The use of ground-borne vibrations for prey localization in the Saharan sand vipers (Cerastes).

Abstract

Sand vipers of the genus Cerastes are specialized semi-fossorial snakes that launch predatory strikes at rodents and lizards while partially buried in the soft sand of the Saharan desert. This study attempted to document which environmental stimuli are used by these snakes as a trigger for the ambush behavior. Denervating the olfactory and vomeronasal organs produced no changes in prey capture behavior in Cerastes cerastes. Occluding the eyes of the denervated specimens resulted in significant decreases in strike distance, diversity of strike angle and strike accuracy, demonstrating the importance of visual stimuli for target acquisition in this species. Nevertheless, every olfactory-denervated, temporarily blinded specimen succeeded in capturing free-ranging mice in every trial. Presentation of chemosensory-neutral targets to the olfactory-denervated, temporarily blinded specimens resulted in similar predatory behaviors, whether the target was isothermic to the environment or heated to mammalian body temperature. Collectively, these results provide evidence for the importance of visual stimuli during foraging in C. cerastes, the first experimental evidence for foraging by vibration detection in snakes and the strongest evidence to date that snakes are capable of 'hearing' vibrational stimuli.