IGUANA Volume 10, Number 2 June 2003 US$6...focusing on some aspect of iguana husbandry. The first...

A male Ctenosaura bakeri (Swamper or Utila Iguana) on Utila Island, Honduras, March 2003. Photograph by John Binns.

IGUANAJournal of the International Iguana Society www.iguanasociety.org

Vo l u m e 1 0 , N u m b e r 2 J u n e 2 0 0 3 U S $ 6 . 0 0

I.I.S. Board of DirectorsJoseph Wasilewski, PresidentHomestead, FL

Joseph Burgess, Vice-presidentJacksonville, FL

A.C. Echternacht, Ph.D., TreasurerUniversity of Tennesee, Knoxville, TN

AJ Gutman, Executive Secretary andAssociate Editor of IGUANAWest Harford, CT

John & Sandy Binns, Directors, AssociateEditor of IGUANA and Internet OperationsInternational Reptile Conservation Foundation,San Jose, CA

Gunther Köhler, Ph.D. and Elke Köhler,DirectorsForschungsinstitut und NaturmuseumSenckenberg & Herpeton, Frankfurt, Germany

Robert Powell, Ph.D., Director and Editorof IGUANAAvila University, Kansas City, MO

I.I.S. Editorial/AdvisoryBoardAllison C. Alberts, Ph.D.IUCN/SSC Iguana Specialist Group andZoological Society of San Diego, San Diego, CA

John Bendon, Illustrator for IGUANABath, England

Gordon M. Burghardt, Ph.D.University of Tennessee, Knoxville, TN

Frederic J. BurtonBlue Iguana Recovery Program, Grand Cayman,Cayman Islands

Jorge FerrariOrganización de Rescate y Protección deReptiles y Anfibios, Tegucigalpa, Honduras

Matthias Goetz, Dipl.-Biol.Durrell Wildlife Conservation Trust, Jersey,British Isles

Alexander Gutsche, Dipl.-Biol.Humboldt Universität, Berlin, Germany

Richard HudsonInternational Iguana Foundation and Fort Worth Zoo, Fort Worth, TX

John B. Iverson, Ph.D.Earlham College, Richmond, IN

Chuck KnappUniversity of Florida, Gainesville, FL

Michael Ripca, Managing Editor of IGUANALeaping Lizards Graphic Design, Atco, NJ

Thomas Wiewandt, Ph.D.Wild Horizons, Tucson, AZ

Founding DirectorsRobert W. and Marcie EhrigBig Pine Key, FL

Statement of PurposeThe International Iguana Society, Inc. is a not-for-profit corporation dedicated to preserving the biological diversity ofiguanas. We believe that the best way to protect iguanas and other native plants and animals is to preserve naturalhabitats and to encourage development of sustainable economies compatible with the maintenance of biodiversity.To this end, we will: (1) engage in active conservation, initiating, assisting, and funding conservation efforts incooperation with U.S. and international governmental and private agencies; (2) promote educational efforts relatedto the preservation of biodiversity; (3) build connections between individuals and the academic, zoo, and conserva-tion communities, providing conduits for education and for involving the general public in efforts to preserveendangered species; and (4) encourage the dissemination and exchange of information on the ecology, populationbiology, behavior, captive husbandry, taxonomy, and evolution of iguanas.

Membership InformationIguana, the Journal of The International Iguana Society, is distributed quarterly to members and member organizations.Annual dues:Individual U.S. and Canadian Membership . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $25.00Individual Foreign Membership . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $35.00U.S. and Canadian Organizational Membership* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $35.00Foreign Organizational Membership* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $45.00

(*receives double copies of Iguana)Additional copies are available at a cost of $6.00 including postage.

Write to:The International Iguana Society, Inc., 133 Steele Road, West Hartford, CT 06119

Membership questions? Call AJ at 860-236-8203. OR VISIT OUR WEB SITE AT: www.iguanasociety.org

SolicitationsMembers of the I.I.S. are encouraged to contribute articles, letters to the Editor, news items, and announcements forpublication in Iguana. General articles can deal with any aspect of iguana biology, including conservation, behavior,ecology, physiology, systematics, or husbandry. Submission of photographs to accompany articles is encouraged.

Manuscripts may be submitted via e-mail (send to [email protected]). For any contribution, please include yourname, address, phone number, and e-mail address. Authors of one page or more of print are entitled to five copies ofthe issue in which their article appears.

Advertising Policy of IguanaWe advertise only non-living products (except feeder insects). All products have been examined and been found tobe high quality and fairly priced. Contact I.I.S., 133 Steele Road, West Hartford, CT 06119, for more information.

Iguana Copyright ©2003 by The International Iguana Society, Inc., 133 Steele Road, West Hartford, CT 06119 USA. ISSN # 1098-6324. The contents of Iguana, excluding Research Articles, Research Updates, andreprinted articles, may be reproduced for inclusion in the newsletters of other herpetological societies, provided the material is reproduced without change and with appropriate credits, and a copy of the publication issent to The International Iguana Society. Occasional exceptions may be made to this policy.

FEATURE: IIS Conference on UtilaUtila: Home to Three

Native Iguanas...................27Utila Island Swampers............28Brief History of the

Iguana Station ...................30The Zen of Swamping —

Adventures on Utila...........32

SPECIES PROFILE: Utila’s Reptiles....................36

FEATURE: Stout IguanasStout Iguanas: Historical

Perspectives and Status Report.....................39

Guana and Necker IslandPopulation Assessments 2002 .................................49

HUSBANDRY: Green IguanaCommunication.................50

PROFILE: Fred Burton: The Man Behind the BlueIguana Recovery Plan.........53

HISTORICAL PERSPECTIVES: The Black Iguana ...............56

IGUANA NEWSBRIEFS............58LETTER FROM THE

PRESIDENT.........................59

Editors’ RemarksThis is a special issue of IGUANA. One reason is that it is half again as long as a regular issue. We owe this to agenerous donation by Henry and Gloria Jarecki, who subsidized the extra pages in order to accommodate thefeature on Stout Iguanas (p. 39). They already have made tremendous contributions to the species’ chances forsurvival by providing it with a second home on Guana.

This issue also includes for the first time several new regular features created in response to discussions by the Boardof Directors during the IIS Conference on Utila (p. 27). Each issue from now on will include at least one articlefocusing on some aspect of iguana husbandry. The first of these, on Green Iguana communication (p. 50), wasexcerpted from the excellent book by Gunther Köhler, which, unfortunately for most U.S. iguana enthusiasts, iscurrently available only in German. In addition, each issue will profile an individual who has made significantcontributions to our understanding of iguanas. The inaugural profile (p. 53) features Fred Burton, the man behindthe Blue Iguana Recovery Programme. Also appearing for the first time is an historical perspective. These features will appear from time to time in order to lend some insights into the changing perceptions of iguanas over the years.This issue’s perspective (p. 56) addresses Black Iguanas (Ctenosaura), which is particularly appropriate in light of thectenosaurs of Utila that so delighted the Conference participants.

We also provide a Species Profile (p. 36) that presents a suite of species instead of only one. We do not necessarilyintend for this to become the normal mode for these features, but decided that it was appropriate, at least this onetime, because of the unusual reptilian diversity on Utila and because it emphasizes how iguana conservation canbenefit an entire biotic community.

Bob Powell, AJ Gutman, and John Binns

In This Issue...

Utila, site of the 2003 IIS Conference(see related stories, p. 32 and 59), is thesmallest of the principal Honduran BayIslands (41 km2). This relatively tiny

body of land, however, supports a phenomenalreptilian diversity (see Species Profile, p. 36) thatincludes three native species of iguanas(Ctenosaura bakeri, C. similis, and Iguana iguana)— the only island so blessed anywhere in theworld.

27IGUANAJune 2003

UTILA:Home to Three Native Iguanas

continued on page 30

Adult male Iguana iguanaat the Utila IguanaResearch and BreedingStation. Photograph byJohn Binns. Adult male Ctenosaura

similis; note the aggressivereaction to the photographerin the photo to the left.Photographs by SandyEchternacht.

Adult female Ctenosaura bakeri on a mangrove branch.Photograph by Robert Powell.

“Why do humans have an apparentlyinsatiable desire to take something naturaland beautiful, chop it down or kill it, cover it over with cement, and then proceedimmediately to the local lumber, nursery, and pet stores to purchase poor copies of what they just destroyed?”

John Binns, IIS Director

28 IGUANA Volume 10, Number 2

“Swampers,” as the endemic Utila Spiny-tailedIguanas (Ctenosaura bakeri) are called locally, arearguably the most remarkable inhabitants of little UtilaIsland. Differing from all other species of Ctenosaura,which live almost exclusively in dry, open, sunny areas,C. bakeri is limited to mangrove swamps.

Maximum known size is 315 mm (head-bodylength) and 923 g for males and 229 mm and 424 g forfemales. Although ctenosaurs often are called “BlackIguanas,” Swampers are relatively colorful. Juveniles arelargely uniformly blackish-brown with a few darkerbrown stripes on the upper side of the body and tail(coloration that renders them quite cryptic against themuddy substrates of the swamp). Adults, in contrast,vary from grayish-brown to an amazing turquoise,which is most obvious in bright sunlight.

Living exclusively in a mangrove swamp requiresspecial adaptations, including the need to deal with asalty diet and the lack offreshwater. In addition,the substrate is muddyand frequently sub-merged during hightides, forcing Swampersinto the trees — wherethe only retreats are nat-urally occurring tree

holes. Suitable trees with holes are very much indemand. Juveniles and adults are strongly territorial andwill strenuously defend their home trees even againstlarger opponents. Tree holes are mostly restricted toolder mangroves, especially Black Mangroves (Avicenniagerminans), which are scattered on Utila. The result is apatchwork-like distribution of C. bakeri, even in other-wise apparently suitable habitat.

The few other reptiles known to be mangrove spe-cialists are exclusively carnivorous. Swampers, however,are omnivorous. Mangrove leaves and, if available, man-grove flowers form the main part of the diet. The secondlargest part of the diet is fiddler crabs, which have beenfound in 72% of analyzed scat. To catch crabs, iguanaswait for low tide and either forage actively for prey or,usually with more success, employ a sit-and-wait strat-egy until a crab crawls within range. The fact that man-grove leaves contain only 7% crude protein versus 34%

in crabs may explain theintensive efforts to huntcrabs. Both mangroveleaves and crabs are salty,which creates an osmoticproblem for Swampers.Since freshwater is avail-able only during the rainyseason, water usually isacquired with food(50–70% water) or bydrinking the brackishswamp water. Reptiliankidneys are unable toexcrete excessive salt, somost is eliminated by spe-cialized salt glands locatedin the nasal cavity. In effect,the salt is sneezed out.

Reproductive activityoccurs during the dry sea-son. Triggered by decreasesin rainfall (to <200 mm/m2)

and increases in air temperature (to >24°C), usually fromlate January through March, adult males begin patrollingthe invisible border around a mating territory, using dis-plays and aggressive behavior to exclude male intruders.Egglaying takes place from mid-March through earlyMay, when the ground temperature is about 30°C.Hatching usually occurs from mid-June to early August,before the onset of the next rainy season. In associationwith recent warming trends, a shift of the entire repro-ductive season to as much as two weeks earlier has beenrecorded.

Because of the saturated substrate, gravid femalesmust migrate to nesting sites, which are restricted to afew sandy beaches. Females may travel up to 1.3 km

Utila Island Swampers Alex Gutsche

Humboldt Universität, Berlin

An adult male “Swamper” (Ctenosaura bakeri) baskingon a mangrove stump near the canal. Photograph byA.C. Echternacht.

Adult male Ctenosaurabakeri from Iron Bound.Photograph by RobertPowell.

29IGUANAJune 2003

(direct line) to lay their eggs before returning to theirhome tree in the swamp. Nesting sites must have sandy,well-drained soil and realize an average incubation tem-perature of 30.5°C. Females stay at the beach for sev-eral days, searching for a suitable nesting site at up to50°C surface temperatures. Nesting tunnels range from510–1240 mm in length and nesting chamber are atdepths of 150–450 mm. Clutches contain 6–16 eggs.Three months later, hatchlings emerge and headstraight for the mangroves.

Large Brown Basilisks (Basiliscus vittatus), Great-tailed Grackles (Quiscalus mexicanus), raptors, andsnakes all prey on juvenile iguanas, but only large boas(Boa constrictor) pose a significant threat to adults.Consequently, the major threats to C. bakeri areincreases in uncontrolled human development and theconsequent loss of habitat.

The total range of C. bakeri on Utila consists ofthree separate mangrove areas with a total area ofabout 10 km2. Egglaying areas are much more limitedand have a total size of less than 1 km2. As a result,Utila Iguanas have the smallest and most threat-ened distribution of any ctenosaur. Populationnumbers will invariably decrease in the nearfuture if the habitat, especially the nesting areas,becomes unavailable.

Although, hunting still occurs despite regulationsagainst it, tourism and land sales that are increasing theextent of Utila Town are of greater concern. Theseresult in deforestation or despoilment of mangroveareas with landfills. Sandy beaches are in great demandfor development, so nesting sites close to town arecleared of debris, rendering them unsuitable foriguanas even before construction begins. Invasiveplants also overgrow the open nesting sites and mustbe controlled.

Protection of suit-able mangrove areasand nesting sites is criti-cal — and must beimplemented as quicklyas possible. All beachesare privately owned, so purchasing keystretches for the use ofiguanas is the only solu-tion. Creating an iguanarefuge on Utila willenhance the likelihoodof the Utila Iguana’slong-term survival andalso would serve to pro-tect areas used as roostsby migratory birds andas nesting sites for critically endangeredLoggerhead andHawksbill turtles.

A female Ctenosaura bakeri on a mangrove stump.Photograph by John Binns.

The distribution of Ctenosaura bakeri on Utila Island (gray areas) corresponds closely tostands of old mangrove forest, especially large Black Mangroves with tree holes. Femalesmust migrate to nesting beaches (dark gray) in order to lay their eggs. All nesting beachesare in imminent danger of development. Other threats to the species are indicated withX’s: the area near West End is being deforested; Utila Town, especially near the newairstrip, and Pretty Bush are expanding into Swamper habitats and garbage is beingdumped into the mangrove forests; iguanas in areas near East Harbor, Rock Harbor, andRed Cliff remain vulnerable to hunting, which continues despite prohibitions. Modifiedfrom a figure by Alex Gutsche.

As might be expected when three large specieswith generally similar lifestyles occupy such a smallarea, they must in some way partition the severelylimited resources in order to avoid direct andmutually disoperative competition. In fact, theseiguanas are largely restricted to distinctly differenthabitats. Green Iguanas (I. iguana) inhabit theremaining upland forests, where continuouscanopies allow them to remain inconspicuouslyhidden in the treetops — except when the femalesare forced to descend in order to nest. BlackIguanas (C. similis), referred to locally as“Highlanders,” favor more open areas, occupyingforest edges and rockpiles, fallen logs, or isolatedtrees in otherwise open fields. These lizards arequite capable of effectively utilizing heavily dis-turbed areas and frequently coexist closely withhumans (seeing individuals basking on rooftops oralong heavily traveled roads is quite common).Unlike Green and Black iguanas, both of whichhave broad distributions throughout the entireNeotropics and Middle America, respectively, theUtila Iguana (C. bakeri) is found only on Utila.Possibly because of their smaller size or more retir-ing nature, Utila Iguanas are found only in theapparently inhospitable mangrove swamps, wherethey fare quite well on a diet of mangrove leavessupplemented with small fiddler crabs. Known tothe local Utilians as “Swampers,” Utila Iguanas doface a problem when nesting seasons roll around.Since the swamps are regularly inundated and thesoils totally saturated with brackish water, they areunsuitable nesting sites. Instead, females mustmigrate considerable distances to one of the rela-tively few sandy beaches (only 38 ha on the entireisland) to lay their eggs. Interestingly, when theyreturn, they reestablish residence in the very samemangrove they left some weeks before. How theyfind their homes with such inerring accuracydespite the bewildering similarities of one tangledtree and the next is one of several mysteries sur-rounding this ecologically unique iguana.

* Upon recommendations by the IIS, consideration is beinggiven to holding hatchlings until two years of age, whenchances for survival are greatly enhanced.

Brief History of the Iguana Station

Karsten Gees, DirectorUtila Iguana Research and Breeding Station

The story began with an American Consul atthe end of the 19th century. While visiting Utila,he collected some iguanas in the mangroves andsent them to the Washington Zoo. The zoo direc-tor, a Mr. Baker, sent these animals to the famousherpetologist, Leonhard Stejneger at the NationalMuseum of Natural History in Washington, DC.Stejneger determined that the iguanas of Utilawere a new species, and he described them for-mally in 1901, giving the Utila “Swamper” thename Ctenosaura bakeri in honor of Mr. Baker.

The herpetological world essentially forgotabout C. bakeri until 1994, when a group ofGerman researchers led by Gunther Köhler redis-covered these iguanas in the wild. In the followingyears, the group determined that C. bakeri isendemic to Utila and that its habitat is restricted tothe mangrove swamps, with a total area of only 8km2 (see article on p. 28). Furthermore, theyfound that C. bakeri is threatened by hunting andby the unchecked development of infrastructurefor the burgeoning tourist industry. Thus was bornthe Conservation and Research Project UtilaIguana. In 1997, a breeding program was estab-lished to support the wild population. Half of thehatchlings each year are released immediately tothe wild while the others are reared at the Stationfor one year* before release. Concurrently, anongoing research program was initiated for thestudy of the distribution and behavior of the UtilaIguana. The Zoologische Gesellschaft Frankfurtand the Senckenbergische NaturforschendeGesellschaft Frankfurt have been the principal sup-porters of the project and enabled the originalacquisition of property and construction of theIguana Research and Breeding Station in 1998.

The Iguana Station continues to grow andimprove. It now has a visitors’ center with exhibitsfocusing on C. bakeri, but also addressing theother reptiles and amphibians of Utila. Spaciouscages have been constructed on the grounds forrearing hatchling Swampers, along with cages forGreen Iguanas (Iguana iguana) and BlackIguanas (C. similis), both species of which also arenative to Utila. About 100 tourists visit the Stationeach month.


continued from page 27

31IGUANAJune 2003

An adult male“Swamper” (Ctenosaura

bakeri) at the ResearchStation. Photograph by

John Binns.

Main building at theIguana Research andBreeding Station.Photograph by JohnBinns.

Outdoor enclosuresfor head-starting

iguanas. Photographby John Binns.

In addition to maintaining the breeding andresearch program, volunteers from all over theworld provide environmental education programsfor the local schools. In cooperation with BICA(Bay Island Conservation Organization), the otherNGO on Utila, all grades have been covered thisyear. The goal of this outreach program is toenhance the sensibility and feelings of responsibil-ity of the children for their island home, with itsphenomenally abundant natural treasures. Last butnot least, the Iguana Station is working with theIIS and other organizations to acquire funding forthe purchase of beach properties that serve as nest-ing sites for C. bakeri and which are, at themoment, the most critically threatened portions oftheir habitat (see related story on p. 28).

The Zen of Swamping — Adventures on Utila

AJ Gutman

What do you do when you’re dripping withsweat and knee-deep in fetid swamp mud thatthreatens to yank the boots off your feet withevery step? You scramble to capture another tinyFiddler Crab to stuff in your cargo pockets (tofeed to the young Utila Iguanas in the rearingcages at the Iguana Research and BreedingStation). Eyes alert for an endangered “Swamper”(as the endemic mangrove swamp-dwellingiguana, Ctenosaura bakeri, is known locally), youreach for the hand of a smiling friend as you climbonto a sturdy mangrove root, ready to lend a handto the next person stuck in the mud. As muddyhands meet, you both burst into laughter, repeat-ing “smacks of adventure!”

Perhaps not everyone would answer that ques-tion in quite the same manner, but all of the par-ticipants in the 2003 International Iguana Societyconference on Utila definitely would. SeventeenIIS members and assorted other conservation afi-cionados from around the world spent a weektogether on Utila, a small island off the northerncoast of Honduras. Much of that time was devotedto trekking through wet and muddy Swamperhabitat.

Our hosts included personnel from the Stationon the island and Dr. Gunther Köhler, Director ofthe Conservation Project Utila Iguana (CPUI),from Frankfurt, Germany. I first read about Dr.Köhler and his research and conservation work on


Organizations that have supported the Conservation Project Utila Iguana: the Senckenbergische NaturforschendeGesellschaft Frankfurt, the International ReptileConservation Foundation, and the Zoologische Gesellschaft Frankfurt.

Only true iguana lovers (i.e., IIS members) could have thismuch fun on a stomp through the swamp. Photograph byJohn Binns.

John Binns, representing the International ReptileConservation Foundation (IRCF), installed about$2,500 in computer and network equipment in thelab at the Utila Iguana Research and Breeding Station.This replaced aged equipment and dramaticallyimproved the Station’s ability to communicate whilealso aiding in its research efforts.David Nieves and Rick Morrow, representing theKansas City Herpetological Society (KCHS), donatedabout $500 worth of equipment including twoelectronic scales (full-size for the lab and a miniatureversion for use in the field), a Gentle Giant Tong®, anda selection of tools including forceps, hemostats,dosing needles, and probes. All of these items werepurchased from Midwest Tongs (www.tongs.com).

behalf of the remarkable Swamp Iguana years ago inthe Iguana Times. Eager to meet him and his wifeElke, I was entirely prepared to be dumbstruck withawe. What I didn’t expect was a warm and wonder-ful couple with whom I would make my countryand western singing debut performing Gunther’soriginal rendition of the “Swamper Song.”

The Station also proved to be delightful.Walking there fromwhere we were staying,we would regularlyencounter several BlackIguanas, Ctenosaurasimilis, that had takenup residence in hollowtrees and on piles ofrocks along the edgesof Utila Town. TheStation “greeter” wasRosalita, a charmingRed-naped AmazonParrot who loved tohave her neckscratched. The tidygrounds were dottedwith Hibiscus flowersand spacious enclo-sures filled with hatch-ling C. bakeri, as wellas a few C. similis andIguana iguana that areused in environmental

education programs for Utilian school children.Among my personal favorite animals were thelarge Swamper male, who I named Willy Nelsonbecause of his long dorsal spines, and a gorgeousfemale I called “Marlene.” Marlene is an astonish-ing hybrid between C. bakeri and C. similis. Halfof her tail, divided along the midline, has scalationcharacteristic of C. bakeri and the other half ischaracteristic of C. similis!

One of our field trips was by boat through amangrove-covered canal where we were delightedby numerous Swamper sightings. Our final desti-nation that day was a beach in an area called “RockHarbor,” where we cleared exotic invasive vegeta-tion choking important egg-laying sites. What wedidn’t know while we were doing this work is thatthis area is one of the few remaining beach sitesavailable for purchase. In cooperation with theCPUI and the International Reptile ConservationFoundation, the IIS is initiating a fundraising

33IGUANAJune 2003

Gunther Köhler (right), indulging his passion for countryand western music, is joined by his wife, Elke (center), andAJ Gutman (left), performs the “Swamper Song” forconference participants. Photograph by John Binns.

A juvenile “Highlander”(Ctenosaura similis) on a rock wall.

Photograph by Robert Powell.

Rosalita, a Red-napedAmazon Parrot, was theStation “greeter.”Photograph by JoeBurgess.

A Swallowtail Butterfly visits aHibiscus flower at the Station.Photograph by Robert Powell.

effort to help purchase and preserve this area forthe Utila Iguana (details are given in the letterfrom the President on p. 59). This site also is partof the proposed Ecotrail, which will allow touristaccess to critical iguana habitat for the economicbenefit of the island while minimizing impact onthe endemic species.

Another field trip to the Big Bight took us pastan extremely unattractive garbage dump (Utilacurrently has no formal plan for waste disposal andthe risk of contamination to groundwater is veryreal). Given the number of Anolis enthusiasts inour group, many people were eager to hunt forthe endemic Anolis utilensis (a really swell anolefound in the swamp; see the Species Profile on p.36). Up to our knees yet again in water-inundatedswamp, we happily climbed trees in pursuit of lit-tle lizards under the watchful and amused gaze ofa Black Hawk.

Additional hikes, in which at least some of theconferees participated, went through primeSwamper habitat to Iron Bound on the northerncoast, to the beaches below Pumpkin Hill, whichwere graced by colorful “Shaky Paws” (see theSpecies Profile), and, after a long boat trip aroundthe western tip of the island, on an unsuccessfulsearch for Don Quickset Pond, freshwater home

to the few turtles known to occur on Utila.Although the pond remained elusive, hikers onthat trip did manage to find a frog, one of fivespecies known from the island but rarely seenexcept during the rainy season.


An educational sign near the harbor promoting Swamperconservation. Photograph by John Binn.

“Marlene,” a female hybridCtenosaura bakeri x similis.Photograph by John Binns.

“Willie Nelson,” an adultmale Swamper at the Station.Photograph by Robert Powell.

After showering off the mud, we spent ourevenings at the Bush Bar, a wonderful open-airpavilion, which the owner had graciously offeredas a venue for our presentations. Conference par-ticipants, Iguana Station staff, and several Utilianswere treated to talks on “Spiny-tailed Iguanas,”“Aspects of the Ecology and Population Biology

of Ctenosaura bakeri,” “Lizard Ecology on WestIndian Islands,” “Lizard Wars” (invasive versusnative reptiles in Florida), and “ModernConservation Practices in the Caribbean.”

35IGUANAJune 2003

Gunther Köhler addressing the conference. Photograph byAlex Lau.

AJ Gutman, Joe Wasilewski, and Betsy Davis engage insome hands-on conservation by clearing invasive vines thatare choking an important nesting site near Rock Harbor.Photograph by John Binns.

A Common BlackHawk (Buteogallus

anthracinus)supervising our

Anolis hunt in theBig Bight.

Photograph byRobert Powell.

Bob Powell, Sandy Echternacht, Alex Lau, WendyTownsend, Mark Keoppen, and an unnamed boat driver(from front to back) heading for and through the canal toRock Harbor. Photographs by Joe Burgess.

The only frog (Leptodactylus melanotus) seenon the trip. Photograph by Joe Burgess.

The IIS thanks Gunther Köhler, Sven Zörner, AlexanderGutsche, Karsten Gees, and the volunteer staff of theIguana Research and Breeding Station for making ourConference an unforgettable experience. Specialthanks also to the thoroughly wonderful Sandy Binnsfor making all of our impossible travel arrangements.We never could have done it without you!


In addition to an already remarkable three nativeiguanas, tiny Utila (only 41 km2) supports a phenome-nal reptilian diversity: 15 lizards (including the threeiguanas), 11 snakes, a freshwater turtle, and a croco-dilian. Most are representatives of widely rangingCentral American species, but two are endemic to Utila(Anolis utilensis and Ctenosaura bakeri) and three oth-ers are found only on the Bay Islands (Anolis bicaorum,Phyllodactylus palmeus, Sphaerodactylus rosaurae).

The American Crocodile (Crocodylus acutus) pop-ulation on Utila may be extirpated already and the tur-tle, a Slider (Trachemys sp.), is known to occur in onlyvery small numbers in a single, largely freshwaterpond in the undeveloped western half of the island.

The snakes range in size from the Boa constric-tor and Indigo Snake (Drymarchon corais), which mayexceed 2 m in length, to the tiny Thread Snake(Leptotyphlops goudotii), a termite- and ant-eatingspecialist that reaches a maximum known totallength of 18.5 cm. Swamp Snakes (Tretanorhinus

nigroluteus) are highly aquatic and the very slenderVine (Oxybelis aeneus and O. fulgidus) and Treesnakes (Imantodes cenchoa) are adapted for a largelyarboreal existence. The remaining snakes tend to behabitat and prey generalists of moderate size. Theseinclude the Tropical Ratsnake (Pseudelaphe flavirufa)and three “racers” (Coniophanes imperialis,Dryadophis melanolomus, and Leptophis mexicanus).

The lizards include a beach-dwelling racerunner(Cnemidophorus lemniscatus), a skink (Mabuya uni-marginata), the Common or Brown Basilisk (Basiliscusvittatus), three anoles (Anolis bicaorum, A. sericeus,and A. utilensis, all of which are sometimes assignedto the genus Norops), and six geckos (Coleonyxmitratus, Hemidactylus frenatus, Phyllodactyluspalmeus, Sphaerodactylus millepunctatus, S. rosaurae, and Thecadactylus rapicauda).

SPECIES PROFILE: UTILA’S REPTILESRobert Powell

The Boa constrictor usually is considered a predator ofmammals, but it will readily hunt and consume iguanasand is relatively common in the mangroves, whereCtenosaura bakeri would seem to be the primary prey.Photograph by Robert Powell.

The Green-headed Parrot Snake (Leptophis mexicanus) isa habitat generalist that is equally at home on theground or in trees and bushes. Although it will feed onbirds and small mammals, its preferred prey is lizards. Thismay be the most common snake on Utila. Photograph byRobert Powell.

Like most skinks, the local species (Mabuyaunimarginata) has smooth scales well-adapted toforaging in leaf litter. They are most frequently encoun-tered when they climb vegetation to bask. Photographby Robert Powell.

Tiny Dwarf Geckos (Sphaerodactylus millepunctatus) areabundant inside rotten logs and in surface debris, wherethey feed on a variety of small arthropods. Photographby Joe Burgess.

37IGUANAJune 2003

Anolis bicaorum is the mostcommon anole on Utila, butis abundant only in theforest-mangrove interfaces,where pairs occupy most ofthe larger trees. This male isresponding to an intruder inits territory. Photograph byJoe Burgess.

Basilisks (Basiliscus vittatus) areknown best for their ability to runquickly on their hindlegs, to theextent of being able to run onwater. However, they are abundantin a variety of habitats, many ofwhich are not associated withstreams or ponds. Photograph byRobert Powell.

This brightly coloredracerunner(Cnemidophoruslemniscatus) is some-times referred to as theRainbow Lizard. Becauseof a tendency to twitchan elevated forelimbwhen it pauses in itssearch for food (as thisindividual is doing), thislizard is known locally asthe “Shaky-paw.” Theyare locally abundant onsandy beaches.Photograph by RobertPowell.

The Tropical Rat Snake (Pseudelapheflavirufa) is a capable climber. Inaddition to rodents and othermammals, this species, like all ratsnakes, also will consume birds andlizards. Photograph by RobertPowell.

The very tiny Striped Thread Snakes (Leptotyphlopsgoudotii) are most frequently encountered in associationwith termite and ant nests, where they feed preferentiallyon eggs, larvae, and pupae. This specimen, however, wasdiscovered in the open on a sandy beach. Photograph byRobert Powell.


The Turnip-tailed Gecko(Thecadactylus rapicauda) is namedfor the shape of its regenerated tail(the original is more typicallytapered). These large geckos areabundant on trees and, more rarely,buildings. They are unusual amonglizards in that they can retract theirclaws into “sheaths” when not inuse. Photograph by Robert Powell.

This Leaf-toed Gecko(Phyllodactylus palmeus) isabundant on trees andbuildings, but is beingdisplaced on the latter bythe recently introducedHouse Gecko (Hemidactylusfrenatus). Photograph byRobert Powell.

Coleonyx mitratus is an unusual gecko in that it lacksadhesive lamellar scales on the undersides of its digitsand doesn’t climb. These lizards are common in andaround surface debris and trash. Photograph by RobertPowell.

Anolis utilensis, like the other Utila endemic, Ctenosaurabakeri, is a mangrove specialist. Common only in theBlack Mangroves of the Big Bight, these well-camou-flaged lizards behave in a very gecko-like fashion,crawling on the tree trunks and adpressing themselvestightly against the bark when threatened. Photograph byRobert Powell.

AnegadaR.H. Schomburgk first noted the presence of

Cyclura pinguis (Stout or Anegada Iguana) onAnegada in 1832, but literature documenting thestatus of this species has been sparse. However,each progressive publication has described orimplied an ever-increasing concern for its survival.Accounts from the 1940s and 1950s are essentiallynon-existent. By the early 1960s, large-scale devel-opment was planned for Anegada. Although theseplans were never fully realized, the initial ground-work destroyed the traditional stone paddocks usedto corral livestock, unleashing goats, sheep, cattle,and burros to roam and propagate freely. Excessivegrazing has since reduced the natural plant com-munity to secondary, largely toxic vegetation.Today, almost all free-ranging cattle and burros areemaciated and only goats are thriving.

In 1968, W. Michael Carey conducted a fieldstudy on the ethoecology of the Stout Iguana and,in his classic 1975 paper, stated: “whatever themethods, steps must be taken now to ensure thecontinued existence of C. pinguis on Anegada.”

This statement was based in large part on hisobservations of competition for available foodbetween Stout Iguanas and livestock and of pre-dation on iguanas by domestic mammals.

Following Carey, James Lazell worked withStout Iguanas in 1980 and 1982–1986 and NumiMitchell worked with them in 1987–1996. GlennGerber, then with the University of Tennessee andpresently with the Zoological Society of SanDiego, began working on the species in 1998under auspices of the IUCN/SSC IguanaSpecialist Group (now funded by the InternationalIguana Foundation) and the British Virgin IslandsNational Parks Trust (BVINPT).

James Lazell first observed Stout Iguanas onAnegada in 1980 while employed by TheDepartment of Natural Resources and theEnvironment (DNRE), Government of the BritishVirgin Islands. Expecting to find large densities atCitron Bush, the site of Carey’s 1968 study, heinstead found that iguanas had completely disap-peared from the area in the intervening 11 years.Lazell subsequently found the highest remaining

Stout Iguanas: HistoricalPerspectives and Status Report

John BinnsInternational Reptile Conservation Foundation

(All photographs are by the author unless otherwise indicated)

39IGUANAJune 2003

Emaciated cattle are a common sight on Anegada.Although the vegetation appears rich, the plant matter is allsecondary growth.

This Anegada Iguana was estimated to be over 20 years old.

concentration of iguanas at Bones Bight, which todayremains one of the core areas for the species.

Carey’s warning was reiterated by others, butefforts to fund the removal of livestock and feralpredators remain mostly unsuccessful, despitesome recent activity. In 1997, concrete efforts tosecure the species’ future materialized in the formof the Anegada Iguana Headstart Facility. InOctober 1997, at the request of BVINPT, WestIndian Iguana Specialist Group (WIISG) membersRick Hudson (Fort Worth Zoo), Jeff Lemm (SanDiego Zoo, CRES), and Rondel Smith (BVINPT)constructed a small facility to house three juvenileStout Iguanas found floating in Manhead Pond.The facility provides a safe haven for collected

hatchlings until they are large enough to reducethe threat of feral predators A year later, a grantfrom the UK Foreign Commonwealth Office tothe BVINPT and WIISG T-shirt and poster salesfunded construction of the main complex by RickHudson and Jeff Lemm, joined this time by MikeFouraker and Glenn Gerber. In August 2001, theInternational Reptile Conservation Foundation(IRCF) and the BVINPT funded an upgrade tothe facilities to increase captive capacity. Teammembers for this project were John and SandyBinns (IRCF), Alberto Alvarez (PR-DNRE),Juliann Sweet, Joel Friesch (IRCF), and RondelSmith and Lee Vanterpool (BVINPT).

To date, none of these head-started captiveshave been released into the wild, but a limitedrelease on Anegada, coupled with the relocation ofa few captives to a neighboring island, has beendiscussed. In conjunction with this dialogue, apopulation assessment of Stout Iguanas is planned


Aerial photograph of Bones and Windlass Bight, Anegada,BVI. This small stretch of land that lies between the oceanand salt ponds is the only core Stout Iguana habitat left onAnegada. Access cuts as well as the main road passingthrough the area are visible in the photograph.

The Anegada Iguana Headstart Facility’s new sign isdisplayed proudly at the entrance.

This five-year-old captive Anegada Iguana is one of theolder animals at the facility. Captive iguanas at the facilitytend to be smaller than iguanas observed on Guana andNecker in the same age groups.

The Anegada Iguana Headstart Facilities currently holdabout 80 captives. The two structures at the front left arenew cages located close to the gate, allowing visitors toview these rare animals. The main cage system lies behindthese new cages. Current keepers, Rondel Smith and LeeVanterpool, have made substantial improvements and allanimals are in good health.

during July 2003 to update the previously pub-lished estimate of fewer than 200 remaining inexistence.

Controlling livestock or feral predators onAnegada is nearly impossible due to the island’sremote location and the tens of thousands of dol-lars that would be required. So, in 1980, in lightof the obviously rapid and apparently uncheckeddecline of the iguana population during the previ-ous decade, Lazell and his colleagues believed thatthe species was headed for extinction — unlesssomething was done immediately. Because a solu-tion on Anegada was not feasible and Anegada wasthe only place where the species still existed, theobvious recourse was to establish a second popu-lation — but where and by what means?

GuanaEssentially all possible relocation sites in the

British Virgin Islands were equally infested withferal predators and goats. However, in 1932,Chapman Grant had noted the presence of iguanason Guana Island and had identified the species asIguana iguana (Common or Green Iguana), butthe presence of that species was never confirmedand none has been seen since. Sometime in themid-1930s, Louis Bigelow, then owner of GuanaIsland, had extirpated goats and had bannedwoodcutting for making charcoal. This had leftonly a couple of domesticated burros and free-ranging sheep on the island. The latter are far lessdestructive than goats.

In 1974, Henry and Gloria Jarecki purchasedGuana Island. Access to this small island (300 ha)is limited, although it lies only a few kilometersfrom Tortola. The exclusive Guana Island Clubhad been constructed in a location designed to

41IGUANAJune 2003

Fallen Jerusalem, BVI: this small island is a possible reloca-tion site for some of the head-started animals on Anegada.This island, with no feral livestock, is well fortified withlarge rock boulders that offer a degree of protection duringheavy storms and hurricanes.

Heavily degraded habitat on the East End of Anegada nearCrasy Pond once supported subpopulations of StoutIguanas. In 1984, the DOA converted a deep freshwaterlimestone solution hole called “The Fountain” to an above-ground watering hole, providing a permanent water sourcefor feral livestock. Recent surveys in and around the EastEnd suggest that Stout Iguanas have been extirpated.

A Guana Island view to the north showcases its rich flora.

Guana Island’s lush habitat clearly demonstrates the positiveresults of controlling feral animals.

minimize impact on the natural habitat, attribut-able to the foresight of Louis Bigelow, who chosethe construction site of the main clubhouse in the1930s. Hiking trails around the island also wereconceived to protect and minimize destruction ofthe lush vegetation.

In 1980, Lazell initially approached MaryRandall, then Guana Island Club Manager, todetermine if the owners would allow relocation ofStout Iguanas. Randall was very enthusiastic aboutthe concept, but two years would pass before Lazellwould meet the owners and take the next step.

In the interim, he continued working on aplan that would establish a second population ofStout Iguanas while promoting other conservationand restoration goals in the British Virgin Islands.An idea for an exchange of species came with therealization that the vast salt ponds of Anegada,which had supported large colonies of GreaterFlamingos (Phoenicopterus ruber) in the 19th cen-tury, could be restored if funds could be found.The beauty of this plan was the mutual benefits toall parties involved: the British Virgin Islands andthe residents of Anegada would benefit from thereintroduction of flamingos and, at the same time,the second population would provide some assur-ance for the long-term survival of Stout Iguanas.

Lazell first discussed the plan with severalAnegada residents. One of them was the lateClement Faulkner, who maintained a Stout Iguanafeeding station adjacent to his home in BonesBight. The plan next was presented to RobertCreque (DNRE), Lazell’s boss at that time.Everyone agreed that the idea made eminentlygood sense.

In March 1982, Lazell finally discussed thepossibility of relocating iguanas with the Jareckis,who were initially apprehensive. Would StoutIguanas damage the island they had worked sohard to protect? Would they bite staff or visitors ordestroy ornamental plants on the hotel grounds?These questions would take some time to answer.However, that meeting was instrumental in devel-oping the long-term relationship between theJareckis and The Conservation Agency (Lazell)that continues today.

During the remainder of March and April1982, Lazell surveyed the island with the help ofLianna, Divonne, and Tom Jarecki (nieces and sonof Henry and Gloria) and the late author, GeraldDurrell, who happened to be vacationing there.

Lazell visited Guana regularly over the nextseveral years, conducting fieldwork with the aid ofthe managers, Mary Randall and her successorJohn Damron. Lazell also continued to build aportfolio of published papers and testimonials not-ing the disastrous effects of feral competitors andpredators on Stout Iguanas and their habitat.Major contributors were the late Dr. WilliamMacLean (University of the Virgin Islands), WalterPhillips of Water Island, USVI, Dr. RobertChipley, and Nick Clarke, former Director of theNational Parks Trust, BVI.

In 1984, the Jareckis agreed to rid their islandof sheep, provide a sanctuary for Stout Iguanas,and fund the relocation of flamingos. Their deci-sion certainly was influenced by Lazell’s efforts,but they also were drawn into wildlife conservation


Practically any view from Guana Island is breathtaking.

“Hambone,” one of the founding iguanas on Guana Island,frequents the vicinity of the Club. Photograph by NumiMitchell.

through the interest their sons and nieces hadshown. Today, Eugene Jarecki remains interestedin conservation, Tom Jarecki works for theEnvironmental Defense Fund, and Lianna Jareckiis teaching biology at H.L. Stoutt CommunityCollege on Tortola, BVI and is finishing her Ph.D.with a thesis on salt pond ecology.

In July 1984, Lazell and four colleagues set offto Anegada in search of the first Stout Iguana des-tined for relocation to Guana Island. Lazell even-tually captured a large, healthy, gravid female (SVL46 cm) that was taken to Guana, where she wasreleased on 29 July 1984. The other seven iguanasthat comprised the founding stock (sex, SVL, andrelease date) were: male (41 cm; 19 July 1985),female (44 cm; 19 July 1986), female (22.4 cm, 27July 1986), two females (33.5 and 43 cm, lattergravid) and two males (50.4 and 50.9 cm; 31 July1986). Guana now had the foundation for a sec-ond population, but years would pass before thesuccess of the relocation could be evaluated.

Lazell next set out to complete the speciesexchange plan. The Bermuda Aquarium, Museum,and Zoo (BAMZ) had both captive-bred andwild-stock flamingos and agreed to donate a num-ber sufficient for establishing a population. NumiMitchell (TCA) arranged the international transferof the birds (BVI Agriculture and Fisheries Permitand veterinary certification of the birds’ health,especially Newcastle’s Disease). Numi and GlennMitchell (TCA) and James Conyers (BAMZ)transported the birds by jet from Bermuda toTortola and then by boat to Anegada. The flaming-os initially were released into a net holding pen atthe salt ponds, allowing them to recuperate and

adjust to their new environment. On 7 March1992, in a ceremony at the north end of the saltponds, the Governor, the National Parks Trust,and the Anegada community celebrated the arrivalof the first 18 birds. By 2002, the flock had multi-plied to approximately 80 resident birds (Guanaalso supports six pinioned flamingos in a small saltpond, but they do not reproduce because the pop-ulation density is too low).

NeckerNecker Island, like Guana, is privately owned

and exclusive, with a single luxurious resort, theBalinese Great House, situated on the highestpoint and overlooking the coral reef-studdedwaters of the Caribbean. The island supports densetropical vegetation, composed of both native andnon-native plants and enhanced by irrigation. Theother half of the island is more typical of theregion, with rocky terrain and small clusters ofhardy trees, low shrubs, and dense stands of cacti.Designated a bird sanctuary, Necker is home topelicans, doves, and hummingbirds.

In 1994, Richard Branson, owner of NeckerIsland (30 ha), expressed an interest in establish-ing a third population of Stout Iguanas. Becausethe iguanas on Guana had enhanced the naturalsetting of the island and were well received by vis-itors, Branson was eager to expand the conserva-tion effort. Lazell had worked previously onNecker and knew the island to be free of feral live-stock and rats.

43IGUANAJune 2003

Greater Flamingos (Phoenicopterus ruber) in holding pensshortly after their arrival on Anegada. Photograph by NumiMitchell.

Necker Island, BVI: high atop the island is the Balinese GreatHouse.

In October 1995, four hatchlings were takento Necker and head-started for a year before beingreleased. During that time, one female escaped,but was seen later and appeared to be gravid. In2000, Lazell reported seeing the first hatchlingand subsequent reports from the island indicatedthat Stout Iguana hatchlings were abundant.Although the population is still in its infancy, dur-ing the October 2002 population on Necker,founding stock, young adults, and hatchlings wererecorded.

TodayLong after these second and third populations

were established, their existence is not commonlyacknowledged, little pertinent information is avail-able, and some controversy remains regarding the

circumstances under which they were established.In 2002, I was invited to participate in an assess-ment of the Guana and Necker populations. Thatsurvey, directed by Lazell and Mitchell, was con-ducted during “Scientists Month” from 4–29October (each year, Guana hosts a large contin-gent of scientists who conduct research on theisland).

After 14 hours of travel and delays, Guana wasa little piece of paradise. At the dock, my gear wasloaded into the Club’s pickup and we proceededup the steep, twisting road to the clubhouse. TheClub overlooks the dense tropical vegetation ofthe island’s southern end, the salt pond — hometo the six flamingos, and the white beach of a lit-tle cove that merges imperceptibly with the crys-talline waters of the Caribbean.

When I arrived at the patio, which overlooksthe equally picturesque northern end of the island,it was alive with more scientific dialog than I couldbegin to imagine — scientists, some 20 of them, atlunch. After brief introductions, focus quicklyreturned to the population survey that was alreadyin progress.

That same afternoon, we were issued several 2-oz syringe barrels loaded with white latex paintand began a survey of the Club’s wooded perime-ter and nearby support structures. Many StoutIguanas, including the founders, live in close prox-imity to the Club. The weather was cloudy anddamp from the morning’s rain, which kept iguanasfrom venturing far to bask or forage.


A Stout Iguana hatchling on Necker Island basking on thelight sand walkway that leads to the beach. Small tail dragswere numerous along these walkways.

A southerly view of Guana Island from the Club. The saltpond with the six flamingos is located in the lower left andthe beach and docking area in the center.

Dr. James Lazell on Guana Island, 2002.

The first sighting was somewhat unusual. Wecame upon four workmen digging a ditch next toa small structure while talking loudly to be heardover the radio playing in the background. Abovethem on a rock ledge, a large iguana lay casually, asif supervising their work. We marked the animalwith paint, which did not appear to disturb it, andit remained nearby, seemingly unaffected by theintrusion. The remainder of the day includedmarking or sightings of younger adults and juve-niles, but the weather was clearly hampering ourefforts. The founding iguanas and other olderadults were nowhere to be found.

The next day, Mitchell and I explored the areawest of the main facility, accessed from the“Iguana Trail,” while another team surveyed thesouthern area. The weather had improved, butremained partly cloudy and cool compared to typ-

45IGUANAJune 2003

A hatchling Stout Iguana on Guana Island seeks refugeamong the branches of a bush, reducing the likelihood offalling prey to a Racer, but increasing the chances of beingspotted by a Kestrel.

Guana Island’s North Trail was created to minimize impacton the habitat, yet it provides hikers with fabulous views ofthe surrounding natural features. About 300 m beyond thispoint, an adult Stout Iguana was sighted thundering offinto a cactus thicket.

Iguana Trail: a path originating at the lower Guana Clublevel and leading leisurely to the salt pond and beach below.

This subadult Stout Iguana was foraging casually along thehillside near the Iguana Trail and allowed us to approachwithin 3 m. This animal was marked after the photographwas taken.

ical conditions. Our first marking was a subadulton a steep wooded slope not 50 m from the trail’sentry point. Like our first iguana on the previousafternoon, it was rather nonchalant about ourpresence.

That afternoon, we focused our attention onthe northern section of the island where iguanaswere not known to occur. Tail-drags are commonon trails in the area south of North Beach, butthey abruptly disappear to the north of a lineroughly parallel with Crab Cove. The trail eventu-ally splits into two routes, and Mitchell and I sep-arated to cover more ground. About halfwaybetween Crab Cove and Chicken Rock Steps, Iobserved one large, unmarked adult, who, unlikeothers we had observed, responded to the intru-sion by quickly thundering off into a cactus

thicket. We saw no other iguanas or tail-drags, butdid see some scat.

The survey continued and the weatherimproved each day, as did the frequency of iguanasightings. In addition to the population size esti-mate (see “Assessment” on p. 49), we recordedthree incidents of predation on juvenile StoutIguanas, two by Racers (Alsophis portoricensis) andthe other by a female Kestrel (Falco sparverius).

Early on the morning of 14 October, ten of usleft Guana by boat for Necker Island to assess thethird population of Stout Iguanas, only seven yearsafter the initial four hatchlings were released. Thesurvey was limited to two days, and the teammembers quickly dispersed upon arrival.

Mitchell and I began our survey at a locationnear the main facilities where iguanas are fed twicea day. The ground and trails showed many signs oftail-drags clearly produced by individuals of vastlydifferent sizes. We saw several iguanas in the thickshrubs around this area. From there, I worked thevery dry northern section of the island and saw


A southerly view from the north side of Necker Islandreveals habitat more typical of the region, with rocky terrainand small clusters of hardy trees, low shrubs, and densestands of cacti.

A southwesterly view of Necker Island showing the BalineseGreat House (upper right) and the retreat quarters in thepagoda styled structure (foreground). Stout Iguanas weresighted within this area.

only one drag and one scat. Mitchell sighted a fewanimals as she worked an area near where theiguanas are fed.

Others on the survey team successfully markedseveral individuals and recorded sightings of hatch-lings along the pathways around the maintenanceand support facilities. Two Racers also wereobserved in the same area.

The next day, starting where the iguanas areoffered food, we saw two of the founding iguanas.A conservative estimate placed these animals atabout 47 cm SVL and well over 5 kg. Bothappeared in excellent health, alert, and with col-oration of rich brown above blending intoturquoise flanks. We spent our remaining timearound the nursery and beach facilities and sawseveral iguanas, including a subadult and hatch-lings. As on Guana, the Necker iguanas appearedto concentrate near the developed areas.

In stark contrast to the boisterous excitementthat characterized the boat ride to Necker, we qui-etly sought a comfortable spot for the return trip.Although tired from the day’s hard work in blaz-

ing sun, we had time to reflect on events that hadled us to this point in time and space.

The absence of committed, long-term fundingcontinues to impede efforts to secure the species’survival on Anegada. Compounding loss of habi-tat is ongoing development. Consequently, StoutIguanas are fighting for survival, suffering simulta-neously from habitat degradation and predationon juveniles. Some fear that the upcoming assess-ment will determine that the Anegada populationhas declined to critically low numbers and may befunctionally extinct in the wild. However, I believewe all shared a warm feeling knowing that the out-look for Stout Iguanas had improved considerablythrough the efforts of a few very special people.

47IGUANAJune 2003

Racers on Necker Island commonly feed on juvenile StoutIguanas.

One of the four founding Stout Iguanas on Necker Island(shown near the feeding area) was hiding behind a clumpof debris, straining to see if his morning serving had arrived.

This lightly wooded area near a salt pond on Anegadashows vegetation heavily damaged by feral animals seekingshelter from the sun or areas to rest. Habitat such as thishas no chance of recovery while feral animals are allowedto roam free.

AcknowledgementsI thank James Lazell and Numi Mitchell for

the invitation to participate in the Guana andNecker island population assessments, and Henryand Gloria Jarecki and Richard Branson for theirhospitality and enduring commitment to ensuringthe survival of Stout Iguanas. Allison Alberts, RickHudson, and Glenn Gerber have been instrumen-tal in all my conservation efforts, and my wifeSandy has her sleeves rolled up right beside me.This article has benefited from comments by GadPerry and Robert Powell.

ReferencesBinns, J. 2001. Taxon report: Anegada Iguana (Cyclura pinguis).

IUCN/SSC Iguana Specialist Group Newsletter 4(2):12–13.

Carey, W.M. 1975. The Rock-iguana, Cyclura pinguis, on Anegada,British Virgin Islands, with notes on Cyclura ricordii and Cycluracornuta on Hispaniola. Bulletin of the Florida State Museum19:189–234.

Gerber, G.P. 2000. Conservation of the Anegada Iguana, Cyclurapinguis. Field Research Report, prepared for the BVI NationalParks Trust, Fauna and Flora International, and the ZoologicalSociety of San Diego. Zoological Society of San Diego, SanDiego, California.

Goodyear, N.C. 1992. Flamingos return to Anegada: status update.National Parks Trust News, British Virgin Islands, August 1992:1.

Goodyear, N.C. and J. Lazell. 1994. Status of a relocated popula-tion of endangered Iguana pinguis on Guana Island, BritishVirgin Islands. Restoration Ecology 2:43–50.

Grant, C. 1932. Herpetology of Tortola: notes on Anegada and VirginGorda. Journal of the Department of Agriculture of Puerto Rico16:339–346.

Hudson, R. 2001. ISG 2000 Meeting Minutes: Anegada, HeadstartingProgram. IUCN/SSC Iguana Specialist Group Newsletter 4(1):4.

Lazell, J. 1995. Natural Necker. The Conservation Agency OccasionalPaper (2):1–2.

Lazell, J. 1997. The Stout Iguana of the British Virgin Islands. IguanaTimes 6:75–80.

Lazell, J. 2002. Restoring vertebrate animals in the British VirginIslands. Ecological Restoration 20:179–185.

LeVering, K. and G. Perry. 2003. Cyclura pinguis (Stout Iguana,Anegada Rock Iguana). Juvenile predation. HerpetologicalReview: in press.

Mitchell, N.C. 1999. Effect of introduced ungulates on density,dietary preferences, home range, and physical condition of theiguana (Cyclura pinguis) on Anegada. Herpetologica 55:7–17.

Mitchell, N.C. 1999. Anegada Island Iguana, Cyclura pinguis, pp.45–70. In: A. Alberts (comp. and ed.), West Indian Iguanas:Status Survey and Conservation Action Plan. IUCN/SSC WestIndian Iguana Specialist Group, IUCN, Gland, Switzerland andCambridge, UK.

Mitchell, N.C. 2000. Anegada Iguana, pp 22–27. In: P. Reading andB. Miller (eds.), Endangered Animals: A Reference Guide toConflicting Issues. Greenwood Press, Westport, Connecticut.

Schomburgk, R.H. 1832. Remarks on Anegada. Journal of the RoyalGeological Society 2:152–170.


49IGUANAJune 2003

Only rarely is a population so thoroughly knownthat every member is individually recognized and afull census possible. Because of this, a variety of sta-tistical methods, some of them extremely sophisti-cated, are normally employed to estimate populationsizes. As with all statistical methods, population esti-mates have limitations. The amount of available datais one crucial factor: the more, the better. In addition,certain assumptions, some of them unique to one setof estimators or another, apply.

Unfortunately, studies on critically endangeredspecies tend to run afoul of one or both issues, mak-ing reliable population estimates difficult. This is thecase with Stout Iguanas. Not only are the populationssmall, they are unreliable subjects (a captured adultiguana may retreat into its burrow for up to threeweeks in response to the stress), hard to spot in thefield (the terrain is rough and the animals are crypti-cally colored), and often not accessible (work onGuana normally can be conducted only during themonth of October). These limitations render any esti-mate of population size less reliable than one wouldlike and therefore much less satisfying to a wildlifemanager. Nonetheless, work with endangeredspecies requires that their population sizes be esti-mated, so that one can determine if the populationis stable, growing, or — in a worst-case scenario —declining. A preliminary estimate, known to beimperfect, is better than none, as long as the limita-tions of the estimate are kept firmly in mind whenmanagement decisions are being made.

Several attempts to monitor the Guana iguanapopulation were made over the years. Combinedwith the evidently growing numbers of hatchlingsevery year, they suggested that the population wasdoing well and growing at a steady pace. In October2002, a more concerted effort was made by markingseveral individuals with water-based, white, exteriorlatex paint (which quickly dries and is waterproof)squirted from a two-ounce (60 cc) syringe barrel.Marking began on 4 October and continued until 13October. Twenty-three individuals were marked, buton most days some sighted iguanas escapedunmarked. Beginning on 15 October, we did six

“round-up” counts of marked and unmarked indi-viduals, finishing on 29 October. These provided sixpopulation estimates, based on the Petersen Index:69, 115, 138, 138, 138, and 207. The numbers arerelatively close to one another, suggesting that theyprobably represent a fairly robust estimate. A calcu-lated mean (134) is probably not too far from the realnumber. A calculated standard deviation (45 in thiscase) allows us to say that we are 95% confident thatthe true population size is between 44 and 224: twostandard deviations from the mean in each direction.Unfortunately, this method does not meet all of theassumptions of the test, which renders the numbersuncertain.

A second method for calculating population sizeswas proposed by Z.E. Schnabel in 1938. Using thismethod, we can add to the six Petersen Index talliesthe data from 4–13 October. This method generatesremarkably similar numbers, estimating the popula-tion size at 95 individuals and the 95% confidenceinterval at 58–185. Once again, not all of theassumptions are met, but the fact that two very dif-ferent methods with different assumptions led to sim-ilar estimates gives us more confidence that the pop-ulation size really is about 100 individuals.

We arrived on Necker Island on the afternoon of14 October 2002 and quickly marked five StoutIguanas. The next day before our departure, we sawsix iguanas, only one of which was marked. Theimplication is that one-sixth of the population wasmarked; so five times six is 30. No statistics can bedone on a single estimate, but this observation con-forms remarkably well with the opinion of residentnaturalist and caretaker, Brian Andrews, who believesthat about 20 individuals are present, not countingthe current year’s hatchlings.

ReferencesRicker, W.E. 1975. Computation and interpretation of biological

statistics of fish populations. Fisheries Research Board ofCanada Bulletin No. 191.

Schnabel, Z.E. 1938. The estimation of the total fish populationof a lake. American Mathematical Monthly 45:348–352.

Guana and Necker Island Population Assessments 2002

Gad Perry and Numi MitchellThe Conservation Agency

Green Iguanas (Iguana iguana) havehighly developed and very complexsocial behavior, using both chemical(scent) and visual (body language) sig-

nals to establish and maintain social relationshipswithin the species. Although iguanas are capable ofhearing noises, sound production is limited to hiss-ing, which they do when threatened.

Head-bobbing, flattening of the body, andscratching movements are important elements ofbody language. One study differentiated five formsof head-bobbing which vary in duration and func-tion: a single vertical bob (head-jerk), a vibratingbob (shudder), a roll or assertion bob (roll), atransitional roll with shaking (roll-shudder), and anidentity or signature bob. However, this catego-rization is an oversimplification that only begins toprovide an understanding of the very complexbobbing behavior in I. iguana.

The vertical bob is characterized by rapid ver-tical head movements. This is not a social signalbut rather a visual aid. Iguanas will use this move-ment while basking or ovipositioning (particularlyfemales exiting their nesting burrows) beforeentering unprotected or open territory to helpthem identify any potential danger. The vibratingbob (shudder) is a rapid, jerky, but flat head-bob

with the dewlap extended to the maximum.Sometimes, an iguana will accompany this by lift-ing its head and swinging it from side to side. Thisshudder can be observed during close contactbetween males and females. However, this is notmating behavior. The rolling head-bob, in con-trast, is clearly linked to mating and territorialbehavior, and is most frequently seen during themating season. An iguana will lift its head towardsone corner at a 45° angle and rotate it along thelongitudinal axis. The roll is also performed withthe dewlap fully extended. The roll-shudder liesbetween the shudder and the roll in both form andfunction. The identity or signature bob is charac-terized by strong vertical head movement, fol-lowed by another head movement during whichthe head is held aloft for a longer time (plateau).This is followed by a series of smaller noddingmovements. The signature bob is always associatedwith an activity, such as aggression, mating, terri-torial behavior, changing basking logs, or othertypes of movement. Researchers have suggestedthat this motion is connected with species identifi-cation, and also may serve to identify individuals ormembers of the same population.

H U S B A N D R Y50 IGUANA Volume 10, Number 2

Green Iguana CommunicationGunther Köhler

Forschungsinstitut und Naturmuseum Senckenberg, Frankfurt, Germany

Head-bobbing is a critically important component of iguanacommunication.

An adult male assuming an aggressive posture; notice thelateral compression, erect crest, and extended dewlap, alldesigned to make him appear larger.

From G. Köhler. 1998. Der Grüne Leguan: Biologie, Pflege, Zucht,Erkrankungen. Herpeton Verlag, Offenbach, Germany. Translatedfrom German by AJ Gutman.

Threat BehaviorGreen Iguanas display a wide range of threat

behaviors. When they wish to intimidate a poten-tial predator or rival, they will flatten themselveslaterally, displaying their ventral stripes, and fullyextend their dorsal crests and dewlaps in order toappear larger. This often is accompanied by a wrig-gling of the tail in a snake-like fashion. Ifapproached more closely, the iguana will gape withmouth wide open, hiss loudly by expelling air, andwhip his tail towards the source of disruption.With its sharp teeth and powerful jaws, an adultiguana can inflict a painful bite.

51IGUANAJune 2003

Diagrammatic representations of different types of head-bobbing behavior.

Adult males readily revert to biting and fighting if communication breaks down.

Refusal and Submissive BehaviorScratching upward with the forelimbs towards

the rear is clear refusal behavior. This motion isoften observed in females being approached frombehind by a male who is interested in mating andwhen one individual is climbing over another.Green Iguanas will close their eyes as a sign of sub-mission, for example, in reaction to a threat froma dominant male. Very shy iguanas will also closetheir eyes when they are picked up to indicate thatthey are “resigned to their fate” (pers. obs). Whenstroked by their handlers, iguanas will often closetheir eyes. Contrary to the widely held belief thatthe iguana (like a cat) is indicating a sense of well-being, this indicates refusal and is an expression ofindisposition. Unlike in mammals, tenderness inthe form of stroking is not part of the behavioralrepertoire of lizards.

Chemical SignalsExcretions from the femoral pores consist of

large, non-volatile proteins and various smallervolatile and non-volatile fats. To collect scent mole-cules from objects or from the air, iguanas willextend and retract their tongues, passing scent mol-ecules to the so-called Jacobson’s organ, a sensitivescent detection organ located in the roof of themouth. If a Green Iguana is placed into an unfamil-iar environment, it will explore intensively with itstongue. Even new objects placed into a familiar envi-ronment will elicit a thorough tongue examination.

Due to individual differences in the composi-tion of femoral pore secretions, iguanas can distin-guish between familiar and unfamiliar members oftheir species. In the dense foliage of a tropical rain-forest, an unknown iguana can easily intrude unseeninto the territory of a dominant male. Under thesecircumstances, the ability to distinguish between thescent of a familiar and an unfamiliar individual isuseful in determining the presence of a rival.

Pertinent LiteratureAlberts, A.C., N.C. Pratt, and J.A. Phillips. 1992. Seasonal

productivity of lizard femoral pore glands: Relationship tosocial dominance and androgen levels. Physiology andBehavior 51:729–733.

Alberts, A.C., T.R. Sharp, D.I. Werner, and P.J. Weldon. 1992.Seasonal variation of lipids in femoral gland secretions ofmale Green Iguanas (Iguana iguana). Journal of ChemicalEcology 18:703–712.

Alberts, A.C., L.A. Jackintell, and J.A. Phillips. 1994. Effects ofchemical and visual exposure to adults on growth, hormones,and behavior of juvenile Green Iguanas. Physiology andBehavior 55:987–992.

Alberts, A.C. and D.I. Werner. 1993. Chemical recognition ofunfamiliar conspecifics by Green Iguanas: functional significanceof different signal components. Animal Behavior 46:197-199.

Distel, H. and J. Veazey. 1982. The behavioral inventory of theGreen Iguana, Iguana iguana, pp. 252–270. In: G.M.Burghardt and A.S. Rand (eds.), Iguanas of the World, TheirBehavior, Ecology, and Conservation. Noyes Publications, ParkRidge, New Jersey.

Dugan, B.A. 1982. A field study of the head bob displays of maleGreen Iguanas, Iguana iguana: variations in form and context.Animal Behavior 30:327–338.

Hazlett, B.A. 1980. Temporal pattern of the assertion display ofthe lizard Iguana iguana. Herpetologica 36:221–224.

Rodda, G.H. 1992. The mating behavior of Iguana iguana.Smithsonian Contributions to Zoology 534:1–40.

Weldon. P.J., B.S. Dunn, C.A. McDaniel, and D.I. Werner.1990. Lipids in the femoral gland secretions of the GreenIguana, Iguana iguana. Biochemical Physiology 95B:541-543.


A female scratching herself with a forelimb indicates thatshe is rejecting the overtures of a male.

Closed eyes are a sign of submission.

Conserving endangered species is a taskfraught with scientific, economic, political, logistic,and sometimes cultural and even religious imped-iments that can make the undertaking difficult atbest. Such efforts ultimately involve many people— but the impetus and success of each is quiteoften dependent on the dedication and persever-ance of a single individual. In their book, LastChance to See (Harmony Books, 1990), DouglasAdams, better known for his Hitchhiker’s Guide tothe Galaxy, and co-author Mark Carwardine doc-umented the heroic efforts of a few of these dedi-cated individuals to save some of the rarest animalson Earth. This is the first in a series of articles inwhich we will profile a few of the dedicated indi-viduals who are devoting a significant part of theirlives, and sometimes their bank accounts, to thestudy and conservation of some of the mostendangered of the world’s iguanid lizards.

The Grand Cayman Blue Iguana, Cycluralewisi, is the largest native land animal on GrandCayman Island and one of the most highly endan-gered vertebrates in the world. A census con-ducted in 1992 estimated the wild population tobe 175–200 individuals — but, by 2002, a follow-up survey reduced that number to fewer than 25.Fortunately for the iguanas, Caymanians have astrong conservation ethic, and fortunately, theyalso have Fred Burton.

Fred was born in England’s Lake District, butspent much of his early life in Kuwait, where hisfather was employed by the Kuwait Oil Company.There he developed a keen interest in reptiles andother animals of the Arabian desert. He eventuallyenrolled in Gonville and Caius College ofCambridge University where he graduated with anhonors degree, and subsequently a Master’s degreein Natural Sciences. Although he was encouragedto apply for the Ph.D. program at Cambridge,

Fred was not attracted to the academic life nor tothe research he would have had to pursue. Instead,he was hoping to have a more direct impact on theworld around him. His attention was drawn to anadvertisement that appeared on the biologydepartment notice board about a position for aGraduate Research Assistant with the MosquitoResearch and Control Unit (MRCU) in theCayman Islands. Neither Fred nor his friends knewwhere the Cayman Islands were, but more-or-lessas a joke, Fred applied anyway. Things took a seri-ous turn, however, when he received a telegramfrom the MRCU and, in 1979, he began what heassumed would be a two-year sojourn in theCaribbean.

P R O F I L E53IGUANAJune 2003

Fred Burton: The Man Behind the

Blue Iguana Recovery PlanSandy Echternacht

University of Tennessee

In a thoughtful moment, Fred Buton discusses captivemanagement at the Blue Iguana breeding facility during theISG meeting on Grand Cayman, November 2002.Photograph by John Binns.

Beginning as a Research Assistant at theMRCU, Fred conducted field studies of mosqui-toes in mangrove swamps, monitored oil pollu-tion, and was, for a while, the sole staff member ofthe MRCU Natural Resources Study, which even-tually evolved into the Cayman Department ofEnvironment. He was subsequently promoted toDeputy Director of the MRCU and served asActing Director when the Director became seri-ously ill. While working in the mangroves, Fredbecame fascinated by the ecosystem but disturbed

by the fact that his study sites kept being torn up,dredged, and filled for real estate developments.When the National Trust for the Cayman Islands(roughly equivalent to the Nature Conservancy inthe U.S.) was founded, Fred was often asked fortechnical information on the environment andended up volunteering for all sorts of conserva-tion-related activities. Eventually, he was “loaned”by the MRCU to the Trust and became a regular,full-time member of the Trust staff in 1993. AsDirector of Science, and later EnvironmentalProgrammes Director, his major emphasis was onestablishing a system of protected areas in theCayman Islands equivalent to an existing system ofmarine areas, and he initiated the Trust’s environ-mental programs. These programs grew out ofideas developed by Fred and other members of agroup of environmentalists, notably Gina Ebanks-Petrie, who also had been on the MRCU staff and currently is Director of the Department ofEnvironment in the government of the CaymanIslands.

In 1990, while still a volunteer at the Trust,Fred founded the Blue Iguana breeding programwith a breeding pair received from a private col-lector in Florida. The animals were initially housedin two cages at the old MRCU facility behind thehospital in George Town. The breeding programwas immediately successful and the facility at thehospital had to be expanded. At the same time,


Fred (second from right) showing visitors the latest addition to the Blue Iguana facility at theMosquito Research and Control Unit facility at the hospital in George Town, Grand Cayman(May 1990). Photograph by Sandy Echternacht.

A very young-lookingFred Burton at his deskin the old MRCU facilityadjacent to the hospitalin George Town, GrandCayman, in May 1990.Photograph by SandyEchternacht.

international interest was picking up. With fund-ing and research assistance from the (U.S.)National Zoo, facilitated by its then Curator ofReptiles, Dale Marcellini, field studies of wildiguanas were initiated. Additional assistance andfunding has come from the zoo community, par-ticularly from the Ft. Worth Zoo and its Curatorof Reptiles, Rick Hudson, and the Center forReproduction of Endangered Species of the SanDiego Zoological Society and Allison Alberts, whois the Society’s Head of Applied Conservation. In1995, with funding from the Milwaukee Zoo andthe Foundation for Wildlife Conservation, a muchlarger breeding facility was established at QueenElizabeth II Botanic Park (QEIIBP) and therelease of two-year-old iguanas into the Park beganshortly thereafter. The QEIIBP facility is currentlyundergoing a major expansion and additionalrelease sites are being sought. The latter is a defi-nite problem since Grand Cayman is undergoingexplosive development.

The Blue Iguana program has been a resound-ing success and Fred has been the driving forcebehind that success, but Fred’s activities have notbeen limited to the iguana program. He has beenheavily involved in conservation efforts directedtoward native plants of the Cayman Islands and to the two subspecies of parrots endemic to the

Cayman Islands (Amazona leucophala caymanen-sis and A. l. hesterna). He has mapped vegetationin the Cayman and Turks & Caicos islands andconducted floristic surveys and other botanicalstudies in the Caymans. He has authored a fieldguide to the wild trees of the Cayman Islands. In2001, he left the Trust to spend more time as aprivate citizen pursuing conservation initiatives inthe Cayman Islands and elsewhere. He continuesto lead the Blue Iguana Recovery Programme(http://www.BlueIguana.ky) and hopes to see theday when Blue Iguanas have recovered to thepoint that they can be removed from the list ofendangered species. In whatever spare time he has,and it obviously isn’t much, he handcrafts hard-wood sea-going kayaks and plays classical violin.Fred is clearly a dedicated conservationist and envi-ronmentalist and a consummate naturalist in thebest sense of that word. The Blue Iguanas ofGrand Cayman are fortunate indeed that he ulti-mately took the job opening with the MRCU assomething of a joke!

55IGUANAJune 2003

Fred Burton holding a Blue Iguana named “Santa” at theQueen Elizabeth II Botanic Garden on Grand Cayman in2002. Photograph by Rachel Goodman.

Fred Burton and Rachel Goodman, University of Tennesseegraduate student, built enclosures in 2001 to catchhatchlings as they emerged from nests of released femaleiguanas in QEIIBP. Photograph by Sandy Echternacht.

The Spiny-tailed Iguanas (Ctenosaura Wgm.[translator’s note: “Wgm.” Refers to A.F.A.Wiegmann, a German zoologist who describedmany saurian genera in Herpetologia Mexicana,which was published in 1834]) are restricted toMiddle America. They can be distinguished fromCyclura by the short rows of femoral pores. Theyare imposing animals that are primarily terrestrialor, at the most, seek shelter in the hollow trunksof trees. They have laterally compressed bodies, arelatively low middorsal crest, and tails equippedwith whorls of spiny scales. The best knownspecies is the Mexican Black Iguana, Ctenosaura

acanthura Shaw [an English naturalist whoapplied proper Latin names to many “amphib-ians,” which, around the turn of the 19th century,included reptiles]. This proud creature can reach atotal length of over 1.20 m and is either uniformlygraphite-black in color or bears black crossbands

H I S T O R I C A L P E R S P E C T I V E S56 IGUANA Volume 10, Number 2

Black Iguana, Ctenosaura acanthura Shaw 1/6 natural size.

The Black Iguana*Franz Werner

* excerpted and translated from Franz Werner (1913. DieLurche und Kriechtiere von Alfred Brehm. Zweiter Band:Kriechtiere (Schuppenkriechtiere). In: O. z. Strassen (ed.),Brehms Tierleben. Allgemeine Kunde des Tierreichs.4th ed. Bibliographisches Institut, Leipzig and Wien).Translated by R. Powell.

on its rump and decorative black rings around itstail, both over a light ground color (light olive-brown, yellow-gray, or green). In captivity, theselizards readily consume both plant and animalmatter. According to Sumichrast [FrançoisSumichrast, a 19th century Swiss naturalist], sev-eral female Spiny-tailed Iguanas, like CommonIguanas, lay their eggs in a communal chamber;however, females do not appear as a rule to gatherin large numbers during the nesting season, as onerarely finds more than 6–7 dozen eggs in a singlenest. Ruthven [Alexander G. Ruthven, a famousAmerican herpetologist] observed the subspeciescompleta Boc. [completa is now considered to be asynonym of Ctenosaura similis; “Boc.” refers toM.-F. Bocourt, a French naturalist, who collectedextensively in Middle America during the secondhalf of the 19th century] primarily in the savannasof Mexico where trees form isolated clusters. Infact, each individual is true to the tree which it hasstaked out as its own, so that Ruthven almostalways saw these animals on the trunks of theirtrees as he approached a given clump, oftenremaining in one place for hours at a time. Theirdiet consists largely of leaves.

The Black Iguana is considered especially tastyand, as a consequence, according to Sumichrast, iscommonly hunted, particularly prior to festivals.Hunters seek these animals in burrows or split treetrunks, particularly those that are in the vicinity oftemporary pools that hold water only during therainy season. Should a lizard be caught, it issecured in the typical fashion. Even more favoredthan the meat, which is considered a delicacy, arethe eggs. Quatrefages [an unknown source] tells arelevant tale of the traveler Sallé. As the latterentered a humble hut one evening in MiddleAmerica, he found only soup to quench his con-

siderable appetite. To his surprise, however, hishost, who had already apologized for the sparsemeal, knew just how to spice it up in a most pecu-liar fashion. At the host’s command, several smallboys ran off to the woods and returned shortlythereafter with a large lizard that seemed destinedfor the traveler’s plate. Instead of killing and broil-ing the animal, the host merely made a small inci-sion in its side, reached in with his fingers, andcarefully pulled out two strings of eggs.Subsequently, the host cleanly stitched the cut,rubbed a few hot ashes on the edges of thewound, and released the lizard. The eggs wereplaced in front of Sallé, who queried his host andwas told that it was common practice to treat theseanimals in such a fashion, since one could there-fore count on harvesting another batch of eggs inthe following year.

H I S T O R I C A L P E R S P E C T I V E S57IGUANAJune 2003

Black Iguana, Ctenosaura acanthura Shaw. 1/9 natural size. Photograph by W.S. Berridge, F.Z.S. – London.

Distribution of the genus Ctenosaura. The question markindicates uncertainty regarding the presence of iguanas insouthern Baja California and the arrow denotes theintroduction of Spiny-tailed Iguanas into southern Florida.Modified from Gunther Köhler (2002. Schwarzleguane.Herpeton Verlag Elke Köhler, Offenbach, Germany).


I G U A N A N E W S B R I E F SThe IISContributes toConservationContributions fromInternational Iguana Societymembers have made itpossible for the IIS toprovide assistance to severalongoing projects. Withinthe past year, the Society hasmade contributions to: (1)the Blue Iguana RecoveryProgram on Grand CaymanIsland (with special thanksto the Pacific NorthwestHerpetological Society fortheir generous donation),(2) graduate student RachelGoodman to support herBlue Iguana (Cyclura lewisi)research, (3) new cages forheadstarting Ctenosaurabakeri at the IguanaResearch and BreedingStation on Utila, Honduras,and (4) shipping mongoosetraps to Jamaica, where they will be used to trapmongooses that prey onJamaican Iguanas, Cycluracollei.

The IIS plans to continuesupport for the implementa-tion of the Blue IguanaRecovery Plan (seewww.Cyclura.com) and isactively engaged infundraising to help purchasecritical Ctenosaura bakerinesting habitat on Utila (seeLetter from the President,p. 59). Your membershipdues and contributions helpthe IIS make a differencefor endangered iguanas inthe wild. We appreciate yourcontinuing support.

A New FossilIguana from FijiGregory K. Pregill andTrevor H. Worthy (2003.Herpetologica 59:57–67)described Lapitiguanaimpensa based on fossilremains found in lateQuaternary sediments onViti Levu, the main islandof Fiji. The differencesbetween this spectacularlylarge (SVL ca. 500 mm)iguana and extant Fijiiguanas in the genusBrachylophus were suffi-ciently substantive that theauthors placed this newdiscovery in a separategenus. Like Brachylophus,however, this iguana appearsto be basal among theIguanidae, although exactrelationships cannot beresolved with the availableevidence. This giant formprobably became extinctsoon after humans firstcolonized the islands about3000 years ago.

The new generic namederives from Lapita, aproper name given to thedistinctive pottery associ-ated with the first humansettlers of Fiji, whodisappeared from thearchaeological record soonthereafter, and iguana,an aboriginal Amerindianname apparently designat-ing a kind of lizard. Thespecies name is from theLatin impensa (= ample orlarge), in reference to thelarge body size of this lizard.

Although the data aresparse, they do not seem to support a sister-taxonrelationship betweenLapitiguana andBrachylophus, suggestingthat Fiji might have beencolonized twice by iguanidlizards. The authors alsosuggest that Brachylophuswas able to coexist withhumans primarily due to itscryptic, arboreal lifestyle. In contrast, Lapitiguana,which was most certainly aconspicuous, terrestrialform, became extinct as adirect result of humanagency soon after the Lapitapeople arrived in Fiji.

IIS Member WinsScience FairIIS member NicholasJones of Little Rock,Arkansas recently won firstplace in zoology at hisschool Science Fair forresearch on the use of colorvision in food selection byGreen Iguanas. In furthercompetition, Nicholas’sresearch paper again placedfirst at both the CentralArkansas Regional ScienceFair and the Arkansas JuniorAcademy of Sciences.

In an earlier experiment, inwhich the same foods werepresented to a GreenIguana on different coloredplates, Nicholas’s iguana,Frank, had selected foodpresented on a red platefour times as frequently asthat presented on a blackplate. In the currentexperiment, Frank waspresented with hibiscusflowers in two differentcolors. Both a red blossomand a pale yellow or whiteblossom were offered to theiguana 23 separate timesand records kept of whichblossom he chose to eatfirst. At each feeding, theplacement of the blossomswas switched to eliminatethe possibility that theiguana was just eating onthe same side of the cage.Frank chose to eat the redblossoms first in 18 of the

23 trials, leading Nicholasto conclude that his iguanawas indeed using colorvision in selecting food.

Nicholas now goes on tocompete in the nationalDiscovery Channel ScienceChallenge. We wish himthe best of luck and hopehe continues his scientificpursuits!

CHS Works toHelp IguanasThe ChicagoHerpetological Societyconservation booth at theannual CHS Reptile Fest(April 5–6) was a hugesuccess. IIS members LoriKing and Betsy Daviswere on hand to educatepeople about GrandCayman Blue Iguanas andUtila Iguanas, as well asMassassauga Rattlesnakes.Lori’s juvenile Ctenosaurabakeri, Nagual, made hisfirst public appearance andproved to be the star of theshow. A variety of generalmerchandise such as UtilaIguana T-shirts, Christmasornaments, bookplates, andstuffed animals worked likemagnets to draw everychild to the table — withparent in tow, begging for a stuffed animal.Altogether, the effort raised $1,505 for the UtilaIguana nesting propertyfund. Of incalculable value,however, was the opportu-nity to explain the plight ofthese exquisite animals toevery visitor to the table.The Grand Cayman Blue Iguana (Cyclura lewisi) is function-

ally extinct in the wild. The IIS is promoting and supportingthe Blue Iguana Recovery Program (see Profile, p. 53).

59IGUANAJune 2003

L E T T E R F R O M T H E P R E S I D E N T

What a great week we had at the IIS conferenceon Utila, Honduras. Seventeen IIS members joinedGunther and Elke Köhler, Alex Gutsche, KarstenGees, and the rest of the staff and volunteers of theIguana Research and Breeding Station. Our schedulewas quite full and included lectures and discussionsalmost every evening during the week.

The Iguana Station staff arranged several dailyfield trips of varying degrees of difficulty. Most of thetrips involved efforts to find and see the elusiveCtenosaura bakeri in its natural habitat. This iguana,unlike the other sixteen varieties of Ctenosaura, justlydeserves the nickname, “Swamper.” On the first tripinto the swamps, many of our group members sankpast their knees in the mud as they ventured into theSwampers’ home range.

In a sense, these animals’ comfort with a swampyenvironment helps preserve the species. The man-grove wetlands that this animal calls home are unat-tractive to developers, and could well be the lastvestige of property remaining on the rapidly develop-ing island of Utila.

However, all is not well in the world ofCtenosaura bakeri. Although some local people stillhunt iguanas for food, the work of Gunther and hiscolleagues over the years has had a positive impact andthe ban on hunting is commonly observed. Signsthroughout the island inform both locals and visitorsof the protected status of this endemic species.

By far the greatest threat to the continuedsurvival of Ctenosaur bakeri is the rapid loss of nestinghabitat to tourist-related development. For example,the group was taken to a 31⁄2 acre beachfront propertythat has been a nesting site for up to 500 femaleiguanas. We were later informed that this was one ofonly two remaining beachfront properties not yetsold, and the other was not part of the Swamper’srange! Without a place for the females to lay theireggs, the species would rapidly dwindle and becomeextinct. As a conservation-minded group, we cannotallow this to happen. The IIS is now concerned withraising part of the $165,000 for purchasing andpreserving this remaining vestige of nesting habitat.This is a tangible goal. Already, donations areapproaching $5000 and fundraising is ongoing.

If you are interested in donating or assisting inraising money for this notable cause, contact theInternational Reptile Conservation Foundation (IRCFc/o John or Sandy Binns, 3010 Magnum Drive, SanJose, CA 95135) for more information. All donationsare tax-deductible.

You should think about joining the group on ournext adventure.

Joe Wasilewski

A large male Swamper basks next to his tree hole in thevicinity of Rock Harbor. This animal had toe-clips indicatingit had been released from the Utila Iguana Research andBreeding Station a number of years ago. It was likely one ofthe original animals adopted through the Utila IguanaAdoption Program. Photograph by John Binns.

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