Prey processing in lizards: behavioral variation in sit-and-wait and widely foraging taxa

Abstract

We determined the degree to which lizards process (i.e., chew) and manipulate their prey, using a phylogenetically broad sample of 12 species. Two transport and two chewing behaviors were identified. The transport behaviors included side-to-side movements and lingually mediated posterior movements of the prey. Chewing behaviors included puncture crushing and a previously undescribed behavior we term palatal crushing. Iguanian lizards (sit-and-wait predators) engaged in more palatal-crushing behaviors than autarchoglossans (widely foraging predators) did. However, iguanians also engaged in fewer cycles of chewing and transport behaviors per feeding bout. Autarchoglossan lizards used puncture crushing extensively and exhibited more variability in the sequence of behaviors used within a bout ( interspersion of transport behaviors among chewing behaviors). Three behaviors (puncture crushing, interspersion, total) were shown to be coevolving after the effects of phylogeny were removed. The variation in feeding behavior we observed between iguanian and autarchoglossan lizards parallels patterns in tongue morphology and foraging mode in these large groups. Thus, it seems likely that each represents a component of a highly integrated character complex linking feeding morphology, behavior, and ecology.