THE RELATIVE IMPORTANCE OF VISUAL AND CHEMICAL CUES FOR FORAGING IN NEWBORN BLUE-STRIPED GARTER SNAKES (THAMNOPHIS-SIRTALIS SIMILIS)

Although vision is known to be important for natricine snakes that specialize in aquatic predation, its relative importance for those species having more general diets is not clear. In this study, I experimentally manipulated exposure of newborn blue-striped garter snakes (Thamnophis sirtalis similis) to a) different combination of visual and chemical cues and b) aquatic prey that differed in their visibility to snakes. Visual cues, in the absence of chemical cues, were insufficient to elicit foraging although were important in successful capture of prey. These results support earlier observations that visual cues are not involved in eliciting attacks but may serve to orient attacks elicited by chemical cues.