HAYWARD, L.S.; WINGFIELD, J.C.; Univ. of Washington, Seattle; Univ. of Washington, Seattle: Maternal Corticosterone Slows Chick Growth and Increases Adult Stress Response

In all vertebrates levels of circulating gluccocorticoids rise in response to perturbations ranging from food shortage to encounters with predators to infection. We experimentally elevated the primary avian gluccocorticoid, corticosterone, in laying Japanese quail to levels experienced naturally in response to capture and restraint, and found concentrations of maternal corticosterone in egg yolk to more than double. Chicks that hatched from eggs laid by females with elevated corticosterone grew more slowly than controls, suggesting an organizational role of maternal corticosterone in offspring development. Also, after reaching sexual maturity, offspring of females with elevated corticosterone showed heightened activity of the hypothalamo-adrenal axis in response to capture and restraint, implying that maternal corticosterone has long-term effects on adult stress response in birds similar to effects of maternal stress in rodents. By simulating a transitory perturbation for laying birds we altered not only yolk steroid composition but also offspring development and adult phenotype. These results suggest a novel mechanism by which local environment and maternal condition alter chick growth and adult physiology in ways that may prove adaptive in a natural context.