Meeting Abstract
In many tetrapod groups, manual and pedal grasping is crucial for locomotion, reproduction, and acquisition of resources. Studies on locomotion of grasping arboreal lizards in terms of manual and pedal torques are absent from the literature. This study employs biplanar high speed videography and a custom designed, segmented, instrumented branch that can measure 3D forces and torques with resolution of 0.01 N and 0.001 N·m, respectively. Closely related pairs of lizard species from four major clades are being examined. In each pair, one species is primarily a ground dwelling lizard with some climbing ability and the other is a branch specialist lizard (BSL). A comparison of these lizards may help in answering the question of how reptile arboreal specialists move along a branch without falling. During locomotion along a branch, the center of mass (CoM) oscillates from left-right. If the CoM is not directly above the branch, the lizard must reposition the CoM above the branch, expend energy to hold the position, or fall. In this study, a few hypotheses are being tested: 1. BSL CoM forward velocity will be significantly slower during locomotion, 2. BSL will employ out-of-phase left-right tail movements to assist in repositioning the CoM above the branch, and 3. BSL will use grasping torques to assist in repositioning the CoM. The goal of this study is to shed light on the structure-function relationships of grasping appendages during branch locomotion in reptiles. This study may help further future work on understanding mechanisms for balance, control, and propulsion of tetrapods on narrow substrates.
