Elevation in tongue-flick rate after biting prey in the broad-headed skink,Eumeces laticeps

Abstract

A postbite elevation in tongue-flicking (PETF) rate occurs in adult male broad-headed skinks,Eumeces laticeps. Males having bitten neonatal mice showed significantly higher tongue-flicking rates in the 2 min following experimental removal of the prey than did males in several control conditions. In a second experiment designed to separate the effects of tactile and chemical stimulation of the oral cavity during biting, males tongue-flicked at significantly higher rates in response to swabs bearing surface chemicals from neonatal mice than to identical swabs lacking the surface chemicals. These findings agree with previous data showing that PETF and searching movements occur in those families of lizards that can detect prey chemicals and use the tongue to do so during active foraging. The occurrence of PETF and putative searching movements supports the interpretation that PETF represents an attempt to relocate lost prey by chemosensory means. PETF was much briefer inE. laticeps than in many snakes and in a representative species from another lizard family and was not detectable after the first minute. This brevity is consistent with the prediction that PETF should be brief in squamates that feed on prey not likely to be located by scent-trailing.