Compensation for Altitudinal Changes in the Thermal Environment by Some Anolis Lizards on Hispaniola

Populations of the Anolis cybotes species group on Hispaniola behaviorally compensate for changes in the thermal environment associated with altitude. Lizards occupy more open habitats, increase basking frequency, and restrict times of activity at high elevation: a result is that the change in mean cloacal temperature with elevation is very small relative to that known for other anoles. In contrast to this large behavioral variation among populations, physiological differences appear to be minor. In this regard, the cybotes group has several parallels with the well—studied cristatellus group of Anolis on Puerto Rico. However, the cybotes group has no equivalent to Anolis gundlachi, which employs physiological adaptations to compensate for different thermal environments.