Acute, short-term effects of early-life stress and associated glucocorticoid upregulation on physiology and survival are widely documented across vertebrates. However, the persistence and severity of these effects are largely unknown, especially through the adult stage and for natural systems. Here, we investigate effects of post-natal glucocorticoid upregulation across the nestling, juvenile, and adult life stages in house sparrows (Passer domesticus). We manipulate circulating corticosterone (the primary avian glucocorticoid) concentration in wild, free-living house sparrow nestlings and monitor body size, body condition (i.e., scaled mass index), and survival in a captive environment until adulthood. We also test juvenile and adult birds for evasive behavior in response to a direct "predator" threat, simulated by human capture in their home cage.
Results/Conclusions
We find that early-life corticosterone exposure depresses nestling body condition in both sexes, with no strong effect of the treatment on body size. This effect largely disappears in juvenile and adult birds, suggesting that house sparrows are able to compensate for negative effects of high early-life corticosterone exposure on body condition. Corticosterone treatment had no effect on nestlings survival, however, we detected a negative effect on survival through one year of age. Additionally, early-life corticosterone treatment had a delayed effect on evasive behavior: evasive behavior was depressed in adults but not juveniles, and influenced by current body condition. These results highlight the importance of state-behavior interactions and life stage in assessing long-term effects of early-life glucocorticoid exposure, and suggest that long-term compensation for negative early-life "stress" experience comes at a price.