Meeting Abstract
The developmental environment can have pervasive and sustained effects on phenotype and performance. Environmental cues during development can induce phenotypic responses that transmit information about the post-natal environment, and are sustained across life-history stages (i.e. developing programming). Glucocorticoids are stress hormones that can act as mediators between the developmental environment and the post-natal phenotype. While many phenotypic effects of glucocorticoid exposure during development are negative, there is increasing evidence for an adaptive role in shaping the postnatal phenotype. To test this hypothesis, we examined the effect of glucocorticoids on flight performance across life-history stages in the zebra finch. Flight performance can directly influence individual fitness via avoiding bodily damage, escaping predation, mating, and foraging success. We administered the glucocorticoid corticosterone (CORT) and quantified flight performance at four life stages. We find that flight velocities during take-off were not affected by treatment for birds at 15, 28, and 60 days post-hatch (dph). However, at 100 dph CORT-fed birds had significantly higher flight velocities compared to controls. Surprisingly, we found in younger birds (15, 30 dph) that clutch size affected flight velocity; birds from smaller clutches exhibit higher take-off velocities. These data indicate an adaptive role of CORT on the postnatal phenotype, suggesting that early environment can have sustained effects on performance measures. Further, some developmental factors have stronger effects than others (e.g. brood size versus CORT treatment).
