Meeting Abstract

117.1  Monday, Jan. 7  Corticosterone and fitness: effects of incubation temperature WADA, H*; ALLEN, NR; KRIENGWATANA, B; SCHMIDT, KL; SOMA, KK; MACDOUGALL-SHACKLETON, SA; Auburn University; University of Western Ontario; University of Western Ontario; University of Western Ontario; University of British Columbia; University of Western Ontario haruka@auburn.edu

In the recent years, there has been growing interest in how glucocorticoids mediate fitness. Two non-mutually exclusive hypotheses, the “Cort-fitness” hypothesis by Bonier et al and the “Cort-condition” hypothesis by Breuner and Hahn, posit that baseline corticosterone and/or the amplitude of adrenocortical responses should relate to fitness. However, such relationships between corticosterone and fitness-related traits will likely dependent on the developmental environment and context. To explore how developmental stress and context alter this relationship, we manipulated egg incubation temperature (36.2, 37.4, 38.4ºC) and examined the effect of prenatal stress and mate’s behavior on the relationships between stress physiology (adrenocortical responses, responses to ACTH and dexamethasone), reproductive performance, and survival in captive zebra finches (Taeniopygia guttata). Suboptimal incubation temperature had no effect on reproductive performance but lowered survival. Stress physiology did not correlate with survival but significantly correlated with several measures of reproductive performance. However, this relationship depended on incubation temperature. Days to first egg was negatively correlated with adult adrenocortical responses but only in 37.4ºC. Egg viability was linked to nestling baseline corticosterone but the direction depended on the incubation temperature. Parental behavior was not affected by stress physiology but affected mostly by the mate’s behavior. The results suggest a complex relationship between corticosterone and fitness altered by developmental stress.