Reproduction of the Critically Endangered Anegada Island iguanaCyclura pinguisat San Diego Zoo

Abstract

Details are given of the first reproduction of the Critically Endangered Anegada Island iguana Cyclura pinguis at a zoological facility. Two pairs of iguanas were housed indoors in enclosures measuring 3.6 m × 3 m × 2.4 m high and an additional pair was kept in a large outdoor semi-circle display enclosure measuring 12.1 m × 10.6m. Annual average temperature in the indoor enclosures ranged between 16.1 and 31.5°C, with temperature at each of the basking spots (two per enclosure) reaching as high as 65.5°C on the substrate surface. For fertile, unbroken eggs that hatched, failed to hatch or are still incubating (n= 25), average egg mass was 73.1 +4.5 g and average egg length and width were 6.9 × 0.4 cm and 4.4 × 0.7 cm, respectively. Eggs were incubated on perlite and water (at a ratio of 1:1 by mass) or vermiculite and water (at a ratio of 0.75:1 by mass), at a temperature of 30–30×2°C. Ten eggs hatched after an average incubation period of 88.1×4.1 days. Hatchlings averaged 49.4×12.8g mass and 9.7×0.4 cm SVL (snout-vent length). Average growth rates for the first 6 months were recorded as 0.67 g/day (mass) and 0.02 mm SVL/day (n= 7).