Cyclura rileyi ssp. cristata
|Scientific Name:||Cyclura rileyi ssp. cristata Schmidt, 1920|
See Cyclura rileyi
|Red List Category & Criteria:||Critically Endangered B1+2e, C2b ver 2.3|
|Assessor(s):||Carter, R.L. & Hayes, W.K.|
|Range Description:||This subspecies occurs on only a single island, White (Sandy) Cay, in the southern Exumas of the Bahamas. This island is small, comprising about 25 ha (Schwartz and Carey 1977). The iguanas were probably much more widely distributed during the last ice age when many of the Exuma Cays were presumably connected due to lower sea levels. They possibly occupied additional adjacent cays in recent centuries but, if so, have vanished without a trace.|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The island can support only a limited number of iguanas. According to Lincoln-Peterson surveys conducted in 1997, the size of the population has been estimated at 150 to 200 individuals.|
Only one small sub-population remains and illegal wildlife smugling has been confirmed.
|Habitat and Ecology:||Except for informal visits mainly to collect specimens, this isolated subspecies has been largely ignored by scientists. Essentially nothing has been published about its ecology or natural history.|
Illicit smuggling and the possibility of introduced animals are likely the greatest threats to this population. From photos that appeared in the April 1994 issue of a popular reptile magazine, it is clear that at least some C. rileyi, potentially from White Cay, have been recently smuggled. At least eight individuals of C. rileyi, presumably of this subspecies, were discreetly exhibited in the showrooms of several Florida reptile wholesalers in 1993 (R. Ehrig pers. comm.), which suggests that more than a trivial number of animals were taken. Another potential threat is inbreeding depression due to centuries or longer of effective isolation.
In 1996 the footprints of a raccoon were observed on White Cay. It may have dispersed there on its own after several were formerly introduced to nearby Hog Cay. Although that animal has since been confirmed dead, it appears to have predated a significant proportion of the iguana population, particularly juveniles and females. Black rats formerly threatened the iguana population, but have since been removed from the cay.
|Conservation Actions:||A grant from the Chicago Zoological Society has facilitated eradication of black rats from White Cay. The project was a collaborative effort of the West Indian Iguana Specialist Group, the Bahamas National Trust, the Bahamas Department of Agriculture, and Zeneca Agrochemicals, Inc., which donated the rodenticide used in the eradication. Two cays that appear promising as potential sites for establishment of a second wild population of the White Cay iguana have been identified. Although they have yet to be surveyed on the ground, both look appropriate from the air, both are Crown land, and both have active seabird nesting colonies, a good sign that introduced predators are absent. W. Hayes and R. Carter visited White Cay in 1996 to obtain blood samples and other measurements from the iguanas and to evaluate their status.|
|Citation:||Carter, R.L. & Hayes, W.K. 1996. Cyclura rileyi ssp. cristata. The IUCN Red List of Threatened Species 1996: e.T6046A12358978.Downloaded on 18 December 2017.|