Meeting Abstract
Environmental cues are translated into functional responses via glucocorticoid hormones (corticosterone or cortisol). Across taxa, maternal glucocorticoids have been hypothesized to act as a signal to offspring of local environmental conditions resulting in changes in offspring physiology and behaviour. However, results of studies of the prenatal transfer of glucocorticoids have been inconsistent. We manipulated adult female tree swallows pre-egg laying using subcutaneous silastic implants filled with corticosterone (the dominant glucocorticoid in birds) or empty implants (controls). Nestlings were monitored from hatching until fledging and various morphometric measurements were taken. To examine the interaction between maternal treatment and an ecologically-relevant stressor, we monitored nestling baseline and stress-induced corticosterone levels before and after food-deprivation. Nestling behavioural response to an isolation stress was also measured. The contribution of elevated maternal corticosterone to phenotypic variation in offspring will discussed in light of maternal matching.
