Microhabitat use by a translocated population of St Lucia whiptail lizards(Cnemidophorus vanzoi)

Microhabitat use studies of translocated species are crucial to assess thei r adaptation to the new environment. A total of 42 St Lucia whiptail lizard s (Cnemidophorus vanzoi), an endemic to two islets (Maria Major, 10.2 ha ac id Maria Minor, 1.8 ha) off St Lucia in the Lesser Antilles, were transloca ted from Maria Major to Praslin Island (1.1 ha) in 1995. Three years after the release, we studied the abundance, density and distribution of the tran slocated lizard population in the prevailing five habitat types on the isla nd. Habitats varied from more exposed open grasslands to tall, continuously canopied woodlands. Although lizards were distributed throughout the islan d, some habitats were used more than predicted with respect to availability . Habitat utilization showed a seasonal shift in distribution. Line transec t sampling estimated a population of 145 +/- 23 lizards on Praslin Island. There were significant seasonal differences in estimated lizard abundance i ndicating a change in activity during the dry season. Lizard density was si gnificantly correlated with general habitat characteristics, rather than wi th any specific microhabitat variable measured. Factors affecting distribut ion (thermoregulation, food resources and competitive exclusion) are discus sed and it is suggested that habitat use during the dry season may be best explained by thermal constraint. These results will help managers choose fu ture translocation sites.