Meeting Abstract

3.2  Saturday, Jan. 4 08:15  Nestling begging rate predicts adult physiological stress response in Florida scrub-jays (Aphelocoma coerulescens) ELDERBROCK, E.K.*; SMALL, T.W.; SCHOECH, S.J.; University of Memphis; University of Memphis; University of Memphis kldrbrck@memphis.edu

The young of altricial bird species communicate nutritional need to adults by begging. Begging is hypothesized to be an honest signal and is regulated in part by corticosterone (CORT), the avian glucocorticoid secreted in response to stressful stimuli. Increased CORT exposure during development may have programming effects that shape an individual’s adult phenotype. If begging rate represents nutritional state and is being regulated by CORT, then begging rate may be a useful indicator of the conditions that the nestling is developing under and thus may be predictive of the individual’s future phenotype. We investigated the effects of increased CORT levels on nestling begging, as well as the relationship between begging rates and an individual’s adult CORT response. We manipulated CORT levels of Florida scrub-jay (Aphelocoma coerulescens) nestlings by administering exogenous CORT on days 8-11 post-hatch to a single nestling within each treatment nest. On days 5, 8, 11, and 13 post-hatch we monitored nestling behavior at treatment and control nests using high-def video cameras. We subsequently caught the birds at either nutritional independence (~70 days of age) or 1-year of age and determined stress responsiveness with a standard capture and restraint protocol. To date, our results suggest that administration of CORT does not alter begging rate in CORT-treated nestlings although sibling competition may be masking the effect of CORT. In addition, we found a strong positive relationship between begging rate as a nestling and stress-induced CORT secretion as an adult, suggesting that early life experiences influence the development of the adult phenotype.