Meeting Abstract
Glucocorticoid hormones are dynamic and flexible, and can promote appropriate behavioral responses following predictable perturbations in an animal’s environment. However, climate change is expected to increase the frequency of unpredictable weather in many habitats, and little is understood about how organisms respond to unpredictable changes in their environments. We will explore how glucocorticoids may serve to cope with unpredictability in rainfall—a key driver of insect availability—by comparing the glucocorticoid profiles of superb starlings (Lamprotornis superbus) sampled across 9 populations in Kenya. Our intra-specific endocrine dataset allows us to disentangle the effects of environmental conditions from unpredictability in these conditions, because the populations we studied differ independently in total annual rainfall and the unpredictability of rainfall they experience. Additionally, we sampled each population under two types of conditions (i.e. regular year vs. El Niño year), which enables us to tease apart the effects of short-term weather from long-term environmental conditions on glucocorticoid profiles. We highlight the importance of intra-specific studies in evolutionary endocrinology research, as these allow us to better unravel the relationships between hormones and various environmental variables that otherwise co-vary on a global scale.
