Meeting Abstract
Tail autotomy is the voluntary shedding of the tail, which is often used to distract a predator or escape its grasp. While this increases the likelihood of survival during the encounter, the morphological change accompanying this escape strategy can significantly alter locomotor performance and mechanics. Although previously described on level and vertical substrates, it is unclear how autotomy impacts locomotion on uphill and downhill slopes. In their natural environment, terrestrial animals frequently move over complex terrain, and these sloped surfaces alter the demand on the musculoskeletal system. Similarly, tail autotomy alters locomotor demand due to the rapid loss of mass, cranial shift of the center of mass, and loss of tail function. Therefore, we hypothesize that shedding the tail will impact the kinematic adjustments that lizards make as they move up and down different inclines. Video was obtained for ten leopard geckos (Eublepharis macularius) walking on five inclines: level (0°), up (30° and 60°), and down (-30° and -60°) before and after the tail was autotomized. Three-dimensional kinematics of the body, fore- and hind limbs were assessed for 3-5 strides per individual for each combination of treatments. Compared to level locomotion, walking uphill or downhill resulted in reduced speed and stride length, increased stance time, and increased flexion of the joints. Autotomizing the tail negated these changes (excluding joint flexion) when walking uphill, but not downhill. On all inclines, flexion of the joints was more prominent in post-autotomy trials. These results suggest that autotomy may augment uphill locomotion, but moving downhill remains problematic. Supported by NSF IOS-1147043 and the UCR Newell Fund.
