Abstract # 5889 Poster # 152:

Scheduled for Sunday, September 14, 2014 07:00 PM-09:00 PM: Session 22 (Decatur B) Poster Presentation


MATRILINEAL OVERTHROWS IN CAPTIVE GROUPS OF RHESUS MACAQUES (MACACA MULATTA): A RETROSPECTIVE ANALYSIS

D. M. Sanchez1,2, R. Herman1,2 and K. Wallen1,2
1Emory University, 36 Eagle Row, Atlanta, GA 30322, USA, 2Yerkes National Primate Research Center
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     In rhesus monkey groups, matrilineal dominance hierarchies are a major component of the social structure, governing the dynamics of most social relationships. These hierarchies are kin-based, with maternal rank inheritance. Rank relationships are remarkably stable, which is perhaps why so little is known about the factors contributing to their breakdown. Matrilineal overthrows involve dramatic reordering of the social hierarchy, and in captive populations are associated with severe aggression. The present study is a retrospective analysis of 46 matrilineal overthrows spanning 19 years at the Yerkes National Primate Research Center Field Station. Groups which experienced overthrows were compared to date-matched controls. There were significant differences between specific pathogen-free (SPF) and nonSPF controls, so each group type was analyzed separately. NonSPF overthrow (OT) groups were older (p = .002), denser (p = .033), and had fewer adult males than controls (p = .041). SPF OT groups were older (p = .008), less dense (p = .060) and had a greater percentage of juvenile males than controls (p = .025). SPF OT groups experienced greater rates of OTs than nonSPF groups, and were significantly younger at the time of OT (p < .001). These results suggest that both types of groups are more likely to experience overthrows as they age, and that SPF group formation procedures may have introduced as yet unidentified factors which impact groups’ long-term stability.