Prey Capture Behavior in the Blue-Tongued Skink, Tiliqua scincoides

Abstract

Squamate prey capture evolved in two general directions; one toward an emphasis upon lingual prehension and the other toward an emphasis upon jaw prehension. In basal squamates (Iguania) lingual prehension characterizes prey capture. All other squamates (Scleroglossa) tend to use their jaws for prey prehension and the role of the tongue as a prehensile organ is reduced. However, within some scleroglossan lizards, lingual and jaw modes of prehension are present Selection of a distinct prehension mode during a feeding bout in these lizards has been hypothesized to be related to prey size. To test for the presence of lingual prehension and correlation with prey size, we examined feeding behavior in the blue-tongued skink, Tiliqua scincoides using two prey types (mealworm and cricket). We confirmed that this skink uses both lingual and jaw modes of prehension with accompanying characteristic jaw kinematic profiles. With crickets, only jaw prehension was exhibited, but both modes were used when feeding on equivalently sized prey, mealworms. Consequently, prehension mode is not exclusively elicited by prey size. We, therefore, hypoth- esize that selection of prehension modes, lingual or jaws, in these basal scleroglossans also includes prox- imate factors related to prey behavior.