Intrinsic factors are relatively more important than habitat features in modulating risk perception in a tropical lizard

Abstract

Anti-predator responses in animals are dynamic and depend on multiple factors. However, most of our understanding about animal escape responses comes from studies which examine only a small set of factors at a time and are done over a short period of animal life spans. This limits our understanding of the dynamic nature of animal escape behaviour and the relative importance of individual factors in determining their escape behaviour. We used a repeated-measures study design to assess the anti-predator response of a wild population of a sexually dimorphic tropical lizard, Psammophilus dorsalis. We followed marked individuals throughout their breeding lifespan, repeatedly assayed their escape response and measured representative intrinsic and extrinsic factors that could modulate their escape response. Our findings suggest that intrinsic factors, such as sex and body size, influenced escape response relatively more than extrinsic factors did, such as distance to refuge and perch height. Although individual variables influenced escape behaviour, in a direction mostly consistent with predictions from optimal escape theory, the interaction between factors led to novel insights into how animals dynamically evaluate multiple and changing costs throughout their lifetime to evade predation