Meeting Abstract
Anolis lizards have radiated into many ecological niches, with different ecomorphs using different types of perches. A. sagrei is a trunk-ground ecomorph that has adhesive toe pads, is quadrupedal, and mostly arboreal. However, we show that A. sagreican also run on water, yet it is unknown to what extent the species relies on this behavior in nature. Water running has been studied extensively in Basiliscus, but has never been compared to running on land. Here, we compare the locomotor performance and three-dimensional limb kinematics of Anolis sagrei running on land and on water. Our objective is to address whether A. sagrei does the same movements when running on water as when it runs on land, and if not, to understand what kinematic adjustments it makes when running on water. We used two synchronized high-speed cameras recording at 480 Hz to film A. sagrei running on a horizontal race track lined with cork board, and on water in an aquarium. We quantified locomotion by comparing kinematic and performance variables such as acceleration, velocity, duty factor, stride length, stride frequency, joint angles, and angles of the body. We found that A. sagrei had higher average and maximum velocities on land but higher maximum accelerations on water. Animals also had a lower duty factor on water than on land, so their hind limbs were lifted for more time when running on water than on land. However, stride length was consistently longer on land than on water. A. sagrei individuals also had a higher stride frequency on water than land. Our results suggest that A. sagrei lizards achieve different levels of performance and adjust their limb kinematics when running on water compared to land.
