Meeting Abstract

2.6  Wednesday, Jan. 4  Dancing with the tails: Comparative dynamics of caudal autotomy in geckos HIGHAM, Timothy E.*; RUSSELL, Anthony P.; Univ. of California, Riverside; Univ. of Calgary

Autotomy, the voluntary loss of an appendage in response to mechanical and/or visual stimulation, is common among diverse groups of vertebrates and invertebrates. Tail autotomy in lizards is important for distracting a predator, providing a window of time for the lizard to escape by providing the would-be predator with a dissociated source of visual stimulus. Although autotomized gecko tails can move in rhythmic and complex ways, few species of gecko have actually been examined with regard to the pattern of movement that they display, and how this might relate to ecological and morphological circumstances. To begin to explore how the tails of disparate groups of geckos move, we obtained high-speed video (250 - 500 Hz) from original autotomized tails representing five genera (Rhoptropus, Eublepharis, Tarentola, Hemidactylus and Chondrodactylus) spanning three families (Eublepharidae, Gekkonidae, and Phyllodactylidae). The initial 24 seconds of tail movement following autotomy was observed. Tail movements investigated include tail-swinging rate, tail acceleration, amplitude of tail bending, and frequency of complex flips and jumps (relative to rhythmic swings). Results reveal interesting differences between genera. All species exhibited jumps, flips, and swings. A rolling behavior, particularly when in contact with the arena wall, was observed in Chondrodactylus. Species differed in the rate of movement immediately following autotomy, and the proportion of complex movements within the initial 24 seconds following autotomy also differed between species. Finally, the magnitude of the flips was considerably greater in Eublepharis compared to the other species. The inter-specific differences are discussed in relation to differences in ecology and morphology.