Natural history, demography and dispersal behaviour of a Critically Endangered island endemic, Utila spiny-tailed iguana Ctenosaura bakeri

Ctenosaura bakeri is a Critically Endangered iguana species endemic to the island of Utila, Honduras. It is known to occur throughout the island (41 KM2 extent of occurrence), however it likely occupies less than 25% (10 KM2) of the total area as it only found in certain mangrove habitat areas. This project was started in late January 2016 and fieldwork will continue to early September 2016. We aim to provide an up-to-date estimate of population size, using capture mark-recapture methods and line transacts. Hybridization with another Ctenosaur species on the island, C. similis, is a theorized threat to C. bakeri so DNA samples are being collected from both species to investigate this and give an update to the 2008 study by Pasachnik et al. Very little is known about the nesting behaviour of C. bakeri, we are investigating this currently using radio-telemetry. We have tracked gravid females to nesting sites with some surprising results and gathered information about behaviour and home range in both females and males. The mangrove inhabited by C. bakeri, as well as their nesting sites, are under threat from increasing tourism enterprises and economic development on the island. Hunting of all iguanas, including C. bakeri, is rife throughout Utila with gravid females being particularly highly prized. Observations of hunting were made almost daily at various field sites over the breeding season (February until June). Questionnaires were given out in the community to investigate the local attitude towards the iguana species, and sought to gain insight into hunting activity on the island. This species and its habitat requires protection at a local level, with improved enforcement of existing anti-hunting laws and increased control of development. This project aims to contribute vital evidence that immediate conservation action is necessary.