Meeting Abstract
Individuals of the same species vary in how they react to challenging situations in order to re-establish homeostasis. These ‘coping styles’ comprise a suite of correlated behavioral and neuroendocrine traits, thought to vary on an axis from ‘reactive’ to ‘proactive’ types. Reactive individuals should be more risk-averse and flexible in their behaviors, show higher levels of stress hormones, and react strongly to environmental cues; proactive individuals should be bolder, more consistent, and show lower stress hormones and reactivity. While artificial selection experiments suggest an underlying genetic component to coping style variation, these studies have typically focused on the bimodal end product. Here, we instead estimate the quantitative genetic (co)variation in risk-related behaviors, behavioural consistency, and stress hormones in the Trinidadian guppy (Poecilia reticulata). We show that there is significant genetic variance in, and covariance among, risk-related behaviors. However, at neither the individual nor the genetic level did this behavioural variation conform to a simple ‘reactive – proactive’ continuum as posited by the original verbal models of coping styles. We find genetic variation in not only ‘baseline’ cortisol, but also in the ‘reactivity’ of cortisol production to stressors. We then show genetic variation in the consistency of behavior, indicating a heritable component to how ‘predictable’ animals are. By assessing genetic (co)variation in a multivariate framework, we present an overall view of the underlying genetic links among stress-related traits, and how this covariance structure can shape or constrain the response to selection in natural populations.
