Predatory Behavior of the Snail-Eating Snake Pareas carinatus (Boie, 1828) (Squamata: Pareidae): An Ethogram Study

Abstract

We examined predatory behavior of the keeled-scaled snail-eating snake Pareas carinatus on three types of terrestrial gastropods, the fully shelled dextral snail Cryptozona siamensis, the semi-slug Durgella sp. with the substantially reduced shell, and the slug Semperula siamensis with no shell, by observations in captivity. We devised an ethogram to describe the snakes’ characteristic behaviors toward the putative standard prey Cryptozona siamensis. In three predatory phases, the snake displayed 15 serial behaviors, which could be classified into nine categories of function. After the snake fixed the eyes onto given prey, the snake took a longer time before striking but a shorter time to finish feeding on the semi-slug than on the snail. The snake stared but did not strike at the slug, and flicked the tongue more times before it discontinued staring than before striking at the snail or semi-slug. This suggests that the snake P. carinatus does not prey on a slug. Our results provide the ethological basis to investigate the ecology and evolution of predatory behavior in snail-eating snakes.
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