McCowen, B., Anderson, K., Heagerty, A. et al. 2007. Behavioral management of deleterious aggression in rhesus macaques. American Journal of Primatology 69(S1), 91. (30th Meeting of the American Society of Primatologists Scientific Program, Abstract #125)

New management strategies for detecting social instabilities and promoting social cohesion are needed to reduce aggression-based morbidity and mortality among captive groups of rhesus macaques (Macaca mulatta). This study determined the utility of social network theory for deciphering patterns of aggression and wounding in rhesus macaques. Over 37,000 observations of affiliative, submissive and aggressive activities were collected over a three-year period on about 1300 rhesus macaques housed in 13 1/2-acre enclosures. Data also were analyzed on management factors such as age/sex composition and matriline configuration that might promote aggression. Using negative binomial regression [α=0.05], results indicate that network measures such as subordination-degree (rate and diversity of subordination), displacement fragmentation (connectivity among dominance relationships) and groom reciprocity within social groups were not only significantly associated with rates of contact aggression and wounding requiring hospitalization but with the occurrence of severe aggressive outbreaks. In addition, groups with a lower proportion of adult females and a more uniform distribution of animals across matrilines exhibited significantly higher subordination-degree and lower fragmentation. Manipulating group/matriline composition may reduce the level of aggression and aggression-based morbidity and mortality. These data suggest social network measures are valuable predictors of deleterious aggression indicating that they could be used to track changes in social dynamics to detect significant instabilities, allowing managers to prevent severe outbreaks before they occur in populations of rhesus macaques.