Abstract # 39:

Scheduled for Thursday, June 19, 2008 05:00 PM-07:00 PM: Session 4 (Ball Rooms A and B) Poster Presentation


HAIR CORTISOL CONCENTRATIONS IN TONKEAN (Macaca tonkeana) AND RHESUS (M. mulatta) MACAQUES, TWO SPECIES WITH DIFFERENT LEVELS OF SOCIAL TOLERANCE

K. Jani1, A. M. Dettmer1, S. J. Suomi2, M. F. S. X. Novak2, B. Thierry3, A. Timme3, J. S. Meyer1,4 and M. A. Novak1,4
1Neuroscience & Behavior Program, University of Massachusetts, Amherst, MA 01003, USA, 2Laboratory of Comparative Ethology, National Institutes of Health (NICHD), Poolesville, MD, 20837, USA, 3Département Ecologie, Physiologie et Ethologie, IPHC, CNRS & Université de Strasbourg, France, 4Department of Psychology, University of Massachusetts, Amherst, MA, 01003, USA
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     The genus Macaca includes 22 species of old world monkeys that vary in aggressiveness and the extent of dominance asymmetry. Rhesus macaques show high levels of nepotism, asymmetrical aggressive interactions, and low rates of reconciliation whereas tonkean macaques exhibit little nepotism, symmetrical aggressive interactions and high levels of reconciliation. In Thierry’s recent scaling of macaque social styles (Thierry, 2007), rhesus macaques are placed in grade 1 (least socially tolerant) and Tonkean macaques are placed in grade 4 (most socially tolerant). We examined the relationship between social dynamics and chronic cortisol levels as measured in hair samples collected from tonkean (n=36) and rhesus macaques (n=26) maintained in large social groups in outdoor corrals. Both groups were further divided into adults (>5 years) and juveniles/adolescents (1-5 years). Overall, tonkean macaques had higher cortisol concentrations than rhesus macaques [ANOVA; F(1,54)=19.85; p<0.001], and for both species, cortisol concentrations in juveniles/adolescents were higher than the levels in adults [F(1,54)=7.24; p=0.009]. Age was negatively correlated with cortisol level in rhesus macaques [Pearson r(24)=-0.59; p=0.002] and marginally correlated in tonkean macaques [Pearson r(34)=-0.33; p=0.053]. Our results provide the first evidence that chronic cortisol levels vary in different macaque species. Such variation may, in part, be related to species differences in social dynamics.