Ecology of the Endangered Sandy Cay Rock Iguana, Cyclura rileyi cristata, in the Bahamas

<p>In this thesis I present the results of a study on the population demographics and home range size of <em>Cyclura rileyi cristata</em>. There are eight species of West Indian rock iguanas, genus <em>Cyclura</em>. All are endangered, including <em>C. rileyi</em>which is endemic to the Bahamas. One of three recognized subspecies, <em>C. r. cristata</em>lives on a single cay in the Exumas chain and is among the most endangered lizards in the world. Various size measurements indicate that this taxon is among the smallest within the genus. Distance surveys and a Lincoln-Petersen estimate based on resightings of marked iguanas suggest that the total population is comprised of 134-204 animals. In contrast to other populations of <em>C. rileyi </em>sampled by similar means, the sex ratio was highly skewed toward male iguanas (95% of noose captures). Thus, as few as 10 female iguanas may remain in the population. Glue-traps set near burrows proved to be more effective than noosing for the selective capture of females. However, no females of reproductive size were captured. Three non-native mammals were found on Sandy Cay, including rats <em>(Rattus rattus), </em>mice (probably <em>Mus musculus</em>) and a single raccoon (Procyon lotor). Several estimates based on capture rates and resighting ratios suggested that the raccoon inflicted considerable mortality on adult iguanas (35-67% between 1996 and 1997). Comparisons of density among rat-infested versus rat-free populations and attacks observed on lizard models suggest that rats negatively impact<em> C. rileyi </em>populations. Home range estimates based on radio-tracking of iguanas showed highly variable home range sizes that, in males, may exceed those of other <em>C. rileyi </em>populations. Remarkably few social interactions were observed, which was probably a consequence of low population density. Based on these findings, I offer several recommendations for the conservation of this critically endangered lizard, including translocation and captive headstarting programs to begin a new population and formal protection of the island as a National Park.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Biology

Year

2001

Author dc:creator

• Fry, Shawn Kendall

Contributors dc:contributor

• William K. Hayes
• Ronald L. Carter
• David L. Cowles

• Biology
• Iguanas -- ecology -- Bahamas; Cyclura Carinata.

Statement dc:rights

• This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Language dc:language

English

Repository record dc:identifier

https://scholarsrepository.llu.edu/etd/583

OAI identifier oai:identifier

oai:scholarsrepository.llu.edu:etd-1730