Abstract # 70:

Scheduled for Saturday, September 19, 2009 06:30 PM-09:00 PM: Session 5 (Mission Bay Ballroom CDE) Poster Presentation


EFFECTS OF AGGRESSION FREQUENCY AND INTENSITY ON DOMINANCE RELATIONS AMONG FREE-RANGING ADULT MALE RHESUS MONKEYS (MACACA MULATTA) ON CAYO SANTIAGO, PUERTO RICO

J. Chism and Y. Littman
Winthrop University, Dept. of Biology, Rock Hill, SC 29733, USA
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Many group-living mammals utilize dominance hierarchies as a crucial factor in establishing and maintaining the group’s social structure. Such hierarchies determine access to important resources, including food, grooming partners, and mating rights for group members. Dominance relationships have been well-studied in rhesus macaques, which have distinct dominance hierarchies for both males and females within the group. Here we investigated the effect of adult male social rank on frequency and intensity of male-male agonistic interactions [N=14] in a single social group within a large, free-ranging population at the Cayo Santiago Field Station, of the Caribbean Primate Research Center. We sought to determine whether higher aggressive frequencies or intensities are consistently associated with winning agonistic interactions. Using PCA we correlated multiple variables including age, aggression during feeding, group centrality, grooming, and proximity to assess their combined effect on overall dominance. Dominance rank and aggression frequency were inversely correlated [Pearson, alpha=0.58] and there was a weak positive correlation between dominance rank and aggression intensity [Pearson, alpha=0.09], although neither relationship reached significance. However, we found significantly positive correlations between both frequency [Pearson, alpha=0.0009] and intensity [Pearson, alpha=0.02] of directed aggression and win rates for aggressor males. These results demonstrate that dominance rank is a good predictor of outcomes of aggressive social interactions in group-living primates, while other variables also play a context-dependent role in determining overall dominance systems.