Abstract # 20:

Scheduled for Thursday, June 20, 2013 10:30 AM-10:45 AM: Session 1 (San Geronimo Ballroom B) Symposium


SOURCES OF INTERINDIVIDUAL VARIATION IN THE ACTIVITY OF THE HPA AXIS IN ADULT FEMALES AND INFANTS IN THE RHESUS MACAQUE (MACACA MULATTA) POPULATION ON CAYO SANTIAGO

D. Maestripieri
The University of Chicago, Chicago, IL 60637, USA
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Knowledge of the origins of interindividual variation in the activity of the hypothalamic-pituitary-adrenal (HPA) axis in free-ranging primates can be important for understanding variation in behavior, reproduction, health, and survivorship. In the rhesus macaque colony on Cayo Santiago, variation in the activity of the HPA axis is presumably the result of individual characteristics and environmental influences. Over the course of several years, we have measured fecal and plasma cortisol concentrations in over 100 adult females and infants. Data have been analyzed with correlation and regression analyses. In adult females, fecal and plasma cortisol concentrations are generally positively correlated. Data from the same females trapped in two consecutive years indicated that individual differences in plasma cortisol concentrations are stable over time. Pregnant and lactating females have higher cortisol levels than cycling females. Cortisol levels generally decrease as a function of age and are higher in middle- and low-ranking females than in high-ranking females. In addition, lactation is accompanied by a greater increase in cortisol levels in lower-ranking than in higher-ranking females. Individual differences in infants’ baseline cortisol levels and in cortisol responses to a brief separation from their mothers are in part predicted by their genotype, in part by their mothers’ cortisol concentrations, and in part by their mothers’ behavior toward them in the first few months of life.