. Distributions may overlap in these areas during summer and/or winter, with some similarities in habitat usage and forage selection. Although competition could occur, few comparative studies have been conducted and interrelationships are generally obscure.

Other WiZd Ungu2ates.--Locally, Bison (Bison bison) may occur in association with mule deer as in the case of the National Bison Range. In the southwest, collared peccary (Pecari tajacu), barbary sheep (Ananotragus leruia), and locally perhaps some additional exotic ungulates may occur on mule deer ranges. Knipe (1957) suggested the possibility of competition between pecarry and deer during some years or in some areas where the availability of forage was low. Ogren (1962) indicated that barbary sheep eat some of the same foods taken by deer, but that field observations indicated that the apparent competition may not be real because of differences in use of local habitats.

Mule Deer Interactions With Domestic Ungulates

Domestic livestock grazing has been a dominant use of western rangelands since the late 1800's; and the vast majority of mule deer range has been or is grazed at least seasonally. Viewed either on the basis of its historical and long-term impacts on the kinds and amounts of vegetation on these ranges or in terms of annual forage removal and associated short-term grazing affects, this usage has to rate as one of, if not the single most important land use or environmental factor affecting mule deer habitat values.

Cattle.--Findings of intensive competition studies as well as general comparisons of range use and food habits of mule deer and cattle have indicated that some competition may occur wherever the two species

occur together. Most comparative studies have indicated broad differences in use of local habitat types and physiographic sites as well as in forage preferences of mule deer as compared with cattle such that competition is likely to be minimal in most cases where ranges are properly stocked and in good to excellent condition. However, cattle often make sufficient use of important deer forage plants and feeding areas to compete seriously where stocking rates are high, when plant growth is reduced by drought or prior heavy usage, or when grazing begins too early, extends too long, or occurs on critical winter or other seasonal range areas. Because of this, both the actual occurrence and the intensity of conflict probably vary widely in time and space.

That cattle may "interfere" with deer usage of all available habitats and exclude deer use in some areas has been suggested by McMahan (1966), Firebaugh (1969), Dusek (1971), and Knowles (1975). However, direct evidences of exclusion and quanti- fication of the effects of competition by cattle on mule deer populations is generally lacking. McMahan and Ramsey (1965) reported a low carrying capacity for white-tailed deer in all pastures continuously grazed by a mixture of livestock including cattle, as compared with deer-only managed areas. Repro- duction and survival of fawns in these pastures varied in relation to stocking rates with no fawns ever surviving to yearling age on heavily stocked pastures.

Sheep.--Range usage and food habits of domestic sheep may overlap those of mule deer even more closely than in the case of cattle. Cumulative data on interactions do little to alter the basic conclusion of Smith and Julander (1953) that "the similarity of sheep and mule deer diets is sure to cause conflict wherever the supply of preferred (forage) species is inadequate to satisfy the requirements of both animals...even though an adequate forage supply obviates any actual conflict, there is competition in the sense that if part of the deer population was removed, sheep numbers could be increased and vice versa." Evidences of "interfer- ence" or local exclusion of mule deer from areas grazed by sheep have not been recorded quantita- tively in the literature.

Other Livestock and Feral Ungukxtes.--Both domestic and "wild" horses and burros may be associated with mule deer, grazing similar local areas and habitat types. While "wild" populations have increased due to protection in recent years, concern for possible competition has also increased; but as yet few quantitative data have appeared. Available information suggests considerable differences in forage preferences, but use of herbage as well as winter browse species of mule deer may constitute serious competition affecting mule deer adversely.

Multi-species Relationships

Frequently, mule deer occur in species populations associated with more than one other ungulate. For example, both elk and cattle occur broadly across the range of mule deer. Where they occur together, interactions may be intensified and/or vary from those of observed when only one is present.

Interspeci fic Competition

Numerous s t u d i e s have shown a h igh deg ree of s i m i l a r - t y i n range usage and year long f o r a g e p r e f e r e n c e s of e l k and c a t t l e . I n most r e s p e c t s t h e h a b i t s of e l k ove r l ap t hose of dee r on one hand and c a t t l e on t h e o t h e r . F u r t h e r , e l k c l e a r l y tend t o avo id c a t t l e whenever p o s s i b l e and seek t hose a r e a s where no c a t t l e occur (Skovl in e t a l . 1968, Lonner 1975, Komberec 1976) . Thus t h e p re sence of c a t t l e tends t o i n t e n s i f y o p p o r t u n i t i e s f o r c o n f l j c c between e l k and mule dee r and, perhaps between mule dee r and c a t t l e a s we l l . Elk withdraw i n t o a r e a s l e a s t grazed by c a t t l e and /o r c o n c e n t r a t e i n a r e a s where no c a t t l e occu r , p o s s i b l y caus ing o r i n c r e a s i n g t h e i n t e n s i t y of i n t e r a c t i o n where none o r l e s s occurred w i thou t c a t t l e . Also , r educ t ions i n c a t t l e numbers on many r anges , removal from o t h e r s inclucling many w i n t e r dee r and e l k r anges , and more r e s t r i c t i v e + a n a g e m e n t of e l k on mutual ly used a r e a s have a l l served t o f avo r e l k and i n t e n s i f y p o t e n t i a l c o n f l i c t w i th mule dee r .

PROBLEMS I N ASSESSING INTERSPECIFIC COMPETITION

As t h e preceding d i s c u s s i o n s i n d i c a t e , i t is no t e s p e c i a l l y d i f f i c u l t t o o b t a i n d a t a i n d i c a t i n g t h e p o s s i b l e occu r r ence of some i n t e r a c t i o n and fo r exploi - t a t i o n - t y p e compet i t ion among v a r i o u s s p e c i e s o r s p e c i e s popu la t i ons of l a r g e r he rb ivo re s . C l e a r l y , mule deer may i n t e r a c t i n compe t i t i ve r e l a t i o n s h i p s w i t h each of t h e o t h e r ungu la t e s w i t h which they a s s o c i a t e . Oppor tuni ty , however, need n o t p r e s c r i b e t h e f a c t ; and, by i t s e l f , has l i t t l e p r e d i c t i v e va lue . Yet, e x i s t i n g s t u d i e s , even wi th c a r e f u l de s ign , con- t i nued measurement and o b s e r v a t i o n over s e v e r a l y e a r s , and exhaus t i ve a n a l y s i s , have n o t produced s u b s t a n t i v e ev idence f o r t h e e x i s t e n c e of compe t i t i on nor more than ve ry g e n e r a l conc lus ions abou t i t s e x a c t n a t u r e and importance. The l a c k of adequa t e means of measuring t h e b i o l o g i c a l and e c o l o g i c a l e f f e c t s of compe t i t i on o r o t h e r i n t e r a c t i o n s and d i s t i n g u i s h i n g t h e s e e f f e c t s from those of o t h e r popu la t i on regula-- t i n g mechanisms and f a c t o r s which exp re s s themselves i n t h e same way may b e a major r ea son f o r t h e f a c t t h a t few f i r m conc lus ions have emerged. I n a d d i t i o n , we may l a c k e i t h e r adequa t e means o r s u f f i c i e n t p e r s p e c t i v e t o i n t e r p r e t e x i s t i n g d a t a on h a b i t a t requirements and r e l a t i o n s h i p s . Because of t h i s , both t h e k inds of d a t a and t h e c r i t e r i a which we commonly employ i n a s s e s s i n g i n t e r a c t i o n s probably have some impor t an t l i m i t a t i o n s .

The expected e f f e c t s of i n t e r s p e c i f i c compe t i t i on among ungu la t e s a r e t hose which d i r e c t l y o r i n d i r e c t l y dep re s s c a r r y i n g c a p a c i t y , c r e a t e o r i n t e n s i f y i n t r a - s p e c i f i c compe t i t i on , and u l t i m a t e l y r e s u l t i n changes i n numbers o r d i s t r i b u t i o n , o r both . Most wi ld ungu la t e s , i nc lud ing mule dee r , appear t o be f a i r l y a d a p t a b l e i n t h e i r cho i ce of Food and h a b i t a t r e q u i r e - ments. Thus, under n a t u r a l c o n d i t i o n s they occupy a r a t h e r wide r ange of h a b i t a t s wherein c a r r y i n g c a p a c i t i e s and s p e c i e s d e n s i t y va ry n a t u r a l l y i n r e l a t i o n t o t h e k inds , q u a l i t y , and amounts of food and cover a v a i l a b l e i n l o c a l a r e a s . I n t y p i c a l range- l and s i t u a t i o n s , i n which popu la t i on d e n s i t i e s of e i t h e r o r bo th compe t i t o r s a r e a t o r c l o s e t o t h e i r c a r r y i n g c a p a c i t i e s , i t i s d i f f i c u l t t o d i s t i n g u i s h t h e a d d i t i o n a l e f f e c t s , i f any, of i n t e r s p e c i f i c compe t i t i on from those of i n t r a s p e c i f i c compet i t ion . I t is a l s o d i f f i r u l t t o d i s t i n g u i s h e f f e c t s of i n t e r - s p e c i e s i n t e r a c t i o n s and compe t i t i on from those of v a r i o u s o t h e r environmenta l f a c t o r s which s i m i l a r l y

i n f l u e n c e c a r r y i n g c a p a c i t i e s . Normal f l u c t u a t i o n s i n weather and snow c o n d i t i o n s , f o r a g e p roduc t ion , p r e d a t i o n , hun t ing , and o t h e r f a c t o r s may e l i c i t changes i n c a r r y i n g c a p a c i t i e s o r c e r t a i n s p e c i e s r e sponses and popu la t i on consequences e s s e n t i a l l y i n d i s t i n g u i s h a b l e from i n t r a - o r i n t e r - s p e c i f i c compe t i t i on .

S i m i l a r i t i e s and /o r d i f f e r e n c e s i n d i s t r i b u t i o n , range u se , and food h a b i t s a r e n o t evidence a pr ior i f o r o r a g a i n s t a compe t i t i ve r e l a t i o n s h i p . There may be s e v e r a l r ea sons f o r t h i s .

Only r a r e l y , i f e v e r , have we had oppor tun i ty t o r eco rd t h e s e k inds of d a t a f o r mule dee r (o r any o t h e r s p e c i e s ) i n a s i t u a t i o n where no o t h e r s p e c i e s occu r r ed . Thus, most e x i s t i n g i n fo rma t ion has been c o l l e c t e d i n p l a c e s o r under c o n d i t i o n s when i n t e r - a c t i o n was a m a t t e r of f a c t . Because of t h i s , we u s u a l l y f i n d o u r s e l v e s u s ing d a t a , which i n them- s e l v e s r e f l e c t e f f e c t s of i n t e r a c t i o n , t o determine whether i n t e r a c t i o n and compe t i t i on a r e occu r r ing .

Secondly, n o t a l l i n t e r a c t i o n s need t o be com- p e t i t i v e . There a r e numerous r e p o r t s i n r ange and w i l d l i f e l i t e r a t u r e sugges t i ng i nc rea sed a v a i l - a b i l i t y , p a l a t a b i l i t y , o r p roduc t ion of f o r a g e p l a n t s f o r one animal a s a r e s u l t of g r az ing o r browsing a c t i v i t i e s of ano the r . B e l l (1971) de sc r ibed s i t u a - t i o n s i n t he S e r e n g e t t i P l a i n s of A f r i c a i n which s e v e r a l s p e c i e s of he rb ivo re s grazed t h e same a r e a and, t o a c e r t a i n e x t e n t , t h e same p l a n t s i n a m u t u a l i s t i c o r commensal is t ic r e l a t i o n s h i p . On some wes t e rn rangelands a t l e a s t , t h e convers ion of p e r e n n i a l g r a s s l a n d s t o sh rub and /o r annua l g r a s s - f o r b types a s a r e s u l t of heavy e a r l y l i v e s t o c k g raz ing i s be l i eved t o have improved f o r a g e condi- t i o n s f o r mule dee r . Reduct ions i n d e n s i t i e s of n a t i v e p e r e n n i a l g r a s s e s paved t h e way f o r t h e subsequent abundance of p a l a t a b l e sh rubs and /o r i n t r o - duced g r a s s e s and f o r b s which a r e more d i g e s t i b l e than n a t i v e p e r e n n i a l s (Longhurst e t a l . 1968, 1976) . A s i m i l a r r e l a t i o n s h i p i s i m p l i c i t i n t h e concept t h a t "sound g raz ing p r a c t i c e s p l ay a n impor tant r o l e i n ma in t a in ing adequa t e browse s t a n d s e s s e n t i a l f o r a hea l t hy p o p u l a t i o n of b i g and upland game (Clawson and Lesperance 1973) . "

Furthermore , ou r p r eoccupa t ion w i t h more p r e f e r r e d and impor t an t f o r a g e p l a n t s i n a s s e s s i n g compe t i t i on may have ignored v i t a l r o l e s of l e s s e r s p e c i e s i n t h e d i e t s of g r az ing animals and perhaps more s u b t l e compe t i t i ve r e l a t i o n s h i p s w i th r e s p e c t t o t h e i r u se and a v a i l a b i l i t y . B i o l o g i s t s have lung recognized an appa ren t requirement f o r a v a r i e t y of f o r a g e i tems i n t h e d i e t of l a r g e he rb ivo re s ; and both Smith (1959) and Longhurst e t a l . (1968) have i n d i c a t e d t h a t t h e r e may be p h y s i o l o g i c a l l i m i t s a s t o t he amount of c e r t a i n s p e c i e s , e . g . b i g sagebrush, t h a t dee r can consume. Longhurst e t a l . (1968) r e l a t e d t h i s t o i n h i b i t o r y e f f e c t s of essen- t i a l o i l s on rumen f u n c t i o n . S i m i l a r l y , F ree l and and Janzen (1974) p o i n t o u t t h a t many p l a n t s normal ly f e d upon by he rb ivo re s c o n t a i n t o x i c m a t e r i a l s which can have d e t r i m e n t a l e f f e c t s u n l e s s consumed wi th o t h e r k inds of p l a n t s which e i t h e r o f f s e t o r n e u t r a l - i z e t h e i r t o x i c i t y .

F i n a l l y , compe t i t i on f o r f o r a g e may begin long b e f o r e p r e f e r r e d f o r a g e p l a n t s used i n common a r e "overused". L ives tock g raz ing t r i a l s have shown

Interspecific Competition

repeatedly t h a t r a t e s of weight gain i n heavi ly stocked pastures dev ia te from those under l i g h t e r s tocking almost from the time c a t t l e a r e placed i n the pas tu res (c f . Woolfolk and Knapp 1949, Kipple and Costel lo 1960, Reed and Peterson 1961). The r a t e a t which an animal can f ind food depends upon the dens i ty of food i n i t s environment, t h e amount of time and e f f o r t spent i n looking f o r food, and i ts e f f i c iency i n feeding a l l may be inf luenced by preemption o r common usage wel l before t o t a l u t i l i z a t i o n reaches a "proper" l e v e l .

CONCLUSIONS

The f a c t t h a t we must admit t o knowing l i t t l e about t h e exact na tu re and importance of competition e s s e n t i a l l y precludes any f i rm conclusions a s t o its poss ib le s ign i f i cance i n t h e cur ren t t rends and s t a t u s of mule deer populations i n Western North America. This does not mean t h a t competition i s not o r has not been of some or even cons iderab le in f luence . Rather, i t serves t o point out t h a t much remains t o be accomplished i n t h e way of f ind ing ways and means of more e f f e c t i v e l y assess ing in te r spec ies re la t ionsh ips and applying our current knowledge t o s i t u a t i o n s of p o t e n t i a l competition on rangelands. Since exiat- ing da ta do not o r cannot s a t i s f y the demands of mul t ip le use land managers attempting t o accommodate a l l uses, i t seems imperative t h a t we r e d i r e c t our thinking and e f f o r t s t o e s t a b l i s h v a l i d da ta and conclusions a s rap id ly a s possible . Unt i l we can f u l l y document the b io log ica l and ecological s i g n i f i - cance of in te r spec ies competition we can only con- t inue t o say maybe t o t h e quest ions of whether competition i s occurr ing o r important.

LITERATURE CITED

Anthony, R. G. 1972. Ecological r e la t ionsh ips between mule deer and white- tai led deer i n south- eas te rn Arizona. Ph.D. Thesis. Univ. of Arizona (Lib. Congr. Card No. Mic. 72;31,840). 123 p. Universi ty Microfilms. Ann Arbor, Mich.

Bel l , R. H. V. 1971. A grazing ecosystem i n the Serenget i . Sci. Am. 225(1):86-93.

Clawson, W. J . and A. L. Lesperance. 1973. The environmental r o l e of range l ives tock . Proc. Western Sect ion, Amer. Soc. of An. Sci. 24:38-41.

C l i f f , E. P. 1939. Relat ionship between e l k and mule deer i n t h e Blue Mountains of Oregon. Trans. N. h e r . Wildl. Conf. 4:560-569.

Cole, G. 1958. Big game-livestock competition on Montana's mountain rangelands. Montana Wildl , , Apr i l 1958:24-30.

Dalke, P. D., R. D. Beeman, F. J . Kindel, R, S. Robel, and T. R. Williams. 1965. Use of s a l t by e l k i n Idaho. J . Wildl. Manage. 29(2):319-332.

Denniston, R. H. 11. 1956. Ecology, behavior and populat ion dynamics of t h e Wyoming or Rocky Mountain Moose. AZces aZces shirasi. Zoologica 41(14) : 105-118.

Dusek, G. L. 1971. Range re la t ionsh ips of mule deer i n t h e p r a i r i e h a b i t a t , nor thcen t ra l Montana. M.S. Thesis, Mont. S t a t e Univ., Bozeman. 63p.

Firebaugh, J . E. 1969. Relat ionships of mule deer t o l ives tock on summer range i n t h e Pryor Moun- t a i n s , Montana. M.S. Thesis. Mont. S t a t e Univ. Bozeman. 55p.

Freeland, W. J. and D. H. Janzen. 1974. S t r a t e g i e s i n herbivory by mammals: The r o l e of p lan t secondary compounds. Am. Nat. 108(961):269-289.

Ge is t , V. 1970. A behavioral approach t o the management of wild ungulates. pp413-424. I n E. Duffey and A. S. Watt (ed) . The s c i e n t i f i c management of animal and p lan t communities f o r conservation. The 11th Symposium of t h e B r i t i s h Ecological Society. Blackwell S c i e n t i f i c Publ., Oxford.

Hardin, G. 1960. The competitive exclusion p r inc i - p le . Science 131:1292-1297.

Hunter, G. N. and R. G . Kinghorn. 1950. Mountain sheep d r ive mule deer from food. J. Mammal. 31(2) : 193.

J e f f e r y , D. E. 1963. Fac to rs inf luencing e l k d i s t r i b u t i o n on Willow Creek summer range, Utah. M.S. Thesis , Utah S t a t e Univ., Logan.

Julander , 0 . 1958. Techniques i n studying competi- t i o n between big game and l ives tock . J . Range Manage. 11(1):18-21.

Kipple, G. E. and D. F. Costel lo . 1960. Vegetation and c a t t l e responses t o d i f f e r e n t i n t e n s i t i e s of grazing on short-grass ranges on the c e n t r a l Great P la ins . U.S.D.A.Tech. Bull. No. 1216. 82p

Knipe, T. 1957. The j ave l ina i n Arizona. Ariz. Game & Fish Dept., Wildl. Bull. 2. 96p.

Knowles, C. J. 1975. Range re la t ionsh ips of mule deer , e l k and c a t t l e i n a r e s t - r o t a t i o n grazing system during summer and f a l l . M.S. Thesis , Mont. S t a t e Univ., Bozeman. l l l p .

b Komberec, T. J. 1976, Range re la t ionsh ips of mule

deer , e l k and c a t t l e i n a res t - ro ta t ion grazing sys tan during winter and spring. M.S. Thesis. Mont. S t a t e Univ., Bozeman. 79p.

Kramer, A. 1972. A review of the ecological r e la - t ionsh ips between mule and white- tai led deer. Alberta F i sh and Wildl. Div, Occ. Paper No. 3. 54 p.

- , 1973. I n t e r s p e c i f i c behavior and d i spers ion of two sympatric deer species . J . Wildl. Manage. 37(3):288-300.

Longhurst, W. H., H. K. Oh, M. B. Jones, and R. E. Kepner. 1968. A b a s i s f o r the p a l a t a b i l i t y of deer forage p lan t s . Trans. N. Am. Wildl. Nat. Resour. Conf. 33:181-192.

53 Interspeci f i c Competition

Longhurs t , W . H., E. 0 . Garton, H. '3. Heady, and G . E . Connolly. 1976. The C a l i f o r n i a dee r d e c l i n e and p o s s i b i l i t i e s f o r r e s t o r a t i o n . Paper pre- s en t ed a t Annual Meeting of t h e Western Sec t ion of t h e W i l d l i f e Soc i e ty , Fresno, C a l i f o r n i a . Jan . 30-31, 1976. 37 pp.

a Lonner, T. N. 1975. Montana Coopera t ive Elk-logging s tudy . Job 11-B, Long Tom Creek Study. pp. 60- 72. Prog. Rept. January 1-December 31, 1974. 146 p.

Lovaas, A. L. 1970. People and t h e G a l l a t i n Elk herd Montana Dept. of F i s h and Game, Helena. 44p.

Mair, W. W. 1952. The impact of an i n t roduced popu- l a t i o n of e l k upon t h e b i o t a of Banff Na t iona l Park . Unpub. M.S. Thes i s . Un ive r s i t y of A lbe r t a . 98pp.

McMahan, C. A. and C. M. Ramsey. 1965. Response of dee r and l i v e s t o c k t o c o n t r o l l e d g raz ing i n C e n t r a l Texas. J . Range Manage. 18(1):1-6.

McMahan, C. A. 1966. S u i t a b i l i t y of g r az ing enclos- u r e s f o r dee r and l i v e s t o c k r e s e a r c h on t h e Kerr W i l d l i f e Management Area, Texas. J . Wildl . Manage. 30(1) :151-162.

M i l l e r , R. S. 1967. P a t t e r n and p roces s i n competi- t i o n . Adv. Ecol. Research. 4:1-74.

Odum, E. P. 1959. Fundamentals of Ecology. W. B. Saunders Co., Ph i l ade lph i a . 546p.

Ogren, H. A. 1962. Barbary sheep of New Mexico. New Mexico Dept. of Game and F i sh . Bu l l . No. 11. 32p.

P r e s c o t t , W . H. 1973. I n t e r r e l a t i o n s h i p s of moose and dee r of t h e genus OdocoiZeus. I n t . Symp. on Moose Ecol. 37p. t y p e s c r i p t .

Reed, M. J. and R. A. Pe t e r son . 1945. Vege t a t i on , s o i l , and c a t t l e r e sponses t o g r az ing on nor th- e r n Great P l a i n s range. U.S.D.A. Tech. Bu l l . 1252. 79p.

Sch l adwe i l e r , P. 1974. Ecology of S h i r a s Moose i n Montana. Montana nep t . of F i s h and Game. Big Game Research P r o j e c t s W-98-R and W-120-R, F i n a l Repor t . 100p.

SI Skovl in , J. M., P. J. Edger ton, and R. W. H a r r i s , 1968. The i n f l u e n c e of c a t t l e management on dee r and e l k . Trans. N. Am. Wildl . Nat. Resour. Conf. 33:169-181.

Smith, A. D. 1959. Adequacy of some impor t an t browse s p e c i e s i n over-winter ing mule dee r . J . Range Manage. 12:8-13.

Smith, J . G . and 0. Ju l ande r . 1953. Deer and sheep compe t i t i on i n Utah. J . Wildl. Mgmt. i 7 ( 2 ) : io i -112.

Woolfolk, E. J. and B. Knapp, J r . 1949. Weight and g a i n of r ange c a l v e s a s a f f e c t e d by r a t e of s t ock ing . Mont. S t a t e Co l l . Agr. Expt. S t a . Bu l l . 463. 26p.

In terspec i f ic Competition

' 1 DEER RANGE IMPROVEMENT AND MULE DEER MANAGEMENT -

Paul T. Tue l le r Professor

Renewable Natural Resources Divis ion Max C. Fleischmann College of Agricul ture

Universi ty of Nevada Reno Reno, Nevada 89507

Abstract

Range improvements f o r mule deer i n t h e western United S t a t e s cons i s t of (1) range seedings, (2) grazing management systems including fencing, (3) t r e e and brush removal, (4) water development, and ( 5 ) miscellaneous land t reatments . The b e n e f i t s , while i n t u i t i v e l y p o s i t i v e , have r a r e l y been success fu l ly measured by documenting e i t h e r changes i n mule deer population s i z e o r behavior modif icat ions.

Col lec t ive ly , deer range improvement p r a c t i c e s provide a combination of f a c t o r s t h a t a r e b e n e f i c i a l t o mule deer. Monotypic seedings and most in tens ive grazing management systems developed wi th in the range of the mule deer a r e apparent ly of l i t t l e bene- f i t . Tree and brush con t ro l p r o j e c t s a r e of g r e a t e r b e n e f i t and water developments a r e b e n e f i c i a l primari- l y i n the more z e r i c por t ions of the mule deer range. Prescr ibed burning is genera l ly b e n e f i c i a l bu t only i n c e r t a i n h a b i t a t s . Large v a r i a t i o n s i n range f o r - age p roduc t iv i ty based on seasonal r a i n f a l l , "natural" population f l u c t u a t i o n s , and in tens ive i n t e r s p e c i f i c competition may mask the p o s i t i v e b e n e f i t s of range improvements f o r mule deer .

It is recommended t h a t t h e b e s t poss ib le techniques be used t o eva lua te b e n e f i t s i n terms of popu- l a t i o n s and behavioral changes that r e s u l t from t h e e f f o r t t o improve ranges.

INTRODUCTION

An es t imate of t h e expenditures f o r range improvement f o r mule deer would be reveal ing. Revealing i n t h e sense t h a t considerable t ax d o l l a r s have been spent t o improve t h e general q u a l i t y of t h e mule deer range while t h e b e n e f i t s have r a r e l y been success- f u l l y measured. The b e n e f i t s have been i n t u i t i v e l y pos i t ive . Ranges wi th low amounts of "desirable" deer forage a r e improved by e i t h e r reseeding important spec ies , reducing undesirable spec ies , o r both. Water developments a r e sometimes b e n e f i c i a l and fences e i t h e r he lp o r hinder.

Expected b e n e f i t s , though seldom measured, have been assumed t o be such th ings a s improvement of herd h e a l t h , increased vigor of ind iv idua l animals, i . e . , h e a l t h i e r does and s t ronger bucks. This , then, i n a t l e a s t the hypothet ical sense, is followed by an inc rease i n fawnldoe r a t i o s and herd numbers inc rease - t o the improved carrying capac i ty l e v e l ?

~~~~~

'/ Paper presented a t the Symposium e n t i t l e d - "Mule Deer Decline i n the West," Apri l 29-30, 1976. Logan, Utah.

I n t h i s paper I have attempted t o review t h e . l i t e r a t u r e concerned with mule deer range improvement p rac t i ces . I have, i n my search, sought those s t u d i e s t h a t have shown e i t h e r an inc rease i n herd number a c t u a l l y a t t r i b u t e d t o an improvement o r , secondly, s t u d i e s showing how t h e deer range improvement p r a c t i c e has caused a s i g n i f i c a n t change i n deer behavior r e s u l t i n g i n management a l t e r a t i o n s . Negative e f f e c t s were a l s o sought. Populat ion changes o r f l u c t u a t i o n s reported here a r e assumed t o be v a l i d . Others i n t h i s symposium w i l l t e l l u s how good the est imates a r e .

DEER RANGE IMPROVEMENTS FOR MULE DEER

It appears t o be w e l l e s tab l i shed t h a t overpopulat ions of deer lead t o overuse of the h a b i t a t , followed by deer mor ta l i ty (Severinghaus 1951; Russo 1964). Cheatam and Severinghaus (1950) found v a r i a t i o n s i n f e r t i l i t y r e l a t e d t o range condit ions. Likewise, deer p roduc t iv i ty has been shown t o vary from h a b i t a t t o h a b i t a t (Taber 1953), depending upon t h e a v a i l a b i l i t y and n u t r i t i v e q u a l i t y of t h e fo rage (Julander e t a l . 1961). The l a t t e r s tudy showed t h a t two mule deer ranges i n Utah and Idaho had s t r i k i n g d i f fe rences i n deer product ivi ty . F a l l

55 Deer ,:ange Improvement and Mule Deer Management

weights of the Utah fawn bucks and does were 72 and 65%, respec t ive ly , of weights of the Idaho fawns. Forage production, ovulat ion r a t e s and f e t a l weights were a l l higher on the Idaho range. The authors concluded: "A good summer range, capable of carrying deer i n good condit ion through the breeding season is necessary f o r maximum herd product ivi ty ."

Swank (1958) found t h a t summer forage n u t r i t i o n s t rong ly con t ro l l ed ovulat ion r a t e s and the number of fawns developed per doe. A dry summer coupled wi th excess deer numbers resu l t ed i n poor bucks and an extremely low fawn crops (28 fawns per 100 does).

Robinet te e t a l . (1952) s tud ied deer mor- t a l i t y i n r e l a t i o n to range condit ion a f t e r the severe 1948-49 winter i n Utah and found the fol low ing :

Herd Mortal i ty Lbs. green forageldeer-day use

9% 5 7 26% 13 4 2% 9

Deer winter losses varied inverse ly with t h e amount of a v a i l a b l e forage on the win te r range.

Taber (1953) found t h a t b lack- ta i l ed deer showed d i f f e r i n g reproduct ive r a t e s , depending upon cover type. Open brush types were considerably more productive (147 fawns1100 does) than e i t h e r burned s i t e s (115.6 fawns /does) or s t ands of mature brush (84.3 fawnsllOO does) a t the beginning of the winter .

Another good example of t h e s t rong re la t ionsh ip between deer populat ion changes and h a b i t a t d i f fe rences brought about by management is t h e s tudy by Biswell e t a l . (1952) wi th black-tai led deer i n the North Coast Range of Ca l i fo rn ia . Three a reas were compared: (1) heavy brush cover, ( 2 ) w i l d f i r e burn, and (3) open brush cons i s t ing of an in te r spers ion of g rass with patches of dense brush.

Deer/sq. m i . Ovulation Rates (%)

Heavy brush 10-30 84 Wildfire burn 5-160 116 Opened brush 40-110 14 7

Populations i n the heavy brush and opened brush were ra the r s t a b l e ; b u t i n the w i l d f i r e b u r n , l a r g e num- b e r s of deer moved i n when the sp rou t s were young and tender and moved ou t during cold winter . These d a t a show how deer vary i n t h e i r a b i l i t y t o reproduce and grow i n d i f f e r e n t kinds of h a b i t a t s .

Sege lqu i s t (1974) attempted t o s tudy the e f f e c t s of forage c lea r ings on t h e hea l th and populat ion c h a r a c t e r i s t i c s of a herd of 23 white- tai led deer from 1968-72 i n a 600-acre fenced enclosure i n Arkan- sas . Loss of near ly ha l f the animals a s a r e s u l t of predat ion, the c o l l e c t i n g of animals f o r necrosy, death from unknown causes, and animals escaping from the enclosure precluded the making of v a l i d conclu- s ions concerning the inf luence of management changes on population c h a r a c t e r i s t i c s of deer. This s tudy seems t o exemplify the problems t h a t a r e o f ten encountered.

Several researchers have found a c lose re la t ion- s h i p between t h e percentage u t i l i z a t i o n of b i t t e r - brush by deer and fawn s u r v i v a l . For example, Dasmann and B l a i s d e l l (1954) showed a r e l a t i o n s h i p between the i n t e n s i t y of b i t t e r b r u s h cropping and t h e success of t h e succeeding season's f awn~ng a s r e f l e c t e d by f a l l does/fawn r a t i o s . They concluded t h a t b i t t e r b r u s h can se rve as an ind ica to r spec ies i n t h e management of the deer herd. Under condit ions of t h e i r s tudy, when the cropping of b i t t e r b r u s h l eader growth exceeds 25 percent , a moderate dec l ine i n fawn sur- v i v a l can be expected the following year . When u t i l i z a t i o n exceeds 34 percent , a s t eep populat ion dec l ine can be expected. Can tag s a l e s and con t ro l of hunter success be used t o remove animals from these heavi ly u t i l i z e d ranges?

It has been known f o r many years t h a t good deer forage is c h a r a c t e r i s t i c of "sub-climax eco log ica l condit ions" (Leopold 1950). Lyon (1966) described t h e b e n e f i t s t o deer and e l k populations provided by w i l d f i r e i n the northern Rocky Mountains i n the e a r l y p a r t of t h e century. This pos t - f i r e discl imax vege ta t ion proved t o be very favorable f o r w i l d l i f e . Shrub dominance favorab le t o deer and e l k may con- t i n u e f o r another 50 t o 80 years but w i l l eventual ly be displaced by t r e e s . Future managers w i l l be required t o make dec i s ions r e l a t i v e t o t r e e s versus shrub h a b i t a t and t h e d e s i r a b l e proport ions of each.

Over much of the range of mule deer heavy I ive- s tock grazing has been instrumental i n providing a d e s i r a b l e sub-climax vege ta t ion with g rasses reduced and browse and fo rbs increased. Longhurst e t a l . (1976) be l i eve t h a t the general s h i f t from sheep t o c a t t l e is s t r o n g l y re la ted t o the mule deer decl ine. Their hypothesis i s t h a t c a t t l e tend t o overgraze ranges t o t h e detriment of deer forage o r t h a t sheep do a b e t t e r job than c a t t l e i n maintaining t h e success iona l fo rbs and g rasses which a r e necessary f o r deer.

Deer range i s enhanced when c e r t a i n spec ies a r e prevalent . Numerous s t u d i e s have described deer food h a b i t s (Dasmann and B l a i s d e l l 1954; Anderson e t a l . 1965; Wood e t a l . 1970; Tue l le r and Lesperance 1970; McCulloch 1973; Goodwin 1975; and Tue l le r 1976) showing t h e high preference and apparent p a l a t a b i l i t y of a r e l a t i v e l y f e w spec ies . Overbrowsing by deer g ives l e s s d e s i r a b l e p l a n t s a competitive advantage and t h e e n t i r e f l o r a tends t o s h i f t t o composition l e s s d e s i r a b l e f o r mule deer (Leopold e t a l . 1947). Management programs designed t o increase important spec ies a r e c l e a r l y needed. I n add i t ion , managers should not l o s e s i g h t of the f a c t t h a t c e r t a i n n a t u r a l l y occurr ing p lan t communities a r e much more d e s i r a b l e than o thers wi th respec t t o deer use. Several authors have shown s i g n i f i c a n t d i f fe rences among p l a n t communities r e l a t i v e t o deer use (Darling 1937; Rasmussen 1941; Biswell e t a l . 1952; Depaoli and Tue l le r 1970; Mackie 1970; Tausch 1973; Tue l le r and Monroe 1975). P lan t communities shown to be of s p e c i a l s ign i f i cance should rece ive the highest p r i - o r i t y f o r improvement and maintenance funding. For example, i n Montana, Mackie (1970) found t h e Pinus- Juniperus h a b i t a t type t o be of g r e a t e s t importance during summer, Artemisia-Agropyron i n f a l l and win te r , and the Artemisia-Agropyron and Pinus-Agropyron types received the g r e a t e s t use i n the spring. Tue l le r and Monroe (1975) reported from Nevada t h a t the Artemisia

Deer Range Improvement mzd Mule Deer Mcmagement 56

tridentata/Purshia tridentata/Poa secunda, Cercocar- pus l ed i f o Zius/Symphoricarpos longif Zorus/f orb and Artemisia tridentata o r nova/Purshia tridentata/ Festuca idahoensis or Agropyron spicatwn p l a n t com- munit ies a r e of considerable importance f o r mule deer Statewide and the re fore should rece ive t h e g r e a t e s t management input .

Other genera l ly uncontrol lable f a c t o r s a r e known t o have s t rong d e f i n i t e inf luences on deer range vegetat ion and subsequently on deer population s i z e . These include, bu t a r e not necessa r i ly r e s t r i c t e d t o , the following: drought, c l imat ic anomalies, f looding with in tense e ros ion , and f i r e . Wallmo (1959 & 1962) described the in f luence of drought on mule deer i n the Chihuahuan d e s e r t of Trans-Pecos. Texas. A severe 6-year drought i n the mid-1950's reduced deer dens i ty from 4.5 t o 6.5 deer per 100.ha. during t h e drought. Within th ree years a f t e r t h e drought, the deer popula- t i o n s rose t o over 11 deer pe r 100 ha. Forage, par- t i c u l a r l y shrubs, s i g n i f i c a n t l y increased a t the same time. White-tailed deer populat ions i n Texas, Arizona, and throughout t h e Southwest a r e regulated t o a l a r g e degree by p r e c i p i t a t i o n during the preceding year o r 18 months (Shaw 1965; Teer e t a l . 1965). McColm (1976) reported t h a t a Nevada drought between 1959 and 1961 t r iggered a Statewide deer populat ion dec l ine t h a t d id not bottom ou t u n t i l 1966.

Many years ago, Darling (1937) described s ign i - f i c a n t i n t e r a c t i o n s between cl imate and vegetat ion as i t r e l a t e d t o deer movement. Mackie (1970) des- sc r ibed deer movement o r land use i n r e l a t i o n t o s teepness of s lope and aspec t o r exposure, a s we l l a s cl imate. Mule deer d i s t r i b u t i o n and migrat ion p a t t e r n s a r e s t rong ly inf luenced by cl imate i n t h e Great Basin and Intermountain Region and tend t o vary considerably from year t o year.

These da ta support the i n t u i t i v e f e e l i n g t h a t t h e we l fa re of deer is genera l ly enhanced under good range condit ions and t h a t t h e converse is t r u e , namely t h a t poor range condit ions diminish the vigor , r eproduc t iv i ty , and general we l fa re of our deer herds. The l o g i c a l r e s u l t of t h i s thinking has been programs t o improve range condit ions. These programs gener- a l l y have consis ted of the following:

(1) Range s e e d i n e - most have been done primari ly f o r l ives tock , although mule deer may have received some s i d e benef i t s . Some have been accomplished p r imar i ly f o r mule deer and, i n some cases, l ives tock , a s w e l l have benefi ted.

(2) Grazing management - an obvious example would be fencing t o exclude c a t t l e during t h e summer from important winter deer ranges.

(3) Tree and brush con t ro l - removal of mature, over- mature, and decadent pinyon-juniper t r e e s , by e i t h e r cabl ing o r chaining, has been an exten- s i v e l y used technique f o r improving deer ranges. Also, s tands of heavy brush have been opened t o inc rease the r e l a t i v e composition of browse, fo rbs , and g rasses f o r mule deer use. Prescr ibed burning has sometimes been used a s a technique t o accomplish t h e same r e s u l t s .

(4) Water developments - deer a r e inf luenced i n t h e i r p a t t e r n of land use by the l ack of water

and l ikewise by the provision of new water sources.

(5) Miscellaneous t reatments - f e r t i l i z a t i o n , chemi- c a l t reatments t o remove competing vegetat ion, and o ther techniques have been used t o improve deer ranges.

Range Seedings

The techniques f o r seeding t o r e s t o r e mule deer ranges have been c a r e f u l l y described by P l u m e r e t a l . 1968. Successful seeding requ i res a considerat ion of various techniques, e.g., burning, chemical t reatments , in te r seed ing , and o ther p lan t ing procedures. The need is t o s e l e c t spec ies with the following charac- t e r i s t i c s :

High i n n u t r i e n t s f o r deer . Cured o r mature with a high supply of n u t r i e n t s d e s i r a b l e f o r mule deer heal th. Readily a v a i l a b l e seed source a t a reason- a b l e cos t . Strong emergence (poss ib le need t o p r o t e c t seed and seed l ings from rodents) . High establishment percentages (growth through t h e f i r s t f i e l d season). High surv iva l percentages (regrowth follow- t h e f i r s t and second win te r s ) . Drought and f r o s t hardiness . Rapid growth r a t e s . High p roduc t iv i ty of usable deer forage. Self-renewing (good seed production fo l - lowed by volunteer establ ishment) .

Af te r seed s e l e c t i o n , recommended seeding and management techniques can then be followed t o produce a d e s i r a b l e s tand of vegetat ion wi th t h e impor- t a n t required c h a r a c t e r i s t i c of spec ies d i v e r s i t y (Plummer e t a 1 1968; Tue l le r and Monroe 1975).

Plummer's work with a c t u a l seedings, along with t h e observat ions of Tue l le r and Monroe (1975). Mackie (19701, and many o thers , c l e a r l y show t h e importance of providing a mixture of fo rbs , g rasses , and browse f o r optimum deer use. P l u m e r e t a l . (1966) a l s o l ist the important spec ies t h a t should be considered f o r use on mule deer ranges and they and o thers a r e cont inuing t o sc reen spec ies f o r good adap tab i l i ty .

There is some concern t h a t i t is o f t e n d i f f i c u l t t o ob jec t ive ly eva lua te vege ta t ion t rends f o r mule deer . The reason is t h a t animal numbers o f t e n a r e such t h a t t h e new vege ta t ion is quickly overbrowsed o r overgrazed and cannot su rv ive a f t e r e s tab l i sh - ment. This , of course, suggests t h e need f o r deer number management, including b e t t e r d i s t r i b u t i o n .

Revegetation should be accomplished f i r s t , where needed, f o r c r i t i c a l deer ranges. Often, these c r i t i - c a l deer ranges a r e winter ranges and may be c r i t i c a l only one o u t of 10 years . They a r e an abso lu te necess i ty during t h a t t en th year and may he lp pro- v ide proper use of a l l adjacent deer ranges during t h e non-c r i t i ca l years .

Over one m i l l i o n ac res i n Nevada have been seeded t o adapted e x o t i c perennial g rasses . Simi- l a r acreages have been seeded i n adjoining s t a t e s

57 Deer Range Improvement and MuZe Deer Management

with in the range of mule deer . Do mule deer use perennial g rass seedings i n the Great Basin and Intermountain Region? I f s o , when and how a r e they important? Actual s t u d i e s a r e l imited. Plummer and Stopely (1959) found Agropyron cristatwn (c res ted wheatgrass) t o be one of t h e g rasses grazed by mule deer i n the e a r l y sp r ing o r ranges t r e a t e d f o r pinyon-juniper control . Invest iga- t ions i n south-central Nevada revealed 90% u t i l i - za t ion of A. cristatuni by "deer and rabbi ts"; however, no apparent e f f o r t was made t o d i f f e r - e n t i a t e the r e l a t i v e degree of u t i l i z a t i o n by the two spec ies (St inson 1964). Rumen ana lys i s of two winter ing mule deer on r e h a b i l i t a t e d pinyon- juniper range i n Utah shaved the occurrence of mature seedheads of A . cristatum i n the sample (Plummer e t a l . 1966). Urness (1966) concluded t h a t c res ted wheatgrass " i s a c t i v e l y sought by deer on winter range and i s , when ava i l ab le , Important i n f a l l , sp r ing , and snow-free periods i n winter ."

Cole (1968), i n Nevada, s tudied c res ted wheat- g rass seedings i n areas adjacent t o known mule deer ranges. Of 25 seedings s tud ied , only th ree showed a measurable use by mule deer . Those s i t e s found t o be used by deer contained r e s i - dual browse t h a t was thought t o account f o r the measurable deer use based on p e l l e t group counts and browse use. Cole concluded t h a t mule deer range was not extended by c res ted wheatgrass seedings i n Nevada on ranges not previously used as win te r ranges. The monotypic na tu re of c res ted wheatgrass seeded range apparent ly i n h i b i t s u t i l i - za t ion of a l l but pe r iphera l a reas of such range. I f l a r g e enough, t h i s monotype may r e s t r i c t o r a l t e r mule deer movements from summer t o winter ranges.

Grazing Management Systems

I s i t poss ib le t o include deer i n a grazing system including l ives tock? There is no reason why no t , although i t seems t h a t such has been r a r e l y accomplished. The important considerat ion here would be t o assure t h a t deer and l i v e s t o c k a r e not competing f o r the same forage. I n the Great Basin i t has been shown t h a t the re is a mule deer- l ivestock competition period t h a t occurs i n l a t e summer and e a r l y f a l l when l ives tock feed heavi ly on b i t t e r b r u s h (Tuel ler and Monroe 1975). A t t h i s time the b i t t e r - brush i s s t i l l carrying on photosynthesis and res to r - ing carbohydrates t o depleted roo t s and i s , the re fore , suscep t ib le t o browsing damage. Winter deer browsing of the dormant b i t t e r b r u s h is l e s s damaging i f a t a l l .

I n Nevada, key winter deer ranges should probably have l ives tock use removed by fencing. The fences themselves nay c o n s t i t u t e a hazard, but depending on the t e r r a i n , may be placed i n places t h a t would not d i r e c t l y i n t e r f e r e with known spr ing- fa l l migra- to ry rou tes . Longhurst e t a l . (1976) r e ~ o r t e d black- t a i l e d deer m o r t a l i t y a s one deer l o s t annual ly f o r each 8 miles of fence. This was an a rea with high deer dens i ty (100/square mi le ) . They concluded t h a t fences account f o r the l o s s of severa l thousand deer each year i n Ca l i fo rn ia .

Rest-rotat ion grazing systems or o ther systems designed t o enhance the v igor , reproduction, and growth of a v a r i e t y of range p l a n t s must a l s o have an inf luence on populat ions of w i l d l i f e . Grazing management systems designed t o enhance monotypic s tands may cause a reduct ion i n good mule deer h a b i t a t (Cole 1968). Other systems may, because of t h e i r design, enhance the accumulation and maintenance of a d i v e r s i t y of spec ies . A d i v e r s i t y of spec ies w i l l then se rve t o a t t r a c t deer use (Tuel ler and Monroe 1975) .

No s t u d i e s of grazing management systems have included d e f i n i t i v e ana lys i s of r es iden t deer herd changes. For example, a Wyoming study (Gibbens and F i s s e r 1970) concluded a f t e r a 4-year s tudy of a 68,000 a c r e r e s t - r o t a t i o n grazing system, t h a t , a l - though res iden t deer were seen i n a l l pas tu res , " the re a r e no ind ica t ions of an increase i n the res iden t population."

Fences designed t o remove l ives tock from key deer ranges where competition i s known t o occur c o n s t i t u t e s a p o s i t i v e t reatment t o improve deer range. I found no published s t u d i e s repor t ing such b e n e f i t s bu t such fences i n Nevada have been instrumental i n improving heavi ly used win te r ranges t h a t c a t t l e have grazed f o r browse i n l a t e summer and f a l l .

Tree and Brush Control

Tree and brush con t ro l f o r improvement of mule deer h a b i t a t has been p rac t i ced ra the r extensively f o r the pas t 25 years . T e r r e l and S p i l l e t (1975) quote Box e t a l . (1966) ind ica t ing t h a t between 1950 and 1964, 3 mi l l ion ac res of pinyon-juniper woodland i n 1200 pro jec t s have been converted i n the U.S. Th i s , along with the over t h r e e mi l l ion ac res of sagebrush con t ro l i n t h e West and con t ro l of o the r brush types not so we l l documented, c o n s t i t u t e s a consid- e rab le land treatment f o r the b e n e f i t of mule deer .

The b a s i c quest ion t h a t keeps r i s i n g i s . t h i s : Do these t reatments a c t u a l l y inc rease deer numbers v i a the general ized mechanism discussed i n the in t ro - duct ion? F i r s t of a l l , it seems very c l e a r t h a t deer a r e a t t r a c t e d t o the improved areas. Tausch (1973) showed i n Nevada t h a t deer use increased on the pinyon-juniper con t ro l a reas . However, deer use was found t o be h ighes t on those a reas o r i g i n a l l y containing t h e g r e a t e s t d i v e r s i t y . The l e v e l of use was a l s o dependent upon t h e nearness of untreated escape cover and on the c lose proximity of the t r ea ted a rea t o e x i s t i n g deer use areas.

Cole (1968), a l s o working i n Nevada, found increased deer use i n s i d e pinyon-juniper con t ro l p r o j e c t s . At one s i t e pe r iphera l paired p l o t s showed an 87.5% increased u t i l i z a t i o n i n the t r ea ted range. However, ana lys i s over the e n t i r e a r e a , i . e . , wi th in the chaining, showed only a 15% increase , suggest ing the s t r e n g t h of the edge e f f e c t .

T e r r e l (1973) found increasing deer use i n the v i c i n i t y of pinyon-juniper chainings bu t i n t h e n a t u r a l undisturbed pinyon-juniper. I n the i n i t i a l 12 years post-treatment i n T e r r e l ' s Utah s tudy, no inc rease i n deer numbers was cor re la ted wi th pinyon-juniper conversion.

Deer Range Improvement and Mute Deer Management 5 8

I n an Arizona s tudy (Urness 1974) deer use was found t o be lower by 114 t o 112 on root-plowed a reas when compared t o adjacent brush f i e l d s even though production of high-quality fo rbs was much g r e a t e r on the root-plowed area. The author pointed ou t t h a t the lower deer use f i g u r e s f o r the 80-acre root-plowed s i t e s does no t necessa r i ly r e f l e c t low r e l a t i v e use. Only feeding was taking place on t h e root-plowed ac res , while feeding, r e s t i n g , ruminat- ing , e tc . , a r e taking place on the undisturbed areas. Even though deer spend l e s s time on the brush- con t ro l l ed a reas , t h e increased feed may compen- s a t e f o r the l ack of use, providing treatment s i z e is moderate. This s tudy indicated t h a t brush con t ro l a reas should not exceed 300-400 yards i n width and no more than 50 percent of an a rea should be t rea ted . Also, some i n t a c t brush should be l e f t on a l l exposures s i n c e mule deer i n t h e a rea of the s tudy change exposure preference, seasonal ly. Herd popula- t i o n changes were not reported, although management preferences seemed apparent.

An elongated burn a rea i n an "unthinned" t r e a t - ment on the Wild B i l l s tudy s i t e i n Arizona was considered t o be a " fo res t opening" known t o be pre- f e r r e d by deer (Kruse 1972). Deer use on t h e burned a rea showed a cons i s ten t year ly r i s e from 1968-70. Deer use on the c lea rcu t and thinned ponderosa pine a reas had been s t e a d i l y decreasing ( a f t e r an i n i t i a l high use value immediately a f t e r the treatment) from 1964-67. These da ta (Table 1 ) show t h a t the deer moved from the c lea rcu t and thinned a r e a t o the f r e s h burn i n the unthinned a rea , thus concentrat ing t h e i r use on the most favorable s i t e s . The deer r e a d i l y moved t h e i r use t o a newly created s i t e , i n t h i s case , a w i l d f i r e occurring i n t h e con t ro l o r unthinned s i t e .

Longhurst e t a l . (1976) have reported d a t a i n Ca l i fo rn ia t o show t h a t a decrease i n w i l d f i r e s due t o b e t t e r f i r e con t ro l , i n s p i t e of a t rend toward more f i r e s t a r t s , has reduced deer h a b i t a t . I n some loca t ions they found high c o r r e l a t i o n s between buck k i l l and ac res burned. They suggested the poss ib i l - i t y t h a t f i r e s a t higher e leva t ions may improve t h e supply of forbs. However, i n much of the Great Basin, most f i r e s occur a t lower e leva t ions , thus tending t o reduce t h i s b e n e f i t over much of t h e mule deer range although some use may be made of cheatgrass (Bromus tectorwn) i n win te r and e a r l y spring. Prescr ibed burning c e r t a i n l y must be f u l l y developed i n f u t u r e management programs.

TABLE 1. Deer p e l l e t groupslacre on a ponderosa pine s i t e i n northern Arizona (from Kruse 1972).

1964:1965:1966:1967*:1968:1969:1970:

Clearcut Seeded 1 6 : 7 : 7 : 2 : 0 : 2 : 4 : Native 4 2 : l l : l l : 0 : 7 : 0 : - :

Thinned 2 0 l s q . f t . l 4 : 1 3 : 2 : 9 : - : 0 : - : 401 a c r e of 124 : 31 : 2 : 2 : 0 : 0 : - : 601 b a s a l 36 : 33 : 2 : 0 : 2 : 0 : - : 8 0 1 a r e a 3 6 : 0 : 0 : 2 : 4 : 0 : - :

Unthinned 1 8 : 4 : 0 : 0 : 1 1 : 2 6 : 6 7 : Burned

An a rea of lodgepole pine and spruce-f i r f o r e s t i n Colorado was c lea rcu t i n narrow s t r i p s a l t e r n a t i n g wi th uncut s t r i p s (Wallmo e t a l . 1972). Production of deer forage 15 years a f t e r logging was 47% grea te r on c u t s t r i p s . Tame mule deer used i n grazing s t u d i e s obtained 63.3% of t h e i r forage from c u t s t r i p s , 27.4% from uncut s t r i p s and 9.3% from logging roads. These s i t e s composed 44.2, 49.4, and 6.4 percent , r e spec t ive ly , of the s tudy area. Mule deer dens i ty f i g u r e s derived from carrying capac i ty determina- t i o n s on these s i t e s resu l t ed i n numbers f a r i n excess of deer numbers est imated f o r the area. This is another good example of deer congregating on an a r e a a s a r e s u l t of h a b i t a t improvement b u t without da ta on b e n e f i t s t o herd s i z e or s t r u c t u r e .

Also, a subsequent s tudy (Regelin e t a l . 1974) showed t h a t the unlogged f o r e s t produced enough deer forage, adequate i n the n u t r i t i o n a l parameters measured, t o ca r ry more deer than a r e p resen t ly est imated t o occupy t h e summer range. Deer popu- l a t i o n s i n t h e s tudy a rea a r e apparent ly l imi ted by the amount of ava i l ab le win te r range. I n t h i s case f u r t h e r range improvement and revegetat ion may be f u t i l e s i n c e the l i m i t i n g f a c t o r is assoc ia ted wi th s i t e s removed from those being s tud ied , namely, the winter range.

It seems apparent t h a t new brush or t r e e con- t r o l t reatments have b e n e f i t s due t o increased use i n the years immediately post-dating the treatment. Question! How o f t e n and how many treatments of what s i z e i n a given h a b i t a t a r e required t o provide optimum b e n e f i t t o mule deer populat ions?

Water Developments

Water developments have the p o t e n t i a l t o accom- p l i s h a t l e a s t two things i n a deer range improvement p ro jec t . F i r s t of a l l , increased d i s t r i b u t i o n of water w i l l allow deer t o move onto and use ranges not normally used and second, t h e provision of water i n droughty a reas can provide a n u t r i t i o n a l f a c t o r t h a t can be very i n f l u e n t i a l i n animal v igor and herd h e a l t h and subsequent populat ion increases. A nega- t i v e e f f e c t may be t h e f a c t t h a t l ives tock a l s o move i n .

I n New Mexico (Wood e t a l . 1970) mule deer d e n s i t i e s increased when permanent water sources were developed i n a reas which had l i t t l e o r no f r e e water. Under condit ions of t h i s New Mexico s tudy it was found t h a t the d e s i r a b l e d i s tance between water sources was 2-1/2 t o 3 miles . On one poorly watered range, deer d e n s i t i e s increased from 1.6 deer pe r s e c t i o n i n t h e f i r s t year t o 13.0 the f i f t h year. Subs tan t i a l inc rease i n deer d e n s i t i e s on some a reas wi th in a few months l e d the authors t o conclude t h a t "deer can be a t t r a c t e d i n t o a newly watered a rea very w e l l and t h a t when the water sources were allowed t o d e t e r i o r a t e , i t was demonstrated, equal ly a s w e l l , t h a t deer can be forced t o leave an area." They a l s o concluded t h a t these b e n e f i t s can be maintained and deer held on the a reas permanently.

Mackie (1970) i n Montana found " tha t the use of range by mule deer decreased sharply a t d i s t an- ces of a mile o r more" from water. Observation "during summer and f a l l when 'permanent' water sources would be most important, were wi th in 0.75

Deer ,Tange Improvement and Mute Deer Management

miles of a water source. The number of observa- t ions a t g rea te r dis tances decreased a s d i s tance increased, with neg l ig ib le use a t 2 miles or more." However, the author concluded " tha t the d i s t r i b u t i o n of water on the study a rea even during the most a r i d years was not a s i g n i f i c a n t f a c t o r i n determining mule deer d i s t r ibu t ion . "

Apparently on the more x e r i c New Mexico s i t e the in f luence of d i s t r i b u t i o n and densi ty was s ign i - f i c a n t while on the more mesic Montana s i t e the r e l a t i v e l y g rea te r a v a i l a b i l i t y of water obviated the inf luence of water d i s t r i b u t i o n on mule deer movements and d e n s i t i e s al though, i n the l a t t e r s tudy, densi ty d i f fe rences were not recorded.

Observations by t h i s author i n Nevada i n d i c a t e t h a t the re a r e s e v e r a l p o t e n t i a l summer deer ranges i n Nevada t h a t a r e not used due t o a lack of water . One then wonders i f , because of t h e i r s t rong hab i tua l nature (Gruel1 and Papez 1965), deer can be " in te r - ested" i n these good ranges even i f water is provided. Apparently t h i s happened i n New Mexico. I am not c e r t a i n i t would be successful i n Nevada, but a study has not been conducted.

Miscellaneous Improvement Techniques

It i s important t h a t new and innovat ive deer range improvement p rac t i ces be developed. The l i t e r a - t u r e reveals few good examples. Perhaps increased and wiser use of the time-honored techniques w i l l , i n the long run, provide the bes t means of producing deer forage and increased deer populations up t o optimum carrying capaci ty.

F e r t i l i z a t i o n c o n s t i t u t e s one miscellaneous deer range improvement technique, although i t is most o f t e n used along with revegetat ion and o ther procedures. For example, Anderson e t a l . (1974) s tudied the in f luence of f e r t i l i z a t i n g wavy leaf oak brush i i ~ New Mexico f o r mule deer . Urea o r ammonium s u l f a t e was appl ied t o t h i s range and the r e s u l t was a s i g n i f i c a n t inc rease i n leader growth by mountain mahogany (Cercocurpus Zedifol ius) . No inc rease i n l eader growth was found f o r e i t h e r fourwing sa l tb rush or wavy l e a f oak. Crude p ro te in increased s i g n i f i c a n t l y i n the oak leaves a f t e r urea f e r t i l i z a t i o n . Deer use increased during summer, f a l l , and winter seasons on a reas f e r t i - l i z e d with urea. No s i g n i f i c a n t response i n deer use resu l t ed from app l ica t ion of ammonium s u l f a t e . The authors a l s o reported t h a t a poss ib le s h i f t i n sp r ing food h a b i t s from oak browse t o fo rbs may have precluded s e l e c t i v e mule deer use of the u rea f e r t i - l i z e d areas. No deer densi ty or populat ion changes were presented.

F e r t i l i z a t i o n tends t o inc rease p ro te in content of na t ive browse (Anderson e t a l . 1974). P ro te in content i s s t rong ly cor re la ted with deer weights according t o an e a r l y s tudy by Einarsen (1946). On burned-over ranges with in te r spers ions of timber i n northwest Oregon, mature black-tai led bucks averaged over 200 pounds hog-dressed weight. A second a rea was character ized by a much more closed canopy wi th " sca t t e red glades" and more mature browse p l a n t s with a much lower p ro te in content. On t h i s l a t t e r s i t e mature bucks averaged l e s s than 155 pounds.

A separa te example of a miscellaneous or inno- v a t i v e treatment i s found i n carbon black t reatments i n Colorado (Regelin and Wallmo 1975). High eleva- t i o n (2310-2350 m.) deer ranges i n Grand County, Colorado a r e o f ten l imited due t o deep snow. Carbon black was broadcast on p l o t s a t a r a t e of 336 kglha (34.4 f /m2). Melting of snow was accelerated on a l l treatment p l o t s , bu t p a r t i c u l a r l y on south aspec t s . On these s lopes average snow depth was reduced by 91.8 percent when compared with con t ro l p l o t s (7.4 percent) . The reduct ion was 50.5 percent on e a s t s lopes. The inf luence on the vegetat ion was not inves t iga ted but add i t iona l forage could be made a v a i l a b l e a t d i f f i c u l t time.

Winter feeding of deer may possibly be considered as an i n d i r e c t method of range improvement. How? By "releasing" pressure on heavi ly grazed win- t e r range. However, t h i s technique is of question- a b l e benef i t and d e s i r a b i l i t y . I n a 1944 study i n Utah, Doman and Rasmussen concluded "winter feeding of mule deer . . . i s , a t b e s t , only p a r t l y success- f u l , and expansion of such a program i s of doubtful value. It appears d e s i r a b l e t o regu la te t h e deer population s o t h a t supplemental winter feeding as a regu la r program can be discontinued."

INTERPRETATION AND CONCLUSIONS

Deer range improvement p r a c t i c e s c o n s i s t of (1) range seedings, (2) grazing management systems, including fencing t o enhance c e r t a i n na t ive and introduced spec ies , and n a t u r a l p lan t communities, (3) t r e e and brush removal with and without a r t i f i c i a l revegetat ion, (4) water developments, and (5) miscellaneous t r e a t - ments. The r e l a t i v e amounts of these various prac- t i c e s throughout the range of mule deer i s not w e l l known.

Some genera l observat ions can be made. Approxi- mately 1,000,000 ac res of perennial grasses have been seeded i n Nevada. Only a f r a c t i o n of t h i s , probably l e s s than 2 t o 3 percent , has been of p o s i t i v e bene- f i t t o mule deer . The negat ive e f f e c t s have not been s tud ied ex tens ive ly , only implied, but they might be s i z a b l e . Of course, these revegetat ion p ro jec t s were accomplished f o r l ives tock only. Probably a s i m i l a r amount of seeding has been accomplished i n other s t a t e s with perhaps a higher percentage f e l t t o be u s e f u l i n enhancing mule deer range.

Box e t a l . (1966) reported t h a t between 1950 and 1964, 3 m i l l i o n ac res of pinyon-juniper i n 1200 p r o j e c t s were converted or con t ro l l ed i n the U.S.A. A l a r g e percentage of t h i s land treatment was done t o b e n e f i t l ives tock . Numerous other s i t e s have received brush con t ro l treatment. Possibly 25 percent is usefu l f o r mule deer range enhancement.

The acreage under in tens ive grazing management t h a t d i r e c t l y b e n e f i t s w i l d l i f e i s d i f f i c u l t t o de te r - mine. On Bureau of Land Management administered lands i n Nevada, 6 mi l l ion ac res a r e under in tens ive grazing management systems. The BLM i n Nevada est imates t h a t only a out 1% of t h i s acreage d i r e c t l y b e n e f i t s P deer rang& . I n f a c t , many of the grazing management designs may be detr imental t o mule deer h a b i t a t

- I!Personal communication, Jim Yoakum, Bureau of Land Management, S t a t e Office. Nevada.

Deer Rcni~, Inp~~ovsmant and MuZe Deer Mmzagenrent 60

f o r two reasons. F i r s t , a three-year r o t a t i o n , the design of many, does not a l low f o r the increased production and reproduction of browse spec ies , and, second, the systems a r e o f ten based on an important perennial g rass as the key spec ies and do not con- s i d e r the importance of forbs.

I have found no d e f i n i t i v e f i g u r e s f o r t h e number of water developments designed t o improve mule deer ranges. They a r e probably numerous and t h e i r absolute in f luence is r e l a t i v e l y unknown.

Over much of t h e range of mule deer the re has been l i t t l e prescr ibed burning. Wildfires vary considerably from year t o year , e.g., i n Nevada, 38,903 ac res burned i n 1972 and 190,025 ac res i n 1973 (Tuel ler and Lorain 1974). I know of only a very few ins tances where revegetat ion f o r mule deer was accomplished on w i l d f i r e s i t e s . Burning should be prescr ibed only on those s i t e s where i t has been shown o r can be shown t o provide b e n e f i t s t o mule deer. I t can be expensive. A cos t of $563 annual ly f o r each add i t iona l buck bagged was reported i n one Ca l i fo rn ia s tudy (Longhurst e t a l . 1976). Other benef i t s would have t o be included t o make such a p r a c t i c e economically f e a s i b l e .

The r e l a t i o n between forage composition and ava i l - a b i l i t y and changes i n the s t r u c t u r e of a mule deer population change is not we l l understood. In te r - ac t ions among h a b i t a t f a c t o r s , b i o t i c f a c t o r s , and populat ion changes a r e complex. As one reviews t h e Kaibab s t o r y (Rasmussen 1941; Swank 1958; Russo 1964; Hungerford 1965; Caughley 19701, along wi th t h e o ther s t u d i e s reviewed here , one i s l e f t with the f e e l i n g t h a t a d e f i n i t i v e s tudy showing how these re la t ionsh ips work has never been accomplished.

Deer populat ion changes reported i n the Kaibab re fe rences appear t o be c l o s e l y cor re la ted wi th preda t ion , range d e t e r i o r a t i o n , and range improvement. But, as Caughley (1970) seems t o be asking, is t h e r e a confounding r e l a t i o n s h i p between these c o r r e l a t i o n s and n a t u r a l changes i n populat ions of ungulates? Do n a t u r a l se l f - regu la t ing populat ion changes, i r r u p t i v e o r otherwise, mask t h e in f luence of improvement prac- t i c e s ? These quest ions must be asked and answered before t h e b e n e f i t s of range improvement p r a c t i c e s can be q u a n t i t a t i v e l y described.

It seems though, t h a t c o l l e c t i v e l y , deer range improvement p r a c t i c e s provide a combination of des i r - a b l e f a c t o r s and t h a t these f a c t o r s a r e b e n e f i c i a l t o mule deer. A r t i f i c i a l r evege ta t ion and good range o r grazing management can lead t o good deer range con- d i t i o n with the r e q u i s i t e spec ies d i v e r s i t y (Fig. 1 ) . Good deer range condit ion may be defined a s a presc r ibed l e v e l of p roduc t iv i ty and spec ies composition Providing optimum forage and cover requirements f o r mule deer. The many nega t ive f a c t o r s i n t e r a c t wi th the b e n e f i c i a l management a c t i v i t i e s i n a complex way (Fig. 1 ) .

Hubbard (1962) described success fu l seeding of b i t t e r b r u s h a s one t h a t w i l l provide between 500 and 2200 p l a n t s pe r ac re , depending on the s i t e . He a l s o reported t h a t i t takes between 207 and 587 mature b i t t e r b r u s h p l a n t s t o feed a 100-pound deer f o r one month. This i n d i c a t e s , based on b i t t e r b r u s h alone, t h a t t h e b e s t s tand would produce enough forage on each a c r e t o maintain a deer f o r 3.7 t o 10.6 months.

Providing g r e a t e r d i v e r s i t y would probably improve t h i s carrying capaci ty.

Other examples a r e ava i l ab le bu t i t is s t i l l d i f f i c u l t t o determine the inf luence of t h e improvement on the population. One o ther important f a c t o r i s t h e f a c t t h a t the l i t e r a t u r e provides l i t t l e c lear-cut d a t a on forage consumption. And, i f t o t a l consumption were known, p a l a t a b i l i t y and preference d i f fe rences c o n s t i t u t e add i t iona l confounding f a c t o r s .

Once deer ranges a r e improved o r before they a r e improved, how do we determine t h a t t h e p r a c t i c e w i l l do more than j u s t e n t i c e deer from surrounding range t o a smaller bu t more d e s i r a b l e area? Sometimes we have d i f f i c u l t y i n doing t h a t s i n c e i t may be, i n some cases, d i f f i c u l t t o a t t r a c t deer onto ranges t h a t they do not now use. How can a combination of improvement and management func t ions provide p o s i t i v e herd changes (Fig. 1) over l a r g e a reas of s u i t a b l e h a b i t a t ? We do t h i s by maintaining optimum numbers wi th good h a b i t a t , ameliorat ing t h e negat ive in f lu - ences, and inf luencing deer behavior t o ob ta in g rea te r animal d i spers ion and proper use.

Possibly t h e r e i s one s i n g l e f a c t o r operat ing i n t h e range of mule deer i n the western United S t a t e s t h a t supersedes, o r i n p a r t , r egu la tes a l l dee r range improvements and population changes. This f a c t o r is cl imate. There is a s i g n i f i c a n t c o r r e l a t i o n between range forage p roduc t iv i ty and seasonal r a i n f a l l . This can, on some s i t e s , be as much a s a 1200% d i f fe rence i n forage p roduc t iv i ty from one year t o t h e next (Tue l le r and Monroe 1975). I n add i t ion t o t h i s , adverse winter weather may reduce mule deer s u r v i v a l and thus reduce popu- l a t i o n s even wi th reasonable h a b i t a t condit ions. Longhurst e t a l . (1976) reported t h a t mean monthly temperature i n October, November, and December a r e pos t ive ly cor re la ted wi th buck harves t 1 t o 3 years l a t e r , and t h a t increased p r e c i p i t a t i o n i n December and January is cor re la ted wi th decreased buck take 1 t o 3 years l a t e r . Such v a r i a t i o n s may wel l supersede o r mask t h e in f luence of the deer range improvement p rac t i ce , although t h e inf luence of tremendous f l u c t u a t i o n s i n forage p roduc t iv i ty on populat ions has not been described.

On sane s i t e s in tense i n t e r s p e c i f i c competi- t i o n f o r forage may r e q u i r e t h a t numbers of mule deer b e con t ro l l ed by both sex hunts. I n such cases , con t ro l of deer numbers is an absolutely necessary p r e r e q u i s i t e f o r the p roduc t iv i ty and maintenance of forage on deer range improvement p r o j e c t s and without which the p ro jec t should not be attempted.

Mule deer numbers i n t h e Great Basin have gone through an upswing and downswing (Fig. 2; Barn- grover e t a 1 1975) s i n c e t h e t u r n of t h e century. Has t h i s been an i r r u p t i v e population phenomenon o r a r e t h e t r ends r e l a t e d t o overgrazing, second- a r y succession, a l t e r a t i o n s i n predat ion, o r a com- b ina t ion of f a c t o r s ? Surely more than one f a c t o r is involved. Since most of the heav ies t overgrazing of Nevada ranges occurred p r i o r t o o r during the period of h ighes t deer numbers, and s ince judicious grazing, ad jud ica t ion , and associated l ives tock cu t s have occurred s i n c e t h e peak of mule deer numbers, I suggest t h a t the dec l ine i n recen t years must be due t o f a c t o r s o ther than poor h a b i t a t . However, I am

6 1 Deer Range Improvement and Mule Deer Management

Mule Deer Population

FIGURE 1. A prel iminary diagrammetric represen ta t ion of deer range improvement processes a s they converge i n t o those vectors leading t o p o s i t i v e herd changes ( t o optimum numbers by age c l a s s cons i s ten t with ca r ry ing capaci ty) . Monitor- ing of t h e herd o r populat ion change i s of paramount importance. The arrow s i z e represen t s t h e au thor ' s estima- t i o n of t h e r e l a t i v e importance of various fac to rs . Dashed arrows represent nega t ive inpu ts i n r e l a t i o n t o herd h e a l t h , good deer range condit ion, and/or a tendency away from an optimum herd s i z e . A wavy l i n e represen t s a s i g n i f i c a n t inverse re la t ionsh ip . A s i n g l e s o l i d l i n e represen t s a known r e l a t i o n s h i p bu t f o r which no r e l a t i v e importance i s a t tached.

* A p o s i t i v e short-term benef i t but no t l a s t i n g , May even have a negat ive inf luence over time.

Deer R a g e Improvement and Mute Deer Management 62

YEAR

FIGURE 2. Deer harvest and tags sold i n Nevada 1946-1974. (Data courtesy of Nevada Department of Fish and Game.)

63 Deer Range Improvemnt and MuZe Deer Mmagemt

s u r e t h a t d e t e r i o r a t e d h a b i t a t can be i n d i c t e d i n some ins tances . The g r e a t e s t dec l ine i n dee r ha rves t , and presumably numbers, occurred i n t h e e a r l y 1960's. Most of the ranges had been overgrazed by, say , 1950. Has t h e r e been a 10-15 yea r l a g be fo re t h e m o r t a l i t y i f caused by overgrazing? A t t h e l e a s t , t h e heavy l i v e s t o c k grazing has c rea ted and maintained t h e d e s i r a b l e sub-climax vege ta t ion .

I n t h e Great Basin many a c t u a l and p o t e n t i a l dee r win te r ranges have been heav i ly overgrazed. However, t h e acreage involved i s considerable . Winter ranges a r e probably no t l i m i t i n g i f t h e e n t i r e Great Basin is considered a s a u n i t . On t h e o t h e r hand, i t i s probable t h a t summer ranges a r e l i m i t i n g i n t h e cen- t e r of t h e Great Basin because of. t h e i r l i m i t e d acreage coupled wi th overgrazing, which has reduced d e s i r - a b l e spec ies .

Have changes i n migrat ion r o u t e s due t o freeways, u rban iza t ion , and l i v e s t o c k improvement p r a c t i c e s ( inc lud ing fences) r e s t r i c t e d herd movement and sepa ra ted herds? I f so , has t h e i s o l a t i o n inc reased inbreeding i n r ecen t yea r s , and has such r e s u l t e d i n a poorer v igor of i n d i v i d u a l nimals, i nc reased m o r t a l i t y , and reduced nunbers?lf This may a l s o r e s u l t i n reducing t h e b e n e f i t of a range improvement p r o j e c t .

I am a f r a i d t h a t t h i s paper has asked more ques- t i o n s than i t has answered. Probably one of t h e g r e a t e s t needs i s t h e development and use of techniques f o r monitoring populat ion f l u c t u a t i o n s and coupling such d a t a t o t h e h a b i t a t , e i t h e r improved o r n a t u r a l . It is p o s s i b l e t o summarize mule dee r management techniques a s r e l a t e d t o range improvement i n t h e fol lowing manner:

I. There i s a d d i t i o n a l need t o provide a d d i t i o n a l forage on s p e c i f i c s i t e s throughout t h e range of mule deer i n t h e western United S t a t e s .

2 . Tree and brush removal t o change secondary success ion to a cond i t ion favorab le f o r mule dee r should be continued with g r e a t e r emphasis on s i t e s p e c i f i c i t y and a e s t h e t i c s . Con- t r o l l e d burning w i l l be an important t o o l .

3 . Revegetation p r o j e c t s designed f o r s p e c i f i c s i t e s genera l ly must provide s p e c i e s diver- s i t y . This w i l l r e q u i r e t h e seeding of g rasses , fo rbs , and shrubs p r e f e r r e d by dee r dur ing c e r t a i n pe r iods of t h e yea r . Grasses may provide more fo rage f o r dee r than has been commonly been thought. Mule dee r , whi le gener- a l l y considered t o be browsers, can have a s t r o n g dependency ( p a r t i c u l a r l y on win te r ranges) on g rasses . When Leopold (1950) w r i t e s of t h e l ack of dee r i n t h e mountains of C a l i f o r n i a and t h e Great Basin e a r l y i n t h e l a s t cen tu ry wi th l a r g e r numbers repor ted on t h e f r i n g e s of t h e Sacramento Valley ( h i s t o r i c a l l y , a bunchgrass range), t h i s thought i s enforced.

4. New water development, e s p e c i a l l y i n t h e droughty p a r t s of t h e mule dee r range w i l l a l low t h e u t i l i - z a t i o n of fo rage on both summer and win te r ranges t h a t is no t now a v a i l a b l e .

5. Range management g raz ing systems on pub l i c l ands must be designed t o exclude l i v e s t o c k from "key" s i t e s dur ing c e r t a i n high compet i t ion pe r iods . A r educ t ion i n l i v e s t o c k u t i l i z a t i o n of fo rbs and g rasses on c e r t a i n s i t e s w i l l b e n e f i t mule deer . They must a l s o be designed t o enhance s p e c i e s and p l a n t communities va luab le f o r mule deer . Bal- anced use of t h e dee r range vege ta t ion by both dee r and l i v e s t o c k should be sought and then enhanced a s a technique f o r c o n t r o l l i n g succes- s i o n and mainta ining good cond i t ion range.

6 . Range improvement techniques , along with l i v e - s tock management, should be concentra ted on s p e c i f i c p l a n t communities wi th s p e c i e s and o t h e r c h a r a c t e r i s t i c s t h a t w i l l respond. Less va luab le p l a n t communities can be improved, but on a much lower p r i o r i t y .

7. New and innova t ive techniques f o r range improvements t o b e n e f i t mule deer must be developed and evaluated. For example, has anyone been s u c c e s s f u l i n t h e i r a t t empts t o provide a r t i - f i c i a l cover wi th p l a n t communities wi th good fo rage bu t a l a c k of s u i t a b l e cover? Perhaps l a r g e r shrubs and t r e e s could be p lan ted along n a t u r a l d ra inage ways t o u t i l i z e t h e mois ture t h e r e a s w e l l a s enhancing t h e n a t u r a l appearance of such a t reatment .

Long term s t u d i e s t o eva lua te b e n e f i t s i n abso- l u t e terms should, on s e l e c t e d l o c a t i o n s , accompany t h e e f f o r t t o improve ranges. Th i s w i l l provide evidence of t h e b e n e f i t s t h a t w i l l come from dee r range improvement p r a c t i c e s t h a t a r e now l a r g e l y i n t u i t i v e . A. S t a r k e r Leopold (1950) s a i d i t over 26 yea r s ago: "We cannot cont inue s l a s h i n g and burning t h e f o r e s t s and overgrazing t h e ranges - processes which v i c a r i o u s l y have produced some of our bes t dee r ranges i n t h e p a s t . Creat ion of deer range i n t h e f u t u r e w i l l have t o be d e l i b e r a t e l y planned a s p a r t of wi ldland management, w i th due regard f o r o t h e r va lues and uses."

LITERATURE CITED

Anderson, A. E., W. A. Snyder, and G. W. Brown. 1965. Stomach content a n a l y s i s r e l a t e d t o con- d i t i o n i n mule dee r , Guadalupe Mountains, New Mexico. J . Wildl. Manage. 29 (2) : 352-366.

Anderson, B. L . , R. D. P iepe r , and V . W. Howard. 1974. Growth response and dee r u t i l i z a t i o n of f e r t i l i z e d browse. J. Wildl. Manage. 38(3): 525-530.

Barngrover, L. , W. Molini, and G. Tsukamoto. 1975. Game ha rves t s t a t i s t i c s : b i g game, upland game, migratory game b i r d s , and f u r b e a r e r s 1974-75. Nevada Dept. of F i s h and Game, Reno. Mimeo .

Biswel l , H. H., R. D. Taber, D . W. Hedrick, and A . M. Schu l t z . 1952. Management of chamise brushlands f o r game i n t h e n o r t h coas t region of C a l i f o r n i a . C a l i f . Fish & Game. 38(4) : 453-484.

2 / Persona l communication. A.L. Lesperance, Univ. of - Nevada, Reno.

Deer R m g e Improvement cold Mule Deer Management

Box, T. W. , G. M. Van Dyne, and N. E. West. 1966. Syllabus on range resources of North America. P a r t I V , Pinyon-juniper ranges. Utah S t a t e Univ., Logan. Mimeo. Rpt.

Caughley, G. 1970. Eruption of ungulate populations, with emphasis on Himalyan Thar i n New Zealand. Ecology. 51(1) : 53-72.

Cheatum, E. L., and C. W. Severinghaus. 1950. Vari- a t i o n s i n f e r t i l i t y of white- tai led deer r e l a t e d t o range condit ions. N. Amer. Wildl. Conf. Trans. 15: 170-190.

Clary, W. P. 1975. Range management and its ecologi- c a l b a s i s i n the ponderosa pine type of Arizona: The s t a t u s of our knowledge. USDA For. Serv. Res. Pap. RM-158. 35 p.

Cole, N . J . 1968. Mule deer u t i l i z a t i o n of rehab i l i - t a t e d Nevada rangelands. M.S. Thesis. Univ. of Nevada, Reno. 132 p.

Cowan, I. M. 1945. The eco log ica l r e la t ionsh ips of t h e food of t h e Columbian black-tai led deer , OdocoiZeus hornionus coZwnbianus (Richardson), i n the coast f o r e s t region of southern Vancouver Is land, B r i t i s h Columbia. Ecol. Monogr. 15(2): 110-139.

Darling, F. F. 1937. A herd of red deer. Oxford Univ. Press. London. 215 p. (pg. 147-153).

Dasmann, W. P., and J . A. Bla i sde l l . 1954. Deer and forage re la t ionsh ips on the Lassen-Washoe In te r - s t a t e winter deer range. Ca l i f . Fish & Game. 40: 215-234.

DePaoli, R. L., and P. T. Tue l le r . 1970. Winter deer range study: Ruby-Butte s tudy, Nevada. Nev. Agr. Exp. Sta . Mimeo. Rpt. 80 p.

Doman, E. R., and D. I. Rasmussen. 1944. Supple- . mental feeding of mule deer i n northern Nevada. J. Wildl. Manage. 8(4) : 317-388.

Einarsen, A. S. 1946. Crude p ro te in determinat ion of deer food a s an appl ied management technique. N. Amer. Wildl. Conf. Trans. 11:309-312.

Gibbens, R. P . , and H. G. F i s se r . 1970. Inf luence of grazing management systems on vegetat ion and wild- l i f e h a b i t a t . Wyo. Agr. Exp. Sta. S c i e n t i f i c Rpt. No. 241. 32 p.

Goodwin. G. A. 1975. Seasonal food h a b i t s of mule deer i n southeastern Wyoming. U.S. For. Serv. Res. Note RM-287. 4 p.

Gruell. G. E., and N. J. Papez. 1963. Movements of mule deer i n northeastern Nevada. J . Wildl. Manage. 27(3):414-422.

Hubbard, R. 1962. The place of browse seeding i n game range management. N. Amer. Wildl. & Nat. Res. Conf. Trans. Vol. 27. pp. 392-401.

Hungerford, C. R. 1965. Response of Kaibab mule deer t o reseeded f o r e s t and meadow. N. Amer. Wildl. and Nat. Res. Conf. Trans. p. 310.

Julander , 0.. W. L. Robinet te , and D . A. Jones. 1961. Relat ion of summer range condit ion t o mule deer product ivi ty . J . Wildl. Manage. 25(1):54-60.

Kruse, W. H. 1972. Ef fec t s of w i l d f i r e on e l k and deer use of a ponderosa pine f o r e s t . USDA. For. Serv. Res. Note. RM-226. 4 p.

Leach, H. R . 1956. Food h a b i t s of the Great Basin deer herds of Nevada. C a l i f . Fish & Game 42(4): 243-308.

Leopold, A. S. 1950. Deer i n r e l a t i o n t o p lan t succession. Trans. 15 th N. Amer. Wildl. Conf. pp. 571-580.

Leopold, A. , L. K. Sowls, and D. L. Spencer. 1947. A survey of over-populated deer ranges i n the United S t a t e s . J . Wildl. Manage. 11:162-177.

Longhurst, W. M., and G. E. Connolly. 1970. The e f f e c t s of brush burning on deer. Ca1.- Nev. Wildl. pp. 139-156.

., E. 0. Garton, H. F. Heady, and G. E. Connolly. 1976. The Ca l i fo rn ia deer dec l ine and p o s s i b i l i t i e s f o r r e s t o r a t i o n . Proc. Western Sect ion - The Wi ld l i fe Society, Fresno. January. ( in p ress ) . 64 p.

Lyon, L. J. 1966. Problems of h a b i t a t management f o r deer and e l k i n t h e northern f o r e s t s . U.S. For. Serv. Res. Pap. INT-24. 15 p.

Mackie, R. J . 1970. Range ecology and r e l a t i o n s of mule deer , e l k , and c a t t l e i n the Missouri River Breaks, Montana. Wildl. Monogr. No. 20. 77 p.

McColm, M. A. 1976. Mule deer population t rends i n nor theas te rn Nevada and inf luencing fac to rs . Unpublished paper (mimeo) presented t o t h e j o i n t meeting of the Nevada Sect ions of The Society f o r Range Management and The Wi ld l i fe Society. Elko. 1 5 p .

McCulloch, C. Y. 1973. Deer n u t r i t i o n i n Arizona chaparral and d e s e r t h a b i t a t s . Pa r t I: Season- a l d i e t s of mule and white- tai led deer. Spec. Rpt. No. 3. Arizona Fish & Game Dept. and Rocky Mtn. For. & Range Exp. S ta . pp. 1-37.

Mohler, L. L., J. H. Wampole, and E. F ich te r . 1951. Mule deer i n Nebraska National Forest . J. Wildl. Manage. 15:129-157.

P l u m e r , A. P., D. R. Chris tensen, and S. B. Monsen. 1966. Highl ights , r e s u l t s , and accomplishments of range r e s t o r a t i o n s tud ies . Utah Dept. of F i sh & Game. Publ. No. 67-4.

., and H. D. Stapley. 1959. Research i n game forage r e s t o r a t i o n i n Utah. Proc. Amer. Conf. West. Assoc. of Fish & Game Comm. 30:157-166.

Rasmussen, D . I. 1941. Bio t i c communities of Kaibab Plateau, Arizona. Ecol. Monogr. 3: 229-275.

65 Deer Rmae Inprovement and Mule Deer Maagement

Regelin, W. L. , and 0. C. Wallmo. 1975. Carbon black inc rease snowmelt and forage a v a i l a b i l i t y on deer winter range i n Colorado. USDA For. Serv. Res. Note. RM-296. 4 p.

Regelin, W. L., 0. C . Wallmo, J. Nagy, and D. R. Dietz. 1974. Ef fec t of logging on forage values f o r deer i n Colorado. Jour . of For. 72 (5):283-285.

Robinette, W. L., 0. Julander , J . S. Gashwiler, and J. G. Smith. 1952. Winter mor ta l i ty of mule deer i n Utah i n r e l a t i o n t o range condition. J. Wildl. Manage. 16:289-299.

Russo, J. P. 1964. The Kaibab North deer herd, its h i s t o r y , problems, and management. Arizona Game & Fish Dept. Wildl. Bull . 87. 105 p.

Segelquist , C . H. 1974. Evaluations of w i l d l i f e forage c lea r ings f o r white- tai led deer h a b i t a t management i n a 600-acre Arkansas Ozark enclosure. Ph.D. Disse r ta t ion . Oklahoma S t a t e Univ. 185 p.

Severinghaus, C. W. 1951. A s tudy of p robab i l i ty and mor ta l i ty of c o r r a l l e d deer . J . Wildl. Manage. 15(1) : 73-80.

Shaw, H . 1965. Inves t iga t ion of f a c t o f s inf luencing deer populations. p. 125-143. Wi ld l i fe Research i n Arizona. 1964. Arizona Game & Fish Dept., Phoenix. 251 p.

St inson, T. 1964. An evaluat ion of revegetat ion p i l o t p l o t s es tab l i shed on National Forest ranges i n south-central Nevada. Range Imp. Note. 9(4): 8-11.

Swank, W. G. 1958. The mule deer i n Arizona chapar- r a l . Arizona Game & Fish Dept. Bull . $3. 109 p.

Taber, R. D . 1953. Studies of black-tai led deer reproduction on th ree chaparral cover types. Ca l i f . Fish & Game. 39:177-186.

Tausch, R. J. 1973. P lan t succession and mule deer u t i l i z a t i o n on pinyon-juniper chainings i n Nevada. M.S. Thesis. Univ. of Nevada, Reno.

Teer, J . G . , J. W. Thomas, and E. A. Walker. 1965. Ecology and management of white- tai led deer i n t h e Llano Basin of Texas. The Wildl. Soc. Wildl. Monogr. 15. 62 p.

T e r r e l , T. L . , and J . J. S p i l l e t . 1975. Pinyon- juniper conversion: Its impact on mule deer and other w i l d l i f e . Proc., The Pinyon-juniper Ecosystems: A Symposium. Utah S t a t e Univ. May pp. 105-119.

. 1973. Mule deer use p a t t e r n s a s re- l a t e d t o pinyon-juniper conversion i n Utah. Ph.D. Disse r ta t ion . Utah S t a t e Univ. 187 p.

Tue l le r , P. T. 1976. Food h a b i t s and n u t r i t i o n of mule deer on Nevada ranges. Univ. of Nevada Agr. Exp. Sta . 200 p. (manuscript i n p ress ) .

. , and L. Monroe. 1975. Management guidel ines f o r se lec ted deer h a b i t a t s i n Nevada. Nevada Agr. Exp. S ta . Rpt. R-104. 185 p.

., and A. L. Lesperance. 1970. Competitive use of Nevada's range forage by l ives tock and b ig game. Ca1.- Nev. Wildl. p. 129-138.

Tue l le r , P. T., and G. Lorain. 1974. ERTS-1 and NASA h igh- f l igh t imagery f o r measuring a reas and following secondary succession on w i l d f i r e s i t e s . Proc., Third National Conf. on F i re . Lake Tahoe, Nevada.

Urness, P. J. 1966. Inf luence of range improvement p r a c t i c e s on composition, production, and u t i l i - zat ion of Artemisia deer winter range i n c e n t r a l Oregon. Ph.D. Disse r ta t ion . Oregon S t a t e Univ. Corva l l i s . 193 p.

. 1974. Deer use changes a f t e r : root-plowing i n Arizona chaparral . USDA For.

Serv. Res. Note. RM-225. 8 p.

Wallmo, 0. C . 1959. Big Bend eco log ica l survey. Tex. Game & Fish Dept. Completion Rpt. Fed. Aid Pro jec t W-57-R-7, Job 9. 33 p.

. 1962. Big Bend eco log ica l survey. Tex. Game & Fish Dept. Completion Rpt. Fed. Aid Pro jec t W-57-R-10. Job 9. 27 p.

., W . L. Regelin, and D. W . Reichert . 1972. Forage use by mule deer r e l a t i v e t o logging i n Colorado. J. Wildl. Manage. 36 (4) : 1025-1033.

Wood, J. E . , T. S. Bickle, W. Evans, J. C. Germany, and V. W. Howard, J r . 1970. The Fort Stanton mule deer herd (some eco log ica l and l i f e h i s t o r y c h a r a c t e r i s t i c s with s p e c i a l emphasis on the use of water) . New Mexico Agr. Exp. Sta . Bull. #567. 33 p.

Deer Range Irqrovernent mid Mule Deer Management 66

AN OVERVIEW OF B I G GAME MANAGEMENT

Daniel A. Poole President

Wildl i fe Management I n s t i t u t e 709 Wire Building

Washington, D. C. 20005

Abstract --

Mule deer a r e the most adaptable and widespread western ungu- l a t e . Present population depressions, whi1.e not uniform, a r e evident i n a l l kinds of western ecosystems. The s t a t e s ' propensi ty t o dup l ica te research needlessly may be using l imi ted funds. The unsupported presumption of causes of the mule deer dec l ine may hinder the design and conduct of research t o determine root causes. A follow-up workshop of se lec ted p a r t i c i p a n t s i s proposed t o develop new understanding about mule deer i n order t o improve t h e i r management throughout the West .

I commend Utah S t a t e Universi ty 's College of Natural Resources, the Natural Resources Alumni Asso- c i a t i o n , and the program committee f o r scheduling t h i s badly needed symposium on the major problem of mule deer decl ine. I t i s e s p e c i a l l y f i t t i n g t h a t t h i s symposium i s being held i n Utah, a s t a t e long known f o r the v a s t amount of rec rea t ion provided by mule deer to hunters and nonhunters a l i k e .

Mule deer a r e s o much a p a r t of the n a t u r a l scene here t h a t i t is proper tha t Utah should be one of the f i r s t t o formally address the problem of de- c l i n i n g deer numbers and t o begin t o coordinate e f - f o r t s to determine its reasons and the oppor tun i t i e s f o r i t s correct ion. I a l s o commend a l l those who helped organize t h i s worthwhile endeavor a s we l l a s the p a r t i c i p a n t s , speakers and nonspeakers a l i k e . A problem of t h i s geographical magnitude needs a l l the helping hands t h a t can be mustered i n t o se rv ice .

I am g r a t i f i e d by t h i s opportuni ty t o be with you. The Wi ld l i fe Management I n s t i t u t e is i n t e r e s t e d i n a l l w i l d l i f e and land management i n North America. We have espec ia l ly s t rong t i e s with t h e West and the v a s t acreage of publ ic lands t h a t provide manageable h a b i t a t f o r some of the f i n e s t w i l d l i f e i n the na t ion . The I n s t i t u t e was among the f i r s t , i f not the f i r s t , p r i v a t e organizat ion, t o take an i n t e r e s t i n and ex- press pub l ic cmcerns f o r what were then only local- ized decl ines of mule deer herds i n a few s t a t e s . I t was because of t h i s long-term i n t e r e s t t h a t I quickly accepted the i n v i t a t i o n to speak here tonight . I am g r a t e f u l f o r the opportuni ty t o share with you our concerns f o r the present and our hopes f o r the f u t u r e of the mule deer.

The Rocky Mountain mule deer is the most adapt- a b l e and widespread western ungulate. Mule deer a r e a p a r t of the western scene. They provide bread and b u t t e r r ec rea t ion f o r most of the more than th ree mi l l ion hunters i n the eleven western s t a t e s , a s well a s inca lcu lab le pleasure t o many more mi l l ions of

w i l d l i f e viewers. A major dec l ine i n numbers of any spec ies of t h i s importance a f f e c t s the casual viewer, the hunter , and d iverse economic elements, a s well . The e f f e c t s go beyond deer because they invar iab ly r e s u l t i n dec l in ing income f o r t h e s t a t e w i l d l i f e department and curtai lment of management programs f o r o ther spec ies .

I w i l l make one disclaimer. Please bear with me i f the re is some r e p e t i t i o n of what you heard t h i s af ternoon o r what you be l i eve you may hear tomorrow. Preparing a dinner t a l k i s d i f f i c u l t without an opportuni ty t o read the t echn ica l papers of the symposium. Therefore, I am l imi t ing my remarks pr imari ly t o the problem i n its l a r g e r perspect ive a s seen by our s t a f f .

I don' t need t o t e l l you t h a t the management of mule deer i s , has been, and always w i l l be a complex undertaking. Although present decl ines a r e not uni- v e r s a l i n time o r p lace , they do cu t across the en- t i r e range of the spec ies i n the West. L i t e r a t u r e

reviews bear t h i s ou t , and some recent papers d e t a i l i t extensively.

These decl ines include a l l kinds of ecosystems, from deser t sagebrush t o high mountains. There is no simple answer t o any ecosystem problem. Deer, l i k e grass , shrubs, t r e e s , the other p l a n t s and the hundreds of ve r tebra tes , a r e p a r t of an i n t e r r e l a t e d system. There i s no one answer o r reason f o r changes i n the numbers of any spec ies . These spec ies a r e a product of t h e i r h a b i t a t and they must be r e l a t e d t o changes i n the t o t a l h a b i t a t wherever located and however caused. The f a c t t h a t these changes i n mule deer numbers have been and a r e occurring i n a wide range of d i f f e r e n t h a b i t a t s i s ind ica t ive t o us of t o t a l and general changes i n the .,lany western ecosystems.

As the major cosponsor of the recent Bicenten-- n i a l meeting of the North American Wi ld l i fe and

67 An Overview of B i g Gcrme Management

Natu ra l Resources Conference, t h e I n s t i t u t e p r epa red and pub l i shed an e d u c a t i o n a l b u l l e t i n e n t i t l e d American Landscape: 1776-1976, Two Cen tu r i e s of Change. I t shows many of t h e changes t h a t occu r r ed throughout t h e n a t i o n i n t h e l a s t 200 y e a r s . I c a l l your a t t e n t i o n t o v e g e t a t i v e changes f o r t h e b e t t e r t h a t a r e shown i n some of t h e before-and-af ter p ic- t u r e s . There have been major h a b i t a t changes i n h i s - t o r i c t imes -- y e s , du r ing t h e p r o f e s s i o n a l l i v e s of many of us i n t h i s room. These changes a f f e c t every l i v i n g t h ing on t h e l and . And changes con t inue t o occur .

The I n s t i t u t e ha s s e v e r a l major concerns about t h e management of mule dee r . We a r e no t t o o s o l i c i - t ous about t h e d e t a i l e d management t e chn iques used by t he s t a t e s . But we a r e concerned wi th t h e g e n e r a l e f f o r t and t h r u s t w i th which t h a t management i s accom- p l i s h e d and i n some of t h e p r o b l e m we s e e i n t h a t management d i r e c t i o n . We do n o t rank ou r concerns i n any p a r t i c u l a r o r d e r because a l l a r e i n t e r r e l a t e d . And a l l a r e p r i m a r i l y based on t h e knowledge a v a i l a - b l e and how t h a t knowledge is used i n management.

I f we accep t t h e assumpt ions t h a t funds f o r wild- l i f e management a r e f i n i t e , u s u a l l y i nadequa t e , and always hard t o come by, one of o u r concerns w i l l be p l aced i n p e r s p e c t i v e . That concern is pa roch ia l i sm i n management and r e s e a r c h on mule dee r . We have re- pea t ed ly w i tnes sed t h e dampening i n f l u e n c e t h a t s t a t e boundar ies have on t h e use t h a t i s made of r e s e a r c h d a t a by some a d m i n i s t r a t o r s . Simply because some- t h i n g is l ea rned beyond t h e bounda r i e s of a s t a t e should no t make i t s u s p e c t . Nor does i t mean t h a t such knowledge should be r e j e c t e d o u t of hand because of t he a t t i t u d e t h a t "what a f f e c t s ne ighbor ing s t a t e s does no t apply he re . " Such an a t t i t u d e was t e s fund- i n g and de l ays development of sound management programs. Some s t e p s have been t aken t o reduce t h i s pa roch i a l i sm , such a s t h e workshop program of t h e Western Assoc i a t i on . But t h a t program h a s n o t done t h e job t h a t needs t o be done, and must be done, t o b r i n g s u c c e s s f u l d e e r management i n t o t he t h i r d cen- t u r y of t h i s n a t i o n ' s h i s t o r y .

Tunnel v i s i o n i s ano the r major concern . This shows up i n t h e way some s t a t e s a t t emp t t o determine t he causes of mule dee r d e c l i n e s . Let me i l l u s t r a t e . A major dee r a r e a has undergone a s e r i o u s p o p u l a t i o n d e c l i n e . A r e s e a r c h program is i n i t i a t e d t o f i n d o u t why. S t a t e people s a y , i n e f f e c t , " t he d e c l i n e may be due t o changed l i v e s t o c k u se , o r t o succes s ion - a l changes i n t h e v e g e t a t i o n , o r t o ove rhun t ing , o r t o p r e d a t o r s . But i t is probably due t o p r e d a t o r s , t h e r e f o r e we w i l l r e s e a r c h p r e d a t i o n and igno re t h e o t h e r s . " Locking i n on a predetermined cause t o t h e v i r t u a l e x c l u s i o n of o t h e r s is a d i s s e r v i c e bo th t o s c i e n t i f i c w i l d l i f e management and t o t h e f u t u r e o f a magn i f i cen t w i l d l i f e s p e c i e s .

Another of o u r concerns is the nonapp l i ca t i on of e x i s t i n g knowledge. The p u b l i c l and manager i s changing the p u b l i c l ands d a i l y . The cha in saws a r e buzzing, range d r i l l s a r e s eed ing , and t r a c t o r s a r e up roo t ing j u n i p e r and pinyon. The l and manager a sks f o r h e l p i n l i m i t i n g w i l d l i f e damage. The w i l d l i f e manager answers, "I do n o t have t h e d a t a ; I do n o t have t h e research." Yet t h e r e i s a wea l th of d a t a a v a i l a b l e , some of i t i n summary form, and some of i t i n p r o f e s s i o n a l judgments t h a t can be used t o e s t a b - l i s h l and management g u i d e l i n e s t h a t w i l l make a more

compat ib le ar rangement between commodity p roduc t ion and w i l d l i f e .

Dr. Robert H. G i l e s saw t h i s i n 1962, (G i l e s 1962) when h e wrote :

A g r e a t h ind rance t o t h e advancement of a coo rd ina t ed use program i s f a i l u r e t o imag ina t ive ly use e x i s t i n g knowledge of f o r e s t w i l d l i f e needs and t o develop t h e s e needs i n t o management d i r e c t i v e s . . . C e r t a i n l y , r e s e a r c h i s needed, b u t wh i l e w a i t i n g , we need t o work w i th what we have. Work t o be done is n o t f o r t h e r e s e a r c h s t a f f , b u t f o r t h e management team who s e e s t h e needs , r ecogn ize s l im i - t a t i o n s , and can make mod i f i ca t i ons t o f i t e x i s t i n g c o n d i t i o n s . The a p p l i e d e c o l o g i s t needs t o s t a r t app ly ing , n o t w a i t i n g f o r handouts from r e s e a r c h per- sonne l who have enough p r o b l e m of t h e i r own. Managers must t hen s h a r e i n fo rma t ion on t h e r e s u l t s of t h e i r e f f o r t s w i th t h e i r co l l eagues .

Another concern i s l a c k of knowledge. I am cer- t a i n you a l l know of s p e c i f i c p i e c e s of i n fo rma t ion you b e l i e v e a r e needed t o adequa t e ly manage mule d e e r . Very l a r g e p i e c e s of i n fo rma t ion a r e needed t o h e l p p r o t e c t and enhance w i l d l i f e h a b i t a t . With- o u t q u e s t i o n , t h e r e a r e gaps i n ou r knowledge of mule d e e r and t h e i r s p e c i f i c h a b i t a t requirements and of t h e an ima l ' s r e a c t i o n s t o changes i n t h e ecosystem. At b e s t , t h i s knowledge, when acqu i r ed , may enab le us t o i n c r e a s e d e e r numbers; a t wor s t , i t w i l l en- a b l e us t o make b e t t e r t r ade -o f f s when h a b i t a t i s manipula ted f o r commodity p roduc t ion .

Co inc iden t a l w i t h t h i s l a c k of knowledge is a sometimes overabundance of o t h e r knowledge. Too many s t a t e s have conducted n e a r l y i d e n t i c a l r e sea rch on n e a r l y i d e n t i c a l p r o b l e m f o r many y e a r s , when one o r two p r o j e c t s would have y i e l d e d t h e knowledge needed f o r a l l t o manage t h e animals . Such dup l i ca - t i o n i s a d i r e c t r e s u l t of pa roch i a l i sm . I t uses funds t h a t cou ld be b e t t e r s p e n t f o r f i l l i n g knowledge gaps. A ha rd look shou ld be t aken a t t h i s du- p l i c a t i o n by a l l concerned.

Analys is of w i l d l i f e problems r e q u i r e s some knowledge of how each p a r t i c i p a n t views t h e problems. How do w i l d l i f e managers i n t h e i n t e rmoun ta in a r e a , p a r t i c u l a r l y Utah, view t h e problem of d e e r d e c l i n e ? I cou ld go through t h e many c u b i c f e e t of agency r e - p o r t s , memoranda, r e s e a r c h f i n d i n g s , and h a r v e s t r e g u l a t i o n s . But i n t h i s symposium, t h e work has a l r e a d y been done f o r me by t h e program committee. The committee has i n d i c a t e d t h e impor tance of the many f a c t o r s a f f e c t i n g mule d e e r by t he amount of program time a l l o c a t e d t o each.

There a r e seven hou r s of s u b j e c t m a t t e r on mule dee r d e c l i n e , exc lud ing t h e i n t r o d u c t i o n , t h e symposium summary, and my time t o n i g h t . Broken down i n broad c a t e g o r i e s , I f i n d two hou r s a r e devoted t o v a r i o u s problems i n h a b i t a t . This is 29 pe rcen t of t h e t o t a l . I f i n d t h a t p r e d a t i o n and o t h e r mor- t a l i t i e s cover ano the r 21 p e r c e n t w i th 1-112 hours . P o p u l a t i o n s , i n c l u d i n g census and h a r v e s t r egu l a - t i o n s , a r e impor t an t , w i th 2 hou r s o r 29 p e r c e n t of t h e t ime devoted t o them. Disease f a c t o r s , n u t r i -

An Overview of Big Gmne Management

t ion , and h i s t o r y each have a 30-minute time segment, o r 7 percent each of the t o t a l program. A l l of the top ics s l a t e d f o r discussion a r e important. My only concern i s the f a c t t h a t predat ion and mor ta l i ty fac- t o r s a r e only a p a r t of the mule deer ' s environment, and o f ten a f f e c t the animals f o r but a shor t time a year . Yet they a r e given almost equal weight with t o t a l h a b i t a t .

While t h i s is not a s c i e n t i f i c paper, I have sought the reac t ions of a number of younger research people i n both range and w i l d l i f e management and have read some recent papers regarding w i l d l i f e and land management. I would l i k e t o share with you some of the f a c t o r s t h a t I f e e l a r e important i n p u t t i n g the mule deer i n perspect ive.

I think we a l l know t h a t mule deer a r e succes- s i o n a l , and a r e products of successional r a the r than climax vegetat ion. This c lose ly r e l a t e s them t o commodity land management of f o r e s t r y and range l ive - s tock , both of which tend t o c rea te successional vege- t a t i o n . Deer evolved with o ther animals, p a r t i c u l a r l y the mountain sheep. I s i t not poss ib le , then, t h a t deer requ i re o ther animals a c t i n g on the vegetat ion t o maintain the needed vegetat ive succession? For a number of years , progressive people i n range and w i l d l i f e management i n both the u n i v e r s i t i e s and the agencies have discussed t h i s . Some point out t h a t they foresee the day when l ives tock w i l l be an i n t e - g r a l management t o o l f o r vegetat ion manipulation on a reas where b ig game has a primary use. Some even foresee the day when l ives tock operators w i l l be paid, o r otherwise subsidized, t o graze deer winter ranges beyond the po in t t h a t a prudent l ives tock oper- a t o r would graze them. Not t o graze t o the detriment of the s o i l and water , but r a t h e r as a manipulative t o o l t o maintain o r reach c e r t a i n des i rab le succes- s i o n a l vege ta t ive l e v e l s f o r big game.

We note t h a t mule deer numbers and sheep numbers fol low a s i m i l a r curve: a s sheep dec l ine , mule deer a l s o decl ine. Mule deer a r e down, sheep a r e down. I s the re a vege ta t ive cause and e f f e c t ?

Predat ion research, much of i t e x c e l l e n t , is s t i l l research devoted t o but a small por t ion of the t o t a l ecosystem. I f predat ion is the f a c t o r t h a t some obviously be l i eve , then research should be expanded t o include the f u l l a r ray of predator-prey re la t ionsh ips and t h e i r t i e s with successional changes. Why, i n much of the West, do we not have the g r e a t i r r u p t i o n s of jack rabb i t s t h a t we had ten t o t h i r t y years ago? Could i t be because, l i k e deer , the jack needs c e r t a i n successional s t ages t o have a peak populat ion? What a r e the r e l a t i o n s between white- t a i l e d and b lack- ta i l ed jack r a b b i t s a s vegetat ion moves t o higher successional s t ages?

To the t r a ined eyes of range and w i l d l i f e manage rs , the re a r e changes underway. Western f o r e s t s and ranges show general and sometimes dramatic vege- t a t i v e changes toward climax vegetat ion. What a r e the implicat ions of t h i s to deer populat ions? I hear some occasional discussion, but the re i s l i t t l e gen- e r a l considerat ion of the f a c t t h a t t h e agencies now a r e doing a s i g n i f i c a n t l y b e t t e r job of range management over much of the West. This is bound t o a f f e c t the vegetat ion deer requ i re . Under such condit ions, a mule deer herd, reduced by the catastrophe of s e v e r a l bad win te r s , may not have the same h a b i t a t

t h a t provided its needs when its population was a t a peak. Thus, i t may no t be ab le t o rebound with an- o ther i r r u p t i o n .

New, complex, and important r e la t ionsh ips of ungulates and cover a r e being developed and published. Some of you may have at tended the elk-logging symposium l a s t winter a t the University of Idaho. I f you did n o t , I c e r t a i n l y recommend you study the t r ansac t ions of t h a t symposium when ava i l ab le ; par- t i c u l a r l y the papers r e l a t i n g t o escape and thermal cover. The Forest Service, i n cooperation with o ther agencies , i s doing good work on these sub jec t s i n the P a c i f i c Northwest. Region 6 i s preparing interagency guidel ines f o r w i l d l i f e cover i n the Douglas f i r region. The P a c i f i c Northwest Forest and Range Experiment S ta t ion soon w i l l publ ish, i n book form, interagency guidel ines f o r maintaining and enhancing w i l d l i f e h a b i t a t i n the Blue Mountains of Oregon and Washington. These "cook book" aP- proaches w i l l t e l l the land manager what he must do f o r each c l a s s of w i l d l i f e , and what the e f f e c t s w i l l be i f he neg lec t s w i l d l i f e . Such da ta , both s c i e n t i f i c and judgmental, can be read i ly transposed t o meet condit ions i n other p a r t s of the West, par- t i c u l a r l y f o r l a rge ungulate h a b i t a t .

I am espec ia l ly impressed with the new concepts tha t have been developed concerning energy and energy requirements and t h e i r r e l a t i o n s with cover and land management. These sub jec t s and r e l a t i o n s a r e of such importance t h a t , i f they a r e not f u l l y covered a t t h i s symposium, then the w i l d l i f e scien- t i s t s a t Utah S t a t e University should prepare ab- s t r a c t s and bibl iographies f o r the w i l d l i f e managers i n a l l agencies i n t h i s region. Some of t h i s mate r ia l must be t r ans fe r red from l ives tock use. Outstanding work has been done by Dr. Cook a t t h i s un ivers i ty . Other work, such a s t h a t on white- t a i l e d deer by Moen, can be transposed t o formulate new concepts f o r so lv ing quest ions i n mule deer h a b i t a t needs (Moen 1973).

A hypothe t i ca l example w i l l be of i n t e r e s t . I n work on Utah domestic l ives tock , Cook found t h a t g e s t a t i n g females required 830 k i lo -ca lo r ies per pound of forage i n d i g e s t i b l e energy. Yet some dese r t ranges fu rn i sh only 803 k i lo -ca lo r ies (Cook). The quest ion posed by a range manager was t h i s : could such a shortage of 26 k i lo -ca lo r ies be o f f s e t by b e t t e r p ro tec t ion and thermal cover on deer win- t e r ranges? Would such p ro tec t ion reduce the energy output and enable not only success fu l su rv iva l but success fu l p a r t u r i t i o n ?

These complex re la t ionsh ips should he placed i n a proper w i l d l i f e management conceptual framework and da ta accumulated t o reconci le the e n t i r e range management energy and cover i n t e r r e l a t i o n s . Such h a b i t a t changes as encroachment of timber on moun- t a i n meadows may reduce the s to red energy the animals take t o the winter range. Changes i n f a l l ranges from f a l l green g rasses t o f a l l dormant gras- s e s may reduce the energy intake j u s t enough t o be a s i g n i f i c a n t f a c t o r i n the mule deer dec l ines , when coupled with minor losses of thermal cover. I pose these a s quest ions tha t w i l l r equ i re in tens ive i n t e r d i s c i p l i n a r y research t o resolve.

There i s another a c t i v i t y underway of v i t a l i m portance t o a l l w i l d l i f e on public lands. I r e f e r

An Overview of Big Game Management

t o t he requirements of t he environmenta l a c t s and Fede ra l c o u r t d e c i s i o n s . Mule dee r a r e s o much a product o f p u b l i c l a d s t h a t t h e environmenta l s t a t e - ments now r e q u i r e d on Fo re s t Se rv i ce u n i t p l a n s and environmenta l s t a t emen t s j u s t s t a r t i n g on Bureau of Land Management g r a z i n g systems a r e t h e b e s t chance t h e w i l d l i f e manager and s t a t e w i l d l i f e agenc i e s eve r have had f o r s i g n i f i c a n t i npu t i n t o t h e f e d e r a l land planning p roces s and the e f f e c t of t hose p l a n s on w i l d l i f e . The I n s t i t u t e views them i n t h i s l i g h t , and we urge you t o comment, and comment s t r o n g l y , on every one of t h e s e documents. The p l a n s w i l l n o t l ock r e sou rce management i n t o cement f o r e v e r , bu t you know how ha rd i t is t o t u r n something around once t h e f o o t i n g has been poured. Get i n t o t he se now. I t ' s your oppor tun i ty t o do something p o s i t i v e i n develop- i n g b e t t e r l and management programs.

As a s m a l l , p r i v a t e conse rva t ion o r g a n i z a t i o n , t h e I n s t i t u t e s eeks t o h e l p improve w i l d l i f e condi- t i o n s i n many ways. Of ten , one of t he b e s t a c t i o n s we can t ake t o h e l p r e s o l v e a problem is t o s e r v e a s a s t a r t e r o r a c a t a l y s t f o r a beginning. That I now propose .

We b e l i e v e t h a t a follow-up workshop t o survey t h e s t a t e of t he a r t i n mule dee r management and t h e s t r e n g t h s and weaknesses of mule dee r h a b i t a t r e - s e a r c h i s an e s s e n t i a l n e x t s t e p . The I n s t i t u t e would be w i l l i n g t o o rgan i ze o r t o a s s i s t i n t he o r - g a n i z a t i o n of such a meeting. The workshop would be p a t t e r n e d a f t e r t h e s u c c e s s f u l Wild Sheep Workshop, sponsored i n 1974 by t h e Boone and Crocke t t Club, Na t iona l Audubon Soc i e ty and the I n s t i t u t e . I t would be s t r u c t u r e d t o assemble t he b e s t minds on t he sub- j e c t i n a s e t t i n g conducive t o d e l i b e r a t i o n and d i s - cus s ion f o r t he purpose o f producing a summary pub l i - c a t i o n on t he mule dee r . I t would be a working document, u s e f u l t o a d m i n i s t r a t o r s , managers and re- s e a r c h e r s a l i k e i n i d e n t i f y i n g t hose p a t h s t h a t should be fo l lowed t o o b t a i n needed new unders tanding about mule dee r and t o improve t h e i r management throughout t h e West. The I n s t i t u t e is committed t o t h i s g o a l inasmuch a s a new book on mule d e e r is b e i n g r ead i ed f o r p u b l i c a t i o n i n ou r w i l d l i f e monograph s e r i e s .

As we conceive i t , t h e meet ing would no t be s o l e l y f o r agency d i r e c t o r s and t h e c h i e f s of r e s e a r c h and management. I t would be i n v i t a t i o n a l , w i t h par- t i c i p a n t s drawn from u n i v e r s i t i e s and c o l l e g e s and s t a t e and f e d e r a l agenc i e s . Young peop le would be i nc luded , because we want t o o b t a i n t h e most c u r r e n t w i l d l i f e t h ink ing . We propose t o i n v i t e peop le from the mid-range r e sea rch h i e r a r c h y , a t beginning and middle management and a d m i n i s t r a t i v e l e v e l s , a s w e l l a s some f i e l d r e s e a r c h e r s . W i l d l i f e managers would n o t predominate. We would want and need s t r o n g par- t i c i p a t i o n from range and f o r e s t management r e s e a r c h i n t e r e s t s .

The p a r t i c i p a n t s w i l l be a s s igned f i v e major t a s k s . The f i r s t w i l l be t o d i v i d e t h e West i n t o comparable h a b i t a t u n i t s where t h e r e is no q u e s t i o n t h a t r e sea rch f i n d i n g s w i l l be a p p l i c a b l e w i t h i n t h e u n i t . Two -- they w i l l de termine what knowledge i s a v a i l a b l e f o r each of t he h a b i t a t u n i t s . Three -- they w i l l de termine what a d d i t i o n a l knowledge is needed t o p rope r ly manage mule dee r i n each h a b i t a t u n i t . Four -- they w i l l de termine what d u p l i c a t i o n s i n r e s e a r c h a r e now going on and p repa re recommenda- t i o n s f o r c o n s o l i d a t i o n o r e l i m i n a t i o n . Five -- they

w i l l p r epa re a shopping l i s t o f r e sea rch needs and make recommendations f o r m u l t i - s t a t e and mu l t i - agency p r o j e c t s . The g o a l would be t o a t t a i n r e - s e a r c h e f f i c i e n c y and knowledge needed f o r improved management.

The pub l i shed r e s u l t s of such a bra in-s torming s e s s i o n would be u s e f u l i n p u t t i n g mule dee r under an ecosystem management concept , hope fu l ly p o i n t i n g o u t and s t a r t i n g t o s o l v e some of t he d e c l i n e problems. At t he l e a s t , we w i l l be a b l e t o recognize t h e e f f e c t s of l and management a c t i v i t i e s and a r - range r a t i o n a l t r ade -o f f s more b e n e f i c i a l t o w i l d l i f e than we p r e s e n t l y a r e a b l e t o accompl ish .

I cannot overemphasize t h e a c u t e need f o r i m - proving ou r c a p a b i l i t y i n t h i s r ega rd . I n Washing- t o n , we d e a l r e g u l a r l y w i t h i s s u e s i nvo lv ing t h e management d i r e c t i o n of two l a r g e ho ld ings t h a t a r e t h e domain of t h e mule d e e r i n much of t h e West -- t he n a t i o n a l f o r e s t s admin i s t e r ed by t h e U. S . For- e s t Se rv i ce and t h e n a t i o n a l r e sou rce l ands adminis- t e r e d by t h e Bureau of Land Management. h ro sepa- r a t e l e g i s l a t i v e p roposa l s d e a l i n g w i th t he l ands admin i s t e r ed by t h e s e major agenc i e s a r e pending i n Congress a t t h i s moment. How mule d e e r o r any pub- l i c l ands w i l d l i f e w i l l f a r e under t he l e g i s l a t i o n f i n a l l y approved by Congress w i l l depend i n l a r g e degree on how w e l l o u r p r o f e s s i o n can demonst ra te t he d i r e c t l i n k between pe rmi t t ed management a c t i v i - t i e s and t h e needs of such w i l d l i f e . The more con- c i s e and p e r s u a s i v e i n fo rma t ion t h a t can be p u l l e d t o g e t h e r f o r any s p e c i e s of w i l d l i f e , t h e more e f f e c t i v e a r e c o n s e r v a t i o n i s t s ' r e p r e s e n t a t i o n s t o Congress. The same ho lds f o r s i t u a t i o n s t h a t a r e encountered w i t h i n s t a t e .

I thank you f o r t h e p r i v i l e g e of add re s s ing t h i s d i s t i n g u i s h e d group. L e t ' s n o t f o r g e t ou r most honored g u e s t -- t h e Rocky Mountain mule d e e r . Our purpose t h e s e two days i s t o h e l p him, and t o do t h a t we must develop t h e new concepts and new programs h e needs.

An Overview of Big Game Mmagement 70

MULE DEER NUTRITION AND PLANT UTILIZATION

Donald R. Dietz Fish and Wildlife Biologist

Office of Biological Service, Region 6 U.S. Fish and Wildlife Service Grand Junction. Colorado 81501

Julius G. Nagy Associate Professor

Department of Fishery and Wildlife Biology Colorado State University

Port Collins, Colorado 80521

Abstract

Deer nutrition and range plant utilization are probably both directly and indirectly associated with the possible mule deer decline. The direct effect of malnutrition is starvation: the indirect effects are many and varied, such as susceptability to disease and parasites, low fawn production and inability to withstand environmental stress. Deer ranges are dynamic; the vigor and productivity of important mule deer food species are partially contingent upon the stage of plant succession. Many important browse plant communities are (1) the result of past site disturbances, (2) near the end of their lifespan and (3) may not be replaced because present land management factors tend to prevent recurrence of important disturbance factors such as fire, intensive browsing and grazing, and severe timber harvesting. Deer nutrition is a function of plant nutritional production, deer feeding habits, and the relation of nutrient intake and digestibility to deer physiological requirements. Digestion in the rumen is a function of the microbial population which can be greatly inhib- ited by the levels of volatile oils contained by various plant species.

The seasonal deer diet varies from a growth promoting (high protein and phosphorous) diet in spring to a fattening (high carbohydrate, fat, and energy) .diet in fall to a maintenance (low protein and energy) diet in winter. Seasonal use of plant types varies from high grass use in spring, high forb use in summer and fall to high shrub use in winter. Variability among seasons, deer ranges and years is exceedingly high. The presence of volatile oils in evergreen and semi-evergreen shrubs such as sagebrush. juniper and pine can greatly affect species use by deer. Land management practices, vegetation type conversion and revegetation programs should consider the selection of low volatile oil bearing plants for protection, enhancement and reestablishment.

Deer nutrition discussions often review and re- in the life of the mule deer for meeting nutritive port on the chemical composition and digestibility requirements for various physiological states such of their staple food plants without relating these as growth, lactation, reproduction and winter Parameters to either the nutritional requirements or maintenance. A brief rationale illuminating the to the changing diet of deer. We propose to alter role nutrition may play in the possible mule deer that scheme by following the diet of a mule deer decline in the west is presented in the following herd through their yearly cycle of activities. Thus section. we will discuss plant species and groups important

71 M u l e Deer Nutrition and PZant UtiLiaatim

Deer Nutrition - An Overview

The fate of mule deer throughout the west is intrinsically entwined with the year-long nutritive regime of their food species. The suspected decline of mule deer populations may be due in part to both direct and indirect nutritional factors. The direct effect of malnutrition is starvation, however, the indirect effects work through such vectors as parasites, disease, weakness and susceptibility to predation, failure to conceive, reabsorption of fetuses, inability to nourish offspring and impaired or decreased ability to digest high roughage feeds such as hay and/or new spring plant growth.

Starvation may result from not only lack of food but also because of inadequate levels of protein and phosphorous and/or coupled with the ingestion of toxic materials such as essential or volatile oils contained in sagebrush, juniper and other evergreens or semi-evergreens.

If, as several biologists propose including Julander (1962), the decline of mule deer is a result of a gradual change in habitat, then malnutrition may be the result of too many deer being forced to eat too much material for too long a time, which is detrimental to their vital physiological processes. We are referring, principally, to undue dependence upon sagebrush, juniper, pine and other species which contain high levels of volatile oils.

While the rationale for the change in mule deer habitat is not within the provinces of this paper, it could be as simple as a gradual change in plant community structure due to plant succession. There are only a limited number of plants which meet the dietary requirements of deer in winter. Most are deciduous shrubs such as bitterbrush, mountainmahogany and chokecherry. Others mostly evergreens or semi-evergreens contain more than adequate amounts of important nutrients, but also contain volatile oils which can impair rumen function.

Deer ranges are dynamic. Important deciduous shrubs are rather short lived, 60-70 years according to Roughton, (19721, reproduce by seed such as bitterbrush and mountainmahogany or by root sproutiqg such as serviceberry and chokecherry, and cannot withstand heavy browsing indefinitely (Shepherd, 1971). Many shrub ranges probably resulted from a severe disturbance. In the case of bitterbrush and mountainmahogany this was possibly because heavy livestock grazing reduced the competition from grass and forb species and created a site with growing space for new seedlings. Several other conditions had to occur concurrently: these were low livestock, deer and rodent numbers; a good seed crop on the remnant shrubs; and several good precipitation years in succession. These conditions are not likely to occur again under present land management practices. As the old shrubs die it is not likely they will be replaced.

The root sprouting shrubs offer more promise. They undoubtly became abundant originally following fire, overgrazing, or logging. The natural succession is likely toward a grassland or toward a mature forest. Neither is a good habitat for mule deer. The match, axe or domestic herbivore are management tools for these situations, but they have to be

selectively used and coupled with correct land, human, and animal management practices.

While deer population fluctuations are undoubtedly partially dependent upon nutritional parameters, deer behavior mechanisms may play an even more important part. It has been proposed by Peterle (1975) that white-tailed deer populations may be self-regulatory in that population eruptions do not occur on areas where they are in balance with their food supply, such as on some islands, national parks, etc. Eruptions occur only after some disturbance creates a large surplus of food. Unfortunately the herd is usually still increasing long after the balance between deer and food has passed. A yo-yo effect is then often seen until a new temporal balance is achieved. Possibly mule deer have a similar sociobiology.

Deer are not super-ruminants but rather pre- cise in their dietary needs. Their relatively small rumen is not well adapted to coarse, low quality roughages (Short, 1966, 1969). Given free choice they will select the more nutritious twig tips and young leaves.

Deer nutrition is really rumen nutrition since digestion is carried on in that part of the ruminant stomach by bacteria and protozoa. To remain healthy and carry on all their physiological demands required for body maintenance, growth, and reproduction, deer must supply the rumen with adequate nutritive levels. Rumen microorganisms need nitrogen and certain other minerals and vitamins to breakdown and metabolize carbohydrates. Most of the energy available to deer results from the breakdown of carbohydrates mainly sugars, cellulose, and hemicellulose by rumen microorganisms. The most important end products of these fermentations are the volatile fatty acids (VFA) such as acetic, proprionic, butyric, valeric, and isovaleric (Annison and Lewis, 1959; Church, 1969). These VFA's are absorbed mainly through the rumen wall and supply approximately 50-70 percent of the energy requirements of the host animal (Annison and Lewis, 1959). These acids must be produced in both adequate amounts and in the proper proportion for digestive and other body processes to function properly.

Most of the concentrates such as proteins, minerals, fats, vitamins and soluble carbohydrates are contained within the plant cell. The cell wall is composed of cellulose, hemi-cellulose and other structural carbohydrates. During the spring and early summer the rumen microorganisms can easily breakdown the plant cell wall and most of this material is metabolized. After the autumnal period the cell wall becomes increasingly lignified. This lignin complex is not digestible and thus increasingly less of the cell wall and contents can be digested. Not only do plants contain less of the important nutrients during the plant dormant season but they are also less readily available for assimilation.

Spring - Early Summer Period The spring - early summer period is the time

of best feeding conditions for mule deer in much of their range. Not only are summer ranges more

Mule Deer Nutri t ion and P Z m t UtiZization

heavy producers of dry matter, they also provide a larger variety of plants having higher nutrient content, and plants which are more digestible. Even on non-migratory mule deer range shrubs, forbs and grasses are at their peak levels of the most important nutrients during the early growth phenological stage (Dietz, 1962).

Nutrition Requirements: Spring - Summer The nutritional requirements of mule deer

during the spring period vary according to age, sex, and physiological requirement. A dry doe would require lower protein, phosphorous, and energy levels than either pregnant or lactating animals. While 14-16 percent crude protein would be desirable for young animals and lactating females, barren does could get by on 12 percent or less. The need is for nitrogen rather than protein since these ruminants can synthesize all of the amino acids required by the host.

Possibly as important as protein is phosphorous, usually in short supply on western mule deer range. Again as with protein, young growing animals, pregnant and lactating does, and mature bucks all have heavy demands for phosphorous to satisfy physiological requirements. Optimum requirements for these classes of mule deer are probably in excess of that found on most spring ranges. Over 0.50 percent phosphorous would be desirable in the spring diet of mule deer, while any value less than 0.17 percent would probably result in some adverse effect on body function. Vitamins are usually in ample supply during the vigorous plant growth period of spring, especially carotene, the precursor of vitamin A.

A serious problem which may occur on spring mule deer ranges is the high water content of new growth especially of young grass and forb leaves but also in new growth twigs and leaves of shrubs and trees. The relative small rumen-reticulum of mule deer, especially immature animals, can hold only limited amounts of plant material. If 90 percent of this is water, as frequently happens in new grass growth, the deer simply cannot ingest enough material to meet total dry matter and especially carbohydrate and energy demands (Dietz, 1970). Thus, mule deer coming off a hard winter where a prolonged sagebrush-juniper diet has resulted in large body weight losses plus probably some changes in the rumen flora will tend to gorge on the lush spring growth of immature grasses. The sudden switch from hard browse to lush greens results in immediate stress through scours, rumen function impairment, and frequently secondary infection in the digestive tract. The combined impact may often be fatal.

Spring - Early Summer Diet Kufeld cg (1973) summarized the results of

99 food habit studies conducted on mule deer ranges in the western United States and Canada. They reported the spring diet of mule deer is highly varied with location and in some cases even years. The bluegrasses (k spp.) are highly preferred on many meadows used by mule deer as soon as new growth becomes available. Important grass species in the spring diet of mule deer are wheatgrasses especially crested (Agropyrum cristatum) and bluebunch

(A. spicatum) according to Kufeld 5 & (1973). These authors also reported heavy use on brome ( x s spp.), mutton bluegrass (Poa fandleriana), Sandberg bluegrass (P. secunda), and needle and thread (Stipa comata). Moderate use was made of many genera including Dactylis, Danthonia, Festuca, Koeleria, Oryzopsis and Phleum.

Forbs reported to be receiving heavy spring use by mule deer according to Kufeld (1973) are sulfur wildbuckwheat (Eriogonum umbellatum), cream peanine (Lath +us ochroleucus), Lomatium (Lomatiums spp .-tilla newberr i) , and mountain deathcamus (Zigade- are a great many species of forbs which are rated moderate as to spring food items.

One of the shrubs and trees reported to be subject to heavy spring use is big sagebrush (Artemisia tridentata). This would presumably be very early spring use. Heavy use has been reported on all the mountainmahoganies (Cercocarpus spp.) , Mexican clif frose (Cowania mexicana) , Utah juniper (Juniperus utahensis), and creeping juniper (J. horizontalis), western snowberry (Symphori- carpos occidentalis) , and small soapweed (Yucca glauca). A great many species of shrubs are ranked as moderate in use.

Nutritive Levels of Plants in Spring - Early Summer

The new growth in spring of leaves and stems of grasses, forbs, shrubs and trees often equal or exceed good grade alfalfa hay in such important nutrients as protein and phosphorous. Levels of 20 or more percent protein and 0.30 percent phosphorous are not uncommon (Urness, 1973). Forbs are an especially good source of these two mineral components. Annual grasses such as cheatgrass (Bromus tectorum) also rate very high in protein and phosphorous during early spring growth.

Carbohydrates and true fats are low in all plant types during this period, hence gross energy intake may be limited due to low volume capacity of deer rumens and high water content of ingesta.

Summer - Early Fall Period

As the summer progresses and plant growth reaches maturity as characterized by full leaf and complete stem elongation in shrubs and trees and the appearance of the hard dough stage in grasses or forbs, the mule deer diet switches from a growing ration to a fattening ration.

Nutritive Requirements: Summer - Early Fall

Protein and phosphorous requirements decline for adult deer during summer and early fall but remain high for growing fawns. While adult deer would probably do well on a level of 10-12 percent protein at this period, young growing animals would perform better on a level above this amount. Phosphorous levels of feeds for mule deer should probably exceed 0.18 percent at this period but many plants do not sustain this high of a level into the late summer - early fall period. Energy demands are usually easily met at this season.

73 Mule Deer Nutri t ion and Plant U t i l i z a t i o n

Summer - Early Fall Diet As plant species mature and animals prepare for

the winter season, diet preferences change; Mule deer begin their trek to transitional ranges during this period which also accelerates the change in dietary items.

Grasses comprise a small proportion of the summer diet - generally anywhere from 0 to 22 percent of the diet (Kufeld % & 1973). No grass or sedge species were rated as heavy use feeds during summer, however, several were rated moderate in use class. These were smooth brome (Bromus inermis), sedges (- spp.), orchardgrass (Dactylis glomerata), regal rush (Juncus regelii), and June- grass (Koeleria cristata).

Forbs become very important in the summer - early fall diet of mule deer especially on some game ranges. Kufeld and associates in their report gave ranges of 3 to 77 percent of the diet in summer and from 2 to 78 percent in fall have been reported for forbs. Some heavy use forbs were dogbane (Apocynum spp.), Pacific aster (Aster chilensis), Wyoming indianpaintbrush (Castilleja linariaefolia), hairy goldaster (Chrysopsis villosa), Fremont geranium (Geranium fremontii), American licorice (Glycyrrhiza lepidota), cream peanine (Lathyrus ochroleucus), alfalfa medic (Medicago sativa), yellow sweetclover (Melilotus officinalis), dandelion (Taraxacum ceratophorum), clover (Trifo- lium spp.) and many others.

Several forbs were rated as heavy deer use species in the fall. These were longleaf sagewort (Artemisia longifolia), hairy goldaster, barbey larkspur (Delphinum barbeyi), Wright buckwheat (Eriogonum wri~htii), silvery lupine (Lupinus argenteus), alfalfa medic, yellow sweetclover, toadflax penstemon (Penstemon linarioides), and wildspikenard falsesolomonseal (Smilacina racemosa).

Heavily used shrub and tree species in summer are white fir, Siberian peashrub, curlleaf and true mountainmahogany, redosier dogwood, cotoneaster, Russian olive, Wright silktassel, honeysuckle, desert peachbush, desert and antelope bitterbrush, Gambel and wavyleaf oak, smooth and skunkbush sumac, willows, silver buffaloberry and blueberries. In the fall those most heavily used are: inland ceanothus, curlleaf mountainmahogany, Lewis mock- orenge, aspen, desert and antelope bitterbrush, Gambel and wavyleaf oak, skunkbush sumac, willows, and blueberries.

Nutritive Levels of Plants in Summer and Early Fall

Protein, phosphorous, and carotene levels decline as plants mature in summer, but remain fairly high until leaf color change and subsequently leaf- fall. The leaves of shrubs range from about 10-15 percent crude protein, while stems are much lower -- 4-9 percent. Phosphorous levels range from around 0.20-0.40 percent in leaves to 0.12-0.20 percent for stems. Gross energy averages about 4.8 kcal/g. in leaves to 4.7 kcal/g. in stems.

Grasses may decrease to 6-8 percent crude protein and 0.10-0.15 percent phosphorous but still contain 4.0-4.2 kcallg. gross energy. Forbs decrease

also in nutrient levels to around 8-10 percent protein, 0.15-0.30 percent phosphorous and 4.4-4.8 kcal/g. gross energy.

Carbohydrate content including cellulose and lignin increase along with the fats and oils found in ether extract or crude fat. True fat content is usually at its peak during late summer - early fall and gross energy intake reaches a seasonal maximum. Digestibility is retarded somewhat by increased lignification.

Late Fall - Winter Period Mule deer food values change considerably

from a fattening diet in early fall to a maintenance diet from late fall through early spring. With onset of leaf-fall, shrubs and trees provide at best only marginal levels of important nutrients. Grasses and forbs dry and wither or shatter providing even poorer nutrient levels. Evergreen and semi-evergreen species hold up better in nutritive composition but many contain tannins and essential oils which may inhibit digestibility. Not only are nutrient levels low at this season, but also lignification of the cell wall depresses digestibility by deer rumen microorganisms.

Nutritive Requirements: Late Fall - Winter Deer need access to a total dry matter intake

of 2.35 lbs. per hundredweight of body mass for maintenance according to Carhart (1954) and Nichol (1938). French gt!t (1955) recommended 3 to 4 lbs./100 lb. deer. Deer probably need at least 4,800 kcal of dry matter per hundredweight, however, French %& (1955) recommended 6,300 kcal per hundredweight of deer. Protein probably should not go much below 8 percent of the diet. Cook (1971) recommended about 4.5 percent digestible protein for herbivores for gestation. French et a1 (1955) reported deer need a minimum of 0.25 -- percent phosphorous for maintenance. However, based on nutritive requirements for cattle and sheep, mule deer should be able to survive on around 0.16 percent which is the level given by Cook (1971) as the gestation requirement for herbivores. Cook also suggested herbivores require about 1.6 to 1.7 mgllb. of carotene for gestation.

Late Fall - Winter Diet The onset of winter results in a decreased

dependence upon grass and forb species. Kufeld et a1 (1973) reported heavy use on only one species -- of grass during winter -- crested wheatgrass. These authors reported moderate use on some species of other wheatgrasses as well as on brome, fescue, timothy, and bluegrass. Heavy forb use was reported on only Newberry cinquefoil and Wyeth wildbuckwheat.

Heavy mule deer use was found in winter on Rockymountain maple (Acer glabrum), silver sagebrush (Artemesia cana), and big sagebrush, most species of mountainmahogany, Mexican cliffrose (Cowania mexicana) , green ephredra (Ephedra viridis), creeping juniper, myrtle pachistima (Pachistima myrsinites), both desert and antelope bitterbrush and yucca. Many others were rated moderate in use by Kufeld (1973).

Mule Deer Nutrition und PZmt Ut i l i za t ion 74

In the Black Hills, heavy winter use was the importance of these compounds as defense found on old man's beard (e spp.), chokecherry mechanisms of plants against overutilization, for (Prunus virginiana), ponderosa pine (Pinus onderosa), example, fir, spruce, pine, etc. Others, such as common juniper (Juniperus communis) , - the wide variety of sagebrush and juniper species, (Arctostaphylos uva-ursi), and low Oregongrape deserve our attention in mule deer management , (Berberis repens) (Schneeweis et &, 1972). because these plants are considered important,

especially during winter, as deer forage and cover. Nutrient Levels of Plants in Winter

Crude protein content of deciduous shrub annual growth decline from the 10 to 12 percent range to 5 to 9 percent range with leaf-fall. In a study in the Black Hills, only the winter twigs of chokecherry of shrubs tested contained over 9 percent protein (Dietz, 1971). Studies in Colorado showed only big sagebrush (a semi-evergreen) of the common important shrub species contained over 10 percent crude protein during the winter period (Dietz etg, 1962). Such important winter browse species as bitterbrush, true mountainmahogany, and rabbitbrush supply above adequate levels (7-9 percent) of crude protein. Shrubs which generally contain less than 7 percent crude protein (possibly the critical level) are Gambel oak, wavyleaf oak (Quercus undulata), snowberry (Symphoricarpus spp.), rose (Rosa spp.), aspen, and many others.

Grasses and forbs are normally deficient in crude protein in winter often dropping down to 3 or 4 percent. Evergreen and semi-evergreen shrubs such as juniper, sagebrush, or rabbitbrush retain higher levels of phosphorous during the winter season than do shrubs such as bitterbrush, mountainmahogany, serviceberry, and Gambel oak. All of the latter are deciduous shrubs and contain less than the recommended 0.16 percent phosphorous thought to be minimal.

Grasses and forbs are definitely deficient in phosphorous during winter. Only those that produce a green basal rosette that persists late into the fall and early winter supply more than token amounts of phosphorous. Species such as tufted hairgrass (Deschampsia caespitose) may contain only about 0.05 percent phosphorous even in late summer or early fall.

Grasses are reported by Cook (1971) to be good sources of carbohydrates and energy for herbivores during winter, however, much of this is in the form of fiber and lignin. They are also usually inferior to shrubs in gross energy as determined by a bomb calorimeter. Some shrubs, however, may give erron- eously high caloric values because of high volatile oil content.

Relation of Volatile Oils to Mule Deer Management

A wide variety of evergreen plant species are found in the western part of the North American continent. Many of these plants contain a class of chemical substances commonly referred to as volatile oils. In chemistry the term "volatile oil" means a wide variety of compounds which can be extracted from plants and plant parts by steam distillation. These "oils", although not soluble in water, but soluble in ether, alcohol, and other organic sol- vents, are not true oils, but various terpene derivatives. Plant physiologists consider them as metabolic waste products, while ecologists recognize

In general, volatile oils possess antibacterial properties; and, therefore, knowledge of these properties is important in the nutrition of ruminant animals such as sheep, cattle, deer, and elk. It is a well-known fact that for proper digestion, ruminants must rely on their rumen microbial populations. Any substance, such as the volatile oils, which might interfere with proper function- ing of the rumen microorganism might ultimately reduce the energy supply for the ruminant host.

The antimicrobial activities of volatile oils have been demonstrated on rumen microorganisms &I

vitro (Nagy, &, 1964; Nagy, &, 1967; Oh, et al, 1968; Longhurst, % &, 1968; Nagy, % &, -- 1968). These works showed that the volatile oils of different plant species may exert different degrees of antimicrobial action. As an example. Figure 1 shows that volatile oils obtained from Artemisia tridentata are more inhibitory than those obtained from Artemisia nova. It should be mentioned also that Artemisia nova contains considerably less volatile oils (1.4 percent on dry matter basis) than Artemisia tridentata (2.5 percent). For this reason, on gram per gram basis A. nova is less inhibitory than A. tridentata. Indeed, observations generally agree that A. nova is preferred over A. tridentata by deer and domestic sheep. One should be aware of the fact, however, that the volatile oil content of the species will depend also on site characteristics and are subject to seasonal variations. Figure 2 shows that small concentrations of volatile oils have no or very little impact on rumen microorganisms. At higher concentrations, however, their inhibitory action accelerates. This activity has been demonstrated in vitro with a rumen fistulated goat. When increasing amounts of sagebrush volatile oils were administered daily through the rumen fistula, the goat, receiving a standard pelleted ration, went off feed when the concentration of volatile oils in the rumen reached a level of approximately 15 microlitres per 10 ml of rumen fluid. This concentration corresponds to the concentration of increased antimicrobial activity observed in in vitro studies (Figure 2).

Further investigations on volatile oils were conducted at Colorado State University (Nagy, 1973) using three species of juniper; J. deppeana (alligator juniper), J. osteosperma (Utah juniper), and J. scopulorum (Rocky Mountain juniper). The volatile oil content of these species varied somewhat according to site, but on the average,

scopulorum contained the highest concentration, J. followed by J. osteosperma and J. deppeana.

To examine deer preferences cafeteria type of feeding trials, using fresh branches of the three juniper species every two days, were conducted for two weeks on 6 mule deer. Four animals were placed in individual pens and two (ccntrol) were placed

75 Mule Deer Nutrition and P l a n t V t i l i za t ion

Figure 1. Antibacterial action of the essential oils of A. tridentata

and A. nova against E. c s .

10'9

10'

-4 C R P T I V E DEER lo=I - OFER

o INOCCULUM . R . TRIOENTRTR VS. E . C O L I .- MERN Of fl. T R I O . VS. E. COLI

R . NOVR VS. E . C O L I

Figure 2. Antibacterial action of the essential oils of A. tridentata against the rumen microorganisms of wild and captive deer.

-- MERN OF fl. NOVA VS. E. C O L I

1 o7

1 or

10%

10'

10'

10'

10 '

' 0 2 4 6 0 1 0 1 2 1't 1 6 1 8 2 0

Mule Deer Nutri t ion m d PZmt UtiZization

in a pen together. During the trial, the animals received 45 percent of their previous average daily food intake of a concentrate ration. Alligator juniper was much preferred over the other two species. The average total consumption per sample (two days) per deer was 896 grams for Alligator, 113 grams for Rocky Mountain, and 84 grams for Utah juniper. The average volatile oil content of Alli- gator juniper was 0.6 percent (dry weight basis), that of Rocky Mountain and Utah juniper was 3.5 percent and 0.9 percent respectively. It seemed, therefore, that deer selected against the high volatild oil containing foliage of Rocky Mountain juniper but did nor explain why Alligator juniper was preferred over Utah juniper.

For this reason, we wanted to examine the possibility that deer are able to differentiate between different volatile oil levels in a pelleted ration. Volatile oils of Rocky Mountain juniper were mixed in standard pelleted ration in different concentrations (0, 1, 3, and 5 percent volatile oil levels). Deer were fed this ration in three cafeteria type trials. Results showed a strong preference by deer for rations that contained the lowest concentration of volatile oils in each trial.

Gas chromograms revealed the presence of approximately 20 to 25 different volatile oils in each of the three investigated juniper species. The amount of each individual compound seems to be a characteristic of the juniper species. These volatile oils can be divided into three main groups: monoterpene hydrocarbons, oxygenated monoterpenes, and sesquiterpenes. Longhurst & (1968) suggested that palatability of new growth of Douglas fir may depend on the concentration of oxygenated monoterpenes in the foliage. Our earlier individual trials with rumen microorganisms suggested that oxygenated monoterpenes usually exercised the strongest antimicrobial action. To test the hypothesis that deer, besides total levels of volatile oils in the foliage, would also select according to these groups (or group constituents) pelleted rations containing 1 percent monoterpene hydrocarbons, oxygenated monoterpenes and sesquiterpenes were fed to deer. Results indicated that deer select away from high oxygenated monoterpene concentrations preferring foliagewhich contains more monoterpene hydrocargons or sesquiterpenes. We feel that this selective ability by deer was the reason why Utah juniper with relatively low volatile oil content was low on preference during the feeding trials with juniper branches. Utah juniper showed a much higher oxygenated monoterpene content than either Rocky Mountain or Alligator juniper.

The foregoing discussion illustrated that in general volatile oils exercise antimicrobial action on rumen microorganisms. These microorganisms, however, are able to withstand certain low concentrations of the oils without adverse effects. More- over, it seems that deer during their evolutionary time period learned to recognize these harmful effects and are able to select only for the lowest volatile oil containing forage, but also for the forage that contains fractions of oils with the least antimicrobial action.

Conclusions

There is an indication that in many deer ranges of the west, deciduous shrub species are decreasing in numbers with the simultaneous increasing of some volatile oil containing species such as sagebrush and juniper. Land management agencies are at the same time faced in many areas with large-scale alteration of traditional deer winter ranges, due to proposed energy development and other activities. The task to determine which species and subspecies of plants should be used during revegetation of depleted deer winter ranges will fall on the land use manager. His knowledge in practical and theoretical deer nutrition will be of prime importance during the accomplishment of these tasks.

The solution to reestablishing nutritious shrubs containing low levels of volatile oils may be the recreation of those environmental conditions which originally permitted their establishment and subsequent proliferation. Thus, the judicious use of site disturbance mechanisms coupled with favorable climatic conditions and animal and human management may be the best hope for saving our prime mule deer ranges.

Literature Cited

Annison, E. F. and D. Lewis. 1959. Metabolism in the rumen. Methuen and Co. Ltd., London: John Wiley and Sons, Inc., New York. 184 p.

Carhart, A. H. 1944. What deer eat. American Forests 50:383-385.

Church, D. C. 1969. Digestive physiology and nutrition of ruminants. Vol. 1. 316 p.

Cook, C. W. 1972. Comparative nutritive values of forbs, grasses and shrubs. p. 303-310. In wildland shrubs -- their biology and utilization. USDA Forest Service General Tech. Rep. INT-1, 494 p. Intermt. Forest and Range Exp. Stn., Ogden, Utah.

Dietz, D. R. 1970. Definitions and components of forage quality. p. 1-9, In Range and Wildlife habitat evaluation -- a research symp., USDA Forest Serv. Misc. Pub. 1147.

. 1972. Nutritive value of shrubs. p. 289-302. In wildland shrubs -- their biology and utilization. USDA Forest Service Gen. Tech. Rep. INT-1, 494 p. Intermt. Forest and Range Exp. Stn., Ogden, Utah.

, Robert H. Udall, and Lee E. Yeager. 1962. Chemical composition and digestibility by mule deer of selected forage species, Cache La Poudre Range, Colorado. Colorado Game and Fish Dept., Tech. Bull. 14:89 p.

French. C. E., L. C. McEwen, N. D. Magruder, and others. 1955. Nutritional requirements of white-tailed deer for growth and antler development. Pa. Agr. Exp. Stn. Bull. 600. 50 p.

77 h L e Deer Nutrition and Plant Util ization

Julander , 0. 1962. Range management i n re la - deer n u t r i t i o n i n Arizona chaparral and t i o n t o mule deer h a b i t a t and herd product ivi ty d e s e r t h a b i t a t s . Arizona Game and Fish Dep.,

i n Utah. J . Range flanage. 15:278-281. Res. Div., and USDA For. Serv. , ~ o c k y M t . For. and Range Exp. Stn. Spec. Rep. 3 , 39-52.

Kufeld, R . C . , 0. C . Wallmo, and C . Feddema. 1973. Foods of the Rocky Mountain mule deer. USDA Forest Service Res. Pap. RM-111, 31 p. Rocky Mountain Forest and Range Exp. S t n . , F t . Co l l ins , Colorado

Longhurst, W . M . , H. K. Oh, M. B. Jones, and R. E. Kepner. 1968. A b a s i s f o r p a l a t a b i l i t y of deer forage. Trans. N. Amer. Wildl. Conf. 33:181-189.

Nagy, J . G . , H. W. Ste inhof f , and G. M . Ward. 1964. E f f e c t s of e s s e n t i a l o i l s of sagebrush on deer rumen microbial funct ion. J. Wildl. Mgmt. 28:785-796.

and R . P. Tengerdy. 1967. Ant ibac te r ia l ac t ion of the v o l a t i l e o i l s of Artemisia t r i d e n t a t a and Artemisia nova on aerobic bac te r ia . Appl. ~ i c r o b i o r 1 5 : 819-821.

-- . 1968. Ant ibac te r ia l ac t ion of the v o l a t i l e o i l s of Artemisia t r i d e n t a t a (b ig sagebrush) on b a c t e r i a from the rumen of mule deer . Appl. microbial. 16:441-444.

Nichol, A. A. 1938. Experimental feeding of deer. Univ. Arizona. Agr. Exp. Stn. Tech. Bull . 75. 39 p.

Oh, H. K . , T. Sakai, M. B. Jones, and W . M. Longhurst. 1967. Ef fec t s of various essen- t i a l o i l s i so la ted from Douglas f i r needles upon sheep and deer rumen microbial a c t i v i t y . Appl. Microbiol. 5:777-784.

P e t e r l e , T. J . 1975. Deer sociobiology. Wildl. Soc. Bull. 3:82-83.

Roughton, R. D. 1972. Shrub age s t r u c t u r e s on a mule deer winter range i n Colorado. Ecol. 53:615-625.

Schneeweis, 3 . C . , K. E. Severson, and L. E. Petersen. 1972. Food h a b i t s of deer i n the Black H i l l s : P a r t I. Northern Black H i l l s . South Dakota S t a t e Univ. Agr. Exp. S tn . Bull . 606. 35 p.

Shepherd, H. R. 1971. E f f e c t s of c l ipp ing on key browse spec ies i n Southwestern Colorado. Colorado Div. Game, Fish and Parks Tech. Pub. 28. 104 p.

Short , H. L. 1966. E f f e c t s of c e l l u l o s e l e v e l s on the apparent d i g e s t i b i l i t y of feeds ea ten by mule deer . J . Wildl. Manage. 30:163-167.

. 1969. Physiology and n u t r i t i o n of deer i n southern upland f o r e s t s . p. 14-18. In: white- t a i l e d deer i n the southern f o r e s t h a G t a t . L. K. Hal ls (ed.) Symp. Proc. Nacogdoches, Texas, USDA Forest Serv., Southern Forest Exp. Stn. 130 p.

Urness, P. J . 19731 Chemical analyses and I n Vi t ro d i g e s t i b i l i t y of seasonal deer f o r a g e s . I n y

Mule Deer Nutrition and Plant Ut i l i za t ion

MULE DEER PRODUCTIVITY--PAST AND PRESENT

Phillip J. Zwank Ph.D. Candidate

Utah Cooperative Wildlife Research Unit Utah State University Logan, Utah 84322

Abstract

Productivity data demonstrate that the potential for rapid increase exists in mule deer populations. Fawns are capable of breeding; yearlings generally have single fawns; adult and old does usually produce twins, with recorded instances of triplets and quadruplets. Net productivity is significantly less than potential productivity. Ovulation rates are strongly affected by the quality of nutrition prior to the rut. It appears there are always sufficient bucks for breeding purposes. Approximately 10 percent losses occur between fertilization and parturition. The greatest loss in net productivity appears to occur during the post-natal period. During the first 45 days after birth, 50 percent of the fawn crop may die. Nutritional deficiencies, predation, diseases, parasitism, weather, and accidents may cause post-natal mortality. Nutritional deficiencies appear to be the primary factor responsible for post-natal mortality and winter fawn losses. In certain areas, predation, especially by coyotes, accounts for a large percentage of fawn losses. The incidence and effects of diseases on productivity are little known.

A population is a dynamic entity, the numbers of which fluctuate as a result of changes in productivity, mortality, immigration and emigration. While migration must be considered (Quick 1962), productivity is the primary factor responsible for population gains.

Murie (1951) noted that the rate of increase in a population is of vital interest to the game manager, but is the most difficult factor to determine. This is especially true for mule deer (Odocoileus hemionus), whose productivity varies with both age and geographical area and whose secretive nature hinders accurate determination of reproductive success. For these reasons, extreme care must be taken when comparing productivity of mule deer populations or when generalizing about mule deer productivity.

Both potential and net productivity should be recognized. Robinette (1956) stated that potential productivity is the theoretical rate at which a species can increase if no mortality occurs, and net productivity or net increase is the actual yearly rate of increase after mortality from all causes have been deducted. Only rarely does the net productivity of a herd in the wild ever closely approach the potential productivity (Robinette 1956).

Reproductive Potential

The maximum rate of increase in a population depends upon the genetically controlled reproductive potential (Andrewartha and Birch 1954), which for a mule deer population is determined by the number of does in the population capable of reproducing, and the fecundity of each.

Mule deer inherently possess a high reproductive potential. While mule deer usually breed first as yearlings (Robinette et al. 1955; Asdell 1964), they occasionally breed as fawns. After examining 274 reproductive tracts, Robinette et al. (1955) found evidence that 7 does (2.6 percent) had conceived as fawns. Brown (19601, however, found that 4 of 19 females (21 percent) in the Guadalupe Mountains of New Mexico became pregnant when less than 1 year of age. Papez (1976) determined that 3 of 12 does (25 percent) had ovu- lated first as fawns in the Ruby Butte Mountains in Nevada, and 1 had given birth. While these examples show that female fawns are capable of being bred, their reproductive capacity is believed to be insignificant in the breeding potential of most herds (Hickman 1971).

Yearlings generally bear single fawns, although twins may be produced (Yoakum 1966). Prime adult does (between 3 and 7 years of age) usually produce twins, occasionally triplets (Robinette et al. 1955), and instances of quadruplets have been recorded (Sears and Browman 1955; Trodd 1962).

The reproductive potential appears to drop only slightly for old (7+ year-old) does (Hickman 1971). I recaptured and laparotomized one doe this past winter which had been tagged as a fawn in 1964. She was pregnant with twin fetuses. A second doe, determined to be more than 12 years old by cementum annulation aging, also was carrying twins.

Table 1 illustrates the theoretical reproductive potential for mule deer. Note that the original doe may have 104 direct descendants within a 6-year

79 Mule Deer Productivity--Past and Present

pe r iod . I n a d d i t i o n , penned d e e r s t u d i e s i n d i c a t e t h a t h igh ly p roduc t ive does produce more female t han male fawns (Verme 1969; Rob ine t t e e t a l . 1973) . Thus, fawn crops from h igh ly p roduc t ive popu la t i ons may be weighted toward females .

Two c a p t i v e he rds of w h i t e - t a i l e d d e e r (Odocoileus v i r g i a n u s ) have approached t h e i r t h e o r e t i - c a l r ep roduc t ive p o t e n t i a l . The George Reserve herd i n Michigan (Table 2 ) , which was s t a r t e d w i th 4 a d u l t does and 2 bucks i n March 1938, i nc rea sed t o 160 dee r by December 1943. I n v e s t i g a t o r s a l s o found two dead d e e r on t h e Reserve du r ing t h i s 6-year pe r iod (Chase and Jenk ins 1962) . As fawns were n o t thought t o b r eed , t h e r ep roduc t ive p o t e n t i a l of t h i s herd was 188, which i s ve ry c l o s e t o t h e 162 dee r observed. On t h e Seneca Army Depot i n New York, a he rd of 30 w h i t e - t a i l e d dee r i n 1948 grew t o 1 ,121 i n 1953 (Hessel ton e t a l . 1965) .

The exp los ive c h a r a c t e r of mule dee r popu la t i ons i s demonst ra ted on t h e Kaibab P l a t e a u i n Arizona and i n Cache Na t iona l F o r e s t i n n o r t h e r n Utah. On t h e Kaibab P l a t e a u t h e d e e r popu la t i on was e s t ima ted t o be 4,000. i n 1906 (Russo 1964). By 1924, t h e popu- l a t i o n was e s t ima ted t o be between 30,000 and 100,000 (Caughley 1970) . Doman and Rasmussen (1944) e s t i - mated t h e Cache popu la t i on a t 250 i n 1917 and 6,000 i n 1939. While t h e s e examples of e x p o n e n t i a l r a t e s of i n c r e a s e were under unusual c o n d i t i o n s , g iven f a v o r a b l e h a b i t a t , dee r u s u a l l y produce a n e t annual popu la t i on i n c r e a s e of between 20 and 30 p e r c e n t (Longhurst e t a l . 1952; Rob ine t t e 1956; Chase and Jenk ins 1962; N e l l i s 1968; Hickman 1971) .

Net P r o d u c t i v i t y

The number of fawns r e c r u i t e d i n t o t h e b reed ing popu la t i on determines n e t p r o d u c t i v i t y (Salwasser 1975). Mule dee r p r o d u c t i v i t y g e n e r a l l y i s e s t ima ted by game managers from observed pre-hunt ing and pos t - hun t ing s ea son doe:fawn r a t i o s , which may be b i a s e d . I f t h e p rev ious y e a r ' s n e t p r o d u c t i v i t y was h igh , a l a r g e p ropo r t i on of l e s s p roduc t ive y e a r l i n g s a r e i nc luded i n t h e popu la t i on and t h e doe:fawn r a t i o . Th i s would tend t o dep re s s t h e appa ren t s i z e of t h e p r e s e n t y e a r ' s fawn crop ( N e l l i s 1968). Post -season r a t i o s may add an a d d i t i o n a l b i a s , i f d i f f e r e n t i a l m o r t a l i t y f avo red a c e r t a i n age -c l a s s , e i t h e r du r ing t h e h a r v e s t o r i n t h e "winter k i l l " (Hickman 1971) . While t h e v a l i d i t y of e i t h e r method may be ques t i oned , doe:fawn r a t i o s a r e used e x t e n s i v e l y t o moni tor popu la t i on t r e n d s .

P r o d u c t i v i t y t r e n d s show t h a t r e c r u i t m e n t is d e c l i n i n g throughout t h e West (Table 3 ) . S i g n i f i c a n t l o s s e s appear t o be occu r r ing e i t h e r du r ing pregnancy, t h e immediate pos t -na t a l p e r i o d , o r du r ing t h e f i r s t few months a f t e r b i r t h .

P r i o r t o d i s c u s s i n g t h e e x t e n t of t h e s e l o s s e s and t h e p o s s i b l e causes , perhaps we should review b r i e f l y t h e r ep roduc t ive c y c l e i n dee r . Ovar ian a n a l y s i s , f i r s t d i s cus sed by Cheatum (1949) f o r w h i t e - t a i l e d dee r , ha s r e c e n t l y been o u t l i n e d by Papez (1976) f o r mule dee r . During t h e f a l l , numerous f o l l i c l e s appear on t h e o v a r i e s , one t o f o u r w i l l mature and ovu la t e . The r i p e f o l l i c l e r u p t u r e s spontaneously , r e l e a s i n g t h e ovum i n t o t h e ov iduc t . At t h i s t ime, t h e rup tu red f o l l i c l e develops i n t o a hormone s e c r e t i n g gland--the corpus luteum. The ovum pas se s through t h e ov iduc t , where f e r t i l i z a t i o n may

occu r , and e n t e r s t h e u t e r u s . I f t h e ovum is f e r - t i l i z e d , t h e corpus le teum p e r s i s t s a s a corpus luteum of pregnancy; i f n o t , degene ra t i on beg ins i n 14 t o 15 days . U n f e r t i l i z e d ova a r e e x p e l l e d , wh i l e f e r t i l i z e d ova develop i n t o embryos, implant i n t h e u t e r u s , and begin f e t a l development. During g e s t a - t i o n , t h e corpus luteum of pregnancy p l a y s a v i t a l r o l e i n supp re s s ion of subsequent f o l l i c u l a r development and maintenance of pregnancy. A f t e r approximate ly a 200-day g e s t a t i o n p e r i o d , t he fawn is horn.

Ovula t ion Ra te s

Ovula t ion r a t e s may be e s t ima ted through micro- s c o p i c ova r i an a n a l y s e s . Accurate sampl ing is d i f f i c u l t , because n o n - f e r t i l i z e d co rpo ra degene ra t e r a p i d l y and acces so ry co rpo ra l u t e a and o t h e r l u t en - i z i n g s t r u c t u r e s , which may be found i n t he ovary , must be d i f f e r e n t i a t e d ( G i l l 1972).

Ovula t ion r a t e s appear t o be a f f e c t e d s t r o n g l y by t h e q u a l i t y of n u t r i t i o n j u s t p r i o r t o and d u r i n g t h e r u t ( ~ o n g h u r s t e t a l . 1952) . P a s t and p r e s e n t range comparison s t u d i e s i n C a l i f o r n i a (Taber and Dasmann 1958; Salwasser 1975) and Utah ( Ju l ande r 1961; Pederson 1970) have demonst ra ted t h a t does on good summer and f a l l r anges have h ighe r o v u l a t i o n r a t e s (Table 4 ) .

G i l l (1972) found t h a t o v u l a t i o n r a t e s were h i g h l y c o r r e l a t e d w i t h snow dep ths i n Colorado. During t h e w i n t e r , t h e n u t r i t i o n a l q u a l i t y of t h e f o r a g e i s lowest and snow l i m i t s range a c c e s s i b i l i t y ( G i l b e r t e t a l . 1970). Heavy snows i n October of 1970 and 1971 concen t r a t ed d e e r i n poor cond i t i on on t h e w i n t e r ranges e a r l y i n t h e season. The o v u l a t i o n r a t e du r ing a mi ld w i n t e r was s i g n i f i c a n t l y h i g h e r (P<.10) t han du r ing t h e s e v e r e w i n t e r s (Table 5 ) .

Yoakum (1966) noted t h a t some does may n o t breed when r ange c o n d i t i o n s a r e i nadequa t e , b u t seldom, I f e v e r , a r e t h e r e i n s u f f i c i e n t bucks f o r b r eed ing purposes . Even w i t h a s e x r a t i o of from 10 t o 12 does f o r each buck, s u c c e s s f u l b r eed ing occu r s (Yoakum 1966) . I n Utah, d e c l i n i n g r e c r u i t - ment does n o t appear t o be due t o i n s u f f i c i e n t bucks, s i n c e 1 found a l l 58 does , 1% y e a r s of age and o l d e r , t r apped du r ing t h i s p a s t w i n t e r were p regnan t .

I n t r a - u t e r i n e M o r t a l i t y

Reproduct ive l o s s e s t h a t occur between f e r t i l i - z a t i o n and p a r t u r i t i o n appear t o be minimal i n mule d e e r . Rob ine t t e e t a l . (1955) observed an ova l o s s of 7 .5 p e r c e n t (789 embryos o r f e t u s e s from 853 co rpo ra l u t e a ) du r ing t h e f i r s t month fo l l owing con- c e p t i o n and a 10.5 p e r c e n t l o s s a t midpoint of pregnancy. Recent s t u d i e s by bo th N e l l i s (1968) i n Montana and Papez (1975) i n Nevada found a s i m i l a r 10 p e r c e n t dec rea se between co rpo ra l u t e a and f e t a l r a t e s (25 f e t u s e s from 26 co rpo ra l u t e a i n Montana; 69 f e t u s e s from 71 co rpo ra l u t e a i n Nevada).

Salwasser (1975) found on ly 1 re so rb ing f e t u s and no o t h e r s i g n s of abnormal i ty i n a necropsy sample c o n s i s t i n g of 142 a l l age -c l a s s does . N e l l i s (1968) observed an i n t r a - u t e r i n e m o r t a l i t y r a t e of 2 p e r c e n t o r 4 a t r o p h i c f e t u s e s from 226 recovered f e t u s e s . Again, t h i s i s ve ry s i m i l a r t o t h e 1 .7 pe rcen t m o r t a l i t y (21 of 1 , 2 6 3 ) , based upon v i s i b l e remains of dead f e t u s e s , observed by Rob ine t t e e t a l . (1955).

Mule Deer Produc t iv i t y - -Pas t and Present 80

Early Post-Natal Mortality

The greatest loss in net productivity appears to occur during the post-natal period. Of 224 births recorded under penned conditions, 17 fawns (7.6 percent) died during the first 48 hours (Robinette et al. 1973). Trainer (1975), in Oregon, found only 6 of 189 fawns (3 percent) examined in the field immediately post-partum to be dead or emaciated and not likely to survive. While Trainer's (1975) data showed few fawns to die immediately post-partum, both Salwasser (1974) and Trainer (1975) observed losses approximating 50 percent of the fawn crop during the first 45 days after birth. Habitat deficiencies, predation, diseases, parasitism, weather, and accidents may cause post-natal fawn mortality.

Nutrition

The recurring theme through past and present literature is that nutrition is the prime factor affecting productivity (Leopold et al. 1951; Longhurst et al. 1952; Robinette et al. 1955; Robinette 1956; Julander 1961; Pederson 1970; Salwasser 1975). Does on inadequate winter diets show large weight losses, which impair development of the fetus, resulting in fawn mortality at birth or shortly thereafter (Verme 1969). Fawns born to does in poor condition are in poor condition, stillborn, small, weak, unable to nurse or the mother does not produce enough milk to rear multiple fawns (Yoakum 1966). While insufficient protein usually is considered as the first deficient nutrient, diets lacking in phosphorus also have been shown to reduce productivity (Swank 1956).

Cover - Fawning cover has been implicated as an important

factor in summer fawn survival. Salwasser (1975) found when comparing fawn survival on two areas, while one supported a higher density of coyotes than the other, it also yielded nearly twice the percentage of summer fawn survival. He related the better fawn survival to superior fawning cover.

Water

In drier areas', lack of available free water and low nutritional intake exist during periods of drought. Plants become dormant and protein levels drop below the optimum for deer growth (Swank 1958). Deer concentrate in the vicinity of permanent water and com- Pete for the low quality forage. Longhurst et al. (1952). Swank (1958), and Yoakum (1966) thought that a lack of free water and low nutritional intake may reduce recruitment. Urness et al. (1971), however, determined that reduced recruitment in Arizona was due to high fawn mortality, and nutritional deficiencies probably were not responsible.

Predation

Early authors reported that predation was in- fluential in mule deer population dynamics and that coyotes were responsible for many fawn losses (Murie 1935; Horn 1941; Cahalane 1947). Robinette and Olsen (1944), in Utah, reported 49 percent (22 of 45) of a fawn crop was taken by a coyote in a 500-acre enclosure. Richens (1961), however, recorded Utah mule deer predators (in descending order of importance) to

be: mountain lions (Felis concolor), coyotes (Canis latrans), and bobcats (Lynx rufus).

Trainer (1975) determined that coyotes accounted for 55 percent of the summer radio- monitored fawn losses. Salwasser (1975), on the other hand, felt that it was unlikely that coyotes were totally responsible for summer fawn losses. He further stated that the occurrence of fawn remains in coyote scats probably represented scav- enging to a large degree.

Diseases and Parasites

Little information is available concerning the quantative effects of parasites and diseases on young deer. The incidence of parasitism and diseases generally are linked closely to the nutritional level of the host. Cowan (1956) and Yoakum (1966) claimed that, given a satisfactory food supply, deer appear to resist the various diseases and parasites to which they are susceptible.

In penned studies, Robinette et al. (1973), observed cases of necrotic stomatitis or necrobacillosis caused by Sperophoures necrophores. I also observed necrotic stomatitis in Utah mule deer fawns reared in ,>ens.

Parasitic blood worms (Elaeophora schneideri) may be responsible for neonatal fawn losses in New Mexico (Snyder 1968). In Arizona, a bacteria (Pseudomonas aeruginose), which would be fatal to newborn fawns, was found in the udder of a doe (LeCount 1972). Oregon, Arizona, Utah, and New Mexico currently are investigating the incidence of diseases and parasites in mule deer and their influence on productivity.

Weather

Weather affects net productivity by its direct effect upon forage production (Teer et al. 1965). Also, inclement weather during the fawning period may cause considerable losses. In 1975, 12 dead fawns were found in the Uinta Mountains of northern Utah after a 10-inch snowfall during the fawning period (personal conversation dated 18 April, 1976, with D. Winn, Dept. of Wildlife Science, Utah State University, Logan, Utah 84322).

Accidents

A few fawns may die from accidents, such as falls and drownings (Robinette 1956). During the neonatal period, some fawns are killed on farms by mowing machines, because they attempt to hide rather than flee (Haugen and Specke 1958). Also, fawns have difficulty crossing fences and often become entangled in them and die (Franzen 1968).

Nutrition

Winter die-offs from malnutrition usually involve differential mortality between age-classes, because certain age groups are less able to compete. Fawns, because of their smaller size, cannot move well in deep snow, nor reach as high as adults to browse on shrubs for forage (Huddleston 1964). In 1936, Doman and Rasmussed (1944) observed that of 114 "winter-killed" deer in northern Utah. 80


percent were fawns. Robinette et al. (1957) determined that fawn losses are usually from two to three times that of older deer. Huddleston (1964), however, observed 58 percent (21 of 54) of the winter mortality in the Cache Valley of northern Utah was comprised of fawns.

Predation

Predation, primarily by coyotes, accounted for 79 percent (15 of 19 deaths) of radio-tracked winter fawn losses in Oregon (Trainer 1975). In Utah, 28 of 31 dead deer found during the winter of 1975 were determined to be coyote kills and, of the 28 all but 3 were fawns (Nielson 1975). In Montana, a doe:fawn ratio of 100:40 at the end of the 1975 hunting season dropped to 100:lO in February. This occurred during a relatively mild winter, therefore, coyote predation was thought to be a major cause of mortality (letter dated 10 March, 1976 from R. G.

Janson, Montana Dept. Fish and Game, Missoula,

Montana 59801).

Summary

Productivity data demonstrate that the potential for rapid increases in mule deer populations still exists. Net productivity estimates, derived from doe:fawn ratios, show that significant losses may be occurring during pregnancy, the immediate post-natal period, or during the first few months of the fawn's life. Nutrition appears to be the primary limiting factor responsible for reduced ovulation rates, post-natal mortality and winter fawn losses. In certain areas, predation, especially by coyotes, accounts for a large percentage of fawn losses. The incidence and effects of diseases on productivity are, as yet, little known, but on- going studies may help to determine how these limiting factors influence mule deer populations.

Table 1. Reproductive potential of mule deer over a 6-year period.

Adult Yearling Fawns Total Annual population population percent increase

Introduction 1(2) 0 2(1M, IF) 3 33

Year 1 1(2) 1(1) 3(1M, 2F) 5 60

Year 2 2(2) 2(1) 6(3M, 3F) 10

Year 3 4(2) 3(1) 11(5M, 6F) 18

Year 4 7(2) 6(1) 20(10M, 10F) 33 55

Year 5 13 ( 2 ) - - lO(1) 36(18M, 18F) - 5 9 - 56

Winter count 23 18 64 105

( ) Fawns produced

Table 2. Reproductive potential of George Reserve white-tailed deer.

Year Adult Yearling Fawns Total Annual population population percent increase

1939 4(2) 0 8(4M, 4F) 12 50

1943 32(2) - - 20(0) 64(32M, 32F) - 116 - 62

Winter count 52 32 104 188

( ) Fawns produced

Mule Deer Productivity--Past and Present 82

Table 3. Mule deer p roduc t iv i ty t rends a s reported by s t a t e represen ta t ives a t the F i f t h Western S t a t e s Mule Deer Workshop, 1974.

S t a t e Comments

Arizona "Production came up a year ago, but has probably dropped back down. .. The statewide low has been 25 fawns/100 does and the high has been 65 fawns1100 does."

Ca l i fo rn ia "Twenty years ago production was about 65 fawns1100 does, but now has decl ined t o 35 fawns/ 100 does."

Colorado "There a r e no fawn production f i g u r e s on a s tatewide bas i s , but on one a r e a the re were 31 fawns per 100 does i n 1974 compared t o 1965 when the re were 60-70 fawns per 100 does."

Idaho "Fawn production is up over the l a s t year by about 5 fawns per 100 does f o r a s t a t e average of 75 fawns per 100 does."

Montana "Production i n the western p a r t of the s t a t e i s r e l a t i v e l y low and s t i l l dec l in ing ... I n 1973 they had 40 fawns per 100 does; i n 1974 s o f a r the re has been 37 fawns per 100 does."

Nevada "Population t rends a r e down p r i o r t o t h i s year , but the re a r e no fawn production figures."

New Mexico "Population t rends a r e down s l i g h t l y . Fawn production varied from a low of 12 fawns Per 100 does t o a s tatewide t rend of 35-45 fawns per 100 does."

Oregon "Mule deer a r e s t i l l decl ining and have been doing so s i n c e 1968-1969 winter . A statewide average of 54 fawns per 100 does remained i n December 1974."

Texas "Fawn r a t i o s a r e 19 fawns per 100 does."

Utah* "The severe winter of 1972-1973 resu l t ed i n fawn l o s s e s and a decrease i n the following summer's fawn crop due t o the poor physical condit ion of does."

Washington "The pre-season c l a s s i f i c a t i o n shows 65 fawns per 100 does. This is down from about 80 fawns per 100 does of a year ago."

Wyoming "Reproduction looks good and is increasing."

"(Personal conversat ion dated 5 March, 1975, with Rodney John, Divis ion of Wi ld l i fe Resources, S a l t Lake Ci ty , Utah 84101).


Tab le 4. P a s t and p r e s e n t comparison of p r o d u c t i v i t y from does 1% y e a r s and o l d e r on good and poor r anges .

Area Copora P e r c e n t F e t u s ( e s )

Years l u t e a l d o e p r egnan t p e r doe Fawn:doe r a t i o Source

Shrubland, CA 1951-1953 1 ,60 (18 ) 94(18) 1 .45(18) 811100 pos t -season Taber and h a p a r r a l , CA 1949-1950 0 .82(11) 97(11) 0 .71(11) 721100 pos t -season Dasmann (1958)

D e v i l ' s Garden, CA 1975 1.87(67) 99(67) 1.73(67) 20-501100 pre-season Salwasser Crooked Creek, CA 1975 1 .62(48) 90(48) 1 .56(48) 45-751100 pre-season (1974)

S u b l e t t e , I D Antimony, UT

1954-1956 1 .95(41) 100(9)* 1.85(33) 1221100 pos t -season J u l a n d e r e t 1954-1956 1.31(114) 63(8)* 1 .19(27) 511100 pre-season a l . (1961)

LaSal Mounta ins , UT 1967-1969 ----- ----- 1.01(305) 931100 pre-season Pederson Henry Mountains, UT 1967-1969 ----- ----- .59(299) 591100 pre-season (1970)

( ) Sample s i z e * Year l i ngs o n l y

Tab l e 5. Comparison of p r o d u c t i v i t y from does 1% y e a r s and o l d e r f o r m i ld (1969) and s e v e r e (1970, 1971) w i n t e r s i n Colorado.

Corpora P e r c e n t F e t u s e s Years l u t e a l d o e p r egnan t p e r doe Fawn:doe r a t i o Source

Middle Fork 1969 2.02(41) 100 1 .93 931100 pre-season G i l l (1972)

1970 1 .76 (42 ) 88 1 .64 721100 pre-season

1971 1.73(52) 9 8 1 . 6 1 731100 pre-season

( ) Sample s i z e

MuZe Deer Produc t i v i t y - -Pas t a n d P r e s e n t

LITERATURE CITED

Andrewartha, H. G . , and L. C. Birch. 1954. The dis- t r i b u t i o n and abundance of animals. Univ. of Chicago Press. Chicago. 782 pp.

Asdel l , S. A. 1964. Pa t t e rns of mammalian reproduc- t ion . Cornell Univ. Press. I thaca. 670 pp.

Brown, G. 1960. Deer p roduc t iv i ty s t u d i e s . Nevada Dept. Fish and Game. P-R Pro j . Rep., W-75-R-7. 14 PP.

Cahalane, V. H. 1947. A deer-coyote episode. J . Mammal. 28(1):36-39.

Caughley, G. 1970. Eruption of ungulate populations, with emphasis on Himalayan tha r i n New Zealand. Ecology 51(1):53-72.

Chase, W. W. , and D. H. Jenkins. 1962. Product ivi ty of the George Reserve deer herd. Proc. White- t a i l e d Deer Dis. Symp. Univ. of Georgia. 1: 78-87.

Cheatum, E. L. 1949. The use of corpora l u t e a f o r determining ovu la t ion incidence and v a r i a t i o n s i n the f e t i l i t y of white- tai led deer. Cornel l Vet. 39 (3) : 282-291.

Cowan, I. M. 1956. L i f e and times of the coast black- t a i l e d deer . Pages 523-619. In W. P. Taylor ed. The deer of North ~merica. The Stackpole Co., Harrisburg and t h e Wildl. Manage. I n s t . , Washington, D.C. 668 pp.

Doman, E. V . , and D. I. Rasmussen. 1944. Supple- mental winter feeding of mule deer i n northern Utah. J. Wildl. Manage. 8(4):317-338.

Franzen, R. W . 1968. The abundance, migration and management of mule deer i n Dinosaur National Monument. M.S. Thesis. Utah S t a t e Univ. 128 pp.

Gi lbe r t , P. F., 0. C. Walmo, and R. B. G i l l . 1970. Ef fec t of snow depth on mule deer i n Middle Park, Colorado. J. Wildl. Manage. 34(1):15-23.

G i l l , R. B. 1972. Product ivi ty s t u d i e s of mule deer i n Middle Park, Colorado. Annu. Mule Deer Work- shop. 2:40-48.

Haugen, A. O., and D. W. Speake. 1958. Determining age of young fawn white- tai led deer . J . Wildl. Manage. 22(3):319-321.

Hesselton, W. T., C. W . Severinghaus, and J. E. Tanck. 1965. Population dynamics of deer a t the Seneca Army Depot. New York Fish and Game J . 12(1): 17-30.

Hickman, G. L. 1971. The Coa lv i l l e deer herd i n northeastern Utah: Its ecology and management. M.S. Thesis, Utah S t a t e Univ. 105 pp.

Horn, E. E. 1941. Some coyote-wildl i fe re la t ionsh ips . Trans. N. Am. Wildl. Conf. 6:283-286.

Huddleston, R. J . 1964. Malnutr i t ion and o ther l o s s e s on the Cache deer herd winter 1963-1964. Utah Coop. Wildl. Res. Unit. Sp. Rep. 10. 12 pp.

Julander , O. , W. L. Robinette, and D. A. Jones. 1961. Relat ion of summer range condit ion t o mule deer herd product ivi ty . J . Wildl. Manage. 25(1): 54-60.

LeCount, A. 1972. Arizona 's fawn mor ta l i ty study. Annu. Mule Deer Workshop. 2:8-11.

Leopold, A. S. , T. Riney, R. McCain, and L. Tevis, J r . 1951. The Jawbone deer herd. Ca l i fo rn ia Dept. Fish and Game Bull. 4. 139 pp.

Longhurst, W. M . , A. S. Leopold, and R. F. Dasmann. 1952. A survey of Ca l i fo rn ia deer herds, t h e i r ranges and management problems. Ca l i fo rn ia Dept. Fish and Game Bull . 6 . 52 pp.

Murie, J . 1951. The e l k of North America. Stack- pole Co., Harrisburg, Pennsylvania. 376 pp.

Murie, 0. J . 1935. Food h a b i t s of the coyote i n Jackson Hole, Wyoming. U.S. Dept. Agric. Circ . 362. 24 pp.

Ne l l i s , C. H. 1968. P roduc t iv i ty of mule deer on the National Bison Range, Montana. J. Wildl. Manage. 32(2):344-349.

Nielson, D. B. 1975. Coyotes and deer. Utah Sci . Agric. Exp. Sta . 36(3):87-90.

Papez, J. 1976. The Ruby Butte deer herd. Nevada Dept. Fish and Game. P-R Proj . Rep., W-48-K-6, Bull . 5. IN PRESS.

Pederson, J. C. 1970. Product ivi ty of mule deer on the LaSal and Henry Mountains of Utah. Utah Div. Wildl. Res. Publ. 70-2. 133 pp.

Quick, H. F. 1962. Population dynamics of white- t a i l e d deer . Proc. White-tailed Deer D i s . Symp. Univ. of Georgia. 1:65-77.

Richens, V. B. 1961. An ecological and management s tudy of the Daggett deer herd of northeastern Utah. M.S. Thesis . Utah S t a t e Univ. 193 pp.

Robinet te , W. L. 1956. Productivity--The annual crop of mule deer. Pages 415-429. W. P. Taylor ed. The deer of North America. The Stackpole Co., Harrisburg and t h e Wildl. Manage. I n s t . , Washington, D.C. 668 pp.

, C. H . Baer, R. E. Pi l lmore, and C. E. Kni t t l e . 1973. Ef fec t s of n u t r i t i o n a l change on cap t ive mule deer . J. Wildl. Manage. 37(3) :312-326.

, J. S. Gashwiler, D. A. Jones, and H. S. Crane. 1955. F e r t i l i t y of mule deer i n Utah. J . Wildl. Manage. 19(1):115-136.

, J. B. Low, and D. A. Jones. 1957. D i f f e r e n t i a l mor ta l i ty by sex and age among mule deer. J . Wildl. Manage. 21(1) :I-16.

85 Mule Dcer Productivity--Past and Present

, and 0. A. Olsen . 1944. S t u d i e s of t h e p r o d u c t i v i t y of mule d e e r i n c e n t r a l Utah. Trans . N. Am. Wildl . Conf. 9:156-161.

Russo, J . P . 1964. The Kaibab n o r t h dee r herd-- Its h i s t o r y , >roblems, and management. Ar izona Game and F i s h Dept. P-R P r o j . Rep., W-63-R. 195 pp.

Sa lwas se r , H. J. 1974. North Kings d e e r he rd fawn p roduc t i on and s u r v i v a l s t u d y . C a l i f o r n i a Dept. F i s h and Game. P-R P r o j . Rep., W-51-R. 78 pp.

. 1975. I n t e r s t a t e w i l d l i f e s t udy : Sp r ing 1975 co l l e c t i on - - In t e r im Repor t . Univ. of C a l i f o r n i a , Berkeley . 47 pp.

S e a r s , H. S . , and L . G. Browman. 1955. Quad rup l e t s i n t h e mule dee r . Anat. Rec. 122(3):335-340.

Snyder , W. A. 1968. Major f a c t o r s i n f l u e n c i n g mule d e e r popua t i ons and h a r v e s t t r e n d s i n New Mexico. Ann. Conf. Western S t a t e Game and F i s h Commis- s i o n e r s . 48:237-240.

Swank, W . G . 1956. P r o t e i n and phosphorus c o n t e n t of browse p l a n t s . Trans . N. Am. Wi ld l . Nat. Res. Conf. 21:148.

Swank, W . G. 1956. The mule d e e r i n Ar izona Chapa r r a l and a n a n a l y s i s of o t h e r impor t an t dee r h e r d s . Ar izona Game and F i s h Dept. Wi ld l . B u l l . 3 . 109 pp.

Taber , R. D . , and R. F. Dasmann. 1958. The b lack- t a i l e d d e e r of t h e Chapa r r a l . C a l i f o r n i a Dept. F i s h and Game Bu l l . 8. 163 pp.

Tee r , 3. G . , J . W. Thomas, and E. A. Walker. 1965. Ecology and management of w h i t e - t a i l e d d e e r i n t h e Llano Bas in of Texas. Wild l . Monogr. 15 . 62 PP.

T r a i n e r , C. 1975. D i r e c t c ause s of m o r t a l i t y i n mule d e e r fawns du r ing summer and w i n t e r p e r i o d s on S t e e n ' s Mountain, Oregon--A p r o g r e s s r e p o r t . Annu. Conf. Western S t a t e Game and F i s h Commis- s i o n e r s . 55:163-170.

Trodd, L. L . 1962. Quad rup l e t f e t u s e s i n a whi te- t a i l e d d e e r from Esponola , On ta r i o . J. Mammal. 43(3) :414.

Urness , P. J., W. Green, and R . K. Watkins. 1971. N u t r i e n t i n t a k e of d e e r i n Ar izona Chapa r r a l and d e s e r t h a b i t a t s . J. Wild l . Manage. 35 (3 ) : 459-475.

Verne, L. J. 1969. Reproduct ive p a t t e r n s of whi te- t a i l e d d e e r r e l a t e d t o n u t r i t i o n a l p l ane . J . Wi ld l . Manage. 33(4):881-887.

Yoakum, J. 1966. L i f e and dea th o f d e e r h e r d s . Univ. C a l i f o r n i a Agr ic . Ext . Serv . Deer Seminars. p. 11-19.

Mule Deer P roduc t i v i t y - -Pas t and P r e s e n t

REGULATIONS AND THE MULE DEER HARVEST- POLITICAL AND BIOLOGICAL MANAGEMENT

Richard N. Denney Big Game Supervisor

Colorado Div i s ion of W i l d l i f e Denver, Colorado

Abs t r ac t

The mule dee r popu la t ion i n Colorado, and i n t h e west g e n e r a l l y , began i n c r e a s i n g du r ing t h e 1920 's from a low a t t h e beginning of t h e cen tu ry t o an a c c e l e r a t e d high i n t h e l a t e f o r t i e s t o t h e e a r l y s i x t i e s , t hen began a r ap id d e c l i n e t o t h e p re sen t . Harvests followed t h i s same p a t t e r n . The a p p l i c a b l e season r e g u l a t i o n s r e s u l t i n g i n t hese h a r v e s t s stem from b i o l o g i c a l con- s i d e r a t i o n s (va r ious populat ion and forage parameters) and p o l i t i c a l i n f luences ( t r u e p o l i t i c s , a s w e l l a s s o c i - o l o g i c and economic f a c t o r s ) . The a p p l i c a t i o n of com- pu te r i zed systems a n a l y s i s i n t he form of herd s imu la t ion models i s advanced a s a means of measuring t h e impact of v a r i a b l e man-control led management p r a c t i c e s . Th i s can no t on ly i d e n t i f y a r e a s of concern, b u t a l s o po in t ou t t ypes , amounts and q u a l i t i e s of d a t a needed, wi thout impacting t h e a c t u a l r e sou rce wi th t r i a l and e r r o r methods.

INTRODUCTION

During t h e mid-1850's t h e p ionee r s a r r i v i n g i n t h e t e r r i t o r y of what is now Colorado found v a s t numbers of d e e r , e l k , b ighorn sheep and bea r i n t h e mountains west of Denver. Though most of t h e s e p ionee r s were i n i t i a l l y i n s ea rch of go ld , many com- mun i t i e s were e s t a b l i s h e d , and, because t r a d e and s t o r e goods were l imi t ed and d i f f i c u l t t o o b t a i n , w i ld game was t h e primary sou rce of meat f o r t h e s e people . As t h e communities became more permanent t h e i r meat needs were supp l i ed i n c r e a s i n g l y by pro- f e s s i o n a l e x p l o i t e r s of t h e abundant w i l d l i f e . Market hun te r s began t o make such in roads on va r ious b i g game popu la t ions t h a t t h e c i t i z e n s became alarmed. Hunter (1959) e s t ima ted t h a t 100,000 b i g game animals p e r yea r must have been k i l l e d t o sup- p l y Colorado 's popu la t ion a t t h a t t ime. I n 1867 t h e f i r s t game laws were enacted, which p roh ib i t ed t h e t a k i n g of w i l d l i f e du r ing t h e breeding season. S t i l l , no s p e c i f i c seasons o r l i c e n s e s were i n e f - f e c t , b u t game laws became i n c r e a s i n g l y r e s t r i c t i v e . By 1903 t h e f i r s t d e e r l i c e n s e was au tho r i zed a t $1.00, b u t e l k , an t e lope and bighorn sheep seasons were s t i l l c lo sed , and b i son had disappeared by t h e t u r n o f t h e cen tu ry . The e a r l y 1900 's r ep re sen ted t h e low po in t i n Colorado's b i g game popu la t ions , b u t through sound w i l d l i f e management t h e game he rds were b u i l t up t o t h e po in t t h a t by 1960 they were some o f t he most important i n t h e na t ion .

Th i s is s i m i l a r t o t h e h i s t o r y o f b i g game i n most of t h e western s t a t e s . During t h e 19501s, how- e v e r , t h e management of mule dee r i n t h e va r ious

wes t e rn s t a t e s was a f f e c t e d through many d i f f e r e n t types of r e g u l a t i o n s and a d m i n i s t r a t i v e phi losoph ie s . Regardless of t h e management approach, whether i t was u l t r a - c o n s e r v a t i v e o r super- e x p l o i t i v e , t h e mule d e e r t r e n d has followed e s - s e n t i a l l y t h e same p a t t e r n throughout t h e west: a g radua l bui ld-up of herds beginning i n t h e 19201s, w i th a peaking somewhere i n t h e l a t e f o r t i e s o r e a r l y f i f t i e s t o t h e e a r l y s i x t i e s , and then a g e n e r a l d e c l i n e du r ing t h e s i x t i e s , and con t inu ing t o t h e p re sen t .

There i s an i n c r e a s i n g number of advocates of t h e concept t h a t w i l d l i f e c o n s t i t u t e s an e a r l y warning system of ecosystem d e t e r i o r a t i o n . I n t h e f a c e of c u r r e n t knowledge t h i s can h a r d l y be r e - fu t ed . There a r e many people , p a r t i c u l a r l y t h e g e n e r a l pub l i c , who a r e quick t o l a y t h e mule d e e r d e c l i n e on overshoot ing allowed by l i b e r a l regu- l a t i o n s . The f a l l a c y of t h e a n t l e r e d on ly management concept i s i l l u s t r a t e d by t h e f a c t t h a t s t a t e s (Arizona, C a l i f o r n i a and Oregon) wi th p r imar i ly buck on ly hun t s have c r i t i c a l l y low buck t o doe r a t i o s , wh i l e s t a t e s ha rves t ing both sexes (Colorado, Idaho, Nevada and Utah) have exper ienced on ly h a l f t h e ha rves t d e c l i n e of t h e former (Salwasser 1975).

Inasmuch a s t h e mule d e e r d e c l i n e is gene ra l throughout t h e west , i t i s obvious t h a t t h e cause must be a composite of many f a c t o r s , some of which we probably have no t i d e n t i f i e d t o d a t e . I n view of t h e r e t u r n t o populat ion f l u c t u a t i o n s of t h e

87 Requlutations and the Mule Deer harvest

p a s t , i s i t p o s s i b l e t h a t c e r t a i n c y c l i c phenomena a r e being e x h i b i t e d i n a s p e c i e s t h a t we neve r p r e v i - ous ly considered t o be c y c l i c ? I doubt t h i s , bu t i n t h e l i g h t of t he h a b i t a t dec rea se and deg rada t ion exper ienced i n the west i n t he p a s t 20 y e a r s , we w i l l never aga in s e e t he i n c r e d i b l e h a r v e s t s o f a c e n t u r y ago , o r t he documented k i l l s of t he r ecen t p a s t .

Th i s paper w i l l a t t emp t t o e v a l u a t e t he va r ious r e g u l a t i o n s p e r t a i n i n g t o mule d e e r h a r v e s t i n Colo- r ado (probably a p p l i c a b l e t o t h e e n t i r e wes t ) , how they were e f f e c t e d by b i o l o g i c a l and p o l i t i c a l con- s i d e r a t i o n s and how such c o n s i d e r a t i o n s may a f f e c t r e g u l a t i o n s i n f u t u r e mule d e e r management.

COLORADO MULE DEER HARVEST

During t h e pe r iod 1940 through 1975, Colorado has y i e lded a mule d e e r h a r v e s t of 2 .7 m i l l i o n a n i - mals t o over 4.7 m i l l i o n h u n t e r s f o r a n average succes s r a t i o of 57 pe r c e n t . Th i s 36-year pe r iod cove r s an e r a of r e l a t i v e l y g radua l mule d e e r popu- l a t i o n i n c r e a s e u n t i l a peak was reached i n t h e l a t e f i f t i e s and e a r l y s i x t i e s , a t which time an ac - c e l e r a t e d d e c l i n e t o t h e p r e s e n t was exper ienced. The a n t l e r e d and t o t a l h a r v e s t s , hun te r p r e s s u r e and succes s r a t i o s a r e i n d i c a t e d i n F igu re 1.

F igu re 1. L icense s a l e s and d e e r h a r v e s t , 1940- p r e s e n t , Colorado.

During t h i s 36-year pe r iod a t o t a l of 1 ,533,121 bucks, r e p r e s e n t i n g an annua l average of 42,587, was ha rves t ed . Broken down i n t o t he t h r e e most r e c e n t f i v e - y e a r pe r iods , t h e annua l a n t l e r e d h a r v e s t ave r - aged 60,951 d u r i n g 1961-65, 43,853 du r ing 1966-70, and 44,788 du r ing 1971-75. During t h e 36-year pe r iod , 1971 was t h e on ly yea r i n which t he h a r v e s t was l i m i t e d t o bucks on ly .

Hunter succes s du r ing t h i s pe r iod has ranged from a low of 26 p e r c e n t i n 1975 t o a h igh of 88.6 pe rcen t i n 1957, bu t does not r e p r e s e n t a f u n c t i o n of t h e d e e r popu la t i on a lone . The h a r v e s t regu- l a t i o n s a f f e c t i n g t h e s e h a r v e s t s were two d e e r of e i t h e r s ex i n 1957, and a n t l e r e d only w i th some l imi t ed e i t h e r s ex permits i n 1975. What were t h e c o n s i d e r a t i o n s involved i n t h e s e types of d ive rgen t s ea sons?

Biological ly-Based Regu la t i ons

Colorado has a t tempted t o manage i t s b i g game popu la t i ons on t h e b a s i s of herd u n i t s . The on- the-

ground b i o l o g i c a l d a t a ob t a ined by D iv i s ion person- ne 1 included :

1. Popu la t i on t r e n d coun t s ob t a ined on w i n t e r c o n c e n t r a t i o n a r e a s by a e r i a l and ground obse rva t ions .

2 . Pre- and pos t - s ea son s e x and age r a t i o s ob t a ined by a e r i a l and ground obse rva t ions on s e l e c t e d s ea sona l ranges .

3 . Wounding l o s s assessment based on f i e l d o b s e r v a t i o n s .

4. Winter m o r t a l i t y based on f i e l d work i n w i n t e r c o n c e n t r a t i o n a r e a s .

5. Browse p roduc t ion and u t i l i z a t i o n d a t a de r ived from measured i n t e n s i v e t r a n s e c t s and e s t ima ted e x t e n s i v e t r a n s e c t s on w i n t e r ranges .

6. Deer-days use pe r a c r e de r ived from p e l l e t group coun t s i n a s s o c i a t i o n w i th game range a n a l y s i s t r a n s e c t s .

7. Research d a t a from s p e c i f i c p r o j e c t s on dee r range and popu la t i on dynamics.

Add i t i ona l b i o l o g i c a l d a t a which have been con- s i d e r e d i n fo rmu la t i ng s ea son r e g u l a t i o n s , but de r ived a f t e r - t h e - f a c t , a r e t h e buck, doe and fawn s t a t i s t i c s of t h e annual h a r v e s t s , and t h e per- c en t age of y e a r l i n g s a s determined from d e n t i t i o n de t e rmina t ions a t check s t a t i o n s , cementum a n n u l i from i n c i s o r s ob t a ined a t check s t a t i o n s o r mai led i n by hun te r s , and a n t l e r c o n f i g u r a t i o n i n s p e c t e d a t check s t a t i o n s o r ob t a ined from surveys .

A b r i e f comment on each of t he b i o l o g i c a l f a c t o r s and t h e i r e f f e c t i n s e t t i n g s ea son regu- l a t i o n s fo l l ows :

1. Popu la t i on Trend Counts. A e r i a l and ground coun t s of d e e r a r e made on e s t a b l i s h e d a r e a s o r r o u t e s , u s u a l l y on w i n t e r r anges , and under a s n e a r l y comparable c o n d i t i o n s of t ime of yea r , snow- cove r and sys t ema t i c s a s p o s s i b l e . I n c o n s i s t e n c i e s i n weather , a f f e c t i n g snow dep th and coverage, ambient temperatures and winds, d e t r a c t from t h e r e l i a b i l i t y of such coun t s by i n t roduc ing v a r i a b l e s i n f l i g h t o r count c o n d i t i o n s , v i s i b i l i t y and d e e r behav io r . Popu la t i on de t e rmina t ions a r e no t pos s i - b l e from such coun t s , and, a t b e s t , they can on ly s e r v e a s an index t o t h e g e n e r a l popu la t i on t r end over a r e l a t i v e l y long pe r iod of t ime.

Another t ype of t r e n d count ha s been employed on t he Piceance d e e r herd s i n c e 1947, and t h a t i s a count d u r i n g one o r two days i n A p r i l of comparable pheno log i ca l c o n d i t i o n each yea r of t h e d e e r c o n c e n t r a t i n g on t h e n a t i v e hay meadows of Piceance Creek and i t s t r i b u t a r i e s . A t r a c k count was made of a p o r t i o n of t h i s mig ra t i ng he rd , u s u a l l y du r ing t h e month of May, f o r a number of yea r s u n t i l about 1957 when road cond i t i ons on

Regu la t i ons a d t h e Mule Deer Harves t

Flag Creek forced i t s t e rmina t ion . However, du r ing i t s l i f e , t h e t r a c k counts were up t o two o r t h r e e t imes h ighe r than t h e meadow counts on comparable yea r s . A l l t h a t can be s a i d of such counts i s t h a t t hey may r ep resen t a minimum number p re sen t , bu t what p e r cen t of t h e t o t a l herd popu la t ion i n t h a t a r e a is unknown.

Trend counts on mule dee r have had l i t t l e d i r e c t i npu t i n t h e formulat ion of season regu- l a t i o n s .

2. Sex and Age Ra t io s . While we t a l k about pre- and post -season sex and age r a t i o s , t h e emphasis has been on post -season c l a s s i f i c a t i o n s , and t h e s e a r e p r imar i ly a e r i a l , a l though some ground counts a r e conducted i n s e l e c t e d a r e a s . These d a t a have a g r e a t e r p o t e n t i a l i n i n f luenc ing t h e e s t ab l i shmen t of r e g u l a t i o n s than has been r e a l i z e d i n p r a c t i c e . To t h e b e s t of our knowledge, our buck t o doe r a t i o s have never been low enough t o in f luence fawn produc t ion . The number of fawns y i e l d s an index t o hun t ing season s u r v i v a l , and, b a r r i n g unusual w in te r m o r t a l i t y , an i n d i c a t i o n of herd r ec ru i tmen t i n t h e y e a r l i n g age c l a s s t h e upcoming sp r ing .

S i m i l a r l y , we have long used t h e percentage of y e a r l i n g s i n t h e h a r v e s t a s an i n d i c a t o r of herd h e a l t h . The u t i l i z a t i o n of sex and age d a t a i n herd management r e g u l a t i o n s w i l l be d i scussed i n more d e t a i l i n ano the r s e c t i o n of t h i s paper.

3. Wounding Loss. Other t han s u p e r f i c i a l surveys , we have no documentation of t h e impact of wounding lo s s . We have used a rule-of-thumb f i g u r e of 5-and-10, t h a t i s , a wounding l o s s of f i v e p e r c e n t of t h e h a r v e s t i n buck on ly a r e a s , and t e n p e r c e n t of t h e h a r v e s t i n e i t h e r s ex a reas . I f e e l t h a t t h i s i s t oo conse rva t ive . Wounding l o s s r e - c e i v e s l i t t l e cons ide ra t ion i n e s t a b l i s h i n g regu- l a t i o n s , bu t may r ece ive a t t e n t i o n when more r e f i n e d management is implemented.

4. Winter Mor t a l i t y . Eva lua t ions o f w i n t e r m o r t a l i t y a r e .based on f i e l d checks a f t e r t h e c r i t i - c a l w in te r pe r iod , and usua l ly i n a r e a s of w in te r concen t r a t ions . The percentage of such l o s s i n a s p e c i f i c herd a r e a i s e s t ima ted on t h e b a s i s of dead d e e r coun t s , and r e l a t i v e t o p a s t d a t a . These l o s s e s a r e p r imar i ly considered t o be a func t ion of m a l n u t r i t i o n and a s s o c i a t e d overcrowding and over- u t i l i z a t i o n of l i m i t e d win te r ranges , though t h e amount and c h a r a c t e r o f snow, minimum sus t a ined temperatures , p r o t e c t i v e cover and wind a r e known f a c t o r s . Such d a t a impact on r e g u l a t i o n s pe r - t a i n i n g t o a n t l e r e d on ly o r e i t h e r s ex seasons , and formerly on bag l i m i t s when we he ld two and th ree - d e e r seasons .

5. Range Analysis . Product ion and u t i l i z a t i o n e s t i m a t e s on key browse s p e c i e s on important w in te r range a r e a s a t one time formed the primary b a s i s f o r Colorado mule d e e r management. Unfor tunate ly , t h i s i s no longer t r u e , and w i l l be d i scussed under p o l i t i c a l cons ide ra t ions . During most of t he f i f t i e s and s i x t i e s , however, range t r a n s e c t d a t a provided s i g n i f i c a n t i npu t i n r e g u l a t i o n determi- n a t i o n s , and could s t i l l do so.

Two d e e r seasons were i n i t i a t e d i n 1950 p r i m a r i l y on the b a s i s o f range cond i t i ons i n an

e f f o r t t o b r ing t h e herds i n t o what was f e l t t o be t h e ca r ry ing c a p a c i t y of t h e win te r range, and two, and even th ree -dee r , seasons were held i n l a r g e a r e a s of t h e s t a t e u n t i l 1969. These seasons were e s t a b l i s h e d i n t h e beginning because hun te r p re s su re was l imi t ed and we had t o u t i l i z e t h e sportsman r e source we had a v a i l a b l e . As hun te r r ecep t iveness and p re s su re inc reased , c e r t a i n p o l i t i c a l cons ide ra t ions were brought t o bea r , a s d i scussed l a t e r .

6. P e l l e t Group Counts. P e l l e t group counts were conducted i n con junc t ion wi th range t r a n s e c t s , and conver ted t o d e e r days pe r a c r e on t h e b a s i s of 13 p e l l e t groups pe r dee r pe r day a s determined by r e sea rch i n v e s t i g a t i o n s a t t h e L i t t l e H i l l s Exper i - ment S t a t i o n on Piceance Creek. Because of t h e many v a r i a b l e s and controversy we d i d no t conver t t hese d a t a t o popu la t ions , b u t r a t h e r used them a s a dee r w in te r range p re s su re index r e l a t i v e t o p a s t yea r s and o t h e r a r e a s , and c o r r e l a t e d wi th browse u t i l i z a t i o n . The o t h e r comments under Range Analy- s i s a l s o apply he re .

7 . Research. Deer i n v e s t i g a t i o n s i n important a r e a s have y i e lded d a t a which have in f luenced season r e g u l a t i o n s t o some e x t e n t i n t hose a r e a s s p e c i f i c a l l y . I t was an e a r l y Fede ra l Aid p r o j e c t t h a t s t imu la t ed t h e two-deer season concept i n t h e Uncompahgre P la t eau , which e v e n t u a l l y was app l i ed a lmost western-s lope wide. Ce r t a in types of seasons and mandatory check s t a t i o n s were p a r t of and r e - s u l t e d from t h e Middle Park d e e r s tudy. The r e s u l t s of c u r r e n t d e e r s t u d i e s and t a s k f o r c e s w i l l undoubtedly be app l i ed t o f u t u r e r egu la t ions .

P o l i t i c a l Considerat ions

P o l i t i c a l , i n t h e sense used he re , i s a r e a l Pandora 's box. It not on ly inc ludes p o l i t i c s i n t h e commonly accepted d e f i n i t i o n , b u t a l s o i n t h e con tex t of economics and sociology.

The c o n s t r a i n t s imposed by s t a t e s t a t u t e s o r p o l i t i c a l bodies can d i r e c t l y a f f e c t t h e l a t i t u d e t h a t a conse rva t ion agency can e x e r c i s e i n wi ld- l i f e management. Colorado i s f o r t u n a t e i n t h a t i t s s t a t u t e s a u t h o r i z e t h e W i l d l i f e Commission t o e s t a b l i s h p o l i c i e s and s e t r e g u l a t i o n s f o r w i l d l i f e management. Even wi th t h i s type of a u t h o r i t y , s t a t e w i l d l i f e agenc ie s can be sub jec t ed t o cons ide rab le p re s su re through impl ied t h r e a t s of a l t e r n a t i v e laws, o r even manipula t ions of budget r eques t s . For example, a wes t e rn s t a t e ' s commission e s t a b l i s h e d a r e g u l a t i o n in tended f o r a t h ree -yea r l ongev i ty , bu t a f t e r two yea r s i t was found t o be i n e f f e c t i v e , and, i n f a c t , d e t r i m e n t a l t o t h a t agency's o b j e c t i v e s and suppor t ive d a t a j u s t i f i e d t h e r e p e a l o r r e v i s i o n of t h e r e g u l a t i o n . However, word was r ece ived from t h e s t a t e l e g i s l a t u r e t h a t t hey would s e t t h e seasons i f t h e agency 's r egu la t ions were not con- s i s t e n t . I n t h e p o l i t i c a l world, i t seems t h a t cons i s t ency i s of h ighe r mer i t than being f l e x i b l e enough t o admit a mis take and c o r r e c t i t! I n an- o t h e r ca se a l e g i s l a t i v e committee handl ing a con- s e r v a t i o n agency 's budget r eques t s u b t l y suggested a r e g u l a t i o n p e r t a i n i n g t o t h e i d e n t i f i c a t i o n of sex on a b i g game c a r c a s s be l e s s r e s t r i c t i v e , and i t was changed.

A major p o l i t i c a l impact on s t a t e w i l d l i f e

,?eguZations and the Mule Deer Harvest

agenc i e s could be i n t he o f f i n g , pending the f i n d i n g s of c o u r t s and the r e s u l t s of appea l s i n New Mexico and Montana on non re s iden t l i c e n s e f e e s . I f non- r e s i d e n t s become e n t i t l e d t o hunt on t h e same l i c e n s e s t r u c t u r e t h a t r e s i d e n t s do , s ea son regu- l a t i o n s w i l l have t o be t a i l o r e d t o meet an i n - c r ea sed hun te r demand through r e s t r i c t i o n s on s ex '! and numbers of h a r v e s t and sho r t ened sea sons , t o l e s s e n t h e b i o l o g i c a l impacts on t h e b i g game.

Many p o l i t i c a l impacts on r e g u l a t i o n s a r e s o i n t e r t w i n e d t h a t they i nvo lve economics, soc io logy and biology. An example i s i n t r a - agency p o l i t i c s where f o r p u b l i c r e l a t i o n s and economic r ea sons i t was decided t o s e t t he g e n e r a l season r e g u l a t i o n s i n March t o f a c i l i t a t e g e t t i n g t he i n fo rma t ion on opening d a t e s and a r e a s o u t t o t h e pub l i c . This e a r l y s e t t i n g of seasons was t o meet p r i n t i n g dead- l i n e s and a l l ow t h e sportsmen t o a r r ange neces sa ry vaca t ion time f o r hunt ing. The impact of t h i s reached t o t he f i e l d l e v e l , because w i n t e r m o r t a l i t y coun t s and range t r a n s e c t s could n o t be completed b e f o r e May due t o con t inu ing w i n t e r range use and l ack of acces s , a l t hough t h e numbers of l i m i t e d e i t h e r s ex pe rmi t s would be s e t i n May. Th i s t ime schedu le has probably been one of t h e g r e a t e s t con- t r i b u t i n g f a c t o r s t o t h e d e c l i n e i n o b t a i n i n g t h e i n d i c a t e d b i o l o g i c a l d a t a . Fur thermore , i n r ega rd t o l e g a l p o l i t i c s , t h e a t t o r n e y g e n e r a l has decreed t h a t t h e agency must have i t s recommendations f o r season r e g u l a t i o n s a v a i l a b l e f o r p u b l i c i n s p e c t i o n 20 days p r i o r t o commission a c t i o n . Th i s means, i n r e a l i t y , t h a t t h e r e g u l a t i o n s must be w r i t t e n f o r b i g game season opening d a t e s and a r e a s i n February .

Pub l i c s a f e t y and w e l f a r e a r e a form of p o l i t i - c a l c o n s i d e r a t i o n i n s e t t i n g seasons . Fo r example, i n Colorado, t o spread t h e f i r s t day of season p r e s s u r e and reduce t he p o s s i b i l i t i e s of h u n t e r f a t a l i t i e s and a c c i d e n t s , t h e d e e r season and e l k season were s epa ra t ed i n 1971 from t h e i r p r ev ious ly concu r r en t t iming. Though a h igh percentage of e l k h u n t e r s were a l s o d e e r h u n t e r s , they t hen had t o hunt t h e s e r e s p e c t i v e s p e c i e s a t d i f f e r e n t t imes , t hus reducing t h e t o t a l number of h u n t e r s i n t h e f i e l d d u r i n g one season. True , t h e r e was some economic impact i n reduced t o t a l l i c e n s e s a l e s , because many h u n t e r s , p a r t i c u l a r l y non re s iden t s , who p rev ious ly hunted both s p e c i e s could no t a f f o r d two s e p a r a t e hun t ing t r i p s , and t h e r e f o r e on ly hunted one s p e c i e s .

When a r c h e r y d e e r hun t ing was s t a r t e d i n Colo- rado i n 1948, t h e bow h u n t e r s could hunt on a r e g u l a r d e e r l i c e n s e which was v a l i d a t e d f o r t h a t purpose , and i f unsucces s fu l i n bowhunting, they could use t h a t l i c e n s e i n t h e r e g u l a r d e e r season. I n 1961 a n a r che ry dee r l i c e n s e was e s t a b l i s h e d by t h e l e g i s - l a t u r e , and i f an a r c h e r was unsucces s fu l d u r i n g bowhunting s ea son , he could then purchase a r e g u l a r d e e r l i c e n s e and hunt w i th a r i f l e . Again, i n de- s i r i n g t o d i v e r t hun te r p r e s su re from t h e r e g u l a r s ea son , a one-and-only hunt concept was e s t a b l i s h e d i n 1974 through r e g u l a t i o n , wherein no one could purchase more than one l i c e n s e f o r a g iven s p e c i e s d u r i n g t he yea r . The e f f e c t t h a t t h i s had was t o weed the marginal bowhunters ou t of t h e a r c h e r y r anks and put them r i g h t back i n t o t h e more s u r e - f i r e r i f l e season.

The b io log i ca l l y -based r e g u l a t i o n s p rov id ing

f o r two-deer seasons i n t h e e a r l y f i f t i e s were q u i t e e f f e c t i v e , and l i c e n s e s a l e s i nc rea sed a s a r e s u l t . A new phi losophy, economical ly-or iented , a r o s e . Why g i v e t h a t second d e e r away, when wi th i nc rea sed h u n t e r p r e s s u r e we could s e l l a second l i c e n s e a t a reduced f e e and gene ra t e some more income? The m u l t i p l e l i c e n s e was bo rn i n 1957, and was u t i l i z e d u n t i l 1970.

The i n f l u e n c e of pub l i c a t t i t u d e s , a soc io - p o l i t i c a l c o n s i d e r a t i o n , i s exempl i f ied by t he a c t i o n s of landowners i n t r a d i t i o n a l l y bucks on ly a r e a s i n t h e l a t e f o r t i e s when e x t e n s i v e e i t h e r s e x season r e g u l a t i o n s were implemented. Many of t h e s e p u r i s t s pos ted t h e i r lands a g a i n s t doe hun te r s , and undoubtedly caused some r e s t r a i n t on t h e p a r t of t he Colorado Game and F i s h Department i n d e s i g n a t i n g a d d i t i o n a l e i t h e r s ex h u n t i n g a r e a s , u n t i l some of t h e s e same r anche r s began t o expe r i ence hays t ack damages from t h e burgeoning d e e r popu la t i ons .

The i n c r e a s e s i n Colorado l i c e n s e f e e s e f f e c t i v e i n 1976 w i l l r e s u l t i n socio-economic i n f l u e n c e s on season r e g u l a t i o n s . Res iden t d e e r l i c e n s e f e e s have gone from $10.00 t o $13.00, wh i l e non re s iden t f e e s have gone from $50.00 t o $90.00. We w i l l have t o expe r i ence a t l e a s t one season under t h i s new s t r u c t u r e t o e v a l u a t e t he e f f e c t of p robab le decreased hun te r p r e s s u r e on herd management ob- j e c t i v e s , then c o n s i d e r what r e g u l a t i o n op t ions w i l l b e s t a t t a i n t h e d e s i r e d h a r v e s t .

HERD SIMULATION MODEL

For a lmost 20 yea r s Co lo rado ' s d e e r management e f f o r t s were d i r e c t e d toward reducing overpopu- l a t i o n ~ t o t h e c a r r y i n g c a p a c i t y of t h e most c r i t i c a l f a c t o r - t h e w i n t e r range. I t was always s t a t e d and g e n e r a l l y accepted t h a t t h e d e e r could come back f a s t e r t han t he browse. The r e g u l a t i o n s i n s t i t u t e d t o a f f e c t t h i s r educ t ion began wi th e i t h e r s e x s ea sons , then two d e e r s ea sons , and f i n a l l y m u l t i p l e l i c e n s e seasons (varying from un l imi t ed a d d i t i o n a l l i c e n s e s t o one a d d i t i o n a l l i c e n s e , w i th one d e e r p e r l i c e n s e t o two d e e r a l lowed on t h e second l i c e n s e , and, i n some c a s e s , two d e e r on bo th t h e o r i g i n a l and t h e m u l t i p l e l i c e n s e ) . I n a d d i t i o n t o m u l t i p l e bag l i m i t s , t h e t imes and l eng ths of seasons were v a r i e d t o o b t a i n i nc rea sed h a r v e s t s . Pos t seasons were u t i l i z e d i n r e l a t i v e l y sma l l a r e a s when d e e r were on l a t e f a l l t r a n s i t i o n a l o r w i n t e r r anges . S ince 1963 management o b j e c t i v e s g e n e r a l l y have been e i t h e r t o s t a b i l i z e t h e d e e r he rds , o r t o i n c r e a s e them numerica l ly .

Cur r en t h a r v e s t d a t a a lone do no t a l l ow a n a c c u r a t e de t e rmina t ion of mule dee r popu la t i ons , p a r t i c u l a r l y on a s t a t e w i d e b a s i s , due t o more v a r i a b l e and r e s t r i c t i v e seasons a p p l i e d under p r e s e n t management p r a c t i c e s . The re fo re , game management u n i t s have been combined t o form d a t a a n a l y s i s u n i t s , which a r e considered t o be more r e a l i s t i c t o t a l herd year-round h a b i t a t . Herd d a t a can now be analyzed by a computer s i m u l a t i o n of herd s t r u c t u r e , a s w e l l a s t he e f f e c t of va r ious impacts , both r e a l and s imu la t ed , on t h a t he rd , o t h e r f a c t o r s remaining equa l . This type of sy s - tems a n a l y s i s i s guided by Dr. Jack Gross, U. S.

ReguLations cmd the MdZe Deer Hurvest 90

Fish and Wi ld l i fe Service, and conducted by Tom Pojar , Colorado Division of Wildl i fe . Systems ana- l y s i s has the p o t e n t i a l f o r ind ica t ing the impacts of regulat ions on a given herd, whether they be b io log ica l ly o r p o l i t i c a l l y generated. By plugging i n known da ta f o r the pas t severa l years , c e r t a i n causat ive fac to rs may be ind ica ted a s responsible f o r given herd reac t ions .

The Uncompahgre Plateau i n southwestern Colo- rado represen t s a deer herd on which our most com- p l e t e d a t a a r e ava i l ab le . This herd un i t i s composed of two game management u n i t s , 61 and 62, comprising deer d a t a ana lys i s un i t D-19. The systems model begins i n 1963 and i s projected through 1980. Actual ha rves t d a t a a r e displayed i n Figure 2 r e l a t i v e t o t o t a l and buck (ant lered) harvest , hunter pressure and success r a t i o s from 1950 t o 1975. Inasmuch a s the complete s imulat ion p r in tou t i s extensive, only c e r t a i n d e t a i l s of the ana lys i s w i l l be highl ighted here.

mor ta l i ty r a t e of 22 per cent was used from 1963 through 1971, 40 per cent f o r 1972, 50 per cent i n 1973, then 22 per cent from 1974 onward. Using the year l ing harvest a s an index t o fawn surv iva l from the previous winter , the yearl ing harves t s i n 1973 and 1974 support t h e indicated increased winter loss of fawns reported f o r 1972 and 1973. This ad- d i t i o n a l fawn mor ta l i ty resu l t ed i n a downward popu- l a t i o n t rend i n the s imulat ion, which i s a c t u a l l y what happened i n the f i e l d . The alignment of these d a t a with the s imulat ion i s probably one of the s t ronges t points of t h i s ana lys i s .

Table 1 l i s t s a comparison of simulated and reported values f o r pre- and post-season bucks and fawns per 100 females. The pre-season buck t o doe r a t i o s a r e simulated above the reported values, a s the regional b i o l o g i s t , Hal Burdick, f e e l s t h a t many bucks a r e missed during these counts.

The alignment of these d a t a lend support t o the closeness of t h e s imulat ion model t o the a c t u a l herd s t ruc tu re . and even though s v e c i f i c values a r e - . not always i n agreement numerically, the general t r ends follow t h e same curves.

The model ind ica tes a population of t h i s herd r i g h t now of approximately 35,000 deer , with a post-season population p ro jec t ion by 1980 of j u s t over 50,000 animals, IF the 1975 harvest of 2,500 i s maintained, and IF the system remains s t ab le .

CONCLUSIONS

. . As important and necessary a s b io log ica l ..: management of mule deer i s , the various f a c e t s of

p o l i t i c a l management may present s i g n i f i c a n t obsta- I

"W c l e s t o sound w i l d l i f e management, and the con- s t r a i n t s imposed by po l i t i ca l ly -or ien ted regu la t ions

I / I C m - / o J - a I I I v I I I 5 ,a, 8 , L.8 10 8 , 6, 6 5 6 , r,

a-sa r to, rr 7- , t o 108 I , 5 I , 1 may have on mule deer herds can now be indicated experimentally through systems ana lys i s with simu-

Figure 2. Uncompahgre P la teau (GMU 61 6 62) , 1950- l a t i o n models, thus spar ing t h e resource from t h e 1975, deer data. consequences of i l l a d v i s e d o r poorly timed impacts

wi th in human con t ro l . . .

Three s e t s of fawn mor ta l i ty r a t e s were used The app l ica t ion of systems ana lys i s t o simu- i n the model, based on f i e l d data . A fawn winter l a t i o n modeling of w i l d l i f e populations i s

Table 1. Comparison of simulated and reported values f o r pre- and post-season buck and fawn t o doe r a t i o s on the Uncompahgre Plateau, 1967-75.

Bucks per 100 Females Fawns per 100 Females Pre-season Post-season Post-season Pre-season

Year Simulated Reported Simulated Reported Simulated Reported Simulated Reported --

91 ReguZat im and the Mule Deer Harvest

r e l a t i v e l y new. S e v e r a l s t a t e s a r e beginning t o exp lo re t h e p o s s i b i l i t i e s of t h i s system, i nc lud ing t he I n t e r s t a t e Deer Herd Study of C a l i f o r n i a and Oregon (Salwasser 1975a, Salwasser and Rutherford

975) , and t he Nevada F i s h and Game Department (Glenn Chr i s t ensen , pe r s . c o r n . ) .

Computer a n a l y s i s i s n o t a panacea, and i s only a s r e l i a b l e a s t h e d a t a programmed. S imu la t i on modeling w i l l no t of i t s e l f s o l v e t h e enigma of t h e mule d e e r d e c l i n e i n t h e wes t , b u t i t can h e l p i d e n t i f y a r e a s of concern where a d d i t i o n a l o r more r e l i a b l e d a t a a r e needed.

LITERATURE CITED

Hunter, G i l b e r t N. 1959. A hundred y e a r s of Colo- rado hun t ing . Colo. Dept. of Game & F i s h , Denver. 1959 Colo. Big Game I n f o . , p. 2-3.

Salwasser , Hal. 1975. The i n t e r s t a t e w i l d l i f e s tudy- a f r e s h pe r spec t ive . Mzuri Drumbeat, 2(16) :6-7 , 18-22, 24.

. 1975a. I n t e r s t a t e w i l d l i f e s t udy : Sp r ing 1975 c o l l e c t i o n . Univ. C a l i f . , Berkeley . I n t e r i m Rept . , 47 p.

and Kenneth E. Rutherford . 1975. I n t e r - s t a t e w i l d l i f e s t udy . Data Package #1. Univ. C a l i f . , Berkeley , and Oregon Wildl . Comm. 22p.

~eyubat ions and the Mule Deer Harvest

RELIABILITY OF MULE DEER POPULATION MEASUREMENTS

Michael L. Wolfe Department of Wildlife Science

Utah State University

Abstract

Various methods of enumerating mule deer population trends are reviewed. Naive acceptance of the results of certain "traditional" methods without recognition of their limitations may account in part for recent declines in deer numbers. This probably has occurred in some states where harvest regulations have been formulated primarily from vegetation-based indices. The problems of failure to meet the requisite assumption of population stability in the estimation of demographic parameters from age- structure data are also discussed. Since individual estimates of animal abundance are each based on assumptions of questionable validity, management agencies are cautioned to avoid reliance on a single method or informational input to formulate harvest regulations.

The objective of most deer management programs is to maintain the largest huntable population possible which the habitat can sustain in a healthy condition and is compatible with other recognized land uses. Achievement of this goal requires two informational inputs. One is a knowledge of the vegetation, particularly in terms of the number of animals it can currently support and the effects of plant succession on future species composition and production. At the same time, the manager requires knowledge of deer demography (i.e. population trends, reproductive and mortality rates and the effects of various exploitation levels on the population). With this basic premise, the objective of this paper is to examine critically the current state of the arts with reference to the assessment of mule deer population trends.

Table 1 summarizes the different approaches and information sources employed to measure deer population trends as a basis for the formulation of harvest levels. Virtually all the western states that I surveyed employ these methods or some subset thereof. The categorization of methods is not mutually exclusive but depends to some degree upon the level of resolution, with which they are employed. The application, requisite assumptions and limitations of most of the methods in the second group have been discussed extensively in the wildlife literature and are reviewed by Davis (1963). Overton and Davis (1969), Seber (1973) and others. I will direct my comments here primarily to the first and third approaches.

Measures of occupancy and utilization

the past, management agencies in several western states have relied heavily on observed trends in deer occupancy (animal days use) of critical winter range areas and their utilization of "key browse species" (Aldous 1945, Cole 1959) as indirect indices of deer population trends. This system was initiated during an era (the early 19501s), when

deer populations were excessive and damaging range vegetation as a result of long-standing restrictive harvest regulations. At that time the reduction of deer numbers and protection of their habitat was a necessary and justifiable consideration. The system was useful in effecting liberal harvests to reduce deer numbers, but today - a quarter of a century later - the basic premise is for the most part no longer applicable.

Harvest regulations, formulated solely on indices of occupancy and utilization, are subject to several serious shortcomings. Differential winter severity may greatly influence animal occupancy of a predetermined key area and the intensity of utilization of browse species on that area. Thus, measurements of occupancy and vegetation-use patterns for a given winter may imply spurious population trends. It may be true that the mean level of browse utilization and pellet group counts may be higher over an extended period of high deer densities than during a similar period with low densities. However, annual variations in such indices probably reflect variations in winter weather rather than actual changes in big game numbers. Hence, they constitute a questionable basis for annual decisions on harvest levels. Furthermore, these measurements are (by definition) not predictive, but rather terminal or ex post facto syiiiptoms of a big game animal's impact - on its habitat. This contention has been corro- borated empirically by Mackie's (1976) findings in Montana. He concluded that browse surveys appear mainly to provide hindsight and reflect cumulatively events and conditions of the past more adequately than those at the time the surveys are conducted.

It is my opinion that this frequently overlooked limitation may account:inpart for the decline in mule deer numbers in some states. A possible explanation of how this could happen is illustrated in Fig. 1 (modified from bey 1972). The straight line I is the scalar relationship between actual

93 ,?r?ZtnbiZitu o f Mute Deer Povutation Measurements

1, IkoWsE lrr ILIZATI0N TRENDS

. - . . - . - BROWSE PLANTS REFLECTS M E LEVEL OF M E POPULATION,

A, AERIAL B, GROW

2. ~NDIRECT POPULATION ESTIMATES

A, WINE-IN-RATIO B, FELLET m u p c o w s

1, HERD COMPOSITION SURVEYS

A, FAWN-WE RATIOS B, SEX RATIOS

2, AGE STRUCTURE OF THE HARVEST

3, DEAD DEER SURVEYS

3, ~ E R TREND INDICES

An W V ST TRENDS B, K I d u N I T EFFORT ASSUYIPTION:

IF ME BIASSES INWLVED IN THE INDEX REWIN CONSTANT FROM YEAR TO YEAR, CHANGES I N M E INDEX REFLECT POPP LATION CI-W\IGES,

p ~ ~ u l a t i o n s i z e dnd r e l i a b l e index u t popu la t i on d e n s i t y . Such a c o r r e l a t i o n might be assumed t o e x i s t i f measurements of animal occupancy and browse u t i l i - z a t i o n were t r u e i n d i c a t o r s of animal numbers o r d e n s i t y . The h y p o t h e t i c a l r e l a t i o n s h i p (11) i s , however, d e s c r i p t i v e of t h e s i t u a t i o n , where t h e i n d i c e s a r e de r ived s o l e l y from measurements of animal u s e i n a r e a s of p r e f e r r e d h a b i t a t ( i . e . "key a r ea s " ) . At low popu la t i on l e v e l s (A) p r a c t i c a l l y a l l animals a r e found i n t h e p r e f e r r e d a r e a s . As popu la t i on d e n s i t y r eaches a s a t u r a t i o n po in t ( B ) i n t h e a r e a s sampled, no more animals w i l l u se t h e a r e a , even though the popu la t i on con t inues t o i n c r e a s e . F i n a l l y , a s d e n s i t y becomes extreme (C) , animals u t i l i z e l e s s p r e f e r r e d , marginal a r e a s .

Re t ro spec t ive ly . t h i s r e l a t i o n s h i p may be diagnostic of what has happened t o dee r he rds i n some s t a t e s over t h e p a s t 25 yea r s . Po in t C could be cons t rued t o r e p r e s e n t t h e s i t u a t i o n i n Utah and o t h e r a r e a s of t h e In termounta in West du r ing t h e l a t e 1 9 4 0 ' s when dee r numbers were exces s ive . As he rds were reduced s u b s t a n t i a l l y by con t inu ing l i b e r a l h a r v e s t s - perhaps back t o polnt B - commensurate changes i n t h e occupancy and vegeta t ion-use i n d i c e s were no t ev iden t . Consequentlb, dee r popu la t i ons i n some a r e a s were reduced belcd d e s i r a b l e l e v e l s .

The roregoing arguments should n o t be misconst rued a s a r e n u n c i a t i o n of h a b i t a t o r vegeta t ion-based measurements p e r s e , inasmuch a s t h e s e c o n s t i t u t e a n i n t e g r a l component of a sound management program f o r any b i g game s p e c i e s . I would contend, however, t h a t t h e i n r e r e n c e of popu la t i on t r e n d s i n browsing ~ n i m a l > from measurements of animal u se r e p r e s e n t s a c ~ ~ t . u l t o u s and p o t e n t i a l l y e r roneous approach.

IF POPULATION PARAMETERS (I , , NATALITY AND WRTAL- ITYf CAN BE MEASURED ACCUR- ATELY AND RELATED TO VARYING LEVELS OF EXPLOITATION WE CAN DETERMINE THE HARVEST WICH BALANCES THEM,

0 POPULATION SIZE

Figu re 1. l l y p r t n e t i c a l r e l a t i o n s h i p s between popula- t i o n s i z e and vegeta t ion-based i n d i c e s of popu la t i on t r e n d (modif ied from Aney, 1972) . R e l a t i o n s h i p I re- p r e s e n t s t h e l i n e a r r e l a t i o n s h i p between a c t u a l popu- l a t i o n s i z e expec t ed , i f measurenlents of animal use ( i . e . browse u t i l i z a t i o n and animal days use) were a c c u r a t e i n d i c a t o r s of animal numbers. Xe la t i onsb ip

11 might e x i s t when i n d i c e s a r e based only on animal u se i n a r e a s of p r e f e r r e d h a b i t a t . See t e x t f o r fu r - t h e r exp l ana t ion . A r e l a t i o n s h i p complementary t o cu rve I1 might e x i s t when i n d i c e s a r e based s o l e l y on measurements i n non-preferred h a b i t a t .

9 4 Reziabi l i tU of h 2 e Dee13 PopuZat ion Measurements

More importantly, naive acceptance at face value of the results obtained by these measurements without recognition of their inherent weaknesses may have contributed indirectly to or aggravated population declines in some cases. The dual approach of measuring animal population trends annually in conjunc- tionwithperiodic and more sophisticated vegetational measurements, to evaluate long-term trends in range condition, productivity and species composition represents a more realistic approach.

Indices of population trend:

As game biologists began to question the adequacy of occupancy and utilization measurements, some states have moved in other directions. One of these was toward refining fecal pellet-group counts to obtain "estimates" or at least indices of actual deer population levels. The pellet group technique has received considerable attention in the wildlife literature and has been comprehensively reviewed by Neff (1968). Detailed treatment of the method is not within the scope of this paper, but a few brief comments seem apropos.

The fundamental weakness of the pellet group technique as a source of information for management purposes, is human error. This comes as no surprise to any manager, who has "picked pellets" at some time in his career. Of all the means of collecting data on big game animals, this is the most tedious. Even if the manager is fortunate enough to have well- intentioned and responsible field personnel and he can convince them of the necessity for accurate pellet tallies, some unavoidable errors will occur. Unfor- tunately, these cannot be rectified and we will probably have to live with them in the future.

Beyond this, the use of pellet group counts as a population estimator requires certain refinements in addition to those necessary for the application of the method as a mere index of animal use. Perhaps the most important of these is that of stratifying sampling allocation. Big game animals are rarely distributed randomly or uniformly on winter range areas. This is particularly true in the West, where marked topographic variation and associated vegetational differences produce more or less distinct strata of differential deer distribution and density, which vary annually in response to winter severity (Edwards 1956, Loveless 1967, Gilbert et al. 1970). Sampling variance' in contagious distributions increases with density. If differential density strata are considered in the statistical design of pellet group counts, sampling intensity can be allocated propor- tionally or optimally to the various strata, thereby increasing the precision of the population estimate obtained (Siniff and Skoog 1964, Bergerud 1968). It might be noted that this generalization is applicable, not only to pellet group counts, but also to some of the other methods of assessing population trends and related parameters (e.g. dead deer surveys), listed in Table 1.

In theory, sampling effort in pellet counts should be allocated on the basis of observed deer distribution patterns in the winter immediately prior to the surveys. This implies the use of temporary plots. However, western conditions necessitate some departures from the ideal design. Sparse, xerophytic vegetation on many big game winter ranges precludes reliance upon autumnal leaf-fall to conceal pellets of older origin

ReZiabiZity of &le Deer Population Measurements

than the current winter. This and the fact that older pellets may persist for several seasons dictates the use of permanent "swept" plots. Some of the benefits of stratification could be realized by a compromise solution, whereby sampling effort is allocated on the basis of past patterns of winter deer distribution. Clusters of plots, as used by Eberhardt and Van Etten (1956), Smith (1964), and Stormer et al. (1974), might be employed to vary sampling intensity on transects of standardized length. Several authors (Eberhardt 1960, Bowden et al. 1969, McConnell and Smith 1969) have analyzed the nature of frequency distributions in pellet- group tallies. The results of these or similar investigations should provide additional information with reference to optimal allocation within density . strata.

Dynamics data:

The concept of employing demographic parameters in the analysis of deer population dynamics is not novel, as attested by the classical papers of Taber and Dasman (1957) and Eberhardt (1960). However, this approach has received renewed attention within the past decade, largely as the result of two important developments in wildife science. One is the increasingly widespread application of the cementum annualtion technique for age determination. This technique has given game managers the means to obtain reasonably accurate data on the age distribution of large harvest samples from different herd units and relate them by conventional methods of population analysis to varying harvest strategies. The other important development is the advent of computer technology, which has greatly facilitated the iterative processes involved in demographic analysis and opened up the field of population simulation.

Despite the apparent sophistication in this approach, its limitations should not be overlooked. Referring to Table 1, let us examine the basic assumption involved in this approach. We assume that it is possible to measure accurately reproductive increments to the herd and the mortality or survival rates operating on the population -- especially within the female segment -- under varying harvest regimes. If this is possible, we can determine the level of harvest, which just crops the annual increment, while allowing for natural decrements. We will further stipulate that it is within the manager's wherewithal to assess reliably the recruitment to the population and concentrate on the problem of measuring mortality rates.

Given a sample of the relative age frequencies in a population at a point in time, the age-specific and total mortality rates operative within the population from which the sample derives can be estimated subject to certain important assumptions:

1. That mortality and natality have been constant . and the population has remained numerically constant for some time previous to the point at which the sample was taken;

2. That the sample accurately reflects the relative strengths of the various age classes in the population;

3. That the method of age determination is accurate.

While the iterative procedures involved may differ, the assumptions upon which they are predicated are basically the same. We should be able to satisfy the third condition, given the methods of age determination that are currently available. We also know that some age classes, notably fawns and yearlings, are differentially vulnerable to the gun and will probably not be accurately represented in a hunter-killed sample (Smith et al. 1969, Hayne and Eberhardt 1952, Maguire and Severinghaus 19541, but there exist methods for dealing with these biasses (vide Robson and Chapman 1961).

The greatest single bugaboo remains the rigorous and seldom met condition of population stability. The effects of failure to meet this assumption can be illustrated by a simple demographic convention (Table 2). The strictly hypothetical population shown below is generated over time from an initial cohort of 1000 animals (50:50 sex ratio) of one year of age, in which each yearling or adult female produces two young (i.e. natality = 50 percent); the mortality rate for all age and sex classes is 55 percent. Admittedly, this is not a very realistic represen- tation of act-~al mule deer population parameters, since it fails to account for age-specific fecundity and mortality rates and assumes that all females breed as fawns. These simplistic parameters have been purposely chosen, however, to preserve the clarity of the point that I am trying to make. Examining the total number of animals in the population over time, it is obvious that the population is decreasing by 10 percent per annum. This is to be expected in terms of discrepancy between natality and mortality rates (50 vs 55 percent).

Table 2. Cohort shrinkage in a declining population; annual mortality rate = 55 percent; natality = 50 percent. See text for further explanation.

The actual mortality rate operative withil. the population is reflected in the shrinkage over time for a cohort, born in any given calendar year. However, if one attempts to ascertain the mortality rate from the age-class frequencies in a vertical segment of the population in a given calendar year, (say year 9) the implied mortality rate thus obtained underestimates the true mortality by a factor equivalent to the rate of population change

(in this case 10 percent). Ironically, if the level of harvest were formulated on the implied mortality rate alone, the population decline would be aggra- -7ated. Given an independent estimate of the rate of population change, the true mortality rate could be derived from the implied rate. Paradoxically, accurate and independently derived estimates of the rate of population change are more often than not lacking, and if they were available they would obviate this somewhat circuitous approach to assessing deer population trends. Without them, however, the inference of population trends based on survival rates derived from the vertical age structure of a population is tautological.

The implications of this problem are well known to population ecologists (Caughley 1966, Eberhardt 1969), but may be overlooked by the manager, especially when he may be lulled into a false sense of security with the aforementioned advances in age- determination techniques and computer technology. Computerized iteration of dynamics data and population simulation techniques can and will not rectify biasses inherent in the basic data.

This is merely one of numerous problems involved in the estimation of population parameters from life tables and related methods. Rarely, if ever, are the histories of the several cohorts represented in a time-specific sample of the population indentical as represented in Table 2. Hence substantial annual variations in productivity and winter survival may produce seeming anomalies in the age structure of a population, which complicate or preclude derivation of mortality rates. Separation of these effects from the vagaries of sampling effect may be difficult.

Referring again to Table 2, it was noted that the mortality rates operative within a given cohort could be determined by examining the relative strengths of that cohort in samples taken at consecutive points in time. Such a horizontal approach is of relatively limited utility for deer management for several reasons. Foremost as the requisite assumption of equal sampling intensity over time. Obviously, this assumption does not obtain, when the degree of removal varies annually due to differential harvest regulations and/or differences in weather conditions during the hunting season. Certainly, differences in the relative vulnerability of various age classes must be taken into account here also. Moreover, stochastic variations in natural sources of mortality (e.g. winter losses) will affect the apparent strength of a given age class (especially that of yearlings) and thereby preclude estimation of mortality rates by this method.

CONCLUSIONS

In summary, we find that despite the staggering resources and effort expended annually, real accuracy and precision in the enumeration of mule deer population trends remain elusive. Looking to the future, I do not see any pat solutions to the problem on the immediate horizon. A few years ago, some biologists hailed remote sensing (Croon et al. 1968, Graves et al. 1972, Parker and Driscoll 1972) as the paragon of the future. To date at least, this technique has not lived up to original expectations. Continued

Re Ziabi Zity of Mule Deer Population &asurements

development of remote sensing, especially the implemefitation of more sophisticated hardware and innovative approaches, may ultimately provide more reliable results. However, this will undoubtedly require several years of additional research and development.

1. Management agencies should not rely on a single method or source of information to assess deer population trends and formulate harvest regulations. Individual estimators of animal abundance and related demographic parameters are each based on assumptions of questionable validity. Moreover, problems of sampling error reduce precision and further confound the reliability of population estimates. Given these circumstances, the only feasible alternative is to weigh carefully the results obtained by several independent indices and the effects of inherent biasses on these indices to derive a qualified "best guess" of population levels on an annual basis.

2. Lacking any single, totally reliable census method, a concerted estimate should be directed toward quantifying the fraction of a deer population that is removed annually by hunting. The need for information of this nature seems singularly appropriate in an era of increasing demands - both on the part of the hunting public as well as non-consumptive interest groups - to know the magnitudeand impact of various harvest strategies and natural decrements on deer populations. One possible approach to this problem would be estimation of "harvest rates". Ideally, this would involve the admittedly difficult task of large- sca7.e tagging programs on summer ranges and the use of a reward system to insure reporting most or all of the tagged animals that were harvested. The recovery rates thus obtained would provide an index of the fractionofthe population which is harvested. These rates could be correlated to differential harvest regulations, levels of hunting pressure, deer vulnerability as related to topography and access on different herd units. Comparison of the hunting removal rate under a spectrum of harvest strategies with estimated losses from other factors may serve to establish the proper perspective for the direction of future research on the measurement of mule deer population trends.

LITERATURE CITED

Aldous, C. M. 1945. A winter study of mule deer in Nevada. J. Wildl. Manage. 9(2):145-151.

Aney, W. W. 1972. Statistics as applied to wildlife resource management. Proc. Western Assoc. Game and Fish Commissioners 52:272-289.

Bergerud, A. T. 1968. Numbers and densities. Pages 21-42 & F. B. Golley and H. K. Buechner, eds. A practical guide to the study of the productivity of large herbivores. IBP Handbook No. 7. Black- well Scientific Publications, Oxford.

Bowden, D. C., A. E. Anderson, and D. E. Medin. 1969. Frequency distributions of mule deer fecal group counts. J. Wildl. Manage. 33(4):895-905.

Caughley, G. Mortality patterns in mammals. Ecology 47 (6) : 908-918.

Cole, G. F. 1959. Key browse survey method. Proc. West. Assoc. State Game and Fish Comm. 39:181- 186.

Croon, G. W., D. R. McCullough, C. E. Olson, Jr., and L. M. Queal. 1968. Infrared scanning techniques for big game censusing. J. Wildl. Manage. 32(4):751-759.

Davis, D. E. 1963. Estimating the numbers of game populations. Pages 89-118 H. F. Mosby, ed. Wildlife Investigational Techniques. The Wildlife Society, Washington, D.C.

Eberhardt, L. L. 1960. Estimation of vital characteristics of Michigan deer herds. Report 2282, Game Div., Mich. Dept. of Conserv., Lansing. 192 pp.

Eberhardt, L. L. and R. C. Van Etten. 1956. Evalu- ation of the pellet group count as a deer census method. J. Wildl. Manage. 20(1):70-74.

. 1969. Population analysis. Pages 457- 496 & R. H. Giles, ed. Wildlife management techniques. The Wildlife Society, Washington. D.C.

Edwards, R. Y. 1956. Snow depths and ungulate abundance in the mountains of western Canada. J. Wildl. Manage. 20(2):159-168.

Gilbert, P. F., 0. C. Wallmo, and R. B. Gill. 1970. Effect of snow depth on mule deer in Middle Park, Colorado. J. Wildl. Manage. 34(1):15-23.

Graves, H. B., E. D. Bellis, and W. M. Knuth. 1972. Censusing white-tailed deer by airborne thermal infrared imagery. J. Wildl. Manage. 36(3): 875-884.

Hayne, D. W. and L. Eberhardt. 1952. Notes on the estimation of survival rates from age distribution of deer. Paper presented at 14th Midwest. Wildl. Conf. (unpubl. ms.)

Loveless, C. M. 1967. Ecological characteristics of a mule deer winter range. Colorado Div. Game, Fish and Parks, Tech. Publ. No. 20. 124 pp.

Mackie. R. J. 1976. Evaluations of range survey methods, concepts and criteria (effectiveness of the key browse survey method). Montana Game and Fish Dept. P-R Proj. Rep., W-120-R-6. 20 pp. Multilith.

Maguire, H. F. and C. W. Severinghaus. 1954. Wariness as an influence on age composition of deer killed by hunters. New York Fish and Game J. l(1) : 98-109.

McConnell, B. R., and J. G. Smith. 1970. Frequency distributions of deer and elk pellets. J. Wildl. Manage. 34 (1) :29-36.

Neff, D. J. 1968. The pellet count technique for big game trend, census, and distribution: A review: J. Wildl. Manage. 32(3)597-614.

Overton. W. S. and D. E. Davis. 1969. Estimating the numbers of animals in wildlife populations. Pages 403-455 in R. H. Giles, ed. Wildlife management techniques. The Wildlife Society, Washington, D.C.

LITERATURE CITED (Continued)

Pa rke r , H. D., J r . , and R. S. D r i s c o l l . 1972. An exper iment i n d e e r d e t e c t i o n by t he rma l s cann ing . J. Range Manage. 25(6):480-481.

Robson, D. S. and D. G. Chapman. 1961. Catch c u r v e s and m o r t a l i t y r a t e s . Trans . Am. F i s h . Soc. 90 (2 ) : 181-189.

Seber , G. A. F. 1973. The e s t i m a t i o n of animal abundance and r e l a t e d pa r ame te r s . G r i f f i n , London. 506 pp.

S i n i f f , D. B., and P. 0. Skoog. 1964. A e r i a l c ensus ing of c a r i b o u p o p u l a t i o n s u s i n g s t r a t i f i e d random sampl ing . J. Wild l . Manage. 28 (2 ) : 391-401.

Smith , A. D. 1964. De feca t i on r a t e s of mule d e e r . J. Wild l . Manage. 28(3):435-444.

Smith , R. H., T. J. McMichael, and H. G . Shaw. 1969. Dec l i ne o f a d e s e r t d e e r popu l a t i on . Ar izona Game and F i s h Dept. Wild l . D ige s t , A b s t r a c t 3. 8 PP.

Stormer , F. A., T. W. Hoeks t ra , C. M. White, and C. M. K i r k p a t r i c k . 1974. Assessment o f popu- l a t i o n l e v e l s o f w h i t e - t a i l e d d e e r on NAD Crane Purdue Univ. Agr ic . Exp. S tn . Res. B u l t . 10. 11 PP.

Taber , R. D., and R. F. Dasman. 1957. The dynamics of t h r e e n a t u r a l p o p u l a t i o n s of t h e d e e r . . Odocoi leus hemionus columbianus. Ecology 38(2) : 233-246.

R e l i a b i l i t b o f MULE Deer PopuZation Measurements 98

MULE DEER MANAGEMENT MYTHS AND

THE MULE DEER POPULATION DECLINE

R. B. G i l l Section Chief, Big Game Research

Colorado Division of Wild l i fe Wild l i fe Research Center

P. 0 . Box 2287 Fort Col l ins , Colorado 80522

Abstract

This paper en te r t a ins the thes i s t h a t a general dec l ine i n mule deer numbers i n the West is a myth. Conclusive evidence of such a decl ine is lacking because the re a r e no r e a l est imates of numbers of mule deer i n western United S ta t e s . Inadequate census methodology, i n su f f i c i en t knowledge of mule deer ecology, and impossible s t a f f i n g assignments combine with a t r a d i t i o n of u n c r i t i c a l acceptance of new ideas and techniques t o produce and perpetuate the myth of the mule deer decline.

INTRODUCTION

The prevai l ing opinion among w i l d l i f e managers i n the western United S t a t e s is t h a t mule deer popu- l a t i o n s i n the West have been decl in ing s ince the e a r l y 1960's (Sandfort 1968; Greenley 1968). Evidence c i t e d i n support of t h i s hypothesis includes decl in ing harves ts , e r r a t i c but generally decl in ing deer counts on trend areas , reduced grazing pressure on "key browse plants" wi th in "key areas", and in- t u i t i o n . It is my contention t h a t the grea t mule deer decl ine is a myth, a s a r e many of t he corner- s tones of evidence c i t e d i n proof of the decl ine .

This does no t mean the re hasn ' t been a western- wide mule deer decline. It simply means the evidence f o r t h i s t h e s i s is inadequate o r lacking, and there- fo re the conclusion of a general dec l ine i n mule deer numbers is specula t ive o r "mythical". The d e f i n i t i o n of a myth a s used i n t h i s paper is: "a b e l i e f given u n c r i t i c a l acceptance by the members of a group, e spec ia l ly i n support of e x i s t i n g o r t r a d i t i o n a l p rac t i ces and i n s t i t u t i o n s " (Gove 1961). I n t h i s context , not only is the phenomenon of a mule deer decl ine a myth, b u t s o a l s o a r e some of t he most cherished "principles" of mule deer management. The purpose of t h i s paper is t o examine some of the more persvasive and invidious mule deer management myths and r e l a t e them t o the myth of the g rea t mule deer decl ine .

MULE DEER MANAGEMENT MYTHS

f inge r s of one hand, he has probably been counting b i g game animals. A s a science, t he determination of wild animal populations has gotten l i t t l e beyond t h e point where we can count up t o mul t ip les of the f inge r s on both hands. " This statement, t r u e i n 1946, remains a reasonable summary of t h e s t a t e of t he a r t i n 1976. With respect t o the grea t mule deer decl ine w e should a sk ourselves, where a r e the numbers? I f they e x i s t , what i s the na ture of t h e i r qua l i t y?

After reviewing the per t inent l i t e r a t u r e , I am convinced t h e r e a r e no va l id es t imates of numbers of free-ranging mule deer on any l a r g e port ion of western deer range. There a r e published f igures of deer numbers i n various western s t a t e s such a s 200,000 i n Washington (Lauckhart 1968) ; 300,000 i n Colorado (Colo. Div. Wildl. 1974; Meyers 1975), e t c . However, these f igu res a r e not est imates b u t , r a t h e r , a r e guesses devoid of r e l i a b l e , quant i f ied substan- t i a t i o n . The bulk of the evidence f o r a general mule deer decl ine comes from i n d i r e c t information gener- a t ed from sources such as : t rend counts, harves t es t imates , and range use es t imates . I n addi t ion , t he re is a l so t h e evidence of opinion, i n t u i t i o n , o r "the fieldman's savvy". Le t ' s look a t t hese sources indiv idual ly and s e e what sense (o r nonsense) can be made from them.

Trend Indexes t o Deer Abundance

Myths of Mensuration Tracking populations of wild animals through The Numbers Game space and time has always been an e lus ive w i l d l i f e

management goal . I n the 1930's when the myth of

Some time ago Cronemiller and Fischer (1946: 349) profess ional w i l d l i f e management was born, census

wrote . . "As f a r back a s t h e time when abor ig inal was accorded primacy i n t h e hierarchy of th ings t o man learned to count by t a l l y i n g things on the do i n order t o properly manage w i l d l i f e (Leopold

99 MuZe Peer Mm,crgement Myth

1933). W. P. Taylor ( ~ e o p o l d e t a l . 1938:47) spoke r a t h e r v igorous ly t o t h i s po in t when h e dec la red . . . "any w i l d l i f e management worthy of t h e name w i l l be d i f f i c u l t o r impossible u n t i l we develop s a t i s f a c t o r y methods of inventory. I'

There followed an i n i t i a l f l u r r y of a c t i v i t y t o develop census techniques t o e s t ima t e t o t a l numbers of deer (e .g. Bennett e t a l . 1940; Erickson 1940; Hahn 1949; Rasmussen and Doman 1943). But t o t a l es t imates proved t o be labor ious and c o s t l y , so new approaches were sought . Most western s t a t e s u l t ima t e ly s e t t l e d on indexes c a l l e d "trend counts ." The i d e a was t o s e l e c t a "key a rea" f o r counting. This a r ea was presumed t o be r ep r e sen t a t i ve of a l a r g e r a r ea of i n t e r e s t . Annual counts of dee r were made on t h e key a r ea s and compared t o previous counts . F luc tua t ions i n "key area" counts were assumed t o p ropo r t i ona l l y r e f l e c t f l u c t u a t i o n s i n de e r popula t ions i nhab i t i ng l a r g e r a r ea s .

The problem wi th t r end counts l i e s i n t h e i r i m p l i c i t assumptions. F i r s t , no one a r e a is ever r e p r e s e n t a t i v e of another (Eberhardt 1963). I f t h e r e is one a t t r i b u t e common t o a l l a spec t s of b io logy i t is i n f i n i t e v a r i a t i o n . Hence, t h e f i r s t assumption is bo th absurd and impossible . Secondly, sample d a t a ( i . e . t r end counts) t e l l us on ly about t he sample, n o t about t h e r e a l popula t ion , un less a r e l a t i o n s h i p ha s been e s t ab l i shed . This ha s never been done w i th t rend counts . Consequently, f a i t h i n t h e ex t r apo l a t i on is u n j u s t i f i e d . Yet no myth of mensuration occupies a more hallowed pos i t i on i n mule deer management f o l k l o r e .

It is my opinion t h a t t r end counts were widely adopted because of two pred ispos ing cond i t i ons . F i r s t , t rend counts - e s p e c i a l l y when conducted from a i r c r a f t - a r e r e l a t i v e l y easy and inexpensive. Second, h i s t o r i c a l l y i n t h e w i l d l i f e p ro f e s s ion , t h e r e has been no t r u l y e f f e c t i v e forum f o r c r i t i c a l reviews of new i d e a s o r techniques i n w i l d l i f e ecology, so t rend counts gained r e s p e c t a b i l i t y on ly because so many people unquest ioningly adopted them.

Harvests a s Indexes t o Populat ion Trends

K i l l s t a t i s t i c s have long been used a s an index t o deer abundance. The degree of apparen t s o p h i s t i - c a t i o n has va r i ed from mathematical p ro j ec t i ons of t o t a l popula t ions based upon s e x and age s t r u c t u r e of t he pre- and post-harvest populat ion, s e x and age s t r u c t u r e of t h e h a r v e s t , and t o t a l ha rve s t (Dasmann 1952; Boyd 1970; Aney 1972; Lipscomb 1974; Seber 1973) t o s imple comparisons of annual h a r v e s t f l u c t u a t i o n s and d i r e c t ex t r apo l a t i ons t o deer popula t ion changes (Greenley 1968; Hancock 1968).

I n t h e ca se o f mathematical p r o j e c t i a n s from change-in-ratio and h a r v e s t d a t a t h e r e s u l t is only a s good a s t h e d a t a used i n t h e c a l c u l a t i o n s . I n most a p p l i c a t i o n s of t h i s technique t h e d a t a (pre- and post-season s ex and age s t r u c t u r e of t he ha rve s t ; and t o t a l ha rve s t ) a r e a l l t r e a t e d a s ab so lu t e s (Hanson 1963). Seldom a r e they considered a s v a r i a b l e s , bu t when they a r e and when t h i s v a r i a t i o n is included i n mathematical p ro j ec t i ons , t h e e s t ima t e s can b e r i d i c u l o u s l y imprecise (Wallmo 1964). Also, because t h e parameters a r e f r equen t l y con- s i d e r e d t o be abso lu t e s , l i t t l e s e r i ous a t t e n t i o n

Mule Deer Management Q t h s

is given t o measuring t h e ex t en t of t h e i r va r i - a b i l i t y . I n o t h e r words, pre-designed, s t a t i s t i - c a l l y l o g i c a l sampling s t r a t e g i e s a r e seldom employed. I n add i t i on , few w i l d l i f e managers have considered t h e appropr ia teness of t h e p r o b a b i l i t y models de sc r i b ing frequency d i s t r i b u t i o n s of t h e s e parameters; a binomial d i s t r i b u t i o n is usua l ly assumed. Recent t e s t s sugges t t h e s imple binomial d i s t r i b u t i o n is no t t h e most app rop r i a t e model (Johnson 1976) .

Consider a l s o some of t h e p o t e n t i a l b i a s e s encountered i n t r y i n g t o measure t he se v a r i a b l e s (Paul ik and Robson 1969). F i r s t , t h e r e is good reason t o suspec t a d e t e c t a b i l i t y b i a s wh i l e sampling s e x and age r a t i o s of deer popula t ions . My own exper ience and t h a t o f o the r s (Wallmo 1964; Dasmann and Taber 1956; Poux 1972) sugges ts t h a t fawns and does a r e l i k e l y t o be more e a s i l y de t ec t ed than bucks except poss ib ly dur ing the r u t when t h e r eve r s e may be t r u e . I f t h i s is t h e ca se then popula t ion c l a s s i f i c a t i o n counts may produce f a l s e es t imates of populat ion composition. But t h e e x t e n t of such b i a s remains unquant i f ied , a s does t h e v a r i a b i l i t y of t h e b i a s over time.

A second cons ide r a t i on i s t h e p o s s i b i l i t y of b i a s i n t h e r epo r t ed sex and age s t r u c t u r e of t h e ha rve s t (Eberhardt 1971; Coe 1974). Most wes te rn s t a t e s use d a t a from e i t h e r hun t e r survey o r check s t a t i o n s t o e s t ima t e t h e ha rve s t s t r u c t u r e . Both sources a r e s u s c e p t i b l e t o b i a s . F i r s t , t h e r e could be a tendency f o r hun t e r s t o e r r a n t l y r e p o r t k i l l i n g a buck when they a c t u a l l y k i l l e d a doe o r a fawn (Menzel 1968). Second, no t a l l hun t e r s s t o p a t check s t a t i o n s , even i f they a r e requi red by law t o do so . It is pos s ib l e t h a t hun t e r s w i th mature bucks submit t o checking more r e a d i l y than those w i th fawns o r does. Nei ther source of b i a s h a s been adequate ly eva lua ted (Neilson and Williams 1968).

F ina l l y , t h e es t imates of t o t a l mule dee r ha rve s t s a r e a l s o sub j ec t t o r e p o r t i n g b i a s by hun t e r s . In Idaho t h i s source of b i a s was checked by comparing t h e known k i l l o f i nd iv idua l hun t e r s t o t h e i r r e spec t i ve repor ted k i l l s . Resu l t s i nd i ca t ed t h e es t imated s t a t ew ide ha rve s t was i n f l a t e d by 16 percent because a po r t i on of t h e unsuccessful hun t e r s repor ted k i l l i n g a dee r when they had not (Neilson and Williams 1968). A l l o f t h e s e ques t ions taken toge ther c a s t cons iderab le doubt on t h e r e l i a b i l i t y of popula t ion e s t ima t e s generated from populat ion s t r u c t u r e and ha rve s t da t a .

What can be s a i d then of us ing ha rve s t da t a by themselves a s i nd i ca t i ons of popula t ion t r end . When one cons iders a l l o f t h e v a r i a b l e s o t h e r than changes i n popula t ion dens i t y t h a t can cause f l u c t u a t i o n s i n h a r v e s t s i t i s perp lex ing t h a t t h i s myth h a s p e r s i s t e d s o long (Longhurst e t a l . 1976). Harves t s can b e expected t o vary i n response t o a bewi lder ing a r r a y of f a c t o r s unre la ted t o deer dens i t y . Among t h e more obvious a r e weather; changes i n season l eng th , type ( an t l e r ed on ly , hunter-choice, e t c . ) , and bag l i m i t s ; hunter d i s t r i b u t i o n ; hunter experience; land access ; o the r concurrent competing sources of r e c r ea t i on ; e t c . Each f a c t o r can d i r e c t l y i n f l uence ha rve s t t o t a l s , and they a l s o can i n t e r a c t w i th each o the r i n m u l t i p l e combinations t o produce complex and unpre- d i c t a b l e e f f e c t s . Consequently, i t i s unreasonable

t o assume t h a t harvest t rends cons i s ten t ly mirror population t rends. But even i f they d i d , one would have to know a p r i o r i what the r e a l population was doing before the re la t ionsh ip was obvious.

I n t u i t i v e Index o r the Fieldman's Savvy

Somehow through the years a p e r s i s t e n t myth developed i n which the i n t u i t i v e judgment of the "man i n the f i e l d " was a t t r i b u t e d a degree of high r e l i a b i l i t y which i t did not deserve. Bump (1943:324) summarized t h i s development a s follows: "Beset by an ever mounting pressure to i n i t i a t e management a c t i v i t i e s and produce r e s u l t s , i n many cases they [game managers] were forced t o f a l l back on so-cal led p r a c t i c a l measures based on individual experiences and keen observat ions, r a the r than on r e s u l t s gained through ca re fu l s c i e n t i f i c t e s t s . "

But the fieldman's savvy has been woefully inadequate when i t has been put to a t e s t . The following per t inen t examples c l e a r l y i l l u s t r a t e t h i s po in t . On July 12, 1924 an outbreak of foot and mouth d i sease was discovered among deer i n the S tan i s laus National Forest i n Ca l i fo rn ia . A decis ion was made to exterminate the S tan i s laus herd t o e r a d i c a t e the d i sease . An i n i t i a l poisoning program proved i n e f f e c t u a l , s o shooting was decided upon a s the next a l t e r n a t i v e . I n order t o properly s t a f f and prepare f o r such an enormous t ask , some pre- l iminary information was needed about the estimated s i z e of the population. The b e s t experts ava i l ab le were contacted and asked t o est imate t h e deer popu- l a t i o n l e v e l . These est imates ranged from 6,000 to 10,000 deer . Shooting commenced on December 1, 1924 and continued f o r almost a year , though most of the k i l l i n g was accomplished i n the win te r months while deer were concentrated. The f i n a l t a l l y of deer shot was 22,214, and the re were s t i l l l i v e deer - remaining (Keane 1926) . Thus, the maximum est imate based on the fieldman's s a w y was only 45 percent of the minimum t rue population.

I n 1949 a Game Research Farm was es tab l i shed i n KalQ, Denmark. I n 1950 i t was decided t o e l imina te t h e e n t i r e s tock of roe deer res iden t on the farm and t o rep len i sh it with f resh s tock . The e n t i r e area contained approximately 1,000 ha. Within t h i s 1,000 ha the re were two woodlots of about 170 ha each, the remainder being farmland. Before t h e shooting program was i n i t i a t e d , var ious l o c a l exper t s were pol led t o est imate the s i z e of the roe deer population i n order t o b e t t e r understand the magnitude of the task. The consensus was t h a t approximately 70 roe deer inhabi ted t h e farm. When t h e l a s t deer was sho t the t o t a l t a l l i e d was 213 - 3 times t h e o r i g i n a l e s t imate (Andersen 1953). Commenting on t h i s experience i n a l a t e r pub l ica t ion Andersen (1962:72-74) s a i d . . . "without experience of such a campaign i t i s impossible to form any idea of the a b i l i t y of roe deer t o escape de tec t ion . The complete f a i l u r e of our p r i o r a t tempt a t e s t imat ing herd s i z e is most s t r i k i n g , e spec ia l ly s i n c e t h i s i n i t i a l es t imate was made by t h e f o r e s t r y and game personnel a t Kale who had known the two woods f o r years and who had spent p a r t of every day the re . The r e s u l t was greeted with widespread i n c r e d u l i t y , and I be l i eve t h a t many people considered t h a t our i n i t i a l counting methods were fau l ty . However, con- f i rmatory r e s u l t s were obtained when t h e owners of th ree or four o ther Danish e s t a t e s decided t o k i l l

a l l t h e i r roe deer and to replace them by o thers introduced from d i s t r i c t s with s tock of super io r qua l i ty . In a l l cases , desp i te t h e f a c t t h a t our f igures were ava i l ab le a s a guide, the number of animals ac tua l ly k i l l e d f a r exceeded the most op t imis t i c est imate."

So much f o r the myth of the fieldman's savvy, but f o r those of you who may be s k e p t i c a l t h a t these a r e j u s t i s o l a t e d events , I i n v i t e you t o review Andersen (1961).

I n summary i t may be s a i d t h a t cur ren t e s t i - mates of mule deer population l e v e l s i n t h e West and ex t rapo la t ions t o h i s t o r i c t rends a r e not r e a l i t y , bu t myth. This i s s a i d because t h e methods from which the information was generated do no t s tand the t e s t of c r i t i c a l evaluat ion, but r a the r have been accepted simply because they were in- s t i t u t i o n a l i z e d i n p r i n t .

MYTH OF THE BROWSER

Several of the western s t a t e s employ an in- d i r e c t method f o r es t imat ing changes i n r e l a t i v e mule deer abundance. These procedures have been variously c a l l e d "range ana lys i s methods", "range condit ion and t rend t ransec t s" , "browse production and u t i l i z a t i o n t ransec t s" , e t c . (Sandfort 1968; Hancock 1968). But a l l methods have c e r t a i n common c h a r a c t e r i s t i c s . Key a reas a r e se lec ted which supposedly represent a reas c r i t i c a l t o t h e su rv iva l of deer populations. Within the key a reas , key browse spec ies a r e se lec ted which a r e supposed t o de f ine the capab i l i ty of the key a rea to support deer . F i n a l l y , t r ansec t s a r e es tab l i shed wi th in the key browse types wi th in the key a reas . These t r a n s e c t s purportedly provide indexes t o f luctua- t ions i n mule deer food production and u t i l i z a t i o n from year t o year (Denney 1962). There a r e severa l de f ic ienc ies i n t h i s approach t o carrying capac i ty and deer abundance. F i r s t , i s almost t o t a l disregard of the p r inc ip les of s t a t i s t i c a l sampling methodology. In most cases t r a n s e c t loca t ions a r e s e l e c t i v e l y placed ra the r than a l loca ted by some technique which minimizes personal b i a s (Eberhardt 1971). Because of t h i s neg lec t t h e r e s u l t a n t da ta a r e r e a l l y pe r t inen t only t o p a r t i c u l a r p l a n t s and t r a n s e c t s on which they a r e measured. No leg i t imate ex t rapo la t ions can be made t o general populations of browse p l a n t s growing on key a reas nor can ex t rapo la t ions be made from key a r e a s t o general win te r range complexes.

But even more ins id ious is t h e primary assumption b a s i c t o t h e e n t i r e procedure. This assumption i s t h a t mule deer a r e pr imari ly dependent upon browse f o r winter su rv iva l (e.g. Julander 1937; Carhart 1941a; H i l l 1956; Einarsen 1956). The "myth of the browser" i s one of the most anc ien t , p e r s i s t e n t , and pervasive of a l l mule deer myths and continues even today t o dominate most mule deer management philosophy and a c t i v i t y .

The "myth of the browser" developed i n much t h e same way a s most mule deer myths. Methods t o determine what deer e a t were chosen u n c r i t i c a l l y , and the r e s u l t s obtained were accepted u n c r i t i c a l l y . Early information on mule deer foods was based primari ly on four methods; observat ions of f ree-

r ang ing w i l d d e e r (Dixon 1928) , stomach con ten t ana lyse s (Dixon 1934) , snow- t r a i l i ng (Ca rha r t 1941b) , and o b s e r v a t i o n s of f eed ing s i t e s f o r evidence of grazed p l a n t s (Lovaas 1958). L i t t l e c r i t i c a l thought was devoted t o p o t e n t i a l b i a s e s i n method- o logy t h a t might s e r i o u s l y d i s t o r t t h e r e s u l t s .

Wallmo e t a l . (1973:562) t e s t e d t h e d e e r o b s e r v a t i o n method and t h e f eed ing s i t e method under semi-control led c o n d i t i o n s . They remarked ... " a t b e s t , most of t h e major f o r a g e s p e c i e s used by dee r might b e i d e n t i f i e d by t h e grazing-minutes o r t h e f eed ing s i t e method. Q u a n t i f i c a t i o n , however, c an be cons ide rab ly i n e r r o r . " The g r a z i n g o b s e r v a t i o n method p a r t i c u l a r l y f avo r s d e t e c t i o n of browse u se ove r o t h e r f o r a g e s p e c i e s (Wallmo e t a l . 19 73) .

Biases i n stomach con ten t ana lyse s have been r e p o r t e d by s e v e r a l a u t h o r s (Nor r i s 1943; Bergerud and Russe l l 1964; Scoo te r 1966, Murie 1933; Eastman 1974) . Nor r i s (1943:249) compared t h e r e s u l t s o f domest ic sheep f eed ing t r i a l s and rumen con ten t a n a l y s e s where known d i e t s were o f f e r e d . Among h i s s e v e r a l conc lus ions , he r e p o r t e d ... "stomachs may show l a r g e pe rcen t ages of c o a r s e browse which h a s been e a t e ~ ove r a pe r iod o f days l e a d i n g t h e a n a l y s t t o conclude t h a t browse is the c h i e f a r t i c l e of the d i e t , wh i l e , i n r e a l i t y , r a p i d l y d i g e s t e d , s u c c u l e n t fo r age may have been consumed i n much l a r g e r amounts ."

Bergerud and Russe l l (1964:813) reached s i m i l a r conc lus ions i n s i m i l a r s t u d i e s w i th ca r ibou . They s t a t e d "There appear t o be two s e r i o u s b i a s e s i n abundance comparisons of p l a n t groups and p l a n t s p e c i e s between groups i n rumen c o n t e n t s a s a r e s u l t of d i f f e r e n t i a l d i g e s t i o n : (1 ) p l a n t groups a r e n o t p r o p o r t i o n a l l y r ep re sen t ed i n t h e l a r g e r ( i d e n t i f i e d ) f ragments and t h e s m a l l e r ( u n i d e n t i f i e d ) p a r t i c l e s , and (2) t h e i d e n t i f i a b l e f ragments of some p l a n t s d i s a p p e a r more qu i ck ly t h a n o t h e r s . "

Snow t r a i l i n g r e s u l t s a r e s u s c e p t i b l e t o t h e same k ind of shrub b i a s a s t h e o t h e r 3 methods but f o r d i f f e r e n t r ea sons . Snow cove r profoundly in- f l uences t h e fo rage cho ice s o f d e e r . Smith e t a l . (1975) r e p o r t e d t h a t g r a s s and f o r b consumption i nc rea sed i n t he d i e t s of tame dee r and shrub consumpl . > n decreased a s snow mel t i n c r e a s e d grass- f o r b availability. Bergerud and Nolan (1970) observed t h e same gene ra l phenomenon w h i l e s t udy ing food h a b i t s o f tame ca r ibou . I n Middle Pa rk , Colorado, d i e t s o f tame dee r s h i f t e d a b r u p t l y o v e r a 24 h r pe r iod fo l l owing a 6-8 i nch s n o w f a l l . Shrub use was accen tua t ed and grass- forb u se d iminished fo l l owing t h e snowfa l l (Ca rpen te r e t a l . 1976, unpubl ished d a t a ) . These s t u d i e s sugges t t h a t snow t r a i l i n g can be expected t o over-emphasize t h e w in t e r - l ong importance of browse, w h i l e de- emphasizing t he r o l e o f g r a s s e s and f o r b s .

A l l o f t h e fo rego ing sugges t s t h a t t h e over- s i m p l i f i e d c l a s c i f i c a t i o n o f d e e r a s browsers is e r roneous and misleading. But even i f d a t a de r ived from t h e s e d i f f e r e n t t e chn iques were t aken a t f a c e va lue , t hey s t 1 1 1 d o n ' t j u s t i f y t h e ove r - s imp l i f i - c a t i o n . Severa l s t u d i e s which were based upon t h e s e v a r i o u s methods b e l i e t h e g e n e r a l i z a t i o n t h a t dee r i r e predominant 1 y browsers (e .g . Dixon 1934; Leach 1956; Nichol 19 36; Dunkeson 1955; N e l l i s and Ross

1969) . The conc lus ion of Bergerud and Nolan (1970:350) t h a t . . . "car ibou a r e n o t s p e c i a l i z e d f e e d e r s b u t a r e g e n e r a l i s t s . They appear o p p o r t u n i s t s and when neces sa ry e a t most k inds of vege t a t i on" , is e q u a l l y germane t o mule dee r .

Some might a rgue t h a t a l t hough dee r may e a t a v a r i e t y of foods , t h e r e i s s t i l l a r e l a t i o n s h i p between t r e n d s i n t h e p roduc t ion and u t i l i z a t i o n of browse and t r e n d s i n dee r numbers. I f t h i s c o n t e n t i o n i s t r u e i t s t i l l remains t o b e demonst ra ted . One of t h e few a t t emp t s a t such a demonst ra t ion (Anderson e t a l . 1972) was incon- c l u s i v e . The c o n s i d e r a b l e evidence t h a t browse twigs may n o t b e p r e f e r r e d , b u t cont ingency food, compl i ca t e s t h e i n t e r p r e t a t i o n of browse-use measurements w i t h r e s p e c t t o dee r popu la t i on l e v e l s (Sho r t 1969) . Improved f o r a g e c o n d i t i o n s con- duc ive t o p o p u l a t i o n i n c r e a s e s may b e accompanied by decreased browse u se . Poor f o r a g e c o n d i t i o n s conducive t o popu la t i on d e c r e a s e s may r e s u l t i n i nc rea sed u se of browse. Meanwhile, growing c o n d i t i o n s f o r browse s p e c i e s can e i t h e r a c c e n t u a t e o r mask t h e evidence of u se i r r e s p e c t i v e of t h e d i r e c t i o n of change i n t h e dee r popu la t i on . Con- s e q u e n t l y t h e d e f i c i e n c i e s o f sampl ing methodology and inadequa t e knowledge o f t he ecology of mule d e e r on shrub r anges r ende r s t a t e w i d e o r region- wide dee r popu la t i on t r e n d e v a l u a t i o n w i t h t h i s method b o t h meaningless and my th i ca l .

MYTH OF THE MULTI-PURPOSE MAN

I n t h e fo rego ing s e c t i o n s , technique de- f i c i e n c i e s were r e l a t e d t o t h e e v o l u t i o n o f mule dee r b i o l o g i c a l myths. I n t h i s s e c t i o n a t t e n t i o n w i l l b e d i r e c t e d toward a n o r g a n i z a t i o n a l and p h i l o s o p h i c a l d e f i c i e n c y which s e r v e s t o per- p e t u a t e t h e b i o l o g i c a l myths. Most wes t e rn s t a t e s d id n o t r e a l l y g e t i n t o comprehensive w i l d l i f e management programs u n t i l a f t e r t h e pas sage of t h e W i l d l i f e R e s t o r a t i o n Act o r t h e Pittman-Robertson B i l l of 1937. This a c t provided neces sa ry funding t o expand s t a t e programs, which h i s t o r i c a l l y had been " p r o t e c t i o n i s t " o r law enforcement o r i e n t e d , t o i nc lude d e t a i l e d i n v e s t i g a t i o n s of t h e b i o l o g y and ecology of game s p e c i e s . I n i t i a l l y , new pe r sonne l were h i r e d s p e c i f i c a l l y a s game b i o l o g i s t s . The i r r e s p o n s i b i l i t i e s were t o a c q u i r e t h e knowledge r e q u i s i t e t o e f f e c t i v e management s t r a t e g i e s f o r r e a l i z i n g t h e h a r v e s t p o t e n t i a l o f t h e s e s p e c i e s .

I n t h e 1940 's and e a r l y 1950 's t h e endeavor and amount of knowledge gene ra t ed was t r u l y impres s ive . With r e s p e c t t o d e e r , s e r i o u s a t t e m p t s were made t o sample popu la t i on dynamics parameters and h a b i t a t a t t r i b u t e s (Cronemi l l e r and F i s c h e r 1946; Ca rha r t 1941b; Edwards 1942; Longhurst e t a l . 1952; McCain 1948) . Then e a r l y i n t h e 1950 ' s , a t r e n d began t o combine t h e d u t i e s of t r a p p e r , game warden,and game damage o f f i c e r i n t o a s i n g l e p o s i t i o n . I n Colorado t h i s p o s i t i o n was c a l l e d t h e W i l d l i f e Conservat ion O f f i c e r ( F e l t n e r 1961) , and t h e s t a n d a r d s fo r r e c r u i t m e n t and s a l a r i e s were r a i s e d t o r e f l e c t i n c r e a s e d p ro fe s s iona l i sm . A c t i v i t i e s funded by Fede ra l cos t - sha r ing programs (Pittman- Robertson) were s t i l l l e f t t o t h e game b i o l o g i s t s .

A long-simmering c o n f l i c t between the game b i o l o g i s t s and the w i l d l i f e conservat ion o f f i c e r s f l a r e d i n t o open h o s t i l i t y over who should be responsible f o r game management funct ions. Eventually i n Colorado t h i s c o n f l i c t was decided i n favor of the Wi ld l i fe Conservation Off ice r s and t h e i r d u t i e s were expanded to include game and f i s h management. These developments marked the b i r t h of the multi- purpose man concept.

Today these r e s p o n s i b i l i t i e s have been expanded s t i l l fu r the r t o include information and education, environmental impact assessment, a ss i s t ance i n county land use planning, interagency l i a i s o n , and non-game and endangered spec ies management, t o name only a few. In shor t i t became impossible to do a l l th ings we l l . Respons ib i l i t i e s simply expanded beyond c a p a b i l i t i e s and s t a f f i n g . The r e s u l t was t h a t something had t o s u f f e r . That "something" i n Colorado has been w i l d l i f e management.

The organizat ional s t r u c t u r e required t h a t w i l d l i f e population and h a b i t a t d a t a and management recommendations o r i g i n a t e with the Wi ld l i fe Conservation Off ice r l e v e l . Since the re was l i t t l e time a v a i l a b l e t o devote t o w i l d l i f e population and h a b i t a t measurements, only those techniques which were expedit ious and simp1 e were re ta ined . The r e s u l t was the development and i n s t i t u t i o n a l i z a t i o n of the myths of mensuration and t h e myth of the browser. I n the process , a new myth became par t of our w i l d l i f e he r i t age - the myth of the multi- purpose man. When one considers the i n f i n i t e complexity of ecosystems i t i s inc red ib le t h a t a reasonable person could s t i l l be l i eve t h a t any s i n g l e ind iv idua l could do an adequate job of w i l d l i f e management alone, disregarding the remainder of h i s multitudinous funct ions.

S t i l l , the myth p e r s i s t s and meaningful wild- l i f e management progress is stymied. In t h e minds of admin i s t ra to r s , p o l i t i c i a n s , and the general publ ic , the image and the myth o f the multi-purpose man, who does a l l things competently, i s f i rmly entrenched. With a he r i t age of inappropriate methodology i n h i s t o o l bag, and too l i t t l e time t o apply i t , he understandably has resorted t o t h i s r epu ta t ion t o ca r ry him through the t r i a l s of decision-making. It takes only the concurrence of severa l such persons t o tu rn an unsubstant iated opinion in to an accepted t r u t h . The "fact" of a western-wide dec l ine i n mule deer populations r e s t s on such a foundation.

MYTH MANAGEMENT

I f , by now, you accept t h e o r i g i n a l t h e s i s of t h i s paper - t h a t t h e assumption of a dec l ine i n mule deer numbers i n the West and much of mule deer management methodology i s mythical r a the r than fac tua l - then what can be done t o e x t r i c a t e management philosophy and p r a c t i c e from counter-productive t r a d i t i o n s ? I suggest t h e following presc r ip t ions a s s t e p s i n the r i g h t d i r e c t i o n :

1. Es tab l i sh a t r a d i t i o n of c r i t i c a l evalua- t i o n of w i l d l i f e ecological p r i n c i p l e s , t h e o r i e s , and techniques. A necessary coro l l a ry i s to use the education process a s a forum t o encourage novice w i l d l i f e eco log i s t s t o th ink a n a l y t i c a l l y ,

c r i t i c a l l y , and ob jec t ive ly . This process i s not s o used now.

2 . The individual s t a t e s with mule deer populat ions must e s t a b l i s h goals and p r i o r i t i e s f o r ob ta in ing minimum information r e q u i s i t e t o r e a l i s t i c management dec i s ions . The f i r s t p r i o r i t y wi th in these programs is t o develop bas ic popula- t i o n inventory systems (Eberhardt 1971). These systems w i l l have t o consol idate the b e s t knowledge of s t a t i s t i c s and biology to insure a high p robab i l i ty of obtaining r e a l and genera l ly pe r t inen t da ta . I n i t i a l l y t h i s information w i l l be crude because t h a t i s t h e cur ren t s t a t u s of the a r t (Overton 1971). Much research is needed concerning mule deer behavior , remote sensing technology, and biometr ics t o s i g n i f i c a n t l y advance t h i s s t a t u s .

3. It is c l e a r t o me t h a t t h e multi-purpose man concept, a s i t i s employed i n Colorado, a t l e a s t , can not possibly produce mule deer management data of s u f f i c i e n t qua l i ty and quan t i ty t o support fundamentally sound management programs. These programs a r e a ful l - t ime job i n themselves. A t l e a s t 3 a l t e r n a t i v e s a r e ava i l ab le : ( a ) Remove w i l d l i f e management from the severa l responsi- b i l i t i e s of the Wi ld l i fe Conservation Off ice r and reduce the WCO s t a f f i n g l e v e l s . Replace these WCO s t a f f reduct ions with loca l w i l d l i f e management b i o l o g i s t s who design and d i r e c t mule deer management surveys. These mule deer management survey teams could be s t a f f e d by temporary employees o r with W C O ' s on temporary, seasonal assignments; (b) Increase s tatewide s t a f f i n g of w i l d l i f e b i o l o g i s t s without reducing WCO s t a f f i n g . The w i l d l i f e b i o l o g i s t s could work i n teams over l a r g e a reas o r regions t o secure management da ta ; (c) Plan a l l a c t i v i t i e s wi th in a WCO d i s t r i c t on a p r i o r i t y b a s i s with w i l d l i f e management (and s p e c i f i c a l l y mule deer management) receiving a very high p r i o r i t y . Then a l l o c a t e money and man- power necessary t o adequately execute those plans.

These suggest ions a r e over-simplified and t e n t a t i v e . Reorganizing the bureaucracy i s f u t i l e i f we cont inue t o do the wrong things under t h e new organ iza t ion . At the hear t of the present i s s u e is t h e f a c t t h a t we have not employed inventory systems capable of de tec t ing whether o r no t deer populat ions a r e changing s tatewide or region-wide. To have done so would not assure t h a t we would then make the b e s t management decis ions; t h e problem of human sociology compounds t h e i n f i n i t e l y complex ecological problems t h a t confront us i n w i l d l i f e management. However, i t would inc rease the p o s s i b i l i t y f o r r e a l i s t i c , ob jec t ive problem ana lys i s .

Meanwhile, we should be forewarned by Overton (1971:404): "Complexity is the p r i c e of real ism and t h e present degree of real ism is none too great ." There is no pat method f o r est imating deer numbers over l a r g e a reas . I f , a s t h i s symposium suggests , i t is important t o have such information, we must face our r e s p o n s i b i l i t i e s more r a t i o n a l l y and ob jec t ive ly .

It is important, f i r s t , t h a t we recognize t h a t we a r e a l a r g e p a r t of the problem (Anderson 1962) . We have been too eager t o be l i eve , too quick t o

103 Mute Deer Management Myths

apply, and too busy t o th ink! Cronemiller, F. P . , and G. A. F i sche r . 1946. Censusing a deer he rd by sampling methods. N. Amer. Wildl. Conf., Trans. 11:349-354.

LITERATURE CITED

Andersen, 3. 1953. Analysis of a Danish roe-deer populat ion (Capreolus capreolus L.) based upon exterminat ion of t h e t o t a l s t o c k . Danish Rev. Game Bio l . 2:127-155.

. 1961. Biology and management of roe-deer i n Denmark. La Tarra e t l a Vie 1:41-53.

. 1962. Roe-deer census and populat ion a n a l y s i s by means of modified marking r e l e a s e technique. pp. 72-82, E. D. l e Cren, and M. W . Hodgate (eds .) . The e x p l o i t a t i o n of n a t u r a l animal populat ions . Blackwell S c i e n t i f i c Publ. , Oxford. 399 p.

Anderson, A. E., D. E. Medin, and D. C. Bowden. 1972. Mule dee r numbers and shrub y i e l d - u t i l i z a t i o n on win te r range. J. Wildl . Manage. 36(2) :571-578.

Anderson, J. M. 1962. Can b i o l o g i s t s break t h e bo t t l eneck? N . Amer. Wildl . Conf., Trans. 27:479-484.

Aney, W . W. 1972. S t a t i s t i c s a s app l i ed t o wild- l i f e resource management. W. Assoc. S t a t e Game and Fish Comm.. Proc. 52:272-289.

Bennet t , L. J. , P. F. Engl ish , and R. McCain. 1940. A s tudy of dee r populat ions by use of p e l l e t group counts . J. Wildl . Manage. 4(4):398-403.

Bergerud, A. T., and L. Russe l l . 1964. Evaluat ion of rumen food a n a l y s i s f o r Newfoundland car ibou. 3 . Wildl . Manage. 28:809-814.

, and M. J. Nolan. 1970. Food h a b i t s o f hand- r ea red ca r ibou Rangifer t a r randus L. i n Newfoundland. Oikos 21:348-350.

Boyd, R. J. 1970. Elk of t h e White River P l a t e a u , Colorado. Colo. Div. Game, F i sh and Parks Tech. Publ. 25. 126 p.

Bump, G. 1943. W i l d l i f e management - f a c t and fancy. N . Amer. Wildl . Conf., Trans. 8:323- 328.

Carhar t , A. H. 1941a. What deer e a t ; by s p e c i e s , by season, by range and by p re fe rence . Amer. For. 50(8) :383-385.

. 1941b. Report of t h e deer-elk survey 1938-1941. P a r t I. Deer food requirements i n Colorado. Colo. Game and F i sh Corn. Pittman- Robertson Pro j . Colo. 4-R. 28 p.

Coe, R. J. 1974. The causes of b i a s i n white- t a i l e d dee r k i l l d a t a . M.S. Thesis . V i rg in ia Polytechnic I n s t i t u t e and S t a t e Univ., Blacksburg. 84 p.

Colorado Divis ion of W i l d l i f e . 1974. The s t r a t e g y of today f o r w i l d l i f e tomorrow. Colo. Div. Wildl . Denver, Colo. 103 p.

Dasmann, R. F. 1952. Methods f o r e s t ima t ing deer populat ions from k i l l da ta . C a l i f . Fish and Game 38(2) :225-233.

, and R. D. Taber. 1956. Determining s t r u c t u r e i n Columbian b lack- t a i l ed dee r populat ions . J. Wildl . Manage. 20(1):78-83.

Denney, R. N . 1962. Browse t r a n s e c t a n a l y s i s and a p p l i c a t i o n . Colo. Dep. Game and F i sh . Fed. Aid Quar t . Rep. ( A p r i l ) . P r o j . W-101-R-4; WP-3, Job 3. pp. 51-96.

Dixon, J. S. 1928. What dee r e a t . Amer. For. and For. L i f e 34(411):143-145.

. 1934. A s tudy o f t h e l i f e h i s t o r y and food h a b i t s of mule dee r i n C a l i f o r n i a . P a r t 11. Food h a b i t s . C a l i f . Fish and Game 20(4) : 315-354.

Dunkeson, R. L . 1955. Deer range a p p r a i s a l f o r t h e Missour i Ozarks . J . Wildl . Manage. 19 (3) : 358-364.

Eastman, D. S. 1974. Procedural a s p e c t s of moose rumen analyses . Can. Field-Natur. 88:331- 335.

Eberhardt , L. L. 1963. Problems i n eco log ica l sampling. Northwest Sc i . 37(1):144-154.

. 1971. Populat ion a n a l y s i s . pp. 457-495. i n R. H . G i l e s , Jr. ( e d . ) . W i l d l i f e manage- - ment techniques . The Wildl. Soc., Wash. D.C. 633 p.

Edwards, 0 . T. 1942. Survey of w i n t e r dee r range Malheur Nat ional Fores t , Oregon. J. Wildl. Manage. 6(3) : 210-220.

Einarsen, A. S. 1956. Some a s p e c t s of mule deer management. pp . 461-482. i n W . P . Taylor (ed. ) . The dee r of North America. The Stackpole Co., Harr isburg, Pa. and t h e Wildl . Manage. I n s t . , Wash. D.C . 668 p.

Er ickson, A. B. 1940. Notes on a method f o r censusing whi t e - t a i l ed dee r i n t h e s p r i n g and summer. J. Wildl . Manage. 4(1):15-18.

F e l t n e r , G. 1961. A look back: a 65 y e a r h i s t o r y o f t h e Colorado Game and Fish Department. Colo. Game and F i sh Dep. Annual Rep. 65 p .

Gove, P. B. ( ed . ) . 1961. Webster 's t h i r d i n t e r - n a t i o n a l d i c t i o n a r y of t h e Engl ish language unabridged. G. and C. Merriam Co., Publ. S p r i n g f i e l d , Mass. 2662 p.

Greenley, J . C. 1968. Major f a c t o r s i n f l u e n c i n g mule deer populat ion and ha rves t t r e n d s s i n c e 1962. W. Assoc. S t a t e Game and Fish Corn., Proc. 48:258-259.

kt2e Deer Management Myths

Hahn, H. C. 1949. A method f o r censusing deer and i t s app l ica t ion i n the Edwards Plateau of Texas. Texas Game, Fish, and Oyster Comm. Feb. 1949. 24 p.

Hancock, N. V. 1968. Major fac to rs a f f e c t i n g mule deer population and harvest t rends i n Utah s i n c e 1962. W. Assoc. S t a t e Game and Fish Comm., Proc. 48:245-252.

Hanson. W. R. 1963. Calculat ion of p roduc t iv i ty , su rv iva l , and abundance of se lec ted verte- b r a t e s from sex and age r a t i o s . Wildl. Monogr. 9. 60 p.

H i l l . R. R. 1956. Food h a b i t s and range management of the mule deer. pp. 393-414. i n W. P. Taylor (ed.) . The deer of North ~ m e r i c a . The Stackpole Co., Harr isburg, Pa., and the Wildl. Manage. I n s t . , Wash. D.C. 668 p.

Johnson, E. G. 1976. Some probab i l i ty models f o r fawn and doe counts. M.S. Thesis. Colorado S t a t e Univ., Fort Col l ins . 96 p.

Julander , 0 . 1937. U t i l i z a t i o n of browse by wild- l i f e . N. Amer. Wildl. Conf., Trans. 2:276-287.

Keane, C. 1926. The ep izoo t ic of foo t and mouth d i sease i n Ca l i fo rn ia . Cal if . Dept. Agr. Spec. Publ. 65. 54 p.

Lauckhart, B. 1968. Mule deer management i n the s t a t e of Washington, W. Assoc. S t a t e Game and Fish Comm., Proc. 48: 253-254.

Leach, H. R. 1956. Food h a b i t s of the Great Basin deer herds of Ca l i fo rn ia . Ca l i f . Fish and Game 42(4) :243-308.

Leopold, A. 1933. Game management. Charles Scribner 's Sons. New YorkILondon. 481 p.

, W. P. Taylor, R. Bennett, and H. H. Chapman. 1938. Wi ld l i fe research - is i t a p r a c t i c a l and necessary b a s i s f o r management? N. Amer. Wildl. Conf., Trans. 3:42-55.

Lipscomb, J. F. 1974. A modelling approach t o ha rves t and t rend data ana lys i s . W. Assoc. S t a t e Game and Fish Corn., Proc. 54:56-61.

Longhurst, W. M., A. S. Leopold, and R. F. Dasmann. 1952. A survey of Ca l i fo rn ia deer herds, t h e i r ranges and management problems. C a l i f . Dept. Fish and Game Bul. No. 6. 136 p.

, E. 0. Garton, H. F. Heady, and G. E. Connolly. 1976. The Ca l i fo rn ia deer dec l ine and p o s s i b i l i t i e s f o r r e s t o r a t i o n . Paper presented a t the W. Sec. The Wildl. Soc. Fresno, Ca l i f . 38 p. ( typewr i t t en) .

Lovaas, A. L. 1958. Mule deer food h a b i t s and range use, L i t t l e Be l t Mountains, Montana. J . Wildl. Manage. 22(3):275-283.

McCain, R. 1948. A method f o r measuring deer range use. N. Amer. Wildl. Conf., Trans. 13:431-441.

Menzel, K. E. 1968. Accuracy of hunter repor t ing on b i g game harvest quest ionnaires . Central Mtns. and P la ins Sec. The Wildl. Soc., Trans. 13:lO.

Meyers, B. 1975. Deer hunters promised bigger herds i n fu tu re . The Denver Post . Dec. 21. p. 74.

Murie, 0. J . 1933. Some observations i n b i g game s t u d i e s . pp. 34-38. & T. G. Taylor and B. C. Pittman (eds . ) . Game-management developments and needs. Utah Agr. Exp. S ta . and Ext. Serv. Misc. Publ. 10. 5 1 p.

Neilson, A. E . , and R. M. Williams. 1968. Major fac to rs inf luencing mule deer populations and harves t t r ends s i n c e 1962 - Idaho. W. Assoc. S t a t e Game and Fish Corn., Proc. 48: 232-236.

N e l l i s , C. H . , and R. L. Ross. 1969. Changes i n mule deer food h a b i t s a ssoc ia ted wi th herd reduct ion. J. Wildl. Manage. 33(1):191-195.

Nichol, A. A. 1936. The experimental feeding of deer . N. Amer. Wildl. Conf., Trans. 1:403- 410.

Norr is , J. J . 1943. Botanical analyses of stomach contents a s a method of determining forage consumption. Ecology 24:244-251.

Overton, W. S. 1971. Estimating t h e numbers of animals i n w i l d l i f e populat ions. pp. 403- 455. i n R. H. G i l e s , J r . (ed.) . Wi ld l i fe management techniques. The Wi ld l i fe Soc. Wash. D.C. 633 p.

Paul ik, G. J., and D. S. Robson. 1969. S t a t i s t i c a l ca lcu la t ions f o r change-in-ratio es t imates of population parameters. J. Wildl. Manage. 33(1) :1-27.

Poux, R. J., Jr. 1972. Deer behavior a s i t a f f e c t s sex and age r a t i o counts. M.S. Thesis . Vi rg in ia Polytechnic I n s t i t u t e and S t a t e Univ., Blacksburg. 42 p.

Rasmussen, D. I., and E. R. Doman. 1943. Census methods and t h e i r app l ica t ion i n the management of mule deer . N. Amer. Wildl. Conf., Trans. 8:369-379.

Sandfort , W. W. 1968. Major f a c t o r s inf luencing mule deer population and harves t t r ends i n Colorado s i n c e 1962. W. Assoc. S t a t e Game and Fish Comm., Proc. 48:219-231.

Scooter , G. W. 1966. Sieve mesh s i z e a s r e l a t e d t o volumetric and gravimetr ic ana lys i s of car ibou rumen contents . Can. Field-Natur. 80:238-241.

Seber, G. A. F. 1973. The est imation of animal abundance and r e l a t e d parameters. Hafner Press . New York. 506 p.

Short , H. L. 1969. Physiology and n u t r i t i o n of deer i n southern upland f o r e s t s . pp. 14-18. i n Anonymous. White-tailed deer i n the - southern f o r e s t h a b i t a t . Proceedings of a

105 MuZe Deer Manapement Muths

symposium. Southern For. Exp. S t a . , For . Se rv . U.S.D.A.; Fo r . Game Committee S.E. Sec. The Wi ld l . Soc . , and School o f Fo r . , S tephen F. Aus t i n S t a t e Univ. 130 p.

Smith , M. A., K. 0. Fulgham, and J . Malechek. 1975. D ie t s o f w i n t e r i n g mule d e e r on r ange grazed h e a v i l y by sheep i n s p r i n g . Paper p r e s e n t e d a t t h e 29th Annual Meet ing , Soc. f o r Range Manage. Omaha, Neb. 1 5 p. ( t y p e w r i t t e n ) .

Wallmo, 0. C . 1964. Problems i n t h e u se o f he rd c l a s s i f i c a t i o n d a t a . N. Mex-Ariz Sec . The Wi ld l . Soc . , Proc . 3:6-18.

, R. B. G i l l , L. H . C a r p e n t e r , and D. W . R e i c h e r t . 1973. Accuracy o f f i e l d e s t i m a t e s of d e e r food h a b i t s . J . Wi ld l . Manage. 37 (4 ) : 556-562.

Mule Deer Management Myths

THE POSSIBLE INFLUENCE OF THE MOUNTAIN LION

ON MULE DEER POPULATIONS

Maurice Hornocker Unit Leader

Idaho Cooperative Wi ld l i fe Research Unit College of Forestry, Wi ld l i fe and Range Sciences

Universi ty of Idaho Moscow, Idaho 83843

Any discussion of the inf luence o r e f f e c t of m u n t a i n l i o n predat ion on prey populations becomes, of necess i ty , a discussion of predator-prey re la t ionsh ips . The reason is obvious - the re a r e p r a c t i c a l l y no da ta ava i l ab le on lion-prey i n t e r a c t i o n s . Lions a r e known to k i l l deer wherever t h e two spec ies occur together b u t t h i s merely e s t a b l i s h e s the f a c t . The e f f e c t of t h i s k i l l i n g on deer numbers - t h e ' r e a l l y meaningful and important a spec t to consider - has sca rce ly been looked a t i n an ob jec t ive way.

Therefore, today we a r e a b i t l imited. We c a n ' t c r i t i c a l l y review the l i t e r a t u r e because the re i s n ' t any. We w i l l discuss what is known of l i o n s and t h e i r e f f e c t on prey from research thus f a r reported. We w i l l t a l k about the p o s s i b l e inf luence and e f f e c t , o r l ack of e i t h e r , of l i o n s on mule deer populat ions and the f a c t o r s t h a t a r e important i n these re la t ionsh ips . We'll a l s o consider some negat ive evidence concerning the e f f e c t of l i o n predat ion, t h e r o l e con t ro l might play, and needed research.

I don' t intend t o launch i n t o a general ized discussion of predat ion - I don' t be l i eve t h a t ' s necessary here. It w i l l , however, be he lp fu l to out- l i n e a few of the things b a s i c to predator-prey re la t ionsh ips . None of these a r e my o r i g i n a l thoughts - they a r e those of numerous authors s e t down over a long period of time.

F i r s t , what a r e the poss ib le e f f e c t s of l i o n predat ion ( o r any predat ion f o r t h a t matter) on prey populations?

1. The predator can be s t rong ly l i m i t i n g t o the po in t of reducing t h e prey to e x t i n c t i o n o r near ex t inc t ion .

2 . The predator can be regulatory i n t h a t it helps keep prey populat ions wi th in the carrying capaci ty of t h e i r resources, o r another way, it con- t r i b u t e s to a s teady s t a t e i n t h e dens i ty of the prey.

3. The predator may be n e i t h e r l i m i t i n g nor regu la t ing ; i n o t h e r words, the predator is i n s i g n i f i c a n t i n the population dynamics o f t h e prey.

Which s i t u a t i o n e x i s t s between t h e predator and its prey depends on d i f f e r e n t f a c t o r s . Leopold (1933) c l a s s i f i e d these i n t o 5 groups:

1. dens i ty of the prey populat ion

2 . dens i ty of t h e predator populat ion

3. c h a r a c t e r i s t i c s of t h e prey

4. dens i ty and q u a l i t y of a l t e r n a t e foods ava i l ab le f o r t h e predator

5. c h a r a c t e r i s t i c s of t h e predator

Each of these va r iab les may e x e r t considerable inf luence and the e f f e c t of any one may depend upon changes i n another . Considered separa te ly each t e l l s l i t t l e b u t when considered i n combination, sound i n t e r p r e t a t i o n s of t h e re la t ionsh ips can be made.

Further , i t is important t o know the h i s t o r y of i n t e r a c t i n g populat ions. Did the spec ies evolve together? Is t h e r e l a t i o n s h i p an o l d one o r is it of recen t o r ig in? I s the ecosystem s t a b l e o r changing? Knowing t h i s , we can make some general s ta tements :

1. The l i m i t i n g e f f e c t s of predat ion tend t o be reduced and t h e regulatory (or s teady s t a t e ) e f f e c t s increased where t h e i n t e r a c t i n g populat ions have a comnnn evolut ionary h i s t o r y and they occur i n a r e l a t i v e l y s t a b l e ecosystem.

2. Violent predator-prey i n t e r a c t i o n s happen frequently when t h e i n t e r a c t i o n is of recen t o r i g i n o r when the re has been recen t l a r g e s c a l e d i s tu r - bance of t h e ecosystem by c l i m a t i c change, n a t u r a l holocaust , o r by man.

So much f o r the poss ib le e f f e c t s of predat ion. What a r e its inf luences?

1. Predat ion can dampen and p r o t r a c t v i o l e n t f luc tua t ions i n numbers of prey animals. Damping can a c t t o reduce range damage and se r ious over- s tocking may be averted u n t i l such time a s o ther l i m i t i n g fo rces , such a s disease, may come i n t o operat ion.

2 . Predat ion is a l s o a s t rong s e l e c t i v e fo rce a c t i n g t o remove prey ind iv idua l s possessing l e s s d e s i r a b l e adapt ive charac te r s .

3. Predators may a l s o a c t to d i sperse prey animals and thus cause them t o be more evenly dis- t r i b u t e d on c r i t i c a l range.

The Possible Influence of the Mountain Lion

These a r e the t h e o r e t i c a l poss ib le e f f e c t s and inf luences of mountain l i o n s on mule deer populat ions. What i s the real-world evidence f o r any of these re la t ionsh ips? This i s , o r could be, q u i t e important a t a time when we a r e experiencing a region-wide decl ine i n mule deer populat ions.

Unfortunately we don't have much information. Published information l a rge ly , again, deals with the f a c t , no t the e f f e c t . There a r e s e v e r a l research p ro jec t s cur ren t ly under way, bu t most of them a r e i n t h e i r e a r l y s t a g e s . The work by my colleagues and I i s the only recent published da ta on the i n t e r - ac t ion of l i o n s and mule deer and t h e e f f e c t s of t h a t l i o n predat ion. I n 10 years of s tudy we found t h a t l i o n s were not l i m i t i n g populat ions of mule deer i n a wilderness environment i n c e n t r a l Idaho. Their predat ion had l i t t l e e f f e c t on u l t imate numbers of mule deer during t h i s period. The deer populat ion increased s t e a d i l y during the f i r s t f i v e years , s t a b i l i z e d and remained s t a b l e f o r the remainder of the p r o j e c t . A t the same time t h e mountain l i o n population remained s t a b l e because of a f a i r l y r i ~ i d system of t e r r i t o r i a l i t y . In t h i s s i t u a t i o n under these ecological condit ions, l i o n predat ion was con- s idered benef ic ia l .

Harley Shaw (pers . comm.) of the Arizona Game and Fish Department has worked with a l i o n population f o r severa l years i n Arizona. He has assessed the l i o n k i l l of domestic s tock and has recorded k i l l s of deer . Shaw concludes tha t l i o n predat ion i s an important f a c t o r i n determining mule deer numbers on h i s study a rea . He be l i eves t h a t deer numbers could be increased on h i s a r e a by removing l i o n s .

These d i f f e r i n g r e s u l t s point up the f a c t t h a t d i f f e r i n g eco log ica l u n i t s have t h e i r own proper t i e s and each must be looked a t ind iv idua l ly i f v a l i d i n t e r p r e t a t i o n s a r e to be made. This i s p a r t i c u l a r l y important with the mountain l i o n , a reasonably adaptable p reda to r .

We a r e , of course, s p e c i f i c a l l y concerned about the mule deer decl ine. I t is v a l i d to quest ion what r o l e l i o n s play i n t h i s dec l ine . Lacking ob jec t ive da ta , i t may prove use fu l t o examine p a s t h i s t o r i e s of i n t e r a c t i n g populat ions.

I t i s general ly accepted t h a t mule deer popula- t ions peaked i n western North America during the period 1940-1970. During t h i s time, mountain l i o n s were regarded as vermin i n a l l western s t a t e s , and unregulated k i l l i n g was encouraged. We could po in t to t h e con t ro l of l i o n s a s the f a c t o r responsible f o r high deer numbers, bu t the re i s negat ive evidence t o r e f u t e t h i s . F i r s t , the dec l ine began before unregu- l a t e d l i o n k i l l i n g ceased. Deer numbers rose s i m i l a r l y during t h i s period i n a reas where the re was no l i o n con t ro l a t a l l - i n severa l of our l a r g e na t iona l parks and some of t h e l a r g e r r e l a t i v e l y inaccess ib le wilderness a reas . Similar negat ive evidence i s ava i l ab le today - the dec l ine of mule deer appears uniform throughout the West i n a reas where few o r no l i o n s occur as we l l a s a reas where they a r e bel ieved to be numerous. Further , white- t a i l deer populations a r e not dec l in ing . On the contrary, they appear to be f lour i sh ing , a t l e a s t i n the Northwest, both where l i o n s occur and where they do no t .

So we r e a l l y don' t know a g rea t dea l about the e f f e c t and inf luence of mountain l i o n s on mule deer throughout t h e i r range. We do know t h a t once prey population s i z e i s lowered then any depressing f a c t o r may have a proport ionately g rea te r e f f e c t on t h a t prey populat ion, ac t ing to depress i t even f u r t h e r . It appears self-evident t o many people t h a t removal of any depressing inf luence w i l l r e s u l t i n g rea te r numbers of a prey species . Predators a r e the most obvious of the depressing fac to rs and n a t u r a l l y a t t r a c t t h e most a t t e n t i o n . It is here t h a t pub l ic and p o l i t i c a l pressure comes f o r con t ro l . We know t h a t predator con t ro l i n some cases w i l l ob ta in the des i red r e s u l t s . We a l s o know t h a t these r e s u l t s o f ten a r e short- l ived and do n o t solve the long-range problem. Further , t h e cos t s a r e high, both i n an economic and ecologic sense a s pointed out by authors from Er r ing ton ' s time on. To these we can now add c u l t u r a l cos t s - publ ic r e l a t i o n s problems. At the same time, some con t ro l programs w i l l always be i n i t i a t e d on a b a s i s of p o l i t i c a l o r emotional expediency only, with no b io log ica l o r eco log ica l considerat ions a t a l l .

To r e c t i f y t h i s s i t u a t i o n we need t h e r i g h t kind of research. This research needs t o address i t s e l f , simultaneously and concurrent ly, t o t h e predator populat ion, the prey populat ion, and an assessment of the prey h a b i t a t . Further, the e f f e c t s , and no t merely the f a c t , of the predat ion on the prey populat ion should be t h e foremost ob jec t ive . Too o f t e n i n t h e pas t , t h i s kind of research has go t ten side-tracked on predator biology only, on the reveal ing f a c t s of predat ion (gee whiz, these c r i t t e r s are s u r e knocking o f f the deer!) , on i r r e l e v a n t f a c t s of a l l kinds. These things a r e important, bu t the r e a l i s sue , the e f f e c t s of preda- t ion , a r e never r e a l l y learned. At t h e same time we need to s tudy populations not subjected to predat ion - what happens t o deer population l e v e l s i n the absence of predat ion? This o f t e n i s long- term research and s o f a r f edera l and s t a t e agencies havea ' t been eager t o provide funding. But short- term e f f o r t s won't help.

I f I may, I ' d l i k e t o quote from some things I s a i d about predators and predator con t ro l i n 1972 . I be l i eve these comments s t i l l a r e v a l i d , and a r e appropriate f o r a discussion of our understanding of mountain lion-mule deer in te rac t ions :

"We need t o know more of t h e biology and ecology of predatory species . We need t o know more about se l f - regu la t ing mechanism and how they can be used to advantage. We need t o s tudy and compare, simultaneously, exploi ted and unexploited populat ions. We need t o recognize the gene t ic d i f fe rences between populations of predators and prey t h a t have evolved together and those t h a t have not . We need ob jec t ive assessments of the socio- economics of predator management. We need research on a l t e r n a t i v e s to d i r e c t k i l l i n g , o r reduct ion control . . . . I be l i eve the app l ica t ion of spec ies biology, a s suggested by Knowlton (1972), i s the key to f u t u r e predator management. But f i r s t , we must know species biology."

The E'ossib d Influence of the Mountain Lion

Summing up:

1. We don' t have much ob jec t ive da ta concerning lion-mule deer re la t ionsh ips .

2. Lion predat ion, l i k e any o ther predat ion, under c e r t a i n condit ions a c t t o l i m i t prey popu-

l a t i o n s . When a prey population is lowered d r a s t i - c a l l y by whatever f a c t o r then any depressing f a c t o r gains more importance. I n t h i s s i t u a t i o n , predator con t ro l may help, b u t usua l ly doesn ' t so lve the problem.

3. Lion predat ion, l i k e any o ther predat ion, normally is i n e f f e c t i v e i n d r a s t i c a l l y reducing numbers of prey spec ies when t h a t prey spec ies has s u i t a b l e h a b i t a t .

4. Predator con t ro l is a v a l i d w i l d l i f e management t o o l , b u t i f s u i t a b l e h a b i t a t is no t a v a i l a b l e f o r a prey spec ies , then no amount of predator con t ro l w i l l b r i n g about f lour i sh ing populat ions of t h a t prey spec ies .

Mountain l i o n s and mule deer evolved together i n the West. Both have survived, o f t e n f lourished. Their r e l a t i o n s h i p is a s impl i f i ed s t r a i g h t l i n e one: H a b i t a t j m u l e d e e r 3 l i o n s . Mule deer depend on h a b i t a t , l i o n s depend on mule deer . I f we improve h a b i t a t , we can inc rease the numbers of deer i n the long run; i f we decrease l i o n s only, wi th no h a b i t a t change, the r e s u l t s won't be the same.

LITERATURE CITED

Hornocker, M. G. 1972. Predator ecology and management - what now? J. Wildl. Manage. 36:401-404.

Knowlton, F. F. 1972. Preliminary i n t e r p r e t a t i o n s of coyote populat ion mechanics with some management implicat ions. J. Wildl. Manage. 36: 369-382.

Leopold, A. 1933. Game management. Charles Scribners Sons, New York. 481pp.

109 The Possible Inftuence of the Mountain Lion

POTENTIAL INnUENCE OF COYOTES

ON MULE DEER POPULATIONS

Frederick F. Knowlton

U. S. Fish and Wildlife Service Logan, Utah

Abstract

There have been no comprehensive studies of the influence of coyotes upon populations of mule deer. Such a study of a white-tailed deer herd in Texas indicated that coyote predation was a major mortality factor among new-born fawns, accounting for 53 to 75 percent of the fawns born. Coincidental observations, however, showed that other environmental factors were important mediators of the percent of fawns killed by coyotes. Precipitation, as it influenced the quality and quantity of forage available to does. affected the number, size and vigor of fawns born. This was secondarily reflected in the survival rates of fawns and ultimately in the sex ratio of the adult portion of the herd. Exclusion of coyotes from a portion of the herd resulted in increased survival rates of fawns during the first three months after birth, but in subsequent years these gains were offset by increased mortality in later months. Observations from several mule deer and black-tailed deer herds seem consistent with these interpretations. In addition to their impact during the neonatal period, coyotes may kill significant numbers of deer, primarily those under one year old, in mountainous areas where winters are harsh. Malnutrition appears to be a common "facilitator" in many of these cases of predation. In summary, it is apparent that coyotes kill and eat substantial numbers of deer, but the evidence suggests nutritional health of the deer is an important arbitor of many environmental effects, including predation. There are some indications that increased fawn survival can be achieved for brief periods and that deer populations can react more quickly to favorable environmental circumstances in the absence of coyotes. Whether these effects can be translated into a greater abundance, or harvest, of deer remains to be demonstrated.

In assembling and synthesizing the fragments of data that might convey some information about the potential impact of coyotes upon mule deer populations, I feel like a novice paleontologist at the edge of some prehistoric bone pile. Collecting and examining each "specimen," I am haunted by questions of propriety. Is each really part of the same entity or phenomenon? Are we indeed looking at a common process, and do we have the "pieces" arranged appro- priately? If not, we may be placing the foot of a Brontosaurus upon a Pterodactyl fitted with the head of a Tvrannosaurus.

To maintain some semblance of order in this presentation, I chose to synthesize from a sequence of studies of coyotes and white-tailed deer and then seek analogs among the data available for coyotes and mule deer.

Throughout. I have relied heavily on researches and data provided by others. I am grateful to the individuals who were so willing to share.

111 Potential Influence of Coyotes

THE WELDER DEER STORY Some Rela ted Observat ions

The 7,800-acre Welder W i l d l i f e Refuge on t h e Texas Gulf Coast ha rbo r s a herd of 1,100 t o 1,600 d e e r (1 dee r p e r 5-7 a c r e s ) . The herd is e s s e n t i a l l y nonmigratory and t h e on ly "hunt ing" r e s u l t s from co l - l e c t i o n s made t o a s s e s s b i o l o g i c a l parameters . The d e e r a r e g r a z e r s , f eed ing p r i m a r i l y on g r a s s e s and he rbs yea r around, (Chamrad and Box 1968) . Forage c o n d i t i o n s may become r e s t r i c t i v e du r ing t h e c o o l w i n t e r months a s w e l l a s t h e h o t , d ry summers.

Genera l B io log i c Parameters

We determined from t h e number of ova and f e t u s e s produced (Table 1 ) t h a t g r o s s p r o d u c t i v i t y was h igh (K= 169 and 163 pe r 100 does r e s p e c t i v e l y ) w i th r e l a t i v e l y l i t t l e m o r t a l i t y through g e s t a t i o n . By January 1 , however, t h e number of fawns was reduced dpp rec i ab ly , w i th mean c a l c u l a t e d s u r v i v a l r a t e s approximate ly 34 pe rcen t (Table 2 ) . Considerable yea r t o yea r v a r i a t i o n i n t h e o v u l a t i o n r a t e s , num- b e r s of f e t u s e s produced, and s u r v i v a l of fawns through the f i r s t s i x months was appa ren t .

Two s o u r c e s of i n fo rma t ion were used t o d e f i n e t h e pe r iod when most fawns were l o s t . On the b a s i s of t h e remains of 174 fawns found dead i n t h e f i e l d , most d i e d w i t h i n t h e f i r s t 3 weeks a f t e r b i r t h (Fig . 1 ) . Minimum s u r v i v a l of fawns tagged and marked s h o r t l y a f t e r b i r t h , a l s o suggested t h e major- i t y were l o s t w i t h i n t h e f i r s t 21 days of l i f e (F ig . 2 ) . Both d a t a s e t s sugges t t h e f i r s t t h r e e weeks post-partum i s c r i t i c a l t o fawn s u r v i v a l .

Concurrent s t u d i e s of t h e f eed ing p a t t e r n s of coyo te s on t he Welder Refuge sugges t t h a t dee r com- p r i s e d n e a r l y 40 pe rcen t of t h e annua l d i e t of coyo te s (Knowlton 1964) . There were two p e r i o d s when d e e r were p a r t i c u l a r l y impor t an t i n t h e d i e t . During t he summer, co inc id ing w i t h t h e fawning p e r i o d , d e e r comprised up t o 80 pe rcen t of t h e coyo te d i e t (F ig . 3 ) . Another pe r iod of heavy use of d e e r was noted i n w i n t e r .

To determine t h e n a t u r e of t h e r e l a t i o n s h i p between t h e l a r g e l o s s of neo-nata l fawns and heavv

While ana lyz ing t h e d a t a from t h e s e s t u d i e s , we noted s e v e r a l i n t r i g u i n g r e l a t i o n s h i p s . The a d u l t s e x r a t i o of t h i s unhunted dee r popu la t i on approxi- mated 40 males pe r 100 females . Furthermore, ex t r ap - o l a t i o n s of age r a t i o r e g r e s s i o n s (Fig . 4) combined wi th t h e a d u l t s e x composi t ion of t h e herd suggested 10.7 male and 17 .0 female fawns p e r 100 a d u l t s needed t o s u r v i v e u n t i l January 1 t o ma in t a in t h e he rd s i z e and s t r u c t u r e . This imp l i e s t h a t t h e s e x r a t i o among fawns s u r v i v i n g t o s i x months of age should be 63 males:100 females . Small samples of f a l l - t r a p p e d fawns r evea l ed a r a t i o of 55.6 t o 100, ve ry c l o s e t o t h e c a l c u l a t e d f i g u r e . S ince t h e f e t a l s e x r a t i o was 117 males pe r 100 females , twice a s g r e a t a m o r t a l i t y r a t e is sugges t ed f o r male fawns a s compared t o female fawns.

V a r i a t i o n s i n g r o s s p r o d u c t i v i t y ( t h e number of ova and /o r f e t u s e s produced) appear r e l a t e d t o p r e c i p a t i o n i n t h e yea r p r i o r t o concept ion (F ig . 5 ) . Th i s was p r i m a r i l y a f u n c t i o n of t h e f requency of twinning r a t h e r t han changes i n t h e pe rcen t of does t h a t became p regnan t . P r e c i p i t a t i o n p a t t e r n s a l s o appear t o e f f e c t changes i n t h e temporal a s p e c t s of t h e fawn drop, p o s s i b l y a s much a s 10 t o 14 days . An advance i n p a r t u r i t i o n d a t e s could be expected fo l l owing y e a r s of above normal p r e c i p i t a t i o n and a de l ay i n p a r t u r i t i o n s f r e q u e n t l y fo l lowed more z e r i c c o n d i t i o n s .

Net p r o d u c t i v i t y , which is l a r g e l y a f u n c t i o n of fawn s u r v i v a l r a t e s , appeared t o be r e l a t e d t o t h e amount of p r e c i p i t a t i o n du r ing g e s t a t i o n (F ig . 6 ) . When p r e c i p i t a t i o n was p l e n t i f u l , fawn s u r v i v a l was h i g h e r than when r e l a t i v e l y l i t t l e p r e c i p i t a t i o n f e l l .

As a r e s u l t , we were f aced w i th t h e dilemma of t r y i n g t o e x p l a i n e x c e s s i v e fawn l o s s e s , a p p a r e n t l y r e s u l t i n g from coyo te p r e d a t i o n bu t whose e f f e c t is mediated by p r e c i p i t a t i o n . Furthermore, we had t o account f o r a n appa ren t "preference" of coyo te s f o r male fawns.

Cur r en t I n t e r p r e t a t i o n s

f eed ing upon fawns by coyo te s , Cook e t a l . (1967) i n i t i a t e d a program o f p l a c i n g r a d i o t r a n s m i t t e r s on

F r u i t i s a n impor tant c o n s t i t u e n t of t h e coyo te

young fawns t o f a c i l i t a t e s u r v e i l l a n c e ove r an d i e t (Fig . 7 ) . Following y e a r s of below ave rage

extended p e r i o d . As r e p o r t e d by White (1966), 8 1 p r e c i p i t a t i o n , when concept ion is de l ayed , p a r t u r i -

fawns were tagged wi th r a d i o t r a n s m i t t e r s . F i f t y t i o n of dee r f a l l s midway between s p r i n g and summer

e i g h t (72 p e r c e n t ) of t h e s e fawns d i ed w i t h i n t h e f r u i t i n g p e r i o d s (F ig . 8 ) . When r a i n f a l l ha s been

nex t few months. ~ i f ~ ~ - ~ h ~ ~ ~ percent apparently died abundant , concept ion and fawning a r e advanced by 10

a s a d i r e c t r e s u l t of predation and an add i t i ona l 22 o r more days . T h i s , coupled w i t h a h i g h e r i nc idence

pe rcen t had been f e d upon by coyo te s , b u t d i r e c t of twinning, r e s u l t s i n : ( a ) a major p o r t i o n of t h e

ev idence t h a t coyo te s had k i l l e d t h e fawns was ob- fawn d rop occu r r ing wh i l e t h e coyo te s a r e "still i n

s cu re . Thus coyo te s appear t o have been r e s p o n s i b l e the berry patch;" and (b) over-saturati0n with

f o r t h e dea th of between 53 and 75 pe rcen t of t h e fawns f o r a s h o r t pe r iod w i t h coyo te s be ing unab le

ins t rumented fawns. t o t a k e f u l l advantage of t hose a v a i l a b l e . Both phenomena enhance fawn s u r v i v a l

I f ou r a n a l y s e s had t e rmina t ed a t t h i s p o i n t , we would have been p r o f e s s i o n a l l y n e g l i g e n t n o t t o con- I n a d d i t i o n , f e t a l growth r a t e s a r e g r e a t e r

c l u d e t h a t t h e h igh p o s t n a t a l l o s s of fawns was a d u r i n g wet y e a r s t han d ry ( ~ n o w l t o n and White, i n

s i g n i f i c a n t fac tor influencing herd dynamics and that p r e s s ) r e s u l t i n g i n a 20 p e r c e n t d i f f e r e n c e i n t he

coyo te p r eda t ion was a primary f a c t o r i n t h e low mean b i r t h weight of fawns (Fig . 9 ) . Presumably

s u r v i v a l r a t e s observed. Fur thermore , t o enhance t h e Larger fawns a r e h e a l t h i e r and more v i a b l e . We

herd productivity, there seemed little else to sug- a l s o have d a t a i n d i c a t i n g t h a t t h e p o s t n a t a l growth

g e s t but t o e l i m i n a t e t h e "nas ty l i t t l e va rmin t s . " r a t e of male fawns is app rec i ab ly g r e a t e r than t h e i r female c o h o r t s (0.45 v s . 0.33 l b . / day r e s p e c t i v e l y ) .

Potential InfZuence of Coyotes

A t t h i s point i t does not seem inappropriate t o specu la te t h a t on t h i s area:

1. The n u t r i t i o n a l content of forage, both i n qua l i ty and quan t i ty , is r e l a t e d t o p rec ip i t a t ion ;

2. secondari ly , these e f f e c t s a r e r e f l e c t e d i n the number, s i z e and presumably v igor of the fawns a t b i r t h ;

3. such n u t r i t i o n a l considerat ions could be expected t o i n t e n s i f y during l a c t a t i o n when the energy and p ro te in demands on the does a r e maximal;

4. the e f f e c t s would probably be most pronounced among the animals with the g r e a t e s t n u t r i t i o n a l demands (male fawns) f o r growth and with the g r e a t e s t a c t i v i t y schedules (Jackson e t a l . 1972); and t h a t

5. the foregoing may be compounded by seeming s l i g h t changes i n the timing of the pa r tu ran t process and possibly even the a b i l i t y of a doe t o meet the n u t r i t i o n a l demands of the fawn.

Consequently, p ~ e c i p i t a t i o n operat ing through n u t r i t i o n , becomes a primary determiner of fawn surv iva l and u l t imate ly the sex r a t i o among the adu l t port ion of the herd (Fig. 10) . A t t h i s po in t i t i s important t o remember t h a t coyote predat ion i s a major instrument of t h i s dynamic process , but apparent ly p r e c i p i t a t i o n i s the programmer.

Ef fec t s of Excluding Coyotes

The obvious quest ion concerns the poss ib le e f f e c t s of e l iminat ing the impact of coyotes from the herd. In 1972 a 965-acre predator exclosure was completed. As reported by John Kie (pers . comm.), fawn surv iva l through 3-months postpartum was s ig - n i f i c a n t l y g rea te r i n s i d e the exclosure than ou t s ide during 1973; an e f f e c t which ca r r i ed through March of the next year. In 1974. t h e ga ins apparent i n e a r l y pos tna ta l su rv iva l wi th in the predator ex- c losure (compared t o ou t s ide ) were negated by increased mor ta l i ty i n l a t e r months (Table 3 ) .

F a l l dens i ty of deer i n s i d e the exclosure was near ly double t h a t ou t s ide a t the s t a r t of the study. Concurrent with the high fawn surv iva l i n 1973 and 1974, dens i ty ins ide near ly doubled. Subsequently, t h e population leveled off and/or decl ined (Fig. 11). I n t h e meantime, deer d e n s i t i e s ou t s ide t h e enclosure increased but a t a s u b s t a n t i a l l y lower r a t e and were s l i g h t l y lower than ins ide t h e exclosure by the spring of 1976.

HOW DOES THIS APPLY TO MULE DEER?

There i s l i t t l e doubt t h a t coyotes e a t mule deer . Horn (1941) reported about f o r t y percent of the coyote d i e t on the Los Padres National Forest was comprised of mule deer (Fig. 12) . I n Washington, Brigharn (1958) noted an abrupt inc rease ( t o over 50 percent) of deer fawn i n the coyote d i e t coincident with the fawning period. On the b a s i s of too th punctures and subcutaneous hemmorhages, Nielsen (1976) reported t h a t 28 of 31 deer found dead near Hardware Ranch i n Utah had been k i l l e d by coyotes. There a r e problems, however, i n t ry ing t o recons t ruc t

the circumstances surrounding these observat ions and i n assessing the population consequences.

The I n t e r s t a t e Deer Herd

On the bases of da ta provided by Salwasser (1976), it seems apparent t h a t the I n t e r s t a t e Deer Herd has been decl ining s i n c e the 19601s, precipi- tously i n the pas t 5-7 years (Fig. 13) . Gross p roduc t iv i ty has remained high, i n the v i c i n i t y of 150 fawns per 100 mature does. Fawn surv iva l , e spec ia l ly through summer and f a l l , has been decl ining s i n c e the mid-1950's (Fig. 14). As depicted i n Figure 15, the number of bucks per 100 does has a l s o decl ined (s ince the sex r a t i o da ta was co l l ec ted a f t e r the hunting season, the impact of the harvest upon the sex r a t i o should be kept i n mind). From an e a r l i e r paper (Salwasser 1974) i t is apparent t h a t coyotes i n comparable s i t u a t i o n s feed exten- s i v e l y on deer during the e a r l y pos tna ta l period (Fig. 16) . On the o ther hand, Eastman (pers . comm.) o f f e r s evidence suggesting the re has been no sub- s t a n t i a l change i n coyote abundance on the summer range of the I n t e r s t a t e Deer Herd (Fig. 17) which might account f o r the dec l ines noted i n su rv iva l and recrui tment within the deer herd.

The Steens Mountain Deer Herd

The s t a t e of Oregon has been concerned about decl ining deer product ivi ty i n the Steens Mountain a rea . As reported by Trainer (1975), 106 new-born fawns were captured and equipped with rad io t rans- m i t t e r s . F i f ty - f ive percent of the fawn mor ta l i ty wi th in the f i r s t 45 days of l i f e apparent ly was r e l a t e d t o predat ion. Coyotes were responsible f o r 69 percent of i t (Table 4) . However, s ince t h e l o s s of fawns t o coyotes did not exceed 10 percent , i t hardly seems t o be a p i v o t a l event among the herd dynamics.

There i s reason f o r concern, because a s Trainer po in t s out , the number of fawns per hundred does declined from 131 i n June t o 86 by September and 29 by March (Table 5 ) . This implies a 78 percent l o s s of fawns before one year of age. To address t h i s problem, fawns were radio-col lared i n e a r l y winter . Subsequently, 50 percent died between January and Apr i l , with coyotes the immediate cause of death i n 74 percent of the cases. It may be s i g n i f i c a n t , however, t h a t two t h i r d s of the carcasses examined revealed advanced s t a t e s of malnutr i t ion.

With t h i s i n mind, i t may be per t inen t t o re- c a l l t h a t Nielson (1975) reported t h a t 28 of 31 deer found dead during winter were k i l l e d by coyotes and t h a t 25 of the 28 were fawns. Since the " s t a t e

of heal th" i n these instances were not assessed, we can only ponder whether t h i s r epresen t s some general p a t t e r n .

Enclosures and Exclosures

To my knowledge, the re have been two "fencing experiments" which provided some information with regard t o the impact of predators on mule deer populat ions. The f i r s t involved the inadvertent

113 Potential InfZuence of Coyotes

Table 1. Gross productivity per 100 does among white-tailed deer on the Welder Wildlife Refuge (from White, 1966).

Year - 1961 1962 1963 1964 1965 1966

Average

Number of n - corpora lutea

-- --- 3 3 167 46 150 20 160 30 197 15 - 187 -

169

Number of fetuses

165 164 143 150 187 173 - 163

Table 2. Net productivity per 100 does among white- tailed deer on the Welder Wildlife Refuge (from White, 1966).

Year - 1961 1962 1963 1964 1965 1966

Average

Number fawns % fawn survival (January 1) (through 7 months)

51 41 26 2 1 13 13 48 40 72 54 50 - 38 - 42 34

Table 3. Fawns per 100 does inside and outside predator exclosure on Welder Wildlife Refuge (from Kie, pers. comm.).

Predator Outside Year Exclosure Exclosure - 1972 (Sept.) 45 45 1973 (Sept.) 66 28 1974 (Mar.) 47 31

(Sept.) 63 4 7 (Dec. ) 51 46

1975 (Mar. ) 45 43

--- -----

Table 4. Mortalities of mule deer fawns on Steens Mountain, Oregon (from Trainer, 1975).

% of % of Number total precedin): - -

Radio-instrumented 106 -- -- June-July mortality 29 27 27

Predation caused 16 15 55 Coyote induced 11 10 69

Table 5. Mule deer fawn mortality based on age ratios from Steens Mountain, Oregon (after Trainer 1975).

Fawns per X mortality % mortality Month 100 does from birth in interval - June 131 -- September 86 34 December 54 59 March 29 78

Table 6. Mule deer fawns per 100 does (January) inside and outside predator exclosure on Three Bar Ranch, Arizona (after LeCount 1974,1975).

Inside Rest of Year - Exclosure three bar

1971 22 26 1972 118 42 1973 82 70 1974 111 59

- 3

Age at death (weeks) Age class

Figure 1. Age at death of 174 fawns found dead on the Figure 4. Age ratio regressions for adult male and Welder Wltdlife Refuge (from White, 1966). female white-tailed deer on Welder Nild-

life Refuge (after Knowlton, 1964).

20 40 60 80 100 120 140 160

Days post partum

Figure 2. Minimum longevity of 128 tagged deer fawns Figure 5. Comparison of gross productivity of white- on Welder Wildlife Refuge (from Xnowlton, tailed deer on Welder Wildlife Refuge and 2964). precipitation in the year preceding con-

ception (after White, 1966).

Yigure 3. Percent of the coyote diet comprised of deer (after Knowlton, 1964).

Figure 6. Comparison of fawn survival to 6 months of age with precipitation during gestation (a£ ter White, 1966).

Figure 7 . Pe rcen t of coyote d i e t on Welder W i l d l i f e Refuge comprised of f r u i t ( a f t e r Knowlton, 1964) .

F igu re 8. Chronology of f r u i t and dee r i n t h e coyote d i e t du r ing a "dry" yea r on t h e Welder I J i l d l i f e Refuge ( a f t e r Knowlton, 1964).

F igu re 9. F e t a l growth r a t e s of w h i t e - t a i l e d dee r du r ing pe r iods of h i g h and low p r e c i p i t a - t i o n (from Knowlton and White i n p r e s s ) .

F igu re 10. Comparison of annual p r e c i p i t a t i o n , fawn s u r v i v a l , and sex composi t ion w i t h i n t h e a d u l t p o r t i o n of t h e Welder w h i t e - t a i l herd ( a f t e r White, 1966).

F i g u r e 11. Deer d e n s i t i e s w i t h i n and o u t s i d e t h e p reda to r exc losu re on t h e Welder Refuge (from Kie pe r s . comm.).

GO

+ 40 .- n "- 20

P)

2 a

F M A M J J A S

Figure 12 . Pe rcen t f requency of mule dee r i n t h e coyote d i e t on Los Padres Na t iona l Fo res t (from Horn, 1941) .

Figure 13. Relative abundance of mule deer in the Interstate area, 1949-1973 (from Salwasser, 1976).

Figure 14. Estimated fawn survival rates for the Interstate mule deer herd between 1954 and 1974 (from Salwasser, 1976).

1-15 16-30 1-15 16-34 1-15 16-31 J U N E J U L Y AUGUST

Figure 16. Percent occurrence of mule deer fawn in the coyote diet in the North Kings deer herd (from Salwasser, 1974).

Figure 17. Index of coyote abundance on the summer range of the Interstate deer herd (from Eastman pers. comm.)

Figure 15. Post-harvest sex ratio in the Interstate deer herd 1950 through 1974 (from Salwasser, 1976).

enc losu re of one coyo te w i th a group of mule dee r i n C e n t r a l Utah. As r epo r t ed by Rob ine t t e and Olson (19441, p r o d u c t i v i t y was 49 pe rcen t lower i n t he p a s t u r e w i th t h e coyote a s compared t o a n a d j a c e n t p a s t u r e w i th no coyo te s .

A p reda to r exc losu re was b u i l t on t h e 3-Bar Ranch i n Arizona i n 1971. According t o LeCount (1974, 1975) , n e t p r o d u c t i v i t y w i t h i n t h e exc losu re s (measured i n January) averaged n e a r l y twice t h a t observed on t h e r e s t of t h e 3-Bar Ranch (Table 6 ) . The number of d e e r w i t h i n t h e e n c l o s u r e was r e l a - t i v e l y s m a l l and s u b s t a n t i a l f l u c t u a t i o n s i n produc- t i v i t y were e v i d e n t . It is a l s o i n t e r e s t i n g t h a t t h e lowest p r o d u c t i v i t y o u t s i d e t h e e n c l o s u r e was i d e n t i f i e d w i th a d rough t , and t h e h i g h e s t produc- t i v i t y w i th a yea r of abundant p r e c i p i t a t i o n .

SUMMARY

At t h e o u t s e t , i t i s e s s e n t i a l t o r ecogn ize t h a t coyo te s e a t and k i l l d e e r . It is e q u a l l y impor t an t t o r ecogn ize t h a t o t h e r environmenta l f a c t o r s may be impor tant med ia to r s of t h e impact p r e d a t o r s may have on d e e r popu la t i ons . I n some i n s t a n c e s , p r e d a t i o n may be symptomatic of o t h e r environmenta l d e f i c i e n - c i e s . C e r t a i n s i m i l a r i t i e s between s t u d i e s on mule d e e r and t h e Welder w h i t e t a i l herd a r e i ne scapab le .

Evidence a t t h i s p o i n t sugges t s t h e n u t r i t i o n a l s t a t u s of t h e d e e r may be a key t o a h o s t of environmenta l e f f e c t s ; e f f e c t s which f r e q u e n t l y syn- e r g i z e i n n a t u r a l environments. Within t h e Welder he rd , t h e number, s i z e , h e a l t h and s u r v i v a l of fawns appea r s c l o s e l y l i nked t o t h e q u a l i t y of food a v a i l - a b l e t o t h e doe. Some p a r a l l e l s seem a p p r o p r i a t e among mule d e e r . A d d i t i o n a l l y , n u t r i t i o n a l h e a l t h of mule dee r i n w i n t e r may c o n t r i b u t e t o t h e impact of coyo te s a t t h a t season. While i t may be r e l a - t i v e l y easy t o a s s e s s t h e " n u t r i t i o n a l s t a t e " of t he w i n t e r range, we may no t y e t be prepared t o d e f i n e , much l e s s e v a l u a t e , t h e l a t e g e s t a t i o n and fawning r anges which appear s o v i t a l t o t h e v i g o r and s u r v i v a l of fawns.

The deg ree t o which d e e r abundance can be i n f luenced by removal of coyo te s remains t o be demonst ra ted . Research is c u r r e n t l y under way. Some ev idence i s a v a i l a b l e sugges t i ng s h o r t te rm e f f e c t s of i nc rea sed fawn s u r v i v a l f o r b r i e f p e r i o d s can b e achieved through e l i m i n a t i o n of coyo te s . There is a l s o evidence t h a t d e e r popu la t i ons may b e a b l e t o r e a c t more qu i ck ly t o f a v o r a b l e environmenta l c i r - cumstances i n t h e absence of coyo te s .

On t h e o t h e r hand, I am r e l u c t a n t t o sugges t t h e r e is c u r r e n t l y any ev idence t h a t we can enhance d e e r abundance ove r e x t e n s i v e p e r i o d s of t ime s o l e l y through t h e removal of coyo te s . I n s h o r t , my f i n a l , d e f i n i t i v e and i r r e v o c a b l e judgment w i th r ega rd t o t h e p o s s i b l e i n f l u e n c e o f coyo te s on mule d e e r popu la t i ons is.. ."Maybe!"

L i t e r a t u r e Ci ted

Brigham, J . H . 1958. Ea r ly m o r t a l i t y i n b lack- t a i l e d dee r i n wes t e rn Washington. M.S. Thes i s . Wash. S t a t e Univ., Pullman. 47 pp.

Chamrad, A. D . , and T . W . Box. 1968. Food h a b i t s of wh i t e - t a i l ed dee r i n South Texas. J . Range Mgmt. 21(3):158-164.

Cook, R. S . , M . White, D . 0 . T r a i n e r and W . C. Glazener . 1967. Radio-telemetry f o r fawn m o r t a l i t y s t u d i e s . Bu l l . Wildl . Dis . Assoc. 3(4) :160-165.

Horn, E. E . 1941. Some coyo te -wi ld l i f e r e l a t i o n - s h i p s . Trans . N . Amer. Wildl . Conf. 6:238-287 ( I n Young, S. P. and H. H . T. Jackson. 1951. The Clever Coyote. The S t ackpo le Co., Ha r r i sbu rg and Wildl . I n s t . , Wash. D.C. 411 PP.)

Jackson, R. M . , M. White and F. F. Knowlton. 1972. A c t i v i t y p a t t e r n s of young wh i t e - t a i l ed dee r fawns i n South Texas. Ecology 53(2):262-270.

Knowlton, F. F. 1964. Aspects of coyo te p r e d a t i o n i n South Texas w i th s p e c i a l r e f e r e n c e t o white- t a i l e d d e e r . Ph.D. D i s s e r t . Purdue Univer . , La faye t t e . 189 pp.

Knowlton, F. F. and M. White. I n p r e s s . Weight p a t t e r n s of w i ld w h i t e - t a i l e d dee r i n South Texas. J . Wi ld l . Mgmt.

Le Count, A. L . 1974. Causes of fawn m o r t a l i t y . Perform. Repor t . , P r o j . No. W-78-R-l8,WP2,Jll, Ar iz . 6 pp. ( m u l t i l . ) .

Le Count, A. L. 1975. Causes of fawn m o r t a l i t y . Perform. Repor t . , P r o j . No. W-78-R-l9,WPZ,Jll, Ar i z . 3 pp. ( m u l t i l . ) .

Nie lson, D. B. 1975. Coyotes and dee r . Utah S c i . 38 (3) :87-90.

Rob ine t t e , W. L. and 0. A. Olson. 1944. S t u d i e s of t h e p r o d u c t i v i t y of mule dee r i n c e n t r a l Utah. Trans N. Amer. Wildl . Conf. 9:156-161.

Sa lwasse r , H. 1974. Coyote s c a t s a s a n i n d i c a t o r of t ime of fawn m o r t a l i t y i n t h e North Kings d e e r he rd . C a l i f . F i s h and Game 60(2):84-87.

Salwasser , H. 1976. S t a t u s and t r e n d s of t h e D e v i l ' s Garden I n t e r s t a t e Mule Deer Herd, 1975. I n t e r s t a t e Wi ld l . Study Newsle t ter 4:17-31.

T r a i n e r , C. 1975. D i r e c t c auses of m o r t a l i t y i n mule dee r fawns du r ing summer and w i n t e r p e r i o d s on S t eens Mountain, Oregon ... A Prog re s s Repor t . Proc . of Ann. Conf. of Western Assoc. of S t a t e Game and F i sh Commiss. 55:163-170.

White, M. 1966. Popu la t i on ecology of some whi te- t a i l dee r i n South Texas. Ph.D. D i s s e r t . , Purdue Univ., L a f a y e t t e . 215 pp.

Potential Influence of Coyotes

MULE DEER DISEASE PROBLEMS

Annie K. Prestwood 1

Victor F. Nettles 1

Charles P. Hibler 2

Frank A. Hayes 1

'southeastern Cooperative Wildlife Disease Study CcQlege of Veterinary Medicine

University of Georgia Athens, Georgia 30602

L . Wild Animal Disease Center College of Veterinary Medicine and

Biomedical Sciences Colorado State University

Fort Collins, Colorado 80523

Abstract

Viral, bacterial, and parasitic diseases are considered important potential causes of mortality among mule deer populations. Various aspects on the pathologic manifestations and epizootiology are presented for the hemorrhagic disease complex (bluetongue and epizootic hemorrhagic disease), necrobacillosis, gastrointestinal trichostrongylosis and lungworm disease.

The importance of diseases affecting human and livestock health long has been recognized and is evidenced in the United States today by enormous expenditures by the Departments of Health, Education, and Welfare and Agriculture as well as by states and private philanthropic agencies. In contrast, diseases of free-living wild animals largely have been ignored, and only recently have+diseases of wildlife received attention. As a result, a relative dearth of knowledge exists on diseases affecting wild populations. This fact was all too evident when searching the literature for accounts of diseases affecting mule deer (Odocoileus hemionus). As a result, this presentation is largely speculative based on information derived from the literature and extrapolated from our experiences with diseases of white-tailed deer (9. virginianus) .

In 1969 we presented a list of 12 fundamental causes of morbidity and mortality among wildlife populations (Table 1) and described a process of elimination whereby potential causes of death could be narrowed from 12 to 3 or 4 (Hayes and Prestwood 1969). When considering diseases potentially capable of causing a widespread decline of mule deer populations, we applied this method of elimination. As a result, a list of diseases of potential importance to mule deer populations was compiled (Table 2).

Viral Diseases - Three viral agents producing two clinical syndromes, hemorrhagic disease (HD)

and malignant catarrhal fever (MCF) respectively, are considered threats to mule deer populations.

Table 1. Fundamental Causes of Morbidity and Mortality Among Wild Animal Populations

Anomalies Stress Trauma Suffocation Neoplasie Toxins Nutritional Deficiencies Viruses and Rickettsia Bacteria Fungi Parasites Senility

The so-called "hemorrhagic complex" consists of two viral diseases, bluetongue (BT) and epizootic hemorrhagic disease (EHD), which cannot be distin- guished clinically or by gross or microscopic lesions. Hemorrhagic disease is characterized by hemorrhage and vascular thrombosis with resultant necrosis of affected tissues.

Bluetongue is enzootic throughout much of the United States. In 1974 BT virus was recovered from

119 Mule Deer Disease Pro~Zems

also in feral cattle in contact with whitetails where 'Table 2. Diseases of Potential Importance for Mule HD was not recognized (Thomas and Prestwood 1976).

Deer Populations.

A. Viral Diseases 1. Hemorrhagic Disease Complex

a. Bluetongue b. Epizootic hemorrhagic disease

B. Bacterial Disease 1. Necrobacillosis

C. Parasitic Diseases 1. Gastrointestinal Trichostrongyles

a. Haemonchus contortus 2. Lungworms

a. Dictyocaulus viviparus b. Parelaphostrongylus odocoilei c. Parelaphostrongylus tenuis

herds of cattle in Colorado and Oregon and from sheep flocks in California, Idaho, New Mexico, Oregon, and Texas (Shoenfeld et al. 1974). In addition, BT-positive modified complement-fixation test reactors were detected in Arizona, Arkansas, California, Colorado, Florida, Idaho, Indiana, Kansas, Kentucky, Louisiana, Michigan, Missouri, Montana, Nebraska, Nevada, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, South Dakota, Texas, Utah, Virginia, Washington, Wisconsin, and Wyoming (Shoenfeld et al. ibid). This agent appears enzootic in the south Atlantic and Gulf coastal plain of the southeastern United States (Thomas and Prestwood 1976) and Texas (Hoff et al. 1974; Marburger et al. 1970). The virus of EHD similarly is widespread throughout much of the United States and Canada. Sero-positive EHD plaque reduction neutralization test reactors were found widely distributed among white-tailed deer populations of the southeastern United States prior to the 1971 epizootic of HD (Thomas and Prestwood 1976). Hemorrhagic disease has been seen annually in this region since that time.

During the 1975 epizootic of HD in New Jersey, only one virus--EHD--was isolated (Anon. 1976). This was in contrast to the 1971 outbreak in the Southeast where both BT and EHD viruses were involved (Prestwood et al. 1974). Similarly only EHD virus was isolated from deer dying of HD in North Dakota during 1971, however, sero-positive reactors to BT were found among hunter-killed deer following that mortality (Hoff et al. 1973).

The virus of BT disease is transmitted by biting aidges (Culicoides). Recent unpublished evidence suggests that EHD virus also is transmitted by this vector. Hemorrhagic disease is seasonal and usually occurs in the late summer and early fall when flies are abundant. Epizootics characteristically cease with the first frost.

Sheep are severely affected by BTV, and vaccina- tion is practiced by some sheep herders. Only occasionally is BT manifest clinically in cattle, however, these animals may harbor the virus inapparently for extended periods. This finding led to the hypothesis that cattle are reservoirs for BT virus (Bowne 1973).

The role of cattle in the epizootiology of EHD presently is unknown, however, antibodies to EHD have been detected among sentinel cattle placed in contact with white-tailed deer during an outbreak of HD and

Mule Deer Disease Problems

Although we were unable to locate published reports of clinical BT in mule deer, one of the authors (CPH) has recovered BT virus from captive mule deer which were dying of an acute hemorrhagic disease syndrome. Mule deer reportedly are relatively resistant to infection with EHD virus, and in outbreaks of EHD, carcasses of white-tailed deer outnumber those of mule deer 23 to 1. Sero-positive reactors to EHD virus were prevalent among mule deer following an outbreak of EHD in deer of North Dakota during 1970 and 1971, suggesting that they were similarly exposed to this viral agent (Hoff et al. 1973). The effects of BT and EHD viruses, particularly latent infections, in mule deer require further study before these diseases can be properly assessed for mule deer populations.

Acute and chronic hemorrhagic disease in white- tailed deer have been delineated (Prestwood et al. 1974). The primary pathogenic mechanism appears to be disseminated intravascular coagulation (Tsai and Karstad 1973). The acute disease is characterized by extensive hemorrhage and thrombosis. In chronic hemorrhagic disease, pathologic lesions are quite variable but reflect sequalae of vascular damage. These changes are most pronounced in the digestive tract but also may involve the coronary band and sensitive laminae of the hooves. Necrotic stomatitis, rumenitis, and omasitis often occur, and ulceration of the rwnenal pillars may be pronounced. Laminitis may be sufficiently severe to cause sloughing of the hooves. Fawns infected while nursing frequently exhibit severe destruction of the rumenal lining. These animals may survive initial infection only to succumb after weaning when the diet shifts to roughage. Starvation or predation are the usual fate for these animals. In adult survivors, secondary infections of the digestive tract and feet are usual sequalae. These lesions may be manifest as necrotic stomatitis, ulcerative rumenitis, or pyogenic infections of the feet. Involvement of the feet often is observed in hunter-killed deer. Infection of does during the early stages of gestation may result in absorption of fetuses or abortion (Thomas and Trainer 1970) and possibly stillbirths or malformed fetuses as observed with domestic livestock. The long term effect of BT on productivity of white- tailed or mule deer populations has yet to be explored.

Presumptive diagnosis of HD can be made on the basis of gross and microscopic lesions, however isolation and characterization constitute the only means for distinguishing the viruses of BT and EHD.

Malignant catarrhal fever (MCF) is a viral disease of domestic and wild ruminants characterized by catarrhal, mucopurulent, or necrotizing inflammation of the respiratory and digestive tracts and eyes. The disease is worldwide in distribution, and most outbreaks in North America are sporadic in occurrence. In the United States, MCF has been diagnosed in axis (Axis axis) and white-tailed deer in southern Texas (Clark et al. 1970; Clark and McConnell 1972), in white-tailed deer of New Jersey and Connecticut (Wyand et al. 1971), and in greater kudu (Tragelaphus strepsiceros) in Missouri (Bolver and Kurka 1974). Additionally, MCF has been recognized in American bison (Bison bison) and

captive mule deer in Colorado (Pierson et al. 1974). One of the authors (CPH) has experimentally transmitted MCF to mule deer. Among cattle the disease appears sporadically in sheep-raising areas of the midwest and west.

The mode of transmission of MCF is unknown, however the recent discovery of MCF virus in nasal secretions of blue wildebeest (Connochaetes taurinus) led to the hypothesis that nasal shedding of MCF virus may be a mechanism for transmission of virus among wildebeest and from wildebeest to cattle (Rweyemamu et al. 1974). In Africa, wildebeest are natural reservoirs of MCF virus. Sheep are considered natural reservoirs elsewhere.

In cattle, peracute, alimentary, head and eye, and mild forms of MCF have been described. Among deer, the disease was best described for axis deer (Clark et al. 1970). Axis deer with MCF were lethargic, emaciated, weak, ataxic, and apparently blind. Neurologic disturbance was present in some animals. Gross lesions consisted of corneal opacity, areas of alopecia encrusted with thick, dried exudate, greatly enlarged lymph nodes and enlarged arteries. Gross lesions in white-tailed deer ranged from none to hemothorax causing sudden death. Diagnosis of MCF is based on histologic lesions consisting of fibrinoid necrotizing vasculitis which are considered pathognomonic for this disease (Jubb and Kennedy 1970). Eye lesions and neurologic signs, when present, serve to distinguish MCF from BT and EHD.

Bacterial Diseases - Only one bacterial disease, necrobacillosis, is considered a serious threat to mule deer populations. The disease is caused bv ~usobacterium (=Spherophorus) necrophorum. Considerable controversy exists on whether F. necrophorum acts as a primary or secondary Tnvader. Jubb and Kennedy (1970) state, "In no instance has it yet been credited with the role of primarily pene- trating pathogen." Rosen (1970) considered F. necrophorum a probable opportunist awaiting an abrasion or injury to serve as an avenue for invasion.

Necrobacillosis has been diagnosed in a variety of wild cervidae, primarily in the western United States. It has been considered a major cause of mortality among mule deer in California (Rosen et al. 1951; Rosen 1970) and among wapiti (Cervus canadensis) of Wyoming (Murie et al. 1944 cited in Rosen 1951). Periodic outbreaks of necrobacillosis occur in many species of domestic livestock. Among sheep and cattle, frequently necrobacillosis is encountered when the environment is dark, dirty, damp, and overcrowded. Epizootics in California deer have occurred when animals have been overly concentrated near muddy water holes due to drought (Rosen et al. 1951). When the environment is sufficiently seeded with F. necrophorum organisms the disease apparently becomes contagious (Jubb and Kennedy 1970).

Lesions produced by F. necrophorum in mule deer are variable depending onthe site of infection. A foot rot syndrome often is present,which is characterized by necrosis of the interdigital tissue, inflammation of the coronary band and sensitive laminae, and extension into the proximal joint above the hoof (Rosen et al. 1951). Necrotic stomatitis, ulcerative rumenitis and abscesses in other organs also may occur.

Diagnosis of necrobacillosis is based on isolation of F. necrophorum from affected tissues. It should be mentioned that the lesions of chronic hemorrhagic disease with secondary bacterial infection in white-tailed deer are markedly similar to those described for necrobacillosis in mule deer. The role of BT virus in producing a portal of entry for F. necrophorum should be a fruitful area for future study.

Parasitic Diseases - Two major groups of nematodes, trichostrongyles and lungworms, are of potential significance in portions of the mule deer's range.

The gastrointestinal trichostrongyles infecting mule deer comprise several genera (Walker and Becklund 1970), and in areas where climatic conditions are conducive to parasitism, Haemonchus contortus s.l., the large stomach worm, is of particular importance. This helminth may cause considerable blood loss among fawns. The occurrence of H. contortus is worldwide, however it is locally more common in some areas than others even in humid environments. In the southeastern United States, for example, H. contortus is more prevalent and has a higher intensity of infection in deer of the lower coastal plain than in more upland terrain (Prestwood et al. 1972). The host range for H. contortus includes cattle, sheep, goats, and nwnerous wild ruminants. Although species of llaemonchus infecting cattle and sheep have been separated, the genus appears to be in a state of evolutionary flux. Das and Whitlock (1960) consider g. contortus to be actively evolving and that the species contains a number of well defined demes, each adapted to a particular host-microclimate interaction.

The principal effects of Haemonchus are due to anemia, which in heavily infected animals is accompanied by edema, emaciation, and generalized digestive disturbances. Both 4th stage larvae and adult 2. contortus cause blood loss. At necropsy submandibular edema ("bottle jawt'), enlarged lymph nodes, and thin, watery blood may be obvious. The lining of the stomach may be swollen, and have petechial hemorrhages with shallow ulcerations. Young deer usually are more heavily infected than the adults (Prestwood and Kellogg 1971).

Conditions that predispose animals to H. contortus also are conducive to heavy infections with other abomasal or intestinal trichostrongyles, and pure infections with a single species of nema- tode are uncommon. Similarly, nutritional status of the animal is of paramount importance since poor nutrition and parasitism often occur concomitantly. Although one helminth, e.g. H. contortus, may be the actual cause of death in deer, overcrowding, food shortage, and competition by other ruminants or swine are important contributing factors leading to death from gastrointestinal parasitism.

Two types of lungworms infect mule deer, viz. 1. those whose adult stage is found in the lung (Dictyocaulus viviparus) and 2. those whose adult stage occurs in sites remote from the lungs but whose eggs and larvae pass through the lungs to the external environment (Parelaphostrongylus spp.).

The large lungworm, Dictyocaulus viviparus, is located in the bronchi and bronchioles of mule deer

121 h Z e Deer visease Problems

where it produces a parasitic bronchitis. Dictyocaulus is worldwide in distribution, with increased prevalence in cool, moist areas. Like other trichostrongyles, D. viviparus has a direct life cycle. Cattle and various wild ruminants serve as definitive hosts for large lungworms, however, recent work has shown that Dictyocaulus of wild ruminant origin has low infectivity in cattle suggesting that there may be host specific strains of this helminth (Presidente et al. 1972, 1973; Gupta and Gibbs 1971).

In the southeastern United States, about 30 percent of white-tailed deer harbor D. viviparus. Infection is most prevalent and intense in young animals, particularly buck fawns. Dictycauliasis is seasonal in occurrence; the prevalence and intensity of infection are higher in late summer and early fall. The parasite is least common during the winter (Prestwood et al. 1971). Outbreaks of D. viviparus pneumonia have been recorded in captive black-tailed deer in Oregon (Presidente et al. 1973).

At necropsy, lesions caused by D. viviparus may be mild to severe. Extensive pneumonia may be present, and there may be numerous lungworms and exudate in the bronchi. Pleuritis and interlobular thickening may be obvious. Occasionally edema and enlarged lymph nodes and lymph vessels are detected. Lung damage may be particularly severe when first-stage larvae of Parelaphostrong* sp. also are present (Prestwood et al. 1971).

Mule deer may be infected by at least two species of Parelaphostrongylus, viz. P. odocoilei and P. tenuis. Parelaphostrongylus odocoileiis located adjacent to or within small vessels in the musculature of the hind- body of black-tailed and mule deer. It also has been found within small vessels in the lungs. This helminth has been reported only from deer of California (Hobmaier and Hobmaier 1934; Brunetti 1969) . Recently, however, similar protostrongylid larvae were found in the feces of mule deer from Western Canada (Samuel and Iiolmes 1'171). One of the authors (CPH) has seen protostrongylid larvae in feces of southwestern mule deer.

The life cycle of P. odocoilei is indirect. Eggs are deposited in the circulation and arrive as emboli in the lungs where hatching occurs. First-stage larvae ascend the bronchial passageways and trachea, are swallowed and eliminated with the feces. Various terrestrial snails and slugs (Helix aspersa, Agriolimax agrestis, A. compestris, Planorbis sp.) serve as intermediate-hosts . Deer become infected after ingesting snails containing infective P. odocoilei larvae. The pre-patent period is approximately 2 1/2 months.

Adult P. odocoilei produce small hemorrhages in the muscula~ure. Extensive tissue damage caused by eggs and larvae of P. odocoilei has been seen histo- logically in the lungs and lymph nodes and has been considered a cause of death among California deer (Brunctti 1969).

Mule deer have been experimentally infected with the meningeal worm, Parelaphostrongylus tenuis (Anderson et al. 1966). This helminth is widely distributed throughout the range of its usual host, the white-tailed deer, and has been recorded as far west as Oklahoma and Minnesota. Adult helminths are

the cranial meninges of white-tailed deer. The life cycle is indirect, and similar to that of P. odocoilei. Detailed studies by Anderson (1963; 1965) and Anderson and Strelive (1967) have shown that after ingestion, infective larvae penetrate the abomasal wall and travel to the spinal cord of white-tailed deer. Development occurs in the dorsal horns of gray matter for 30-40 days, after which worms move to the subdural space. First-stage larvae appear in the feces 90 days or more post-infection.

Neurologic signs are rare in white-tailed deer, however, neurologic disturbances leading to paralysis and death have been observed in unusual hosts, erg. domestic sheep, moose (Alces alces), wapiti, caribou (Rangifer tarandus terranovae) and reindeer (R. t. tarandus) (Anderson 1970). A mule deer fawn was experimentally infected with 5. tenuis, and a fatal paralysis ensued (Anderson et al. 1966). Black- tailed deer translocated into Tennessee from Oregon also were afflicted with fatal neurologic disease caused by P. tenuis, which apparently has been a primary li$iting factor for establishing black-tailed deer in Tennessee. Experimental infection of a hybrid deer (2. h. columbianus x 2. virginianus) resulted in fatal paralysis 52 days post-infection (SCWDS, unpublished).

It appears that the encroachment of white-tailed deer onto the range of mule deer is a definite threat because of the likelihood of exposing mule deer populations to E. tenuis.

Although each of the aforementioned diseases has been considered a specific potential mortality factor for mule deer populations, we should emphasize that seldom does one entity alone cause significant mortality of a wild population. Rather, multiple factors usually are involved, and the specific disease is a product of complex interactions between the animal and its environment. Judging from the apparent lack of information on diseases of mule deer, we respectfully suggest that concerned game and fish agencies place more emphasis on investigating diseases of mule deer. These investigations should include specific information on causes of "die-offs" and probably more importantly, should consider what potential mortality factors are present within apparently healthy populations. Only until we have a basic understanding of the interactions between the disease agent, the animal, and the environment can the causes of the mule deer decline in the west be ascertained.

Acknowledgments: This study was supported in part by funds administered and coordinated under the Federal Aid in Wildlife Restoration Act (50 Stat. 917) and through Contract No. 14-16-0008-2028, Fish and Wildlife Service, U.S. Department of the Interior.

LITERATURE CITED

Anderson, R. C. 1963. The incidence, development, and experimental transmission of Pneumostrongylus tenuis Dougherty (Metastrongyloidea: Protostronevlidae) of the meninges of the white- ", tailed deer docbi bile us virginianus borealis) in Ontario. Can. J. Zool. 41: 775-792 + figs.

located in the subdural space and venous sinuses of

Mule deer Disease Problems 122

. 1965. The development of Pneumostrongylus tenuis in the central nervous system of white- tailed deer. Path. Vet. 2: 360-379.

. 1970. Lungworms. p. 81-126. In Davis, J. W. and R. C. Anderson editors. Parasitic Diseases of Wild Mammals. Iowa State Univ. Press, Ames, Iowa. 364pp.

and Strelive. 1967. The penetration of Pneumostrongylus tenuis into the tissues of white- tailed deer. Can. J. Zool. 45: 285-289.

, M. W. Lankester, and U. R. Strelive. 1966. Further experimental studies of Pneumostrongylus tenuis in cervids. Can. J. 7001. 44: 851-861.

Anonymous. 1976. Foreign Animal Disease Report, January 1976. Emergency Programs, Veterinary Services, APHIS, USDA, Washington, D. C. 12pp.

Boever, W. J. and B. Kurka. 1974. Malignant catarrhal fever in greater kudus. J. Am. Vet. Med. Assn. 165: 817-819.

Bowne, J. G. 1973. Is bluetongue an important disease in cattle. J. Am. Vet. Med. Assn. 163: 911-914.

Brunetti, 0. A. 1969. Redescription of Parelapho- strongylus (Boev and Schuls, 1950) in California deer, with studies on its life history and pathology. Calif. Fish and Game 55: 307-316.

Clark, K. A., R. M. Robinson, L. L. Weishuhn, and S. McConnell. 1972. Further observations on malignant catarrhal fever in Texas deer. J. Wildl. Dis. 8: 72-74.

R. G. Marburger, L. P. Jones, and J. H. Orchard. 1970. Malignant catarrhal fever in Texas cervids. J . Wildl. Dis. 5: 376-383..

Das, K. M. and J. H. Whitlock. 1900. Subspeciation in Haemonchus contortus (Rudolphi, 1803), Nematoda, Trichostrongyloidea. Cornell Vet. 50: 182-197.

Gupta, R. P. and H. C. Gibbs. 1971. Infectivity of D. viviparus (moose strain) to calves. Can. Vet. - J. 56: 56.

Hayes, F. A. and A. K. Prestwood. 1969. Some considerations for diseases and parasites of white- tailed deer in the southeastern United States. Proc. Symposium White-tailed Deer in the Southern Forest Habitat. Nacogdoches, Texas. 32-36.

Hobmaier, A. and M. Hobmaier. 1934. Elaphostrongylus odocoilei n. sp., a new lungworm in blacktail deer (Odocoileus columbianus). Description and life history. Proc. Soc. Expl. Biol. and Med. 31: 509-514.

Hoff, G. L., S. H. Richards, and D. 0. Trainer. 1973. Epizootic of hemorrhagic disease in North Dakota deer. J. Wildl. Mgt. 37: 331-335.

, D. 0. Trainer, and M. M. Jochim. 1974. Bluetongue virus and white-tailed deer in an enzootic area of Texas. J. Wildl. Dis. 10: 158-163.

Jubb, K. V. F. and P. C. Kennedy. 1970. Pathology of Domestic Animals. Vol. 2, 2nd ed., Academic Press, New York. 697pp.

Marburger, R. G., R. M. Robinson, J. W. Thomas, and K. A. Clark. 1970. Management implications of disease of big game animals in Texas. Proc. Southeast Assn. Game and Fish Comm. 24: 46-50.

Pierson, R. E., J. Storz, A. E. Chesney, and D. Thake. 1974. Experimental transmission of malignant catarrhal fever. Am. J. Vet. Res. 35: 523-525.

Presidente, P. J. A. and S. E. Knapp. 1973. Susceptibility of cattle to an isolate of Dictyocaulus viviparus from black-tailed deer. J. Wildl. Dis. 9: 41-43.

, and R. E. Dean. 1973. Treatment and control of Dictyocaulus viviparus in captive black-tailed deer. J. Wildl. Dis. 9:

, D. E. Worley, and J. E. Catlin. 1972. Cross-transmission experiments with Dictyocaulus viviparus isolates from Rocky Mountain elk and cattle. J. Wildl. Dis. 8: 57-62.

Prestwood, A. K. and F. E. Kellogg. 1971. Naturally occurring haemonchosis in a white-tailed deer. J. Wildl. Dis. 7: 1.33-134.

, J. F. Smith, and J. Brown. 1971. Lungworms in white-tailed deer of the southeastern United States. J. Wildl. Dis. 7: 149-154.

, F. A. Hayes, J. H. Eve, and J. F. Smith. 1973. Abomasal helminths of white-tailed deer in southeastern United States, Texas, and the Virgin Islands. J. Am. Vet. Med. Assn. 163: 556-561.

, T. P. Kistner, F. E. Kellogg, and F. A. Hayes. 1974. The 1971 outbreak of hemorrhagic disease among white-tailed deer of the southeastern United States. J. Wildl. Dis. 10: 217-224.

Rosen, M. N. 1970. NecrobacillosiS.. p. 286-292. In Davis, J. W., L. H. Karstad, and D. 0. Trainer - editors. Infectious Diseases of Wild Mammals. Iowa State Univ. Press, Ames, Iowa. 421pp.

, 0. A. Brunetti, A. I. Bischoff, and J. A . Azevedo, Jr. 1951. An epizootic of foot rot in California deer. North Am. Wildl. Conf. 16: 164-177.

Rweyemamu, M. M., L. Karstad, E. Z. Mushi, J. C. Otema, D. M. Jessett, L. Rome, S. Drevema, and J. G. Grootenhuis. 1974. Malignant catarrhal fever virus in nasal secretions of wildebeest: a probable mechanism for virus transmission. J. Wildl. Dis. 10: 478-487.

Samuel, W. M. and J. C. Holmes. 1974. Search for elaphostrongyline parasites in cervids from Alberta. Can. J. Zool. 52: 401-403.

Schoenfeld, F. J. et al. 1974. Report of the committee of diseases of sheep and goats 1974. Report U.S. Animal Health Assn. 78: 393-396.

Thomas, F. C. and A. K. Prestwood. 1976. Plaque neutralization reduction test reactors to bluetongue virus and EHD virus in the southeastern United States. In Page, L. editor. Wildlife Diseases. Plenum ~uixishing Corp., New York. In Press.

, and D. 0. Trainer. 1970. Bluetongue virus (1) in pregnant white-tailed deer, (2) a plague reduction neutralization test. J. Wildl. Dis. 6: 384-388.

Tsai, K. and L. Karstad. 1973. The pathogenesis of epizootic hemorrhagic disease of deer. Am. J. Pathol. 70: 379-400.

Walker, M. L. and W. W. Becklund. 1970. Checklist of the internal and external parasites of deer, . -

Odocoileus hemionus and 2. virginianus, in the United States and Canada. Special Publication No. 1. Index Catalogue of ~edical and Veterinary Zoology. USDA, Washington, D. C. 45pp.

Wyand, D. S., C. F. Helmboldt, and S. W. Nielsen. 1971. Malignant catarrhal fever in white-tailed deer. J. Am. Vet. Med. Assn. 159: 605-610.

Mule Deer Disease Problems

MULE DEER MORTALITY FROM VARIOUS CAUSES

W. L e s l i e Robinet te Re t i r ed W i l d l i f e Research B i o l o g i s t

U.S. F i s h & W i l d l i f e Se rv ice Present Address: 488 So. A l k i r e S t .

Lakewood, Colo. 80228

Abs t rac t

Evidence is presented t h a t s e v e r a l Great Basin dee r herds produced f a l l fawn crops of 100 o r more fawns pe r 100 does be fo re widespread use of t h e range. Subsequently, f a l l fawn crops dropped t o only 60 o r 70 pe rcen t . It is t h e w r i t e r ' s content ion t h a t poorer n u t r i t i o n caused by range d e p l e t i o n was r e spons ib le f o r t h e r educ t ion i n fawn crops and t h a t t h i s has been a major f a c t o r i n t h e genera l dec l ine i n mule dee r populat ions . The s o l u t i o n would seem t o l i e i n even f u r t h e r herd r educ t ions through hunt ing t o a l e v e l t h a t w i l l permit range recovery through n a t u r a l p l a n t success ion o r a r t i f i c i a l r evege ta t ion .

I suspec t t h a t those r e spons ib le f o r t h i s symposium intended t h a t t h i s paper should cover a l l c l a s s e s of dee r m o r t a l i t y no t covered by previous papers and r e l a t e them t o t h e genera l mule deer de- c l i n e . There i s l i t t l e doubt t h a t v e h i c l e s , s t a rva - t i o n and poaching, f o r example, have been o r a r e cur- r e n t l y important m o r t a l i t y f a c t o r s among some herds and i n some yea r s . Many dee r a r e k i l l e d by v e h i c l e s , p a r t i c u l a r l y where i n t e r s t a t e highways c r o s s migra- t i o n r o u t e s o r win te r ranges. S t a r v a t i o n l o s s e s a r e l e s s common now than 2-4 decades ago but s t i l l may occur dur ing seve re win te r s , prolonged droughts , o r among inadequately hunted herds . While t h e s e c l a s - s e s of m o r t a l i t y may be l o c a l l y important , i t i s doub t fu l t h a t they have been t h e major causes f o r t h e genera l dec l ine .

I should l i k e t o t a k e t h i s oppor tun i ty t o d i s - cuss what I f e e l has been one of t h e major causes f o r t h e d e c l i n e among Great Basin he rds and one which can be co r rec ted by management. Th i s invo lves t h e gener- a l l y lower fawn crops which have r e s u l t e d , I b e l i e v e , from d e t e r i o r a t i n g ranges , caused p r imar i ly from ex- c e s s i v e dee r use. Deer h i g h l i n i n g o r hedging of pre- f e r r e d browse has long been recognized a s a s i g n of excess ive use , bu t l e s s recognized has been t h e more s u b t l e disappearance of p r e f e r r e d f o r b s on t h e summer ranges . For many of t h e Great Basin he rds t h e summer range i s even more c r i t i c a l f o r optimum pro- d u c t i v i t y than win te r ranges. Severa l he rds f o r which I have f a l l composition counts had 100 fawns pe r 100 does even when t h e he rds were approaching o r a t peak numbers. However, a f t e r widespread range damage, t h e fawn c rops genera l ly f e l l i n t o t h e 60 t o 70 range. I n many of these he rds t h e dec rease i n fawn p roduc t ion-equa l s t h e p resen t l e g a l k i l l .

F a l l fawn crops of 100 o r more were recorded f o r t h e Duck Creek herd i n e a s t e r n Nevada f o r 1942, 1943, and 1944, bu t they dropped t o around 90 f o r 1945 and 1946 and even f u r t h e r t o an average of 73 f o r t h e 6 subsequent y e a r s (Aldous 1948; Rob ine t t e , unpub- l i s h e d d a t a ) . The d e c l i n e continued d e s p i t e t h e i n t r o d u c t i o n of "1080" i n 1947 which d r a s t i c a l l y

reduced coyote numbers. The d e c l i n e was almost c e r t a i n l y a s soc ia ted wi th an overstocked summer range. The most s t r i k i n g evidence f o r overs tocking was t h e h i g h l i n i n g of c u r l l e a f mountain mahogany (Cercocarpus l e d i f o l i u s ) and aspen (Populus t remuloides) and t h e absence of regenerat ion. Observat ions have ind ica ted t h a t when t h i s occurs , most of t h e p a l a t a b l e f o r b s have l ikewise been depleted.

A d e c l i n e i n fawn crops a l s o occurred on t h e Dixie Na t iona l Fores t i n southwestern Utah, bu t i t took p lace a few yea r s e a r l i e r than i n Duck Creek. C l a s s i f i c a t i o n s gave a fawn crop of 101 pe rcen t i n 1936; 94 f o r 1937; bu t an average of only 65 f o r t h e 6 yea r s , 1940-45 (Noel 1948). Overstocking was recognized by t h e U. S. Fores t Se rv ice and Utah F i s h and Game Department i n t h e l a t e 19301s, s o dep le ted ranges a r e aga in be l i eved respons ib le f o r t h e d e c l i n e i n fawn crops . A d e c l i n e of fawn crops a l s o occurred on t h e F i s h Lake Na t iona l Fores t i n c e n t r a l Utah, bu t they s t a r t e d a t a pe r iod i n t e r - mediate t o t h a t of Duck Creek and t h e Dixie . Fawn crops of 92 t o 100 were recorded f o r 1930, 1937, and 1939, bu t they dropped t o 87 i n 1940; 75 i n 1941; and 71 i n 1942 (Olson and Turpin , 1931; Cos t l ey , 1938; Rob ine t t e , 1950). On t h e Pahvant Range, which is a p a r t of t h e F i s h Lake F o r e s t , t h e va lues were 90 f o r 1939 (we l l a f t e r overstock- i n g was f i r s t recognized) ; 82 i n 1940; and an average of only 68 f o r 12 y e a r s (1941-42, 1946, 1949-57) when c l a s s i f i c a t i o n s were made (Robinet te , unpublished d a t a ) .

An a r e a on which I made a r a t h e r i n t e n s i v e dee r herd s tudy , t h e Oak Creek drainage i n west c e n t r a l Utah, showed a s i m i l a r d e c l i n e i n fawn produc t ion and one almost c e r t a i n l y r e s u l t i n g from summer range dep le t ion . Limited c l a s s i f i c a t i o n s by myself and Cost ley (1940) ind ica ted a fawn crop of 100 pe rcen t f o r 1939. The herd was h e a v i l y damaging i t s range a t t h a t t ime; and d e s p i t e s u b s t a n t i a l doe removals beginning i n 1940, which perhaps reduced herd.numbers t o one-half i n 1946, t h e r e l i e f was

125 Mule Deer Mortality from V&ouq Causes

i n s u f f i c i e n t f o r summer range recovery. From t h e f a l l of 1946 through 1957 when my s tudy was made, f a l l fawn crops averaged but 68 percent o r n e a r l y one-third l e s s than i n 1939. The lower fawn crops p reva i l ed d e s p i t e a s u b s t a n t i a l reduct ion i n dee r numbers, c a t t l e use , and even coyote numbers dur ing p a r t of t h e s tudy. F a i l u r e of t h e p r e f e r r e d dee r f o r b s t o recover was ev iden t from obse rva t ions wi th in a s e t of exc losures e s t a b l i s h e d by t h e Utah F i sh and Game Department i n 1952. A check which I made i n J u l y , 1971, revealed t h a t 9 f o r b s p a l a t a b l e t o dee r had a canopy ground coverage of 29 pe rcen t i n t h e dee r exc losure compared t o only 2 percent i n an ad jacen t exc losure which permi t t ed dee r t o feed but excluded l i v e s t o c k . The ex- c l o s u r e s were not constructed u n t i l s e v e r a l yea r s a f t e r peak dee r use s o t h a t i t ' s e n t i r e l y p o s s i b l e t h a t some of the most p a l a t a b l e f o r b s had a l r eady been e l imina ted from t h e s i t e .

The Oak Creek win te r range was genera l ly con- s ide red t o be i n reasonably good cond i t ion , bu t even he re t h e r e was evidence t h a t t h e most p a l a t a b l e shrub, b i t t e r b r u s h (Purshia t r i d e n t a t a ) , was not r egenera t ing i t s e l f s a t i s f a c t o r i l y . A growth r i n g count made i n 1958 of a l l b i t t e r b r u s h p l a n t s from a p l o t 15 x 30 f e e t on a product ive b i t t e r b r u s h s i t e r evea led t h a t t h e youngest p l a n t of 22 yea r s dated back t o 1936. Th i s was about t h e time when t h e herd was probably nea r ing o r a t ca r ry ing capaci ty . Observations a t Oak Creek make i t q u i t e evident t h a t merely reducing a herd i s no assurance t h a t damaged ranges w i l l recover. Deer numbers must be reduced below ca r ry ing capac i ty and he ld t h e r e u n t i l t h e range can recover .

Many dee r workers have noted t h e adverse in - f luence of seve re win te r s upon herd p roduc t iv i ty . Not only may dee r be l o s t o u t r i g h t through s t a r v a t i o n , bu t because t h e su rv iv ing does a r e i n poor cond i t ion , t h e subsequent fawn l o s s may l ikewise be severe . The most p r a c t i c a l means of minimizing such l o s s e s i s t o mainta in a s tocking of dee r t h a t w i l l i n s u r e maintenance of t h e p r e f e r r e d forage spec ies . This i n s u r e s a forage s u r p l u s f o r t imes of s t r e s s on which t h e herd can r e l y . This view was emphasized by r e s u l t s of winter m o r t a l i t y s t u d i e s of some Utah herds fol lowing t h e win te r of 1948-49 (Robinet te e t a l . , 1952). This win te r was considered t o have been t h e most seve re by t h e U. S. Weather Bureau s i n c e t h e i n c e p t i o n of weather records i n Utah. The herd l o s s on t h e South Oak Creek range where t h e r e was an abundant supply of c l i f f r o s e (Cowania s t ansbur iana ) , a p r e f e r r e d win te r browse, was only 9 percent . Th i s was i n c o n t r a s t t o l o s s e s of 20 t o 50 percent on o t h e r ranges wi th in 100 mi les where t h e r e was l i t t l e pre- f e r r e d browse. The more forage a v a i l a b l e t o a dee r over win te r , t h e g r e a t e r i t s chances f o r s u r v i v a l . The dee r no t only expends l e s s energy i n f i l l i n g i t- s e l f bu t i t s oppor tun i ty f o r s e l e c t i n g p a l a t a b l e s p e c i e s and t h e more n u t r i t i o u s p l a n t p a r t s i s enhanced, thereby i n s u r i n g a b e t t e r d i e t .

Longhurst e t a l . (1968) concluded t h a t penned dee r d id b e s t on forage s p e c i e s t h a t they p r e f e r r e d . S i m i l a r l y , a cap t ive herd a t t h e Denver Federa l Center responded d ramat i ca l ly t o inc reased r a t i o n s of p r e f e r r e d foods (Robinet te e t a l . , 1973). When t h e dee r were fed inc reased q u a n t i t i e s of hydroponically- grown b a r l e y and a commercial concen t ra t e , bo th of which they p re fe r red over a l f a l f a hay, s e v e r a l im- p o r t a n t t h i n g s happened. Food consumption r o s e , weights increased, fawn product ion jumped from 1 . 4 t o 1 .9 p e r doe of breeding age, whi le fawn m o r t a l i t y of

t h e f i r s t week postpartum dec l ined from 10 t o 4 percent .

A comparative s tudy of two wild herds i n t h e Great Basin provided cor robora t ive evidence f o r t h e importance of p re fe r red forage dur ing summer t o o p t i - mum herd p r o d u c t i v i t y (Julander e t a l . , 1961). Sum- mer range on t h e S u b l e t t u n i t of southern Idaho was found t o have s u b s t a n t i a l l y more p re fe r red dee r f o r - age than t h e Antimony u n i t of sou th -cen t ra l Utah. There was 50 times more good deer forage pe r a c r e i n t h e aspen type on t h e S u b l e t t u n i t than on t h e Antimony a r e a and 11 times more i n t h e mountain shrub type. I n a d d i t i o n , dee r s tock ing on t h e S u b l e t t u n i t was only h a l f t h a t of t h e Antimony u n i t . S u b l e t t deer weights were s u b s t a n t i a l l y h igher a s was t h e f e t a l r a t e of 1.85 per doe compared t o 1.19 f o r Antimony. F a l l composition counts i n d i c a t e d around 50 fawns pe r 100 does f o r Antimony and double t h i s f o r t h e S u b l e t t .

I have a f e e l i n g t h a t had no t t h e Oak Creek summer range been so dep le ted by overuse i n t h e l a t e 1930's and e a r l y 1 9 4 0 f s , i t could have adequate ly supported t h e post-hunt d e n s i t y of 1 deer per 15 a c r e s t h a t p reva i l ed dur ing t h e 1947-56 s tudy. I f t h i s assumption i s accepted and two o the r reasonable assumptions a r e made ( t h a t t h e does reproduced a t t h e 1.85 r a t e achieved by t h e Sublet herd r a t h e r than t h e a c t u a l 1.32 and t h a t t h e fawn l o s s from b i r t h t o t h e hunt was a reasonable 15 percent i n s t e a d of t h e a c t u a l 33 p e r c e n t ) , t h e h e r d ' s f a l l fawn product ion would have been an es t imated 1,753 i n s t e a d of 932. The average l e g a l k i l l was 447 pe r year dur ing t h e s tudy, a va lue which seemingly could have more than doubled had t h e herd r e a l i z e d i t s f u l l p o t e n t i a l .

It i s doub t fu l t h a t any Great Basin dee r herd has been s t a b i l i z e d through hunt ing be fo re damaging i t s range. Even t h e S u b l e t t herd wi th i t s e x c e l l e n t summer range had dep le ted i t s win te r range a long t h e sou th s i d e of t h e Raf t River Mountains i n Utah. Even though hunt ing, s t a r v a t i o n l o s s e s , and lowered fawn product ion have combined t o reduce many Great Basin he rds , i t i s doub t fu l i f t h e r educ t ions were g r e a t enough and made soon enough t o have permit ted f u l l range recovery.

Severa l long-term range s t u d i e s wi th l i v e s t o c k have shown t h a t moderate s tock ing provides g r e a t e r economic r e t u r n s than excess ive s tocking. Moderate s tock ing i n s u r e s adequate s u p p l i e s of t h e p r e f e r r e d fo rage and t h i s i n t u r n provides f o r h igher y i e l d s of meat and product ion of young (Hutchings, 1954; Johnson, 1953; Kl ipp le and C o s t e l l o , 1960). By t h e same token, i t i s p o s s i b l e f o r a well-managed dee r herd t o produce a s many o r more animals f o r hun te r t ake than a herd twice t h e s i z e on overstocked range.

I n yea r s p a s t , many game managers have been guided i n t h e i r recommendations f o r dee r removals by u t i l i z a t i o n d a t a on p r e f e r r e d win te r browse. Th i s i s perhaps good i f t h e r e is some b u i l t - i n assurance t h a t t h e key browse s p e c i e s a r e r egenera t ing them- s e l v e s , bu t too o f t e n t h i s has not been t h e case . On ranges such a s Oak Creek where t h e summer range is even more c r i t i c a l t o t h e he rd ' s we l fa re than t h e win te r range, t h e r e have been few, i f any, v e g e t a t i v e t r a n s e c t s f o r t h e purpose of determining cond i t ion and t r end among t h e p re fe r red fo rbs .

Mule Deer Mortality from Various Causes

Deer management has come a long way i n t h e p a s t on c a p t i v e mule deer. J. Wildl. Manage. 37(3): t h r e e o r f o u r decades, bu t i t is unfor tuna te ly t r u e 312-326. t h a t sportsmen s t i l l pack such a p o l i t i c a l wallop t h a t they can e f f e c t i v e l y nega te needed herd reduct ions . , 0. Ju lander , J. S. Gashwiler, and I f win te r s t a r v a t i o n l o s s e s o r lowered fawn product ion J. G. Smith. 1952. Winter m o r t a l i t y of mule r e s u l t i n poorer hunt ing, t h e sportsmen usua l ly clamor dee r i n Utah i n r e l a t i o n t o range cond i t ion . f o r buck hunt ing only , o r even complete c l o s u r e u n t i l J. Wildl. Manage. 16:289-299. t h e herd can recover. I n a c t u a l i t y , s t a r v a t i o n l o s s e s and lowered fawn product ion a r e f i r m evidence f o r t h e need of even f u r t h e r herd r educ t ions . R e h a b i l i t a t i o n of dep le ted dee r ranges w i l l t ake time, whether accom- p l i s h e d a r t i f i c i a l l y o r through n a t u r a l recovery, and w i l l probably n e c e s s i t a t e even f u r t h e r herd reduc- t i o n s . The long-term p o t e n t i a l f o r inc reased hun te r take, however, would seem t o make t h e program worthwhile.

Bibliography

Aldous, C. M. 1948. Control of dee r i r r u p t i o n s i n Nevada. U.S. Detp. I n t e r . , F i s h & Wildl. Se r . , Washington, D. C . , Spec. Sc i . Rep. 57, 16 pp.

Cost ley, R. J. 1938. Deer c l a s s i f i c a t i o n s on t h e Beaver D i s t r i c t of t h e F i sh Lake Fores t . U.S. For. Serv. , Ogden, Utah. 2 pp. Typescr ipt .

. 1940. Oak Creek dee r herd. Report t o Regional F o r e s t e r , U.S. For. Serv. , Ogden, Utah. 2 pp. Typescr ipt .

Hutchings, S. S. 1954. Managing win te r sheep range f o r g r e a t e r p r o f i t . U.S. Dept. Agric. Farmers' Bu l l . 2067, 46 pp.

Johnson, W. M. 1953. E f f e c t of g raz ing i n t e n s i t y upon vege ta t ion , and c a t t l e ga ins on ponderosa pine-bunchgrass ranges of t h e Front Range of Colorado. U.S. Dept. Agric. C i rc . 929, 36 pp.

Ju lander , O., W. L. Robinet te , and D. A. Jones. 1961. R e l a t i o n of summer range cond i t ion t o mule dee r herd p roduc t iv i ty . J. Wildl. Manage. 25(1): 5 4-60.

Kl ipp le , G. E. and D. F. Cos te l lo . 1960. Vegetat ion and c a t t l e responses t o d i f f e r e n t i n t e n s i t i e s of g raz ing on shor t -grass ranges on t h e C e n t r a l Great P l a i n s . U.S. Dept. Agric. Tech. Bul l . 1216, 82 pp.

Longhurst, W. M. , H. K. Oh, M. B. Jones, and R. E. Kepner. 1968. A b a s i s f o r t h e p a l a t a b i l i t y of dee r fo rage p lan t s . Trans. N . Am. Wildl. and Nat. Res. Conf . 33:182-192.

Noel, F. C. 1948. Deer c l a s s i f i c a t i o n s , Dix ie Na t iona l Fores t . U.S. For. Serv. , Cedar C i t y , Utah. 1 p. Typescr ipt .

Olson, 0. A. and R. L. Turpin. 1931. Inspec t ion re- p o r t , Beaver D i s t r i c t , F i s h Lake Na t iona l Fores t . U.S. For. Serv., Ogden, Utah. Typescr ipt .

Robinet te , W. L. 1950. S t u d i e s of t h e mule dee r herd of t h e F i s h Lake Na t iona l F o r e s t , Utah. U.S. F i sh & Wildl. Serv. 83 pp. Typescr ipt .

, H. C. Baer, R. E. Pi l lmore , and C. E. K n i t t l e . 1973. E f f e c t s of n u t r i t i o n a l change

17.7 Mule Deer MortaZitu from Various Causes

PROBABLE CAUSES OF THE RECENT DECLINE OF MULE DEER

I N WESTERN U.S.--A SUMMARY

W. L e s l i e Pengel ly W i l d l i f e B io log i s t

Wi ld l i f e Biology Program Unive r s i ty of Montana

Missoula, Montana 59801

Abstract

The s o l u t i o n s t o mule dee r management seem s imple t o many people. However, i n r e a l i t y t h i s is n o t t h e case. I n f a c t , dee r management i s s t i l l i n i t s infancy and is understood only i n p a r t by even t h e b e s t b iolo- g i s t s . Perhaps t h e most c h e e r f u l way t o look a t low mule dee r numbers is t o look back a t populat ions i n 1900. This makes present-day mule dee r numbers look g r e a t . Winter "die-offs" a s a r e s u l t of poor ranges and overpopulat ions i n i t i a t e d i n c r e a s e s i n h a r v e s t s t o reduce mule dee r numbers. These inc reased h a r v e s t s have r e s u l t e d i n a k i l l of over s i x m i l l i o n dee r i n r ecen t years . Except f o r t h e e f f e c t of hunt ing, i n d i - c a t i o n s a r e t h a t when dee r a r e on a high q u a l i t y d i e t , o t h e r environmental f a c t o r s a r e not a s important.

I approach t h i s assignment of summarizing t h e f a c t and t h e f i c t i o n as soc ia ted w i t h t h e a l l e g e d de- c l i n e of mule dee r wi th t h e same enthusiasm t h a t Marie Anto ine t t e approached t h e s c a f f o l d . I f i t weren ' t f o r t h e honor of i t , I t h i n k I ' d d e c l i n e t h e t r i p . Other t i t l e s f o r such a summary could be equa l ly appropriate--"A Pooling of Ignorance" o r "What Do We Know For Sure?"--because we seem t o be d i scuss ing more of what we don ' t know than what we do. I f I were t o paraphrase t h i s s i t u a t i o n , I would say t h a t l e a r n i n g anything about t h e mule dee r de- c l i n e a t t h i s conference is l i k e l ea rn ing about love i n a b r o t h e l . The l e s sons a r e c l e a r bu t oversimpli- f i e d .

Anyone a t tempting t o summarize t h i s conference i n 30 minutes has t o be foolhardy, and i t j u s t occurred t o me why I was asked t o do t h i s . As one wag s a y s , " I f he seems l o s t i n thought , i t ' s becuase i t ' s such unfami l i a r t e r r i t o r y . " I t r i e d t o a n t i c i - p a t e what would b e s a i d a t s t h i s conference by no t w r i t i n g t o any of t h e speakers . They a n t i c i p a t e d it by not sending me any advance copies . Everything I ' v e had t o do he re is what any one of you could have done, and t h a t is ask your neighbors , read t h e Transac t ions and va r ious j o u r n a l s , and go through t h e popular l i t e r a t u r e . I even thought about going i n t o the a i r p o r t newsstand on t h e way down t o s e e i f t h e l a t e s t Outdoor L i f e had t h e problem solved. Tha t ' s probably where i t w i l l f i r s t come ou t . My sugges t ion f o r anybody working on such a t o p i c i n t h e f u t u r e ,

i s t o w r i t e your r e p o r t on a magic s l a t e . Then you can r i p i t o f f i f you s e e anybody approaching.

As you can s e e , I ' m i n a g r e a t mood f o r t h i s assignment. I ' m n o t even s u r e a t t h e end of these two days whether t h e mule dee r a r e d e c l i n i n g o r not . A f t e r l i s t e n i n g t o Bruce G i l l , one may wonder i f t h i s meeting was even necessary. We could s a y , wi thout t o o much f e a r of c o n t r a d i c t i o n , t h a t t h e r e probably were fewer dee r i n 1975 than t h e r e were i n t h e 1960 t s , and then we can say t h a t t h e r e a r e a l o t more dee r now than t h e r e were i n 1900. I n s t e a d of t e l l i n g t h e p u b l i c about t h e h igh dee r numbers i n 1960, we ought t o compare today's populat ions wi th t h e 1900 es t ima tes and then cond i t ions wouldn't appear s o gloomy.

I f t h e dee r a r e a c t u a l l y d e c l i n i n g , I t h i n k t h e answer is q u i t e simple. It 's only because m o r t a l i t y i s exceeding n a t a l i t y , s o now we can a l l go home. What we ' re r e a l l y t r y i n g t o do, though, is determine i f t h i s is the case s o we can proceed w i t h t h e a u d i t and f i n d out who tapped t h e buckskin till. How about t h a t f o r mixing metaphors? Our p ro fess ion has been descr ibed by some of its d e t r a c t o r s a s a form of s l ipshod animal husbandry. Th i s i s something I t h i n k we should consider . I n a r ecen t Audubon a r t i c l e desc r ib ing t h e g r i z z l y bear controversy, B i l l G i l b e r t wrote down a l l t h e c o n f l i c t i n g arguments i n embarrassing d e t a i l . A t one po in t he paused and

129 Probable Causes of the Recent Decline

s a i d , "So much f o r t h e a r t of w i l d l i f e management." th ing , and they wrote i t down. I th ink we have in - What a put down. s t i t u t i o n a l i z e d i t and i t ' s probably t r u e .

The p a t t e r n of t h e a l l eged d e c l i n e , whatever i t i s , seems t o have been repeated i n a l l t h e s t a t e s s imul taneously . Since a l l t h e workers i n a l l t h e dee r s t a t e s involved seem t o w r i t e t o each o t h e r , and then average out t h e r e s u l t s , t h i s i s not s u r p r i s i n g . But l e t ' s assume t h a t mule dee r numbers a r e down from t h e peak populat ions of twenty yea r s ago, and then seek t h e probable answers. Bud Phelps gave us one when he s a i d , " In Utah we intended t o knock dee r numbers down--we had t o o many." We t e l l them t h a t i n Montana, too. It 's analogous t o t h e bear a t Yellowstone Park. When t h e t o u r i s t s complain about n o t see ing any bea r s they a r e t o l d t h a t t h e y ' r e up i n t h e h i l l s p icking huck lebe r r i e s . We need an equ iva len t of t h a t when t h e p u b l i c asks us where t h e dee r a re .

The 1940's was t h e tu rn ing po in t i n mule dee r numbers, w i th no tab le i n c r e a s e s recorded i n most of t h e western s t a t e s . We can show t h a t the dee r have dec l ined s i n c e then i n d i r e c t p ropor t ion t o t h e in - c r e a s e i n p r o f e s s i o n a l w i l d l i f e managers. Th i s i s c a l l e d a nonsense c o r r e l a t i o n . When i t is shown t h a t 90 pe rcen t of a l l t h e t r a i n wrecks involve t h e caboose, t h e s o l u t i o n i s t o take off the caboose. We're doing s i m i l a r t h i n g s , I t h i n k , i n t h e f i e l d of w i l d l i f e management.

We d id h i r e a l o t of p r o f e s s i o n a l l y t r a i n e d w i l d l i f e b i o l o g i s t s wi th t h e newly a v a i l a b l e PR funds. Simul taneously , we had some tremendous deer d ie -o f f s i n t h e w i n t e r s of 1948 and 1950, which made a l o t of head l ines a l l over t h e West. Hay and p e l l e t s were a i r l i f t e d i n t o l i v e s t o c k , a s w e l l a s dee r , and t h e new game managers dove r i g h t i n t o t h e f r ay . They put on p r e s s u r e t o i n c r e a s e t h e ha rves t i n o rde r t o o f f s e t t h e twin c a l a m i t i e s of s t a r v a t i o n and land depredat ion. About t h e same t ime, t h e ranching i n t e r e s t s were a t tempting t o fo rce t h e s a l e of pub l i c g raz ing land. The s i g n i f i c a n c e of t h a t w i l l come a l i t t l e b i t l a t e r . The a v a i l a b l e h a r v e s t records i n d i c a t e a r ap id i n c r e a s e i n dee r numbers i n t h e p a s t 25 yea r s . We've a l s o inc reased t h e hunter numbers, l i b e r a l i z e d t h e seasons , and inc reased access by p u t t i n g many more roads i n t o formerly i n a c c e s s i b l e a reas . I n o t h e r words, game management has been cha rac te r i zed by an u l t r a l i b e r a l approach-- "a 20-year b lood- le t t ing" according t o some--and how we ' r e having withdrawal symptoms.

Many of t h e speakers a t t h i s conference have pointed out t h e m u l t i p l e game bags and t h e va r ious combinations of seasons t h a t have evolved dur ing t h i s pe r iod , mostly t r i a l and e r r o r , w i th new resea rch f ind ings being app l i ed a s f a s t a s t h e pub l i c would accept them. Each s t a t e has i t s own p e c u l i a r h i s t o r y wi th non-res idents , l i c e n s e f e e s , and landowner- sportsman problems. Now we a r e a l l f ac ing a pub l i c r e a c t i o n t o reduce t h i s l i b e r a l management program, and most s t a t e agencies t a c i t l y admit t h a t dee r num- b e r s may be lower than we ca re t o admit. Wolfe and o t h e r s have commented upon how t h e va r ious s t a t e s a r r i v e a t t h e i r populat ion data . The i n c r e a s e s and decreases can be due t o a hos t of th ings t h a t have nothing t o do wi th t h e t o t a l number of animals. The f i r s t t h ing any s tuden t l ea rns i n w i l d l i f e management i s t h a t a t o t a l census i s probably something t h a t h e won't be ab le t o do. I remember w r i t i n g t h a t down a s a s t u d e n t i n 1946. Last week I t o l d a c l a s s t h e same

The reason most o f t e n quoted f o r t h e a l l eged de- c l i n e is overhunt ing, but i t ' s by no means uniformly t r u e . A unique, and probably odd, c h a r a c t e r i s t i c of t h i s two-day conference has been t h a t t h e r e h a s n ' t been one speaker d i scuss ing t h e removal of mule dee r by t h e gun. Approximately 6 m i l l i o n dee r have been harvested i n t h e l l w e s t e r n s t a t e s i n t h e l a s t 10 yea r s . I f 6 m i l l i o n dee r have been removed by hunt- i n g , including many females, i t i s probable t h a t we have had some e f f e c t on t h e s lope of t h e populat ion curve. Game departments then say , ''We intended t o reduce t h e populat ions"; b u t s imul taneously they seem t o r e j e c t t h e no t ion t h a t hunt ing is a s i g n i f i c a n t m o r t a l i t y f a c t o r . This l a t t e r no t ion seems t o be changing recen t ly .

On t h e o t h e r s i d e of t h e ques t ion , we use t h a t same theme of hun te r removal by t a l k i n g about t h e e f f e c t s of e a r l y market hunt ing. They overharvested deer i n many c a s e s , t o t h e po in t of e x t i n c t i o n i n some a reas . The h i s t o r y of dee r management always inc ludes r e fe rence t h a t p reda to r r educ t ion , c r e a t i o n of game re fuges , and reduced l e g a l and i l l e g a l har- v e s t s , coupled wi th "bucks only' ' s easons , helped b r ing back t h e deer . You can f i n d t h i s sequence i n almost everybody's summary. So, we've go t some s t r o n g cases f o r a wide v a r i e t y of p o q s i b i l i t i e s f o r t h e d e c l i n e , excluding sunspo t s , a e r o s o l sp rays , o r something t h a t somebody is p u t t i n g i n t h e water i n t h e n a t u r e o f an a n t i - f e r t i l i t y substance. I don ' t t h ink we ought t o be s u r p r i s e d t h a t some f a c t o r s a r e compensatory. Our job i s t o unravel these complex- i t i e s . Low and Ju lander pointed ou t t h a t t h e d e c l i n e began i n Utah approximately 10 yea r s ago, bu t i t v a r i e s i n states--some e a r l i e r , some l a t e r , and some unsure.

I f we have removed about 6 m i l l i o n dee r by l e g a l hun t ing , I ' d l i k e t o know why i t h a s n ' t been men- t ioned here . The 1972 proceedings of t h e Western Assoc ia t ion , which d e a l s w i t h t h e h a r v e s t i n 1972, l i s t e d approximately a h a l f a m i l l i o n dee r taken i n 1972-73. The yea r s 1974-76 a r e no t l i s t e d , but i f s o , an a d d i t i o n a l es t imated 2 m i l l i o n ha rves ted d e e r have no t been accounted f o r . We've had p len ty of t ime t o double those e x i s t i n g herds i f hunt ing pres- s u r e were t h e major depressant . Of t h e 11 western s t a t e s r epor t ing i n 1972 on t h e mule dee r d e c l i n e , t h e fol lowing s t a t e s i n d i c a t e d t h a t t h e i r dee r were inc reas ing . Utah s a i d they were up 10 pe rcen t ; Mon- t ana passed on t h e i s s u e ; Colorado was up 10%; Idaho, down; Wyoming, down 20%; C a l i f o r n i a , down 15%; New Mexico, down 5%; Oregon, down 37%; Nevada, up 5%; Arizona, down 39%; and Washington, down 30%. I t is hard t o t e l l what has happened i n t h e l a s t few yea r s . Prom a v a r i e t y of sources , I found mule dee r h a r v e s t f i g u r e s es t imated f o r 1946 f o r t h e western s t a t e s t h a t t o t a l l e d 275,000. By 1959, h a r v e s t had jumped t o 688,000; by 1962, i t was 770,000; 1967, down t o 588,000; and 1972--507,000. There were some s i g n s of recovery i n a few p l a c e s , but no t t o o many. Then I began t o look a t t h e way t h e d a t a were c o l l e c t e d and l i s t e d t h e c a t e g o r i e s t h a t we ought t o have i f we're going t o d i scuss these th ings .

I l i s t e d each s t a t e ' s response t o h a r v e s t , t o number of h u n t e r s , t o c r i p p l e and i l l e g a l k i l l s , t o p reda to r s , t o range cond i t ion , t o compet i t ion wi th l i v e s t o c k , t o compet i t ion wi th o t h e r w i l d l i f e , t o

Pi3obabZe Causes o f the Recent Decline 130

d i s e a s e , t o h a b i t a t l o s s , and then t o miscellaneous f a c t o r s . Each of t h e 11 s t a t e s r e p o r t i n g was t a l l i e d by category wi th many going unreported. The only t h i n g common t o a l l s t a t e s were ha rves t f i g u r e s , hun te r f i g u r e s , and a few random obse rva t ions , t h e kind you can g e t down a t t h e l o c a l pub, and probably wi th more enthusiasm. So t h a t was not very useful . Almost no two s t a t e s used t h e same systems f o r har- v e s t c o l l e c t i o n ; no s t a t e has used i t s own system without change f o r more than a b r i e f pe r iod of t ime; a few s t a t e s lumped t h e s p e c i e s toge the r and then guessed how many of them were mule deer. Every s t a t e has a con t inua l ly evolving system of sex , age, t i m e , and a r e a r e s t r i c t i o n s , changing l i c e n s e f e e s t r u c t u r e , and changing non-resident quotas . There a r e s o many v a r i a b l e s t h a t i t makes you wonder i f you'd blow every fuse i n town i f you put t h i s through t h e com- pu te r .

The hun te r ha rves t d a t a a r e almost always a yea r l a t e , they a r r i v e a f t e p t h e seasons a r e s e t , and may r e f l e c t p o l i t i c a l p ressu re a s much a s herd con- d i t i o n . Colorado and Utah have good mule dee r habi- t a t , and both of these s t a t e s recorded i n c r e a s e s i n 1972. Utah is 11 th i n a r e a , wi th about 85,000 square mi les ; Colorado i s 8 t h l a r g e s t , w i th 104,000 square mi les , and y e t they a r e among t h e l ead ing producers of mule dee r yea r a f t e r year . An inspec t ion of a vege ta t ion map of Colorado r e v e a l s t h a t only h a l f the s t a t e would q u a l i f y a s h a b i t a t f o r mule deer . From t h a t h a l f , you s t a r t e l imina t ing poor dee r h a b i t a t , and you end up wi th s c a t t e r e d remnants of dee r range. My conclusion, from t h i s cursory look, is t h a t Colorado, wi th a l i m i t e d acreage and a very good dee r h a b i t a t , h a s c o n s i s t e n t l y produced h i g h numbers p e r u n i t , even i n t h e f ace of o i l s h a l e development and subd iv i s ions . Utah is a l s o probably producing about a s many d e e r a s i t can, consider ing t h e land use changes of t h e r ecen t pas t . Montana is t h e 4th l a r g e s t s t a t e (147,000 square mi les ) and second i n t h e dee r ha rves ted i n 1972. It has experienced d e c l i n e s s i n c e then and s o i s now lagging be- h ind Utah and Colorado. Montana h a s mule deer over t h e e n t i r e s t a t e bu t n o t uniformly spread. Mule dee r a r e found i n t h e f o r e s t e d a r e a s of t h e western p a r t of t h e s t a t e , where logging opera t ions produce s e r a 1 shrubs . I n o t h e r regions of t h e s t a t e , mule dee r a r e found i n f o o t h i l l ranges combining f o r e s t e d and g raz ing a reas . The h igh p l a i n s g rass l and country i n t h e Glasgow a r e a is no t a s p roduc t ive f o r mule dee r a s i s t h e Miles C i t y r eg ion , b u t i t s t i l l outproduces t h e f o r e s t e d d i s t r i c t of western Montana.

Las t n i g h t Dan Poole suggested t h a t we should develop some kind of a uniform breakdown by h a b i t a t q u a l i t y invo lv ing cooperat ion between s t a t e s where ecosystems over lap. It i s n ' t l i k e l y t o occur because of one f a i l i n g , and t h a t i s human i n e r t i a . We probably j u s t won't g e t around t o it. The demand f o r hun tab le dee r , however, is going t o cont inue. We a r e n ' t going t o slow t h a t down.

Free-lance w r i t e r s a r e sending lengthy quest ion- n a i r e s t o s t a t e game agencies asking f o r a l l s o r t s of informat ion on t h e deer s i t u a t i o n and usua l ly con- c lude by saying, "We c e r t a i n l y a p p r e c i a t e your help ." We could spend many months each yea r answering these r eques t s which a r e only exceeded i n t h e i r demands by those coming from t h e agenc ies o r o rgan iza t ions t h a t a r e about t o w r i t e a book. We can s e e t h a t t h i s form of d a t a c o l l e c t i o n and repor t ing r e s u l t s i s a hap- hazard system. We d o n ' t have any uniform manner of

c o l l e c t i n g d a t a , and some s t a t e s a r e no t even bother- ing. The s t a t e of Washington de r ives i t s ha rves t d a t a from a ca rd ques t ionna i re . Managers e s t i m a t e t h a t t h e s t a t e has deer populat ions i n t h r e e d i f f e r - e n t d e n s i t i e s : medium, heavy, and low. The ha rves t d a t a a r e der ived from t h i s , and they e x t r a p o l a t e backwards t o c a l c u l a t e how many deer they es t ima te f o r a g iven a r e a , Washington a l s o so lves i t s game damage problems and win te r range shor t ages wi th fences and a r t i f i c i a l feeding i n some a reas .

Another s u b j e c t r ece iv ing s c a n t a t t e n t i o n a t this conference i s t h e e x t e n t of wounding losses . Colorado uses a 5 pe rcen t a d d i t i o n a l f i g u r e f o r wounding l o s s on bucks-only hunts and a 10 percent wi th e i the r - sex hunts . A r ecen t New Mexico s tudy showed 92 percent one yea r , and 93 percent two yea r s l a t e r of c r i p p l e and i l l e g a l los ses . I n o t h e r words, non-legal mortality by t h e gun may b e n e a r l y match- ing t h e ha rves t . I f we took 6-8 m i l l i o n dee r ou t of t h i s 11 western s t a t e complex by hunt ing, a r e we w i l l i n g t o add another 6-8 m i l l i o n f o r c r i p p l e and i l l e g a l l o s s ? I t h i n k t h a t a s we s t a r t adding t h e s e l o s s e s up, we can probably show t h a t somebody owes us deer.

The p o l i t i c a l a s p e c t s of dee r management a r e worth a comnent o r two. I have spent t h e l a s t t h r e e and a h a l f yea r s on t h e Montana F i sh and Game Com- miss ion, and now s i t on t h e o t h e r s i d e of t h e t a b l e l i s t e n i n g t o s logans , jargon, c l i c h e s , p l a t i t u d e s , and t au to log ies . C o l l e c t i v e l y i t ' s c a l l e d s c i e n t i f i c management. Biology is only one f a c e t of management. The o t h e r cons ide ra t ions inc lude t h e p o l i t i c a l , l e g a l , s o c i a l , c u l t u r a l , economic, and whatever. Le t me read you two sentences out of a p o l i t i c a l l y o r i e n t e d s ta tement from a Nevada Game Commission member s h o r t l y a f t e r t h e D i r e c t o r of t h e Bureau o f Land Management s a i d , "We're going t o improve t h e ranges i n Nevada." I t ' s two pages long, bu t I ' l l only read t h e s e two paragraphs. It says :

"Today you could remove a l l l i v e s t o c k from Nevada ranges and never hunt dee r again. Without doing anything more, i n a s h o r t pe r iod of t i m e t h e ranges would be i n a worse cond i t ion , and t h e dee r herds would cont inue t o dwindle."

"In c los ing , I ' d l i k e t o say t h a t no t only is i t proven t h a t l i v e s t o c k and w i l d l i f e a r e compat- i b l e , bu t t h a t they a r e d e s i r a b l e . We, t h e r e f o r e , defend t h e l i v e - s t o c k i n d u s t r y i n t h e s t a t e o f Nevada and f e e l t h a t i s t h e wild- l i f e and t h e sportsman eve r had a f r i e n d , i t would be a rancher.' '

Dick Mackie missed t h a t po in t yes terday i n h i s l i t e r a t u r e survey. He s a i d he d i d n ' t know i t had been proven t h a t c a t t l e and dee r were good f o r each o t h e r , bu t h e r e we have it. I t 's a p o l i t i c a l p roof , bu t i t ' s one t h a t w e ' l l probably h e a r more o f . Dean Thad Box t a l k e d t o you yes te rday about more people on t h e same amount of land wi th inc reas ing p ressu res , and he s a i d t h e answer i s a l l o c a t i o n . Al loca t ions may be based on s t ronger p o l i t i c a l than b i o l o g i c a l r a t i o n a l e , b u t I ' m s u r e t h e proponents w i l l s t r e s s t h e need f o r cooperat ion. There 's an o ld anecdote


about cooperat ion t h a t says: "There's room enough f o r one of us on t h i s p iano bench i f y o u ' l l g e t off. ' '

A t t h e r ecen t (1976) N . A . W i l d l i f e and Na tu ra l Resources Conference i n Washington D . C . , a f i s h and game b i o l o g i s t , Steve G a l l i z i o l i , s t a t e d t h a t , " In Arizona, t h e s i n g l e most important range management problem which l i m i t s t h e a t ta inment of p o t e n t i a l f i s h and w i l d l i f e b e n e f i t s is overgrazing by l ives tock . I b e l i e v e t h e problem i s no t unique t o our s t a t e . " Speakers a t t h i s conference (Mackie, Urness, T u e l l e r ) seemed r e l u c t a n t t o confirm t h i s observat ion.

Enough of t h i s s h o r t course on pub l i c r e l a t i o n s on p u b l i c lands . When we g e t t o t h e po in t where we've got enough feed f o r e i t h e r t h e cow o r the dee r , b u t no t enough f o r bo th , I th ink w e ' l l f i n d out how much coopera t ion is going t o t ake p lace . The s ta tement from t h e Nevada Conmission shows t h a t when t h e po- l i t i c a l p ressu res a r e on, a l l t hose g r e a t s t o c h a s t i c p e r t u r b a t i o n s t h a t s t a t i s t i c i a n s a larm me w i t h r e a l l y don ' t count f o r much i n t h e management dec i s ion .

L e t ' s move on t o some of t h e o t h e r s u b j e c t s . Dick Denney got i n t o t h e ques t ion of populat ion regu- l a t i o n s and r a i s e d t h e ques t ion , "Is t h e dee r d e c l i n e a s i g n of ecosystem d e t e r i o r a t i o n ? " P r a c t i c a l l y eve ry th ing we've heard a t t h i s conference i n d i c a t e s t h a t when dee r a r e on a high q u a l i t y d i e t , o the r envi ronmental f a c t o r s a r e not a s important . Speakers d i scuss ing p reda t ion and win te r s u r v i v a l have a l s o s t r e s s e d t h e over r id ing importance of good n u t r i t i o n . Zwank s t r e s s e d t h e importance of n u t r i t i o n i n fawn s u r v i v a l .

Hornocker and Knowlton reviewed much of t h e same m a t e r i a l t h a t 1 d id on predat ion. Hornocker pointed out t h a t no c o r r e l a t i o n e x i s t s between deer numbers and l i o n s i n most a reas . There has t o be some o t h e r c o r r e l a t i o n . He t a l k e d about t h e importance of t h e e f f e c t , no t t h e f a c t , of p reda t ion , and I t h i n k t h e same i d e a was s t r e s s e d by Knowlton. Hornocker missed t h e b e s t quote from Durward Allen, whose grandmother watched h i s dog run t h e c a t up t h e t r e e . She s a i d , "Oh, Lord, why c a n ' t they be n ice . " P reda to r s have a poor p r e s s , and I t h i n k t h a t when we g e t i n t o pub l i c r e l a t i o n s , t h a t ' s probably how we ought t o approach i t . Knowlton was q u i t e candid when he s a i d "maybe" i n regard t o whether p reda t ion was a s i g n i f i - can t l i m i t i n g f a c t o r . The n u t r i t i o n a l a spec t is obvious i n h i s work--healthy dee r can wi ths tand more p reda t ion by compensatory reproduct ion than can dee r on low q u a l i t y ranges. Ne i the r Hornocker nor Knowlton s a i d t h a t t h e removal of t h e coyote o r t h e l i o n could be proven t o he lp deer. The average w i l d l i f e b io lo - g i s t is poorly equipped t o e v a l u a t e n u t r i t i o n a l fac- t o r s . He s h i p s p l a n t s t o somebody e l s e f o r proximate a n a l y s i s . Then we f i n d ou t t h a t t h a t ' s only t h e beginning. V o l a t i l e o i l s t h a t a r e b a c t e r i c i d a l and f u n g i c i d a l upset a l l t h e c a l c u l a t i o n s based on pro- t e i n l e v e l s . S y n e r g i s t i c e f f e c t s cause f o o d s t u f f s t o a c t d i f f e r e n t l y i n combinations. J u s t swi tching t h e combinations on two s p e c i e s i n e i g h t d i f f e r e n t combi- n a t i o n s would blow your mind, and some of t h e animals e a t a s many a s 20 d i f f e r e n t k inds of p l a n t s . You can a p p r e c i a t e what Nagy and h i s col league t a l k e d about today--the need f o r more b a s i c r e sea rch of h igh qua l i - t y . Severa l speakers quoted t h e Kaibab case i n t h e f ace of a r t i c l e s i n BioScience, Ecology, and va r ious Nat ional Park r e l e a s e s po in t ing out t h a t t h e Kaibab deer i r r u p t i o n r e a l l y never occurred, t h a t i t was a figment of someone's imaginat ion, o r a c l e r i c a l e r r o r .

No one i n t h i s audience chal lenged i t , al though T u e l l e r from Nevada d id comment on i t . This debate needs t o be continued.

Wolfe was t e l l i n g u s , i n e f f e c t , t o cha l l enge assumptions. The computer c a n ' t overcome poor i n - pu t s . I ' v e go t a hunch t h a t maybe w e ' l l have t o admit t h a t t h e r e a r e some t h i n g s we j u s t c a n ' t do, l i k e n a i l i n g j e l l o on t h e w a l l , o r p u t t i n g t h e tooth- p a s t e back i n t h e tube. Wamlmo, Reid, and Carpenter analyzed e x i s t i n g d a t a i n Colorado t o provide c l u e s f o r t h e d e c l i n e , and they concluded t h a t t h e i r meager d a t a f a i l e d t o support t h e hypothesis t h a t a l l t hese t h i n g s , s i n g l y o r i n combination, could be he ld r e spons ib le . Tha t ' s t h e approach t h e Chamber of Commerce uses when you t e l l them t h a t a i r p o l l u t i o n i s causing a problem. I would l i k e t o have heard them say t h a t t h e meager d a t a f a i l e d t o support t h e hypothesis t h a t a l l t hese th ings a r e not r e spons ib le . There a r e some pragmatic a s p e c t s t o consider . I f deer a r e no t i n evidence, something must have happened t o them. Longhurst s a i d t h a t t h e s h i f t t o c a t t l e from sheep i n C a l i f o r n i a was d e t r i m e n t a l t o mule dee r , and on annual g r a s s ranges t h a t may w e l l be. Sheep can b e f a r more e a s i l y manipulated on ranges than l i v e s t o c k . That may be what h e had i n mind when he s a i d t h a t t h e i n c r e a s e i n c a t t l e and d e c l i n e of sheep was de t r imen ta l t o dee r ranges.

, r u e l l e r made t h e obse rva t ion t h a t dee r numbers d e c l i n e i n p ropor t ion t o l a c k o f v e g e t a t i v e diver- s i t y . Tha t ' s i n every b a s i c t e x t on ecology I ' v e eve r seen. We t a l k about t h e s t a b i l i t y of d i v e r s i t y , and y e t b i o l o g i s t s have been g u i l t y of a i d i n g and a b e t t i n g e c o l o g i c a l i n s u l t s . We sp ray ranges , we poison ponds w i t h toxaphene, we've suggested mass burning of f o r e s t s t o produce monocultures, and we ' re probably g u i l t y of o t h e r e c o l o g i c a l i n s u l t s on a l a r g e s c a l e wi thout r e a l l y knowing what t h e consequences a r e .

Another p o i n t t h a t T u e l l e r made t h a t ' s worth r epea t ing i s t h a t no t a l l forage produced can b e shown t o d i r e c t l y i n f l u e n c e p roduc t iv i ty . We f e e l t h a t food is important , bu t i t may n o t be t h e only l i m i t i n g f a c t o r . There a r e many cases where we've inc reased fo rage s u p p l i e s wi thout i n c r e a s i n g t h e animal numbers. The f a c t t h a t dee r a r e seen i n an a r e a doesn ' t mean t h a t they a r e produced the re . We may be s h i f t i n g them o r drawing them from one a r e a t o another .

I want t o comment on t h e use o f jargon i n our p ro fess ion . We smirk when a s o c i o l o g i s t de f ines murder a s a c c e l e r a t e d , i n t e r p e r s o n a l a l t e r c a t i o n , b u t w i l d l i f e r s a r e n ' t above doing t h e i r b i t t o in- c r e a s e t h e fog index e i t h e r . Here's an example from t h e Master Plan f o r Grand Teton Nat ional Park. "New i n s i g h t s gleaned from r e c e n t problem-oriented re- s e a r c h w i t h i n t h e parks suggest t h a t environmentally r egu la ted ecosystems can u l t i m a t e l y be r e e s t a b l i s h e d . For example, r e sea rch has suggested t h a t t h e popu- l a t i o n may tend t o be s e l f - r e g u l a t i n g wi thout t h e presence of s i g n i f i c a n t p reda to r populat ions . I n t h e con tex t of inc reas ing knowledge of t h e s e f a c t o r s , park management w i l l cont inue t o work toward the e l imina t ion of hunt ing i n the park." The s t a t e of Wyoming responded more s u c c i n c t l y say ing , "To h e l l you w i l l . "

I ' d l i k e t o make a b r i e f comment on t h e w i l d l i f e d i s e a s e paper . It was of i n t e r e s t t o me because i n

Probak Ze Causes o f the Recent Dee l ine 13?

our z e a l t o r i d t h e ranges of t h e p reda to r s , we f e e l we ' re he lp ing t h e herbivores . Now we' re f ind ing ou t i n some cases t h a t ca rn ivores and herbivores a r e vec- t o r s f o r o t h e r d i seases . I f we do have these r e se r - v o i r s of i n f e c t i o n wi th l i v e s t o c k and w i l d l i f e i n t e r - changing, we've go t some r e a l problems: Bruce l los i s is found i n t h e b i son i n Yellowstone and every time a Park b i son c rosses t h e Montana l i n e , by law we have t o k i l l i t due t o stockmen's f e a r s . I th ink you can s e e t h e consequences. We've taken an animal t h a t evolved from anc ien t times and juxtaposed i t w i t h a domestic animal. Since s i c k animals a r e predisposed t o l o s s e s by p reda t ion and acc iden t s , i t i s d i f f i c u l t t o a s s e s s t h e n a t u r e and e x t e n t of t h e losses .

THE FUTURE

Robinet te t o l d us t h a t i t would have been g r e a t i f we could have cu t t h e dee r numbers down be fo re t h e range was damaged s o s e v e r a l y , and many au thors have pointed out previously t h a t when deer e x i s t on second- c l a s s forage, p e r i o d i c die-offs can be expected i n seve re win te r s . We need f a r more exper imental ev i - dence of t h a t f a c t . Looking i n t o t h e f u t u r e , I t h i n k t h a t we can ag ree t h a t simple minds seek simple so lu - t i o n s . Some of you a r e going t o go home disappointed because I d i d n ' t t e l l you t h e s o l u t i o n t o t h e mystery of t h e dee r dec l ine . The conference speakers d i d n ' t t e l l me t h e answer e i t h e r . The answer may be t h a t we should cha l l enge t h e b a s i c assumptions under which we have been managing dee r t h e s e p a s t 30 yea r s . The demand f o r more hunt ing oppor tun i ty can go no way bu t up. It seems t o be inc reas ing d e s p i t e a l l t h e handi- caps we've imposed upon t h e hun te r s , and t h e r a t e of i n c r e a s e is s t i l l a s r a p i d a s t h e inc reases i n t h e 60 's . The hun te r h imself appears t o be becoming l e s s s k i l l f u l , more r e l i a n t on equipment, more r e l i a n t on somebody e l s e t o w r i t e him a book on how t o hun t , how t o b u i l d a f i r e , and how t o d ress out a deer . I t h i n k h e ' s going t o be s u b j e c t t o f a r more regimentat ion, more r e s t r i c t i o n s , quo tas , pe rmi t s , p l aces , l i m i t e d access , a l l t h e s e th ings . Hunters a r e a l s o going t o be s u b j e c t t o t h e whims and vagar i e s of p o l i t i c a l p ressu re , which they may n o t be a p a r t o f , and they may no t understand t h e reasons . There is going t o be more p r e s s u r e on land managers t o produce q u a l i t y hunt ing exper iences , and t o provide b e t t e r number d i s - t r i b u t i o n . There w i l l b e more an t i -nonres ident s e n t i - ment. The p rov inc ia l i sm i n our own s t a t e is p r e t t y obvious. Simultaneously, we're being chal lenged by cour t cases , which may cause us t o repay a l l t h e non- r e s i d e n t l i c e n s e d i f f e r e n t i a l s back t o 1970. Th i s would mean t h a t w e ' l l probably s e l l t h e p l a c e and go i n t o another l i n e of work.

The an t i -hun te r p r e s s u r e i s expected t o i n c r e a s e everywhere, which may s h i f t t h e dee r h a r v e s t from t h e hun te r t o t h e coyote. C a l i f o r n i a ' s recent r epor t by Longhurst and h i s col leagues s a i d r a t h e r gloomily, "We don't t h i n k we can s t e m t h e t i d e of h a b i t a t des t ruc- t i o n and ant i -hunter pressures ." C a l i f o r n i a is k ind of a be l lwe the r here . They've had t h e problems longer than o t h e r s t a t e s .

The game departments a r e faced w i t h i n c r e a s i n g c o s t s , and i n c r e a s i n g demands f o r more complex in fo r - mation, and s imul taneously they a r e f ac ing a reduc- t i o n i n income. Even I can f i g u r e out what t h a t means. We a r e probably going t o have t o put more money i n t o non-game a c t i v i t i e s , and I don ' t t h i n k i t w i l l come f a s t enough t o f i l l i n t h e gap between now and when t h e l e g i s l a t u r e does i t . So we're having t o

put our funds i n t o o t h e r a r e a s because of t h e pub l i c r e l a t i o n s a spec t s . We have a need f o r more i n t e r n a l c o s t account ing and planning t o s e e where t h e money has gone. We may be s t a r t l e d by t h e amount of money t h a t goes i n t o some resea rch p r o j e c t s when i t is f i n a l l y summarized. Game departments a r e now faced w i t h a r a s h of l e g i s l a t i v e i n t e r v e n t i o n s a f t e r many yea r s of r e l a t i v e l y f r e e s a i l i n g . I t seems t o be our tu rn . Eisenhower once s a i d , "I don ' t t h i n k we need e a s i e r problems, I t h i n k we need b e t t e r men.'' How s e l e c t i v e have we been i n our h i r i n g p r a c t i c e s i n w i l d l i f e agencies? We've h i r e d a l o t of people i n t h e p a s t 30 yea r s . Perhaps what I ' m sugges t ing i s t h a t we've been g e t t i n g along i n a r a t h e r s l ip-shod fash ion which won't work now t h a t we're g e t t i n g i n t o t h e b i g leagues . The re sea rch has go t t o b e b e t t e r and deeper , and I don ' t t h ink t h e u n i v e r s i t i e s , a t p r e s e n t , a r e prepar ing t h e personnel t o do i t . They a r e r e f l e c t i n g t h e market. You c a n ' t g e t a job i n some of t h e f e d e r a l agencies i f t hey ' r e i n a de- c l i n i n g budget yea r because they have t o do what they c a l l "GS averaging.' ' I f you've got t h e home o f f i c e f u l l of 15's and 16 ' s , you've go t t o h i r e 3 ' s and 4 ' s s o y o u ' l l average ou t a t 12. Some of t h e agen- c i e s have r e a l l y not made much of an e f f o r t t o i m - prove t h e q u a l i t y of t h e i r people.

Thad Box po in ted out t h a t 12 c r e d i t s is t h e minimum C i v i l Se rv ice requirement t o be a range examiner. I submit t h a t 12 c r e d i t s i n range ha rd ly q u a l i f i e s one t o go out and make dec i s ions in f lu - encing t h e f u t u r e o f t h e p u b l i c lands a s w e l l a s t h e f i n a n c i a l we l fa re of many c i t i z e n s . Game damage complaints a r e i n c r e a s i n g i n t h e western s t a t e s , and i t has become a very s e r i o u s i s s u e . F i s h and game commissioners and t h e o t h e r p o l i t i c a l l y appointed a d m i n i s t r a t i v e types d e a l w i t h axe handle measurements, t h e game manager fol lows along wi th a yard- s t i c k , and t h e r e sea rche r i s measuring s t u f f t o f o u r decimal p laces . This is p a r t i c u l a r l y i r o n i c when we c a n ' t even make one s imple breakdown, such as a r e we ga in ing , l o s i n g , o r holding our own on mule dee r? Those a r e c l a s s i n t e v a l s of 33 113 percent . I ' m n o t r e a l l y impressed wi th decimal po in t s . I ' d l i k e t o know i f we have such a t h i n g a s a " lack of con- f idence" i n t e r v a l ?

Tha land i t s e l f is obviously under con t inua l ly inc reas ing p ressu re . Land is f i n i t e and r e c r e a t i o n a l p ressu res a r e i n a d d i t i o n t o a l l t h e t r a d i t i o n a l uses. We c a n ' t buy a l l t h e needed game ranges and a r e going t o have t o l e a r n t o ge t a long wi th what we have. This i s going t o invo lve a degree of coopera- t i o n , which h a s h e r e t o f o r e been unknown between t h e agencies . Arizona charges an e x t r a f e e t o hunt on l ands t h a t t h e y have improved. I t h i n k i t ' s a good idea . A $5 f e e t o hunt on t h e Kaibab might b e t h e r i g h t way t o f inance t h e s t u d i e s , because we may soon run out of d o l l a r s . The demand f o r t h e dee r is obviously going t o exceed t h e supply. More buck hunt ing and l e s s trophy hun t ing w i l l be t h e r u l e . Colorado i s a l r eady going f o r l e s s trophy hunt ing and more meat. Th i s is j u s t t h e oppos i t e of what they"re f i n d i n g on Af r i can game ranges where they shoot bucks and fawns. They don ' t shoot t h e i r product ive herd segments. Why t h e d i f f e r e n c e ? I t h i n k t h e t rade- o f f s between t h e dee r o r e l k and l i v e s t o c k a r e going t o b e ha rd fought. Remember t h a t some game depar t - ments, under p o l i t i c a l p r e s s u r e , don ' t provide much of a f i g h t when t h e l i v e s t o c k i n t e r e s t s remind them of t h e i r l o y a l t i e s .


Cr ipp l ing l o s s e s w i l l probably inc rease . Long- range shoo t ing , f e a r of f i n e s (abandonment of does and y e a r l i n g bucks) , more i l l e g a l hun t ing because more r e s t r i c t i o n s make i t more p o s s i b l e t o hunt i l l e g a l l y , and a probable i n c r e a s e i n poaching can be expected. W i l d l i f e d i seases w i l l probably in- c r e a s e , a s D r . Hayes mentioned, wi th t h e i n c r e a s e i n s tock ing on pub l i c l ands and wi th r e s u l t a n t poor n u t r i t i o n . The sad th ing is t h a t t h e r e a r e probably very few w i l d l i f e r s and probably no hun te r s t h a t know anything about w i l d l i f e d i seases . We genera l ly n o t e i n our r e p o r t s t h a t d i sease d i d no t seem t o b e a problem, perhaps because we don't recognize i t . An old Ozark h i l l b i l l y s a i d , "We're genera l ly down on what we a i n ' t up on." P reda t ion w i l l probably in- c r e a s e a s t h e h a b i t a t s h r i n k s , o r degenerates , and i t may decrease i f t h e p u b l i c demands more p reda to r con t ro l . Tha t ' s a toss-up. S t a r v a t i o n can be con- t r o l l e d by reducing dee r numbers i f o t h e r forms of range compet i t ion do n o t e x i s t , o r i t may be brought about by changes i n t h e weather , which we c a n ' t do anything about. We can improve the ranges a t g r e a t c o s t , and discover t h a t i t h e l p s c a t t l e a t t h e expense of deer . The p u b l i c may end up i n s i s t i n g on an a r t i f i c i a l feeding program l i k e t h a t a t Jackson Hole where t h e s t a t e p lus t h e f e d e r a l government pu t out $700,0000+ annual ly f o r supplemental f eed f o r e lk .

J u s t cons ide r what $700,000 could b e used f o r i n o t h e r p r o j e c t s . I f you don't have a w i n t e r range, you go t o t h e s u b s t i t u t e .

Deer l o s s e s t o acc iden t s a r e very l i k e l y going t o i n c r e a s e wi th more roads , more f ences , more r e se r - v o i r s , and more d i t ches . I don't s e e how we can pre- d i c t t h e f u t u r e of dee r h a b i t a t except t h a t w e ' l l cont inue t o l o s e more of i t . What h a b i t a t we do have can be manipulated w i t h t h e use of f i r e , and t h e con- t r o l of f i r e . But I th ink t h e q u a l i t a t i v e l o s s e s , such a s from overuse , a r e bound t o inc rease . The q u a n t i t a t i v e a s p e c t s of h a b i t a t l o s s pose an e n d l e s s , one-way a t t r i t i o n . Twenty thousand a c r e s a yea r a r e converted from one kind of a g r i c u l t u r a l use t o ano the r , and a m i l l i o n a c r e s a y e a r i s l o s t under t h e freeways. It t akes 60 a c r e s t o b u i l d an in terchange. The new n a t i o n a l p l a n t w i l l probably b e a c l o v e r l e a f . We'll be lucky t o l e v e l o f f t h e mule dee r l o s s e s and then f i g h t t o hold our own i n t h e f ace of these end less problems.

I n c los ing , I ' d l i k e t o quote from Santayana, who s a i d , " A l l problems a r e d iv ided i n t o two c l a s s e s . Soluble ques t ions , which a r e t r i v i a l ; and important ques t ions , which a r e insoluble ." Thank you.

ProbabZe Causes of the Recent Decline

MULE DEER DECLINE IN THE WEST A SYMPOSIUM and Settings/37/Site... · 2015-05-28 · MULE DEER...

Documents

Transcript of MULE DEER DECLINE IN THE WEST A SYMPOSIUM and Settings/37/Site... · 2015-05-28 · MULE DEER...