Responses to Ophiophagous Snakes by Snakes of the Genus Thamnophis

Abstract

Naive garter snakes, Thamnophis (Colubridae), were tested for responses to skin chemicals from ophiophagous snakes. Thamnophis elegans emitted a significantly greater number of tongue flicks to swabs rubbed against the skin of the kingsnake Lampropeltis getulus, an ophiophagous species, than to those from some generally nonophiophagous snakes or to blank swabs. Thamnophis sirtalis emitted more tongue flicks to swabs from the black racer Coluber constrictor, another ophiophage, than to control-snake or blank swabs. Olfactometric studies show that T. sirtalis is sensitive to airborne chemical cues from Lampropeltis, emitting more tongue flicks to the scent of this snake than to the scent of the rat snake Elaphe obsoleta or to plain air. The results from this study suggest that some of the same snake species recognized as predators by crotaline snakes are recognized as such by Thamnophis.