Foraging Behavior of Rhabdophis tigrinus (Serpentes: Colubridae) in a Gutter with a Dense Aggregation of Tadpoles

Abstract

Field observations were made on the foraging behavior of Rhabdophis tigrinus in a gutter where numerous Hyla japonica larvae aggregated. It seemed that not only chemical cues but also visual cues play important roles in the foraging behavior in this snake. Rhabdophis tigrinus performed predatory behaviors characteristic of generalists, not of aquatic specialists. Examinations of stomach contents revealed that froglets were the dominant prey item although tadpoles were seemingly more abundant in the gutter. It is likely that this biased predation on froglets is attributable to the differential vulnerability to predation among the developmental stages of the frog. The present observations support the idea that R. tigrinus is not well adapted to an aquatic life. Possible significance of success ratio of predatory attempt as an index is discussed. © 2002, The Herpetological Society of Japan. All rights reserved.