Abstract # 126:

Scheduled for Friday, June 22, 2007 05:00 PM-07:00 PM: Session 14 (South Main Hall) Poster Presentation

Salivary cortisol and self-directed behavioral responses to short-term crowding in hamadryas baboons (Papio hamadryas hamadryas)

B. L. Pearson1, P. G. Judge1,2, D. M. Reeder1,3 and L. Smart1,3
1Bucknell University, Animal Behavior Program, Lewisburg, PA 17837, USA, 2Psychology Department, 3Biology Department
     Induced proximity to conspecifics through reduction of space increases the risk of agonistic interactions. Accordingly, behavioral indicators of stress or anxiety, such as self-directed behavior (SDB), often increase under crowded conditions. However, changes in physiological indicators of stress, such as glucocorticoid activity, have not been examined during crowding in primates. Non-invasive saliva samples and focal observations were collected from a group of 20 baboons housed in an indoor/outdoor enclosure before, during, and after a four-day restriction to indoor housing in order to assess concurrent changes in these indicators. Fifty saliva samples from 9 subjects were assayed for cortisol using enzyme-immunoassay. Trend analysis indicated that mean±se cortisol levels were elevated during crowding (27.10±2.48 ng/ml) compared to samples collected before (14.85±2.15 ng/ml) and after (20.89±2.15 ng/ml) crowding [F(1,8)=10.71, p=0.011]. 5.7 hours of focal data were collected under each condition on 17 baboons. ANOVA indicated that rates of SDB (self-touching, scratching, body shaking, autogrooming, and manipulating) did not differ across conditions for the 17 subjects sampled [F(2,32)=0.78, p=0.466], or for the subset of subjects sampled for cortisol [F(2,16)=0.17, p=0.847]. Crowding resulted in elevated cortisol indicating greater metabolic costs of maintaining homeostasis under stress, but the response was not accompanied by increases in behavior commonly used as indicators of stress. SDB may not be a sensitive index of stress or may assess affective states qualitatively different than biological stress.