Abstract # 4264 Poster # 42:

Scheduled for Thursday, June 21, 2012 07:00 PM-09:00 PM: Session 9 (Gardenia) Poster Presentation


DYADIC AGE DYNAMICS PREDICT THE LIKELIHOOD OF INSUBORDINATE AGGRESSION AMONG FEMALE RHESUS MACAQUES (MACACA MULATTA)

S. K. Seil1, D. L. Hannibal1, B. A. Beisner1,2, M. E. Jackson1, A. L. Heagerty1 and B. J. McCowan1,3
1University of California, Davis, California National Primate Research Center, One Shields Ave, Davis, CA 95616, USA, 2Department of Anthropology, Pennsylvania State University, University Park, PA, USA, 3Department of Population Health & Reproduction, School of Veterinary Medicine, UC Davis, Davis, CA, USA
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     Among rhesus macaques, contra-hierarchical aggression may occur between animals with shifting or ambiguous ranks, or those whose relative ranks are well established. Factors that influence the latter case (termed “insubordination”) are not well understood and are of interest because high rates of insubordination may reflect group instability. We hypothesize that among female dyads with well-established dominance relationships, the likelihood of insubordination is influenced by the age of both opponents. Multivariate analysis of 13091 aggressive interactions between female dyads from six captive rhesus groups shows that age dynamics predict the likelihood of insubordination. Young adults (4-8yrs) are more likely to receive insubordination than mature adults (8-16yrs) or seniors (>16yrs) (predicted likelihoods: young = 0.08, p <0.001; mature = 0.04, p <0.001; senior= 0.06, p=0.095). Furthermore, mature adults and seniors are more likely to be insubordinate than young adults (predicted likelihoods: young=0 .04, p <0.001; mature= 0.07, p <0.001; senior=0 .09, p <0.001). These results suggest that females of all ages assess their competitive ability with respect to their opponent’s age, or perhaps factors correlated with age, such as physical capability, social capital, or experience. Further analyses will attempt to tease apart these potentially correlated variables. Understanding determinants of insubordination will contribute to management practices aimed at maintenance of group stability, as the ultimate act of insubordinate aggression, social overthrow, poses a major welfare and management problem.