Meeting Abstract
Correlations between environment and phenotype are often attributed to the ability of individual organisms to alter labile traits in response to environmental conditions. Most previous discussions of labile traits and phenotypic plasticity have focused on the average phenotypic response of populations across environments; however, focus has recently shifted to how variation among individuals in both average responses (reaction norm intercepts) and direction and magnitude of plasticity in individual phenotypic responses (reaction norm slopes) can influence population level patterns. Yet, despite the torrent of recent studies illustrating significant variation among individuals in plasticity across multiple discrete environments, no study to date has analyzed the effects of treatment variance on either among- or within-individual variation. We quantify individual variation in prey anti-predator behavior in response to varying magnitudes of predator temporal variation using a crayfish (Procambarus sp.), bluegill (Lepomis macrochirus) and freshwater snail (Physa acuta) system. Physa were exposed to indirect chemical cues of predation risk from either crayfish or bluegill for 12 consecutive days and their behavior recorded for 5 hours post exposure. Treatments altered the pattern in which these cues were administered so that snails experienced different levels of environmental variation. We model the time dependence and magnitude of Physa anti-predator behavioral responses and quantify among- and within-individual variation in behavior in response to environmental variation. Higher environmental variation decreased individual variation in behavior by homogenizing anti-predator responses. Increased environmental variation also reduced time to mortality in the presence of lethal predators and altered oviposition site choice by prey.
