56.2 Saturday, Jan. 5 Feather corticosterone predicts offspring performance in a context-dependent manner LOVE, O.P.*; BOURGEON, S.; MADLIGER, C.L.; HARRIS, C.; WILLIAMS, T.D.; University of Windsor, ON; Norwegian Polar Institute, Tromsø; University of Windsor, ON; University of Windsor, ON; Simon Fraser University, BC firstname.lastname@example.org
The use of feather Corticosterone (CORT) as a measure of integrated HPA activity is rapidly increasing in integrative studies of environmental “stressors” in numerous avian species. However, we currently know very little about how biologically-relevant stressors relate to feather CORT levels and even less about whether these levels can predict meaningful metrics of fitness. We examined whether a biologically-relevant manipulation of post-natal developmental stress translated into measurable and meaningful changes in feather CORT for a sexually size-dimorphic passerine, the European starling ( Sturnus vulgaris ). Lower growth rates during the linear phase of growth and higher catch-up growth rates during the asymptotic phase predicted higher feather CORT in the larger, faster-growing males, but there was no such relationship in females. However, higher feather CORT predicted lower predator escape performance in both sexes, independent of treatment. Taken together, these results suggest that feather CORT can indeed capture variation in relevant environmental stressors, but that the context within which this stress is integrated must be well understood to appreciate what feather CORT levels mean for individual performance.