ELSTROTT, J.*; IRSCHICK, D. J.; Tulane University; Tulane University: Evolutionary correlations among morphology, habitat use, and clinging performance in Caribbean Anolis lizards

A central issue in evolutionary biology concerns whether morphology, performance, and habitat use have co-evolved. We investigated evolutionary relationships among the size of the subdigital toepad, clinging ability, and perch height in 12 species of Caribbean Anolis lizard species. Specifically, we predicted that (1) because larger anole species tend to perch high in the canopy, both toepad area and clinging ability should scale with positive allometry to enable small and large lizards to possess approximately similar ratios of both variables relative to mass. (2) Anole species with relatively larger toepads (i.e., size-adjusted) should be relatively better clingers compared to species with relatively small toepads. (3) Species with relatively large clinging abilities should perch high in the canopy (either on an absolute or size-adjusted basis). Our first hypothesis was refuted, as both toepad area and clinging ability scaled close to isometry (0.67) relative to mass, indicating that large lizard species have low ratios of clinging ability divided by mass compared to small lizard species. However, our second and third predictions were confirmed. Anole species with relatively larger toepads were relatively better clingers compared to species with relatively smaller toepads. Finally, anole species that perched high in the canopy (either on an absolute scale, or relative to size) tended to have relatively larger toepads and greater clinging capacities compared to species that perched lower in the canopy. These data provide indirect comparative evidence that the evolution of increased toepad size in some anole species is adaptive, by facilitating the occupation of perches high in the canopy.