Abstract # 39:

Scheduled for Saturday, August 26, 2017 06:00 PM-08:00 PM: (National Ballroom AB) Poster Presentation


SEX DIFFERENCE IN THE IMPACT OF DOMINANCE CERTAINTY AND RANK ON HAIR CORTISOL CONCENTRATIONS IN RHESUS MONKEYS (MACACA MULATTA)

J. J. Vandeleest, S. Winkler, B. Beisner, D. Hannibal, R. Atwill and B. McCowan
University of California-Davis, California National Primate Research Center, One Shields Avenue, Davis, CA 95616, USA
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     Both rank and dominance certainty have been associated with biomarkers of health. Recent research suggests the effects of rank and dominance certainty may be sex dependent, potentially due to differences in how rank is attained. To explore the influence of sex in dominance relationships we used the Perc package in R to calculate dyadic dominance probabilities for all animals which were used to calculate (a) rank order, (b) average dominance certainty with females, and (c) average dominance certainty with males to explore their influence on hair cortisol concentrations (HCC). Event recording of aggressive interactions was done over 6 weeks on three large outdoor social groups of rhesus macaques (N=252) at the California National Primate Research Center, and hair was collected during the 5th week of observation. A best fit generalized linear model was selected based on AIC. Results indicate that low-ranked animals had higher HCC than high-ranked animals (alpha=0.05). Effects for dominance certainty were more complicated. Animals whose relationships with males in the group were highly certain had higher HCC. In contrast, animals whose relationships with females were ambiguous showed higher HCC, but only for males. There was no impact of dominance certainty on HCC among females. These results support the idea that dominance certainty impacts physiology, but highlights the fact that effects of dominance certainty may differ between males and females in important ways.