Meeting Abstract

S3.8  Sunday, Jan. 4  Interactions between hormones and energetics as mediators of performance and reproductive success MOORE, Ignacio/T*; HOPKINS, William/A; Virginia Tech; Virginia Tech itmoore@vt.edu

How an animal performs in its natural environment ultimately determines its reproductive success. Thus, performance traits are often a target of selection, both natural and sexual. While many studies have investigated how selection acts on performance-related traits, fewer studies have examined how hormones are related to performance and ultimately reproductive success. The paucity of information on hormones, performance, and reproductive success is partially because the relationships are rarely simple. Performance traits are often mediated or influenced by multiple hormones and selection that is acting directly on the performance trait is often acting indirectly on the underlying endocrine mechanisms. We propose that, from a physiological perspective, performance and ultimately reproductive success are strongly influenced by interactions among glucocorticoid stress hormones, sex steroids, and energetics. These interactions are often two-way and may be positive or negative. For example, while reproduction is often suppressed during a stress response, baseline stress hormone levels are often elevated during the breeding season and appear to facilitate energetically expensive processes and behaviors. Here we discuss what is known about the interactions among glucocorticoid stress hormones, sex steroids, energetics, and performance traits. We emphasize that if investigators are interested in fully understanding how hormones and energetics influence performance traits and ultimately reproductive success, then investigating the complex relationships and interactions is necessary.