An aerodynamic perspective on hurricane-induced selection on Anolis lizards

Studies have demonstrated that hurricanes can drive selection in Neotropical anoles. In a recent study it was shown that post-hurricane survivors showed increased toepad areas, and surprisingly, shorter femurs. One potential explanation for the reduction in femur length is that increased drag on individuals with longer femurs causes them to be blown off their perch. Consequently, lizards with shorter femora might survive better in hurricanes. To gain insight into the form-function relationships of drag-reduction in perched lizards exposed to high-velocity winds, we quantified drag forces on Anolis lizard models in realistic grasping positions using computational fluid dynamics. We showed that overall drag, as well as the relatively high drag at the hind limbs strongly increases with the distance of the pelvic region from the perch. As optimal postures to resist sustained arboreal pulling involve extended limbs, longer hind limbs increase the chance of having the limbs and pelvi...