Murphy, James B.

English

The University of Kansas: Journals@KU

IGUANA  •  VOLUME 14, NUMBER 1  •  MARCH 2007 45HISTORICAL PERSPECTIVENumerous attempts are made by zoological gardens to dis-play resident populations of iguanids and varanids, butoften these meet with little success. Many species of the twofamilies are imported annually; yet surprisingly, few exhibit thecharacteristic alertness and activity associated with wild speci-mens. After a few months in captivity, their lethargy and obvi-ous lack of health is depressing even to the casual zoo visitor.Since November 1966, we have maintained an exhibit cen-tred around these two families. Rhinoceros Iguanas Cyclura cor-nuta, Andros Island Iguanas Cyclura b. baealopha [Cyclura cych-lura cychlura], Exuma Island Iguanas Cyclura b. figginsi [Cycluracychlura figginsi], Cayman Island Iguanas Cyclura macleayi cay-manensis [Cyclura nubila caymanensis], Green Iguanas Iguana i.iguana2, and the Mexican False Iguana Ctenosaura hemilopha livein complete harmony with a large Water Monitor Varanus sal-vator and a Lace Monitor Varanus varius. They are exhibited ina large glass-fronted display area, measuring 4.6 x 2.4 x 3 m, thetop being screened with wire. A concrete pool, 2.4 x 1.2 m, is inthe centre of the cage. The monitors are often seen swimmingor resting in the water.Because the natural temperature of the area is only 27 °C(80 °F), an auxiliary heat source is needed so that normal meta-bolic functions can proceed. A bank of six 250-W/11O-V Infra-red Heat Lamps (Ken-Rad) and two 275-W/11O-V ‘SunLamps’ (Ken-Rad) are directed to a ‘hot spot’ at the front of thecage where the temperature reaches 41 °C (106 °F). The valueof these lamps cannot be underestimated, for the lizards are mosthealthy when they are in operation. Common or Green IguanasIguana iguana with paralysed hindlimbs and in generally poorhealth are often brought in as donations. In many cases, theircondition has improved after a few months under the sun lamps.For a natural effect, plastic foliage, rocks, and tree limbs areused. The plants must be chosen carefully to withstand the con-stant prowling and climbing of the lizards. The limbs arearranged at an angle one meter from the ground, so the lizardsmay retire to them during the heat of the day. Gravel that willpass through a 1-cm screen is used for the substratum, as thistends to hold the warmth well. It also gives a firm footing for theconstantly scurrying lizards, which seem to feel insecure if placedon material that gives way under their weight.To ensure the health of the saurians, a proper diet must beoffered and they are fed three times a week. Two large alu-minium trays are filled with diced fruits and vegetables.Oranges, apples, bananas, grapes, lettuce, spinach, kale, toma-toes, beets, carrots, papaya, and cantaloupe are used accordingto season. Once a week, strips of lean horsemeat and freshlykilled mice are included in the tray. A multiple vitamin prepa-ration (Pervinal) and steamed bone meal or oyster shell flour arethe only additives. Care is taken to avoid overfeeding, and wejudge this by observing the girth of the hind limbs and proximalportion of the tail.The photoperiod and temperature remain relatively con-stant day by day and the relative humidity is about 40%. Thelights are turned on at 0800 hours, and the lizards begin toemerge almost immediately. Usually, after basking in the heatfor the first 30 minutes or so, they begin to leave the ‘hot spot’and return only periodically to maintain their temperature level.They are fed between 1500 and 1600 hours. After the meal theyreturn to the ‘hot spot’ and remain there for some time. Thisapparently aids digestion. The lights are turned off at 1700hours, and this is the period of greatest activity. Flattening them-selves dorsoventrally, they remain on the ‘hot spot’ area until itcools. During this time, the sunlight that shines through the sky-H I S T O R I C A L  P E R S P E C T I V ENotes on Iguanids and Varanids in a Mixed Exhibit at Dallas Zoo1James B. MurphySupervisor of Reptiles, Dallas Zoo, Dallas, Texas, USA1 This article is adapted with the kind permission of the InternationalZoo Yearbook (International Zoo Yearbook 9: 39–41; 1969), whichis published by the Zoological Society of London. Additional infor-mation about the IZY can be found at http://www.blackwellpub-lishing.com/journal.asp?ref=0074-9664&site=1.2 Note that subspecies of Green or Common Iguanas (Iguanaiguana) are, for the most part, not currently recognized. Extensivestudies of genetic relationships among populations from differentregions are underway (e.g., see “ISG Reports” in Iguana 13(2):127–128).Iguana 14.1 b&w text.QX6  2/25/07  10:46 PM  Page 45light above the cage gradually fades. The only variation in thisroutine is during the introduction of new animals when, if theyare shy and feeding diffidently, the lights will be left burningafter visiting hours so they will emerge and feed.Newly acquired animals are quarantined in fibreglass hold-ing cages for at least 30 days. Upon arrival, they are washed in aprophylactic solution of oxytetracycline hydrochloride (Cosa-terramycin) for 24 hours. Food is presented daily until a patternof feeding can be determined.Maintenance of the exhibit is remarkably uncomplicatedconsidering the number of reptiles involved. Daily, the keeperenters the cage before the lights are turned on, drains the pooland scrubs it with a disinfectant (Roccal), cleans faecal matterfrom the gravel, and polishes the glass. The cage is completelydismantled bi-monthly and the gravel and walls are thoroughlydisinfected. The plastic plants, rocks, and gravel are also cleanedand disinfected.Rudimentary ‘grooming’ by the Exuma Island Iguana hasbeen observed. As the lizards shed their superficial epidermis infragments, pieces adhere to the body. Individuals of the samespecies will investigate the body of the shedding lizard and con-sume the skin whenever possible. Not only are the dorsal andlateral areas checked, but the shedding iguana will lift its leg andallow the others to pull the skin from beneath the leg.Occasionally, more than one ‘grooming’ lizard will be involvedin this process.Hopes for future successful breeding with this arrangementare based on the numerous copulations we have observed;although, unfortunately, the only eggs discovered were broken.The male iguanas display vigorously in typical head bobbingfashion and territories are rigorously defended. For such a largeand varied population, the mortality in the cage has beenremarkably low. Since its inception, only one Nile MonitorVaranus niloticus has died.46 IGUANA  •  VOLUME 14, NUMBER 1  •  MARCH 2007 MURPHYEditor’s RemarksThis is the complete, edited text (e.g., capitalized formal common names, insertion of current scientific names when theydiffer from the original) of the first major publication by James Murphy of the Dallas Zoo, whose profile appears elsewherein this issue. Although relatively recent compared to other studies we have highlighted in this section, this article was animportant milestone.Zoos used to be dismal places. They began as places of entertainment, and animal welfare, conservation, and researchwere not a part of their missions. That eventually began changing, but reptile departments were not at the forefront of thisprocess. The 9th issue of the International Zoo Yearbook (IZY), in which this article appeared, was the first to have a her-petological focus. Other articles examined thermal requirements of captive reptiles (following on the work of Cowles andBogert, which we featured in Iguana 13(1): 53–61), reported on lighting and humidity, and described captive reproduc-tion and incubation techniques. Species covered were primarily large: crocodilians, tortoises, constrictors, iguanas, andmonitor lizards. Most articles were shorter than Murphy’s, and few had references. Zoos were beginning to emphasize schol-arship, and Murphy was a leader in applying this to herpetological collections.Things have changed dramatically over the ensuing decades. The IZY has had a number of herpetologically themedissues over the years, and these reflect the increasing sophistication of zoo research. Some leading zoos (including the DallasZoo, whose herpetological publications can be seen at http://www.dallaszoo.com/oth/oth.asp?page=spubs#reptiles), nowinclude studies of natural habitats and their conservation in their mission. This modest paper led that change.Gad PerryTexas Tech UniversityProducts mentioned in the text: Ken-Rad, Owensboro,Kentucky, USA; Pervinal, US Vitamin andPharmaceutical Corporation, Veterinary ProductsDivision, New York, USA; Cosa-terramycin, CharlesPfizer and Company Inc., New York, USA; Roccal,Winthrop Laboratories, New York, USA.Readers should recognize that combining different speciesin one enclosure is a risky proposition. Behavioral triggersthat cannot be anticipated may result in aggression lead-ing to injury or death of some animals. With very fewexceptions, such practices are not recommended.Iguana 14.1 b&w text.QX6  2/25/07  10:46 PM  Page 46

Notes on Iguanids and Varanids in a Mixed Exhibit at Dallas Zoo

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Notes on Iguanids and Varanids in a Mixed Exhibit at Dallas Zoo

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