Size-based variation in antipredator behavior within a snake (Agkistrodon piscivorus) population

Abstract

Variation in an animal's response to a predator likely reflects the complex interaction of factors that influence predation risk. Due to their high degree of behavioral variation and simplified bauplan, snakes offer a unique model for investigating the influence of sex and body size on antipredator behavior. We examined variation in antipredator behavior within a cottonmouth (Agkistrodon piscivorus leucostoma) population. Behavioral responses to human-induced predation risk were compared across a continuous scale of body size. Defensive responses significantly declined with increasing body size. After controlling for body size, no differences between the sexes were detected. Although this study suggests that variation in antipredator behavior is, in part, related to body size, some studies on snakes have not found this relationship. Likewise, some studies have demonstrated differences between sexes. Such disparate patterns of variation indicate a need for future comparative studies examining the complex interaction of factors that may influence predator–prey relationships.