Meeting Abstract
Begging, thought to be an honest signal of an individual’s nutritional need, elicits feeding from parents. However, a parent is limited in the amount of food it can provide to its offspring, thus creating potential competition among siblings. Corticosterone (CORT), a metabolic hormone, is hypothesized to play a role in regulating a nestling’s behavior. We investigated whether increased exposure to CORT affects nestling behavior in an altricial bird, the Florida Scrub-Jay (Aphelocoma coerulescens). During nestling development, we treated one nestling per treatment nest with a twice-daily dose of exogenous CORT via an injected wax-worm. A second individual within the treatment nest received an oil-injected wax-worm. Additional non-treated jay nests were monitored to serve as controls. We monitored individual nestling and parental behavior at all nests with the use of high-definition cameras for two hours on three different days. Our results found no difference in begging rate between CORT-fed and oil-fed nestlings within a treatment nest. However, all nestlings within the nests containing a CORT-treated individual begged more than those in control nests, regardless of individual treatment. This result, repeatable across multiple years, suggests that CORT treatment of an individual alters its siblings’ behavior. Current work on this species finds that begging rate correlates with physiological stress response as an adult, suggesting that sibling interactions that influence nestling behavior may have long-term implications for an individual’s life.
