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WINTER ECOLOGY OF MOOSJ; IN THE

GALLATIN MOUNTAINS, MONTANA

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38 Journal of \Vildlife Management~ Vol. 34~ No. 1, January 1970

~.·a0 ~ ~~ ~~ ~~· 39'- 1/b;· /~?(/

distributions. J. Eco].

E. 1966. Ecological methods· ,r reference to tl1e study of in: . Js. Methuen and Co. Ltd.~ Lon.

196~. Soil and ve~etation on 1\."Penmental Forest and Range

· st, Proc. 1965:27-30. · 1952. Measures of plant acr.

. :l on contagious distribution~

. :rt. Bioi., Univ. Michigan 53. •

)54. Lin1itations of the "zero pulation counts. Science 119

\V. B. HENsEN. 1959. Some te-s .of tile negative binomial

: :. -special reference to forest ici. 5(4):397-412.

n February 14, 1969.

WINTER ECOLOGY OF MOOSE IN THE GALLA TIN MOUNTAINS, MONTANA1

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:~B~VID R. STEVENS, Montano fish and Game Department, Bozeman::

~tr~~t<; :--Abstract: Moose (Alces alces shirasi) winter range use and foo-:1 l1abits were studied on the north slope of tl1e Gallatin mountain range, Montana, from September, 1965, to December, 1967. Aerial ob­servation indicated a low density population winters primarily on quaking aspen (Populus tremuloides) and Douglas-fir (Pseudotsuga menziesii) vegetation types. Migration from fall to winter range was gradual and lasted tlm:mghout the winter. Highest woose concentrations were found on tl1e aspen and

· Douglas-fire types in March and April. Rumen sample analyses indicated that low red lmckleberry (Vaccinium scoparium), subalpine fir (Abies lasiocarpa), and willow (Salix spp.) were the most important fall food items. Feeding site examinations indicated that willow, western serviceberry (Amelanchier alnifolia), chokecherry ( Prunus virginiana), and red dogwood (Comus stolonifera) were the most impor­tant species in winter. Serviceberry, dogwood, and willow remained important into the spring, when increased use of currant (Ribes spp.) and some forbs was noted. Aquatic plants and grasses were found to be unimportant in tile moose diet. Condition and trend transects in.Jicated that the range was in poor condition and deteriorating further. Reproduction data indicated calf: cow raf1Js of 55:100 and 52:100, in 1965 and 1966, respectively. Aerial observation was effective in determining moose dis~ tribution but not for total census of the stud}' area. Willow was not found as important to this moose populauon as has been reported for the Shiras moose on other areas.

This paper describes the winter range use, food habits, and certain population characteristics of moose on the north slope of the Gallatin mountaji) range, l\1ontana. Quantitative data were accumulated from September, 1965, to December, 1967, to describe the habits of the Shiras moose on various range types. Other authors (Den­niston 1956, Knowlton 1960, Sn1ith .i9B2, Houston 1968) have studied the ecology of the Shiras moose, but primarily on ranges where willow was the major habitat type.

When Montana moose hunting termi-, " nated in 1897, populations were apparently

very low in the areas surrounding Yellow­stone Naticnal Park, including the Gallatin study area. :McDowell and :Moy (1942)

' reported that populations witl1in .the park attained a peak density about 1924. Sub­sequently, moose populations increased rapidly outside the park. A report ( U. S.

1 A contribution of the !\fontana Fish and Game Deparbnent, Research Section, 1mder Pittman­Robertson Projects \V-98-R6, \V-98-R7, and \V-98-RS.

2 Pl'escnt address: National l)ark s~rvice, Estes Park, Colorado.

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Forest Service 1935:64-66) indicated that moose were present in almost every drain­age of the Gallati.n and tl1at forage was still plentiful. The first hunting season was held in 1956 after a closure of almost 60 years. The first seasons were resu·icted to a few bull-only pem1its but in recent years more liberal permits for either sex have been issued.

The author v'Vishes to express apprecia­tion to J. Stradley, who piloted most of the observation flights and tc T. Mussehl and P. Scl1ladweiler, Montana Fish and Game Department, and J. Peek, University of :Minnesota, wl10 reviewed the manuscript. The National Park Sendee contributed time for completion of the manuscript.

METHODS

Classification of vegetation was primarily by dh;ect observation, with quantitative measurements on several types determined important as moose range. Plant nomen­clature follows Booth (1950) and Bootl1 and \Vrigl1t ( 1962).

Aerial observations were utilized to de-

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38 ]ot:rnal of 'Wildlife 111anagement> V'ol. 34, No. 1, January 1970

tennine distribution and use of vegetation types. Eight flights during the \Vinter of 1965-66 and ten in 1966-67 were ·made by Piper Super-cub during early morning hours wl1en moose . were generally feeding and mo~t easily observe~. The time, drainage, age, vegetation type, elevation, and expo­sure were recorded for each of 683 moose . observations. On flights from December to April, an average of 53 moose were ob­served per flight ( CV = 26 percent). One helicopter flight was made each year to obtain age and sex classifications z.nd sup­plement other data.

Moose food habits were studied by ex­amination of feeding sites (Knowlton 1960: 163). If snow was present, animals were back-tracked as far as their previous beds. Instances of use were recorded where the use of one leader was considered to be one instance. Percentages were computed by the aggregate percentage method (:Martin et al 1946). One-quart rumen samples were collected from hunter harvest and acciden­tally killed moose. Analysis followed stan­dard procedures (Cole 1956:20).

To determine range condition and trend, browse survey transects (Cole 1959) were established on winter range areas. Each sample consisted of 25 to 50 plants indi­vidually marked with aluminum tags. Plants were classified to degree of hedging, age, and percentage of the leaders (annual growth) used.

Statistical inferences are from Chi-square tests (Li 1964:461-471).

THE STUDY AREA

The study area (Fig. 1) occupied ap­proximately 213 square miles at the north end of the Gallatin mountain range south of Bozeman, :Montana. The Squaw Creek­Gallatin River drainage formed the south­west boundary and the Yellowstone-Ga11a­tin divide formed the east boundary. The

area generally slopes toward the northn .. '""~""'' from peaks of over 10,000 ft to foothills 5,000 ft. The drainages run generally in a · northwest direction, cutting relatively steep.~ sided canyons toward the lower end. .,. entire area is underlain by metamorphic rock (Tysdal1966). Rock crops.along the canyon walls reveal a t:m<~~ sedimentary strata with extn1sions of ... .<:. .... c._ ous rock lying above.

U. S. \Veather Bureau records in man indicate an average January u .• nnn~=•r!l.:,illl5

ture of 20F and an average July temp of 66F. The annual precipitation 17 inches, the major portion falling spring. Accumulated winter snow on the lower edge of the study area "\VP-1·~"«

generally 1-2 ft, with more at the ....... ~-., ............ _ elevations. Total snow fall at the station was 7 4 inches in 1965-66 and in 1966-67.

Vegetation

Seven basic vegetation types discerna from the air were 1·ecognized.

Tl1e spruce-fir community, ch by Engelmann spruce (Picea rtnd subalpine fir, is common above 7,00 elevation. The understory is primarily mosses and low red huckleberry. It ron~,TP.r~~ about 21 percent of the study area, ext:enci..­ing into the lower vegetation types a ................ streams and northeast exposures.

Abont 18 percent of the study area ( Q"er:t,_ erally undet• 7,000 ft) is occupied by Douglas-fir community. The understory primarily pinegrass (Calamagrostis cens)~ heartleaf arnica (Arnica ~md wl1ite spiraea (Spiraea betulifolia). semi-open canopy type is present on south and southwest exposures with leaf balsam-root (Balsamorhiza sagittata) and lupine (Lupim1s spp.) the understory. On northem exposures a lower elevations the understory is

Fig. 1. The study

t<.'rized by a (Physocarpus ma plwricarpos albu · The canopy has l~:ctive logging

The most OVT'""""''

(occupying abou pine (Pinus

·toward tl1e :northwest­:>,000 ft to foothiUs 2t : es run gene:-ally in a ~-·~~-•.u1:. relatively steep-

the lower P~d. The . ain by Pricambrian · sdal1966). Rock out-• 1 wa!ls 1·evea1 a thick 11 extrusions of igne-

u records in Boze­ge January tempera­age July temperature

rreci1:>ita.tion averages , portion falling in lVinter snow depths

e study area were 1more at the higher i fall at the weather in 1965-66 and 119

m types discemable \gnized.

'ty, characterized Engelmanni)

.nnon above 7,000-ft • 01y is primarily of ~kleberry. It covers ·study. area, extend­!tation types along · *A'IJOSures. 1e study area ( gen­s occupied by the The understory is .

la.magmsti.s rubes­(Amica cordifolia) 1ea betulifolia). A . is present on the . osures with arrow~ morhiza sagittata)

. ) characterizing h~rn exposures at lerstory is charac-

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'VL"\'TER MoosE EcoLOGY m MoNTANA • Stevens 39

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Fig. 1. The ~tudy .ruea, Gallatin Mountains, touthwest Montona.

terized by a dense shrub union of ninebark (Physocm·pus malvaceus)

1 sno\;·berry (Sym­

phorica1'pos albust and rose (Rosa woodsii). The canopy l1as been opened by past se­lective logging on some areas.

The most extensive type vn \he study area (occupying about 44 percent) is lodgepole pine (Pinus contorta) at various densities.

It is considered seral to the climax spruce­fir and Douglas-fir communities ( Oosting 1956:298). The understory varies from profuse to non-existent, with pinegrass at Jnwer elevations being replaced by lo\v red huckleberry in l1igher areas. In many areas~ the lodgepole pine is represented only by large, decadent trees th~t arc being re-

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40 Journal of 1,Vildlife J.fanagement, Vol. 34, No. 1, January 1970

Table 1. Moose distribution by eievation as determined by aerial observation on the lower Gallatin study area.

1965-1966 1960-1967 ELEVATIOX

{feet) Nov.-Dec. Jnn.-.Feo. Mar.-Apr. Nov.-Dec. Jan.-Feb. 1\.lnr.-.Apr. May

5000-5499 0 p 3 10 18 7 5500-5999 11 28 23 15 50 42 12 6000-6499 42 37 60 42 25 31 42 6500-6999 40 23 6 21 12 8 30 7000-7499 5 11 2 20 3 1 7 7500-7999 2 3 2 2 Above 8000 . 3 Total observations 73 9=> .. 113 58 73 140 53

1t Percent of moose observed at that elevation during each period.

placed by spruce and fir in the understory. The numerous logged areas are dominated by lodgepole pine reproduction of various age-classes, with grasses and sedges as an understory:

About 12 percent of the study area is non-forested. The most common cover is the sagebrush-grassland community in parks at various elevations, generally on south­west exposures and on the north edge of the area. Tbe type is characterized by Idal10 fescue (Festuca idah.oensis) and blue­bunch wheatgrass (Agropyron spicatum) on the more xeric sites. Big sagebrush (Ar­temisia tridentata) is often present as an overstory. Timothy (Phleum pratense ), mountain brome (BromtlS marginatus), and sticky geranium (Geranium viscos.si.ssimum) are common in mesic swales. Wet meadows are dominated by sedges and grasses.

Aspen stands are common throughout the study area on sites where moisture is high, especially below the Douglas-fir com .. munity between 5,000 and 6,000 ft. This type, characterized by quaking aspen of various age-classes, occupies less than 5 percent of the study area and is often in­terspersed through the other vegetation types. Ninebark, rose, snowberry, and spiraea are the most common understory shrubs, \Vith chokecheny, western service­berry, and Scouler willow (Salix scouleri­ana) also represented.

TI1e willow community, occupying less than 1 percent of the area, is restricted mainly to stream banks and relatively nar­row bottom areas. The primary Salix spe­cies are myrtillifolia, drummondiana, and geyeriana. Other common species are mon­ticola, wolfii:. and phylicifolia. The tmder­story is primarily grasses and sedges, with shrubby cinquefoil ( Potentilla fnrticosa) and bogbirch (Betula glandulosa) com: .... on on drier sites.

T.ne cottonwood commtmity, also of lim­ited area, is primarily a gallery formation along strear11 banks, generally below 6,000 ft. It is characterized by cottonwood (Pop­ulus spp.) with a dense shrub union of alder (Alnus incana), red dogwood, moun­tain maple ( Acer glabrum), and willow. Douglas-fir reproduction is locally common.

FINDINGS

Distribution and Range Use

:Moose were dist.ibuted throughout the major vegetation types (Fig. 2) between 6,000 and 7,000 ft elevation (Table 1) in December. The Douglas-fir and lodgepole pine communities received heavy use both years, with more moose observed on re­vegetated logged areas during this period than at any other time. Spruce-fir com­munities received significantly ( P < 0.01) heavier use in 196~66 (23 percent of ob-

,..

DEC

Fig. 2. Percent of moose

servations) than in while the aspen less.

Aspen became type for moose ~ ..... L ... .UJ=.!

l~ebruary), averaging servations both years cant differences .... .,.,..,,.., noted. Observations cHeated rather even timbered and logged most woose ( 68 ..,..,,.,. . .,..,.,, communities. In 1 and 60 percent, ''·ere found below 6,

The observations rather gradual early December tions of moose on During this period, gressively in local a

Sollo''"'· study oreo.

~1967

:Mar.-Apr. May

18 7 42 12 31 42 8 30 1 7

2

140 53

, occupying less .1 area, is restricted l and relatively nar­·. prima1y Salix spe-1rwmnondiana., and ( . . ">n spec1es are mon-'-:ifolia. The under­:s ?-nd sedges, with

. 'Jtentilla fruticosa) ··undulosa) common

nunity, also of lim­·. gallery formation terally below 6,000 cottonwood (Pop­

;e shru 'IJ union of d dogwood, moun­·um), atqd willow. is locally common.

Use

:!d tl1roughout the · (Fig. 2) between tion (Table 1) in •-fir and lodgepole ~a heavy use both

. } observe< on re­dming this period . ,Spruce-fir cc;m­cantly ( P < 0.01) 2~'3 percent of ob-

.....

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WINTER 1foosE EcoLoGY L"'l MoNTANA • Stevens 41

DEC JAN FEB

1965-1966

MAR APR DEC JAN

LODGEPOLE PINE

FEB

1966-1967

MAR APR

Fig. 2. Percent of moose observations on major vegetation types by month on the Gallatin study area.

servations) than in 1966-67 ( 7 percent), while the aspen communities were used less.

Aspen became an important vegetation type for moose during midwinter (January~ February), averaging 42 percent of the ob­servations both years. Statistically signifi­cant differences between years were again noted. Observations in January, 1966, in­dicated rather even distribution among the timbered and logged areas while •in 1967, most moose ( 68 percent) were using aspen communities. In 1965-66 and 1966-67, 29 and 60 percent, respectively, of the moose were found below 6,000 ft elevation.

TI1e observations gener~lly indicated a rather gradual movement from scattered ear!y December distTibutions to concentra­tions of moose on Io,ver areas in late March. During this IJeriod~ densities increased pro­gressively in local areas, especially on aspen

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communities where up to seven or eight moose p0r square mile were 1·ecorded. By comparison, densities of 25 moose per square mile have been observed on willow winter range on the upper ~1adison drain­age in :Montana (Stevens 1967:7). Houston (1968:47) reported winter densities of up to 50 moose per square mile in Jackson Hole, 'Vyomin.g on the willow range type.

Late ''"inter use of vegetation types dur­ing the 2 years was more similar, although use of lodgepole pine increased significantly the second year. Combining data for March and April, 31 and 39 percent of the moose were observed on the aspen and 42 and 34 perce11t were observed on the Douglas-fir type in 1966 and 1967, respectively. The differences were not significant.

The cottonwood type received consider­able use in late winter that was not re­corded from the air. ~·foose were distributed

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Journal: of "'Wildlife Management, Vol. 34, No. 1, January 1970

Table 2. Forage species utilized by moose as determined by rurr.en samples• and feeding site examinationsb on the Gallatin study or~o.

FALL '\VINTER SPRING

SPECIES~ ( Oct,-Nov. )(Dec.-1\Iar.) (Apr.-June)

Abies lasiocarpa 20/6011 2/12e ~/10 Acer glabrum 7/12 2/10 Amelanchier alnifolic; 17/35 14/30 Berberis Tepens 2/60 Arctostaphlos twa-ursi - 4/5 Comus stolonifera 13/20 8/10 Populus spp. 7/30 1/10 Prunus virginiana 7/25 16/30 1/5 Pseudotsuga menziesii 7/30 5/8 Ribes spp. 1/25 8/30 14/20 Rosaspp. 2/15 2/15 Salixspp. 11/70 17/63 32/45 Symplwricarpos alba - 5/15 Vaccinium spp. 16/75 4/20 Other browse 24/100 5/50 5/20

Total browse 88/100 99/100 94/90 Cirsium spp. 2/25 Geranium

viscossissimum 3/15 LupinrtS spp. 2/10 Senecio spp. 6/20 Other forbs .t/45 1/15 3/35

Total forbs 11/65 1/15 6/35 Total grass and

grass nke-plants tr/65 tr/10

" Fall food habits detennined by the- examination of 20 rumen samples,

b \Yint~r and spring food habits are detennined by the exammation of 40 and 20 feeding sites, respectively, To compute total use for winter nnd spring the percent use of the spt'cies is .weighted by the perc~nt of the seasonal moose observations ou each vegetative type.

c Species listed formed at least 2 percent of use for one season.

d Average percent of volume/,frequency of item in rumen samples.

e Avernge percent of instances/frequency at sites.

at their lowest elevations at this time, with 85 to 90 percent of the observations below 6,500 ft.

Adult moose, primarily cows with calves, and bull groups, were found to be rela­tively sedentary in winter, tending to re­main on local areas for extended periods. J\tiovements from these areas are probably related to the available forage. Limited movements on the winter ranges were also reported by Houston ( 1968:51).

Extensive early spring use of open park .~ types, as reported by Knowlton (1960:166) . and Houston ( 1968!22 ), was not Jecorded.

Food Habits

Fall food habits were determined by the ~~; analysis of 20 rumens col1ected during the ~ hun~ng seasons in October a~d November, t 196o and 1966 (Table 2). Sa1nples were ~~ tabulated as to probable vegetation type of ~ the feeding site as indicated by location ;~~ of kill. ~

·~ Browse was the primary forage class used ~ by moose in the fall. The species of pri- -i mary importance varied with the feeding ~ site and elevation. Grasses and grass-like ii'f plants were insignificant in the rumen ~ samples. Fall food habits resemble the ~ findings of Knowlton (1960:166). 11

In the spruce-fir and lodgepole pine com- ~ munities, huckleberry (Vaccinium spp.) .~ and subalpine fir formed 62 percent of ~ the volume of rumen samples. Groundsel ~ (Senecio spp.) formed 13 percent of the 4 samples. Tl1e remainder was a variety of ~ other browse species. \Villow, Douglas-fir, ~.}4 and cho 'kecherry were the most important :@ species in the Douglas-fir and aspen com- ~i munities. :\Ider (Alnus tenuifolia), ge~-1 erally considered unpalatable, was prom1- ,;1 ner1t in one sample. In the three rumens~ collected from willow areas, the primary i species was willow. Huckleberry was also I'· present, indicating feeding in adjace. nt tim-: ; ber types. > ·.

"'inter food habits were studied by ex .. :;. amination of 40 feeding sites, recording j 11~068 instances of use on six vegetation ~ types (Table 2). The relatively small num- :, ber (about 10 percent) of moose wintering ~ in spruce-fir communities utilized subalpine ii fir extensively, The use of other species, f such as willow and currant, was probably ~ related to availability as determined by iJ snow depths. Deciduous browse species, .~

primarily mountain m chokecherry, currant, were most important fer communities. more important in ranges than indicated mninations~ In six dm;:ing the winter, 21 percent of the was primarily willow.

In aspen C0111n1ur1itiel

browse species are low, servicebeny, were ~he primacy J.L~:•u1•~-: and willow (stream almost 90. percent of wood type. but the trees are forage for moose. 95 percent of the diet feeding sites. The were S. phylicifolia, S~ drummoncliana.

The overall winter almost entirely of chokecherry, willow, formed 65 percent of Ag.uatic plants and to be important but able. \Vinter food findings of Harry ( 1960:161), and use of forage classes. important on the porced for moose by

Spring food habits the examination of 20 ing 3,211 instances of types (Table 2). In type, moose took a areas around trees on posures. Snowberry, staphylos u.va-ursi), rant were used .... .,. ...... u.,J

Subalpine fir and

use of open park awlton ( 1960:166) was not recorded.

de.t~rmined by the ·alected during the 1er and November,

) . Samples \Vere vegetation type of cated by location

y forage class used species of pri­

; with the feeding ises and grass-like \t in the rwnen bits resemble the I

(960:166). 'dgepole pine com­:v accinium spp.) . ~d' 62 percent of mples. Groundsel

·13 percent of the \ 'vas a variety of ·mow, Douglas-fir, 1e most .important r and aspen com­tenuifolia), gen­

table, was promi­the tl}ree rumens reas, the primary ~kle berry \Vas also ·g in adjacent tim-

•re studied by ex­~ sites, recording on six vegetation atively small num­f moose wintering utilized subalpine of other species,

mt, was probably .s determined by s browse species.

\VINTER MoosE EcoLOGY m MoNTANA • Stevens 43

primarily mountain maple~ :red dogwood2

chokecheny, currant, and Scouler willow, ('""' were most important in the other two coni­t.~ fer c-ommui1ities. Douglas-fir is probably ~· · more important in the diet on the lower ;~;::_' r t' ranges than im:U~teq by feeding site ex-i~.;;.t aminations. In six rumen samples collected · "::~ during the winter, Douglas-fir composed ~···' 1""~ · 21 percent of the volume. The remainder ~ was primarily willow. "~,. I 1 d d r~>· n aspen communities, w lere eci uous f~if browse species are abundant, Scouler wil­t~: low, serviceberry, chokecherry, and aspen .:~~.~ were th~ primary items. utilized. Dogwood ~ ~ : · P.nd wil1ow (stream bank species) formed ' almost 90 percent of tl1e diet in the cotton­i ... wood type. Cottonwood appeared palatable '~.r but the rrees are generally nnavailab1e as ; · ··· forage for moose. vVillow formed almost

95 percent of tl1e diet on willow bottom . ··... feeding sites. The mo~t ~tili~f'd svggies

'vere S. 7Jlzylicifolia~ S. myrtillifolia and S . · drummondiana.

The overaH winter diet was composed almost entirely of browse. Serviceberry, cl10kecherry, willow, and dogwood together fanned 65 percent of the obseNed use. Aquatic plants and forbs were not observed to he important but were used ''rl1ere avail­able. "'inter food habits resembled the findings of Harry ( 1957:56), Know I ton (1960:167), and Houston (1968:2tj) in the use of forage classes. "'illow was not as important on the Gallatin study area as re­ported for moose by these authors.

Spring food habits were determined by the examination of 20 feeding sites, record­ing 3,211 instances of use on six vegetation types (Table 2). In the lodgepole pine type, moose took advantage of snow-free areas around trees on south and west ex­posures. Snow berry, kinnikinnick ( Atcto­staphylos ttt;a~ursi), lmcklebeny, and curw rant were used extensively on these areas. Subalpine fir and willow continued to

domh1ate on sprn~e-fir feeding sites since conditions at higher elevations remained winter-like at the start of the period. Spring feeding site examinations in the Douglas­fir and aspen types showed increased use of willow~ pr~Il}arily the use ()f g!'~~g J~aves as they became available.

In :May and June, moose utilized the open grass-sagebrush parks to a greater ex­tent as green £orbs beeame available. On these areas~ £orbs composed 65 percent of the use on feeding sites. Important species were sticky geranium and bluebells ( /t.1. er­tensia spp.).

Generally, spring \Vas characterized by increased use of forbs, hut browse still fanned the major part of the diet. V\Tiilow 'vas the most important single item on spring feeding sites, fmming 33 percent of the total use.

Range Condition

The conditi0n and trend of vegetation on the GaiJatin moose range was deter­mined by measuring 25 browse transects. Fifteen transects had wiiJow as the key species with deciduous species measured on the other ten. Use measured was be­lieved to be primarily by moose althougl1 mule deer ( Odocoileus hmnionius) and domestic cattle also used the area at vali­ous times.

The condition of the willow plants was deteriorating during the study peliod. In 1965, 63 percent of the plants were heavily hedged and 55 percent were decadent. By 1967, 87 percent were heavily hedged and 77 percent decadent. TI1e difference be­tween the two years was . significant ( P < 0.01) .. Utilization generaliy was high in 1965 and 1967 but declined in 1966. This reduced us0 in 1966 was probably related to the relatiYcly mild winter and the shorter period the animals were on the winter range

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44 Journal of 1\lildlife Management~ Vol. 34~ No. 1~ January 1970

Red dogwood, serviceberry, and. choke­cherry transects indicated the same use patterns but, generally, these species were in poorer condition than willow. One dog­wood transect went from 80 percent heavily hedged in 1965 to 100 percent in 1967. Two serviceberry transects went froiT\ 92 percent heavily hedged in 1966 to 100 per­cent in 1967. Utilization of these species was erratic and difficult to evaluate be­cause of very low forage production due to the poor vigor of individual plants.

Utilization and condition were deter­mined for aspen trees under 8 ft high on sh:: transects in 1967. Although aspen ap~ pears to be less palatable than the othe1· species measured, 60 percent of the plants \Yere severely hedged. Most aspen use oc­ctured in late winter after more palatable species were heavily utilized. Spring and summer use of green leaves was also noted.

Utilization of subalpine fir was difficult to measure because of the extensive areas involved and the nature of use. :Moose ex­tensively used relatively small areas in the ltigher elevation spruce-fir commu­nities until most of the available browse was consumed. Subalpine fir trees were often denuded from the snowline up for approximately 8 ft. These areas may not be used again for long periods. A majority of the high ranges were observed to be in relatively poor condition.

Douglas-fir trees on the lower ranges were generally high-lined by moose to about 8 ft above the ground. As indicate· by winter rumen samples, Douglas-fir wa used when available and may form a sub­stantial part of the diet. The amount of Douglas-fir available as winter forage on the study area was believed limited.

Population Characteristics

Herd composition was determined from December flight data when the sexes were

still easily recognized. The 2-year averaae . 0

post-hunting season composition was 50 .. percent females, 27 percent calves, and 23 ·':. percent males. Other areas show a A~~~·~ ... , percentage of males. Houston (1968:60) reported 42 percent females, 24 calves,· and 34 percent males in J a Hdle, while in the Gravelly-Snowcrest Montana, the composition was 31 percen females, 24 percent calves, and 41 ,..."' .. ,.,.,, ... .._ males (calculated from Knowlton 1960: A pre-hunting season classification cated a l1igher percentage of males on Gallatin area at that time. These rh.f.~o .......

ences may be related to the harvest is weighted toward ma1es on the '-"'C1'u"u.u•

area (Stevens 1967:18). Annual production, indicated by

season calf: cow ratios, was 55 and 52 per 100 cows in 1965 and 1966, tively. The difference was not (P > 0.75). Knowlton (1960:169) a winter ratio of 78 calves per 100 and Houston ( 1968:60) had observed ra of 66, 56, 49, and 63 : 100 in Jackson

The occurrence of twin calves in population was low, about 2.5 percent the observed young. This is similar tl1at reported by Peek ( 1962:362) for Gravelly-Snowcrest area in Montana. ton ( 1968:69) reported 4.5 percent Jackson Hole.

DISCUSSION

Aerial observation was believed e .... o.nrn ......

) determine the general moose ion and range use in winter. It did

.appear to be adequate for total census cause of the rough terrain and dense opy cover of the timber types. The use data may therefore be biased the more open vegetation types. 1f the moose not observed on eacl1 flight (using the highest single flight count of 76 as a

}J,JS(') are \.>VJ.J03J.Io.4v.<

r.wopy timber mum extent of Till' ratio of ... u ......... ._

111~)osc in closed riocl of December

· \Tars, would be ~l'lYCd ratio of 46 .;t;1 tistically L oncentrations moose tracks in fm· this bias. La t•arly fall were eonsiste11t aerial

<'\'cr, were used ing ·winter and winter range. found in the diet ranges, it was did not dominate

The 2-year average ·omposition was 50 . rcent calves, and 23 ueas show a higher .Houston ( 1968:60) emales, 24 percent

· t males in Jackson elly-Snowcrest area, ion was 31 percent ms, and 41 percent

'illowlton 1960: 169). classification indi­ge of males on the me. These differ­the harvest which

es on the Gallatin

~dicated by post-1as 55 and 5.~ calves •and 1966, respec­<,as- not significant 960:169) reported yes per 100 CO\VS

ad' observed ratios ,lin Jackson Hole. · in calves in the ut 2.5 percent of 1is is similar to ;962:362) for the 1 }.1ontana. Hous­, 4.5 percent in

1elieved effective !moose distribu­lter. It did not :total census be-and dense can­?es. The range­: biased toward

types. If the }11 fligl1t (using unt of 76 as n ' ,

r i . \VI:\"TER l\JoosE EcoLOGY IN MoNTANA • Stevens 45

base} are considered to be using the dense canopy timber types, the possible maxi­mum extent of tbis bias can be estimated. The ;ratio of moose in open canopy types: moose in closed canopy types for the pe­riod of December to April, combining both years, would be 30 : 70 instead of the ob­served ratio of 46 : 54. Tllis difference is statistically significant; however, winter concentrations and aerial observability of moose tracks in snow compensate somewlmt for this bias. Late spring, summer, and early fall were more difficult periods for consistent aerial observation. Ground ob­servations ho\vever, are inconsistent during all seasons of the year.

~1ost studies of Shims moose have shown them to be dependent on willO\\-' in tlw winter. These willow l1abitat areas may be extensive flood plains, used by moose al­most to the exclusion of other vegetation types, as in Jackson Hole, Wyoming (Hous­ton 1968:22) or the Big Hole Valley of Montana (Stevens 1965:21). They may also be relatively small willow bottoms along stream courses w lricl1 moose use in conjunction witl1 adjacent vegetation types~ as in the Gravelly-Snowcrest ~.fountains (Knowlton 1960) or Rock Creek, Montana (Smith 1962). The importance of willow in the diet of Shiras moose l1as been shown by food habit stud;es of McMillan ( 1953) and Harry ( 1957).

The willow type was found to be less L"Tlportant as winter range on the Gallatin study area. Willow was represented pri­marily as narrow galleries along s.treains and on some mesic upJand sites. The Douglas-fir and aspen communities how­ever, were used extensively by moose dur­ing winter and were considered the key "Yinter 1·ange. '\¥illow was consistently found in the diet on fall, winter, and spring ranges1 it was used wl1ere available but did not dominate the diet, probably be-

cause it was scarce. Serviceberry, choke­cherry, and red dogwood were used more heavily than willow and appeared to be more palatable to moose when there was a choice. Other important forage species were currant, subalpine fir, Douglas-fir, and aspen. Utilization data indicated aspen to be less palatable than the others.

'3rowse was the most important forage c7 :ass in the moose diet. Forbs were not observed to be important on. winter ranges but became prominent from spring through fall. Grasses and grass-like plants as well as aquatics were not found important to moose. Generally, the food l1abits more closely resembled those described by Al­dous and Krefting ( 1946) and Peterson ( 1955:127) for eastern ranges where more species forn1ed tl1e major portion of the moose diet. The l1igh palatability of sub­alpine fir appears to resemble the use of balsam fir (Abies balsamea) on those ranges.

Differences in distribution of the moose population during the 2 years of study were believed directly related to snow deptl1s. Almost twice as much snow fell in Novem­ber and December, 1966, as in 1965, ap­parently initiating earlier migration. From January ·1 May, an average of 74 percent more snow was present on the ground in 1967 than in 1966 (Soil Conservation Serv­ice 1969).

The range-condition measurements shov,.red l1eavy utilization and a downward trend in condition during the study period. This trend may indicate that present moose densities arc excessive for this range type although they were observed to be con­siderably lower than recorded on other runge types. This may also be reflected in the low twinning rate and t~1e apparent decline in calf production in lfJ67. Pimlott ( 1961:250) n0ted that the environmental

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. . 46 Journal of \Vildlife Management~ Vol. 34~ No. 1~ January 1970 ..... ...

condition mav affect the reproductive status ~

of moose. This study primarily demonstrates the

adaptability of t11e Shiras moose to various range types. However, it also further sub­stantiates the findings of other studies as to the importance of sub-climax ranges and seral deciduous browse species to moose.

LITERATURE CITED

ALDous, S. E., AND L. W. KnEFTING. 1946. The present status of moose on Isle Royale. Trans. N. Am. \Vildl. Conf. 11:296-308.

BooTH vV. E. 1950. Flora of Montana, Part I, C~nifers and Monocots. Research Foundation Montana State Coli., Bozeman. 232pp.

---,. AND J. C. \VnrcnT. 1962. Flora of Mon­tana, Part II, Dicotyledons. :Montana State Coli., Bozeman. 280pp.

CoLE, G. F. 1956. The pronghorn antelope-its range use and food habits in central Montana with special reference to alfalfa. Montana Fish and Game Dept, and 1Iontana Agr. Expt. Sta. Tech. Bull. 516. 63pp.

---. 1959. Key browse survey method. Proc. Annual \Vestern Assoc. Fish and Game Comm., Portland, Oregon. 39:181-185.

DE;-.;xrsToN, R. H. 1956. Ecology, behavior and population dynamics of the \Vyoming or Rocky Mountain moose, Alces alces shirasi. Zoologica 41(3):105-118.

HARRY G. B. 1957. 'Winter food habits of m~ose in Jackson Hole, \Vyoming, ]. \Vildl. Mgmt. 21(1):53-51.

HousTON, D. B. 1968. The Shira.s moose in Jackson Hole, ·wyoming. Grand Teton Natl. Hist Assoc., Tech. Bull. 1, Grand Teton Natl. Park, '\Vyoming. llOpp.

KN'OWLTON, F. F. 1960. Food habits, move­ments and populations of moose in the Grav­elly .Mountains, Montana. J. \Vildl. Mgmt. 24(2): 162-170.

Lr~ J. C. R. 1964, Statistical Inference I. 1st ed. Edwards Brothers, Inc. Ann Arbor, Mich­igan. 658pp.

·~ ~?4 ·~~t

~· J MAim:-:, A. C., R. H. GENSCH, AND C. P. BROWN, ~;I~

1946, Alternative methods in upland ga1ne. ij bird food analysis. J. 'Vildl. Mgmt. 10(1): :.:~ 8-12.

~IcDowELL, L., AND \V. MoY. 1942. Montana moose survey, Helloraring-Buffalo Fork-Slough ., Creek unit. Job Campi. Rept., 1vlontana Fish and Game Dept. 70pp.

McMILLAN, J, F. 1953. Some feeding habits of moose in Yellowstone Park. Ecology 34{1): 102-.110.

Oosrrxc, H. J. 1956. The study of plant ... v.,,P..,.IB munities. 2nd ed. W. H. Fxeeman and "-'Om-~~ pany, San Francisco, California. 440pp. ·

PEEK, J. M. 1962. Studies of moose in the Grav. elly and Snowcrest Mountains, Montana. J, 'Wildl. Mgmt. 26(4):360-365.

PETERSON, R. L. 1955. North American Moose. Univ. Toronto Press. 280pp.

PlMLOTT, D. H. 1961. The ecology and man­agement of moose in North America. La Terre et la Vie. 2:246-265,

Sl\UTH, N. S. 1962. 'I'he fall and winter ecology . of the Shiras moose in Rock Creek drainage, Granit.'! County, :Montana. M.S. Thesis. Univ. of Montana, ~.clissoula. 52pp.

Son., CoNSERVATION SERVICE. 1969. Official ords of snow course readings 1965-1967. Boze. man, Montana.

STEVENS, D. R. 1965. Moose population and forage inventories in southwestern Montana. :Montana Fish and Game Dept. Job ComplC'· tion Rept., P-R Project \V-98-R5. 39pp . .Mul •. ill~. :

---, 1967. Ecology of moose in southwestern Montana, Montana Fish and Game Dept. Job Completion Rept., P-R Project \V-98-R7 28pp. Multilith.

TYSDAL, R. G. 1966. Geology of a part of north end of the Gallatin range, Gallatin County, Montana. M.S. Thesis, Montana S Univ., Bozeman. 95pp.

U. S. FoREST SERvic;E;. 1935. 'Winter studies report. Gallatin National Forest. 64-66. Typewritten.

RecaiDecl for publication March 31

1969.

THE BREEDJN IN THE PHO

Abstract: The from 101 specimens ;tnd also from 91 uwthod for aging tt•stes were generally The majority of sexual but there was a deere[ •;,•,nber. The females l bt•r to March and Jul~ actual litter si~e (rec~ must be at least 3 mor

I

The only major rr' lishcd on reproduct tail in Arizona ( Soi \\ith findings from~

I the desert cotton( breeding season frJ -, ll' . li ch' f £ l <.7a 1210 , 1e o ~

Game and Fish ~ ( Personal commulj Phoenix region of r tails might have a 1 than indicated for J

pnrpose of this stuq breeding season ani breeding biology J . h Ph ' .I Ill t e oenLx J.eg1~

Grateful ackncw]( 1

to R. R. Clothier, Nl Bertke, Arizona Stal help with the va.rj4 M.>arch, and to J. Ged l'niversity, for his SC'ript preparation.

l

MATERIAlS AND ~ A total of 192 cd

this study. Ninety~ were road kil1s, nndj iu the field. Tl1e 1 four live cottontails; 1

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