Abstract # 136:

Scheduled for Friday, June 21, 2013 04:00 PM-04:15 PM: Session 19 (Auditorium) Oral Presentation


SOCIAL, NOT ECOLOGICAL, CONDITIONS IMPACT REPRODUCTIVE AND STRESS HORMONES IN MALE RED COLOBUS MONKEYS (PROCOLOBUS RUFOMITRATUS) IN KIBALE NATIONAL PARK, UGANDA

K. M. Milich1, R. M. Petersen2 and J. M. Bahr2
1University of Chicago, Institute for Mind and Biology, 940 E. 57th Street, Chicago, IL 60637, USA, 2University of Illinois at Urbana-Champaign
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     This study examined the effects of habitat quality, group size, and social rank on testosterone and glucocorticoid concentrations in male red colobus monkeys (Procolobus rufomitratus) living in and around Kibale National Park, Uganda. Fecal samples were collected opportunistically from 3 red colobus groups inside the park and 3 groups in unprotected forest fragments outside the park. Testosterone and glucocorticoid concentrations of 80 fecal samples from individual males were determined by radioimmunoassays and statistically compared with Mann-Whitney U tests. We tested three main hypotheses: 1) males in the park have higher testosterone concentrations and lower glucocorticoid concentrations than males in the fragments, 2) males in a large social group (120 individuals) have higher testosterone and glucocorticoid concentrations than in a small group (60 individuals), and 3) the alpha male has higher testosterone and glucocorticoid concentrations than subordinate males. There was no difference in testosterone (P=0.36) or glucocorticoid concentrations (P=0.26) between the park and fragments, in testosterone concentrations (P=0.18) between the large and small groups, or in glucocorticoid concentrations between dominant and subordinate individuals (P=0.11). However, the alpha male had higher testosterone concentrations than the other males (P=0.04; z=2.10) and males in the small group had higher glucocorticoid concentrations than in the large group (P=0.04; z=2.09). These results have important implications for understanding primate social stressors and the physiological correlates of primate social systems.