Captive Management Guidelines:
Iguana delicatissima
The Lesser Antillean iguana is currently held at three institutions: Jersey Wildlife Preservation Trust (1.1.1), the Memphis Zoo (2.2), and the San Diego Zoo’s Center for Reproduction of Endangered Species (1.1). All eight adult specimens are potential founders, collected on Dominica. All of the specimens are on loan from the Ministry of Agriculture (Division of Forestry) of the Commonwealth of Dominica, and transfers or movement of adults or offspring between collections can only be done with the Ministry’s prior authorization.
The only U.S. Zoo having past experience in maintaining this species is the Philadelphia Zoo, which kept specimens collected by J. Lazell during the late 1950s. A private collector in Europe, L. Wijffels, has kept Lesser Antillean iguanas but reported that his specimens fared poorly, being very shy and reticent to feed. This fragility in captivity, at least with regard to wild caught specimens, appears to be a consistent trait. The recent acquisition of specimens by zoos has begun to shed more light on husbandry parameters appropriate for this species.
In general, basic husbandry parameters applicable to rock iguanas and common iguanas, which are well-documented in the literature, are appropriate for Lesser Antillean iguanas. The information below focuses on management considerations in which the Lesser Antillean iguana differs from most other West Indian iguanas.
Housing
Large enclosures seem to be important. The two Jersey specimens live in an area measuring 3m high x 4m wide x 3m deep, those at Memphis are maintained in a 6m x 8m x 3m enclosure, and those at San Diego in a 4m x 4m x 8m enclosure. Height is critical for providing security to the lizards, at least for the highly arboreal individuals from Dominica. Keepers can enter the cage without disturbing the iguanas as long as the enclosure is high enough to allow the lizards to roost well above intruders. When Lesser Antillean iguanas are kept in a cage too small or short to allow high roosting, the iguanas remain stressed and panic at the slightest disturbance. Equally important for cage security is the provision of adequate plantings and climbing surfaces. M. Day reports that in Dominica, Lesser Antillean iguanas rarely come to the ground, and instead move from tree to tree by way of interlocking branches in the canopy. In captivity, a few bare branches do not provide adequate tactile and visual security for Lesser Antillean iguanas. The Jersey, Memphis, and San Diego enclosures are heavily planted with tall, tree-like vegetation, such as banana, Ficus, and large Hibiscus. It is possible that these parameters may not be as important for specimens originating from more xeric islands.
Lesser Antillean iguana enclosure at the Center for Reproduction of Endangered Species, San Diego Zoo.
In Dominica, female Lesser Antillean iguanas excavate deep burrows prior to oviposition (M. Day, personal communication). This fact, coupled with the observation that most egg-laying in captivity spans several days, with eggs scattered throughout enclosures, suggests that adequate nesting sites with deep substrate may be necessary to elicit normal nesting behavior and oviposition in captives.
As for Cyclura, high intensity, full-spectrum illumination is essential for the successful captive maintenance of Lesser Antillean iguanas. This can be provided naturally in outdoor enclosures or via UV-transmitting skylights, or artificially with a combination of full-spectrum fluorescent tubes and metal halide lamps. Temperatures suitable for rock iguanas are appropriate for this species as well.
Nutrition
Wild-caught specimens are extremely particular in the foods they will accept. Favored items include sweet potato leaves, fresh figs, Opuntia fruit, papaya, grapes (especially red and black), and fresh whole cranberries. These are the best foods to offer freshly captured specimens. With patience and persistence, they will gradually begin to accept a wider variety of fruits and leaves. Captives have taken plums, lettuce, mango, cabbage, kale, collared greens, dandelion, orange, apple, banana, pineapple, and cherimoya. Many of these items are not accepted until the lizards are well-acclimated and routinely feeding on their preferred items. Unquestionably the best item to offer new captives is sweet potato leaves, made available by placing potted plants in the enclosure and allowing the lizards to graze naturally. This is usually the first, and sometimes only, food item that freshly imported captives will accept. Hibiscus (young leaves and red blossoms) and Ficus benjamina are also grazed. The food preferences of captive-born Lesser Antillean iguanas, once they become available, may prove less limited.
The native diet seems to consist almost exclusively of young vines and leaves, with some fruit in season. Field research by M. Day has included fecal analysis and stomach content studies using road-killed individuals. Results of his studies will be invaluable to better assess the suitability of the items offered to captives, and to refine the diet. Data available thus far suggest that limiting the amount of fruit may be advisable. Lazell (1973) reported observing specimens on La Désirade consuming bird eggs, carrion and Opuntia fruit, and induced semi-captives on Dominica to accept a variety of fruit, but noted that citrus and papaya were consistently ignored.
Health
Specimens on St. Eustatius were observed to harbor small, red mites on the head and around the eyes. Fecal examination of wild-caught specimens from Dominica revealed heavy burdens of strongyles and oxyurids, which were eliminated after three doses of fenbendazole (administered orally, 100mg/kg body weight) spaced two weeks apart. Necropsy results of a female housed at Memphis revealed Salmonella sp., although whether this was a contributing factor to the death of the specimen remains speculative.
Breeding
The first captive breeding of Lesser Antillean iguanas occurred on 20 May 1997, when a single egg pipped at the Jersey Wildlife Preservation Trust. No other eggs in the clutch survived. Eggs were incubated at 31°C for 73 days, on a 1:1 water to vermiculite substrate. The hatchling weighed 20g and had an SVL of 75mm (R. Gibson, personal communication). Oviposition has occurred at all three participating institutions, and copulations have been confirmed at Jersey and Memphis. In Memphis, breeding takes place in March, and eggs are laid in May and June. Except for the single viable egg at Jersey, all eggs have failed to hatch despite the fact that many were confirmed fertile. Because all captive specimens are owned by the government of Dominica, the expansion of the captive population and the placement of surplus animals will require consultation with and approval by the Dominican Ministry of Agriculture.
