Meeting Abstract

42.5  Saturday, Jan. 5  Losing Stability: Tail loss and jumping in the lizard Anolis carolinensis BONVINI, LA*; IRSCHICK, D; GILLIS, GB; Mount Holyoke College; Univ. of Massachusetts, Amherst; Mount Holyoke College ggillis@mtholyoke.edu

Lizard tails are functionally versatile and play critical roles in energy storage, balance, and sexual display. However, in many species the tail can also be instrumental in predator distraction and escape via self-amputation, or caudal autotomy. Despite numerous studies of the costs of tail loss in lizards, none has focused on the importance of the tail in jumping. To examine whether the tail is important during jumping we studied body and tail kinematics during takeoff and flight in the arboreal lizard species Anolis carolinensis. Markers were placed along the body and tail of six lizards and high-speed digital video was used to capture four jumps from each animal before and after manually-induced tail loss. Jump distance, takeoff velocity, and takeoff angle, were measured for every jump. In addition, body angle relative to the horizontal and the angle of the tail base relative to the body were characterized throughout the jump. Tail loss had no significant effect on jump distance, takeoff duration, or takeoff velocity. In contrast, caudal autotomy had a clear effect on body angle in flight. Animals with tails rotated 13&deg posteriorly on average between takeoff and landing, as compared to 40&deg of rotation for lizards without tails. In fact, more than half the jumps recorded post-autotomy ended with lizards landing at body angles of greater than 45&deg, while fewer than 10% of jumps pre-autotomy resulted in angles of this magnitude at landing. Such exaggerated posterior rotation of the body in tail-less lizards likely prevents coordinated landing, which is critical in animals that spend much of their time on relatively small branches. Thus, caudal autotomy appears to have significant costs in relation to jumping locomotion in this species.