Abundance, demographics and body condition of a translocated population ofSt Lucia whiptail lizards (Cnemidophorus vanzoi)

The whiptail lizard Cnemidophorus vanzoi is a large-bodied teiid found only on two islands (Maria Major and Maria Minor), off St Lucia, West Indies. I n May 1995, 42 lizards from Maria Major were introduced to the smaller unin habited Praslin Island on the same coastline. Three years post-release, we studied abundance, demography and morphometrics of the translocated lizard population, during a 6-month period covering wet and dry seasons. Age, sex, snout-vent length (SVL), body mass (BM), tail length, tail regeneration, a nd overall condition (moulting, reproductive condition, cuts, external para sites) of 107 animals caught during the study are analysed in the present p aper. Comparisons are also made with the source population. A body conditio n index (CI (BM/SVL)), sex ratio (adult males : adult females), age ratio ( adults :juveniles), and sexual size dimorphism ratio (SVL adult male:SVL ad ult females) were calculated for the study population. Distance sampling an d mark-re-sight surveys were used to estimate population size and lizard de nsity. A total of 155 +/- 26 individuals were estimated. The lizard populat ion was found to have a high growth rate (r = 0.97-3.95). There were signif icant seasonal changes in lizard abundance. Seasonal differences in lizard numbers, BM and CI suggest either severe resource limitation during the dry season, or selective aestivation. A high frequency of tail autotomy may po int to intense intraspecific competition as the island is relatively free f rom main predators such as the black rat Rattus rattles. Sex ratio, sexual size dimorphism and sexual dichromatism all indicate a territorial species in a generally non-territorial family (Teiidae). Some adult males seem to m aintain juvenile colours. It is suggested that the introduced population ha s successfully colonized its new environment and that no significant change in the animals condition or size has occurred during the 3 years since tra nslocation.