Habitat use by an endemic and a non-native gecko: natural habitat provides a last refuge for the Barbados Leaf-Toed gecko

Abstract

Island endemic reptiles face many threats that potentially have a negative effect on their conservation status, such as habitat loss, interactions with introduced predators and competitors, and stochastic environmental events. Since confirmation of the continued existence of the Barbados Leaf Toed gecko (Phyllodactylus pulcher) on the island of Barbados, West Indies, efforts have been made to increase ecological knowledge of the gecko in order to inform conservation direction and safeguard this critically endangered endemic species. The present study is the first to determine the microhabitat use of P. pulcher and that of the non-native gecko Hemidactylus mabouia on Barbados, and makes comparison to patterns of displacement of native geckos following Hemidactylus spp. invasions seen elsewhere. Factor Analyses of gecko locations and habitat data collected during night-time surveys indicated a strong non-random selection by P. pulcher for structurally diverse, rock habitat with an abundance of natural crevices. Where H. mabouia is present in natural habitat along the Barbados coast, the species also selected for exposed rocky habitat, albeit to a significantly lesser degree than did P. pulcher. Measures of body condition suggest the non-native gecko is less able to exploit such habitats and that its ability to thrive on Barbados is due to utilisation of a broader niche as befitting a habitat “generalist”, rather than competitive displacement of the native gecko from cliff side habitat. Our findings highlight the importance for protection of the remaining natural cliff side habitat and promotion of biosecurity on Barbados as being key to the survival of P. pulcher.