Behaviour 2019
The Influence of Drought on Fecal Corticosterone and Dispersal-related Behaviors in Wild Peromyscus boylii
Madeline Strom1, Rebecca Berg2, Karen Mabry1. 1New Mexico State University, Las Cruces, NM, United States; 2Amazon, Seattle, WA, United States

Associations between behavioral attributes or hormonal profiles and dispersal phenotypes are common across vertebrate taxa. More bold, exploratory, or active individuals tend to disperse farther or at a higher frequency compared to more shy and less active individuals. Corticosterone may influence dispersal decisions by enhancing dispersal-related behaviors, and these relationships can be mediated by ecological pressures. Here, we tested the hypothesis that dispersal-related behaviors are influenced by the interaction of corticosterone and drought in wild brush mice (Peromyscus boylii). Boldness, activity, and response to a startle was measured using video-recorded open field, social odor, and startle tests. We collected fecal samples to quantify fecal corticosterone metabolites (FCM). Previous work from this system suggests that juveniles are bolder and less responsive to startle than are adults, and that activity is associated with FCM. We predict that that these relationships will differ between dry and wet years. Our results contribute to understanding potential proximate mechanisms that mediate dispersal decisions or behaviors under varying ecological pressures.