Parental Absence Primes Hypothalamic-Pituitary-Adrenal Axis Activity In Tree Swallow (Tachycineta bicolor) Nestlings

Abstract

Parental presence has often been studied as a mechanism that regulates baseline concentrations of corticosterone (CORT). CORT is essential for regulatory processes in the body, but it also plays a role in stress response. The “social presence” of a conspecific, especially a parent, can function to maintain lower baseline concentrations of CORT. Under stressful conditions, parental attendance may alleviate stress through “social buffering,” a mechanism that serves to enhance stress response. In this context, the presence of an adult can function to alleviate the negative physiological effects of stress through a well-moderated stress response. We predicted that parental attendance would exhibit “social presence” effects which would serve as a predictor of baseline CORT. We also predicted that parental attendance would exhibit “social buffering” effects and that TRES nestlings would have elevated CORT responses when parents were excluded from the nest.