Stimulus Control of Amphibious Predation in the Northern Water Snake (Nerodia s. sipedon)

The first feeding experience of a litter of water snakes in an artificial gravel pool was video-taped and described quantitatively. Over a 9 month period the visual and chemical stimulus control of feeding was investigated through the use of models, water laden with fish odor, and fish surface substances. The experiments, based on hypotheses arising from the behavioral description, examined the snakes' ability to respond to visual and chemical cues (diffuse and local) in air and when submerged. They further sought to determine whether the predatory behavior of these animals consists simply of stages governed by particular sensory modalities, or if different classes of cue are integrated.