Meeting Abstract
An animal’s response to environmental stressors may be influenced by a number of factors, including early life conditions, current phenotype, and current environmental conditions. It is well known that environmental conditions experienced during development can influence phenotypes later in life. However, it is unclear how conditions experienced early in life might influence the hormonal mediators of the response to stress across environmental and life stage contexts. Using a long-term dataset from breeding Tree Swallows (Tachycineta bicolor) that includes both natal and adult breeding records from the same individuals, we tested if environment during different stages of natal development, current environment and phenotype, or an interaction between natal environment and current environment better explained adult corticosterone levels. We focused on adult corticosterone levels during incubation and provisioning, which are energetically demanding periods during which corticosterone phenotype predicts reproductive success in this Tree Swallow population. Among incubating adults, the year of their birth and the ambient temperature during incubation in their birth year predicted baseline and stress-induced corticosterone, respectively. Among provisioning adults, our top models included adult mass and adult clutch initiation dates, but neither had a strong effect on baseline or stress-induced corticosterone. Our results indicate that natal environmental conditions are important predictors of corticosterone levels during adult incubation, and suggest that short-term changes in weather conditions during early development may have life-long impacts on the ways organisms cope with stress.
