Meeting Abstract

9.3  Jan. 4  Cracking the weevil: behavioral plasticity of feeding as a function of prey hardness in the collared lizard HENNINGSEN, J.P.*; LAPPIN, A.K.; NISHIKAWA, K.C.; Northern Arizona University; Northern Arizona University; Northern Arizona University jhenning@nsm.umass.edu

A number of studies have demonstrated that lizards modify their feeding behavior based upon prey characteristics. However, in their experimental design, few of these studies have considered natural prey items. Collared lizards (Crotaphytus collaris) provide a system for examining the effects of the hardness of prey on feeding behavior, as they regularly consume hard prey, particularly curculionid beetles (weevils). The diet of C. collaris also includes orthopterans, including gryllids (crickets). We used crushing tests with a force transducer to measure prey hardness and high-speed digital imaging (250 fps) of feeding sequences to examine the effects of prey hardness on feeding (i.e., prey processing) behavior. We found that (1) curculionids require an order of magnitude more force to crush than crickets, and (2) curculionids induced longer processing times and greater numbers of processing bites than did crickets. Studies that focus on natural extreme behaviors, such as this one, provide a powerful empirical basis for the study of adaptive morphological and behavioral evolution.