Investigating personality in venomous vipers: individual rattlesnakes exhibit consistent behavioral responses in defensive and exploratory contexts

Gibert, Ricardo G.

Maag, Dylan W.

Sanders, Lea N.

Clark, Rulon W.

Department of Biology

San Diego State University

San Diego, California USA

A burgeoning literature in animal behavior has demonstrated that most animals exhibit consistent individual variation in core behavioral traits, or personality. However, the taxonomic spread of animal personality studies is uneven, with some ecologically important and diverse taxa still unstudied. Some of these understudied groups, such as venomous snakes, are also frequent targets of mitigation due to human/wildlife conflict, and conservation researchers have been increasingly focused on developing a general understanding of how individual personality, or temperament, mediates wildlife responses to management or mitigation actions. In this study, we used 20 captive Western Rattlesnakes (Crotalus oreganus) in standardized assays to test for repeatable behaviors (i.e., personalities) between individuals and examine possible relationships in personality traits across contexts (i.e., behavioral syndromes). Repeatability of behaviors was assessed over five repeated trials consisting of a handling assay, an open field test, and a threat assay. We found several behaviors related to exploration/avoidance, activity level, and boldness/shyness showed significant repeatability. However, we found no evidence for behavioral syndromes across contexts. Our analysis shows that, similar to many other species and taxonomic groups, viperid snakes also display individual personality traits when tested under standardized conditions, and we discuss the implications of this finding for mitigation, conservation, and comparative analyses across broadly similar species groups.