Sleeping Behavior in Anolis limifrons and Comparison to Closely Related Species

Sleeping behavior in nonavian reptiles is understudied. In particular, studies of sleep in natural environments and explanatory studies examining sleeping site preference are rare. Here we examine sleeping-perch height and sleeping substrate use in Anolis limifrons, a widespread semiarboreal Central American lizard. We analyze our data both autecologically and combined with published data from four additional species of Anolis. We show that common factors associated with perch use in lizards, such as sex, age, and habitat quality, are not predictive of sleeping perch in A. limifrons. Statistical equivalence analyses demonstrate that males and females as well as adults and juveniles use significantly similar sleeping perches across surveyed sites and that individuals use significantly similar perches in natural and altered habitats. These results may indicate a preponderance of favorable sleeping perches for A. limifrons, spatially uniform selective forces during sleep as opposed to wakeful behavior, or/and generalist sleeping ability in A. limifrons across sex/age classes. This latter explanation may reflect diel inertia from generalist behavior while awake or generalist sleeping behavior distinct from ontogenetically partitioned wakeful behavior. Multivariate analyses of five anole species suggest that species identity is a primary predictor of sleeping-perch use in our studied anole species. Within-species variance in sleeping-perch height is comparable between A. limifrons and additional analyzed species. This result is surprising, given that the additional species show partitioning in sleeping-perch height by age and sex whereas A. limifrons does not, and the additional species are solitary rather than members of multispecies anole assemblages as in A. limifrons.