Truelove, M. A., Perlman, J. E., Martin, A. et al. 2010. Effects of social separation on rhesus macaque (Macaca mulatta) pairs in the laboratory. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 668 (Abstract #PS52).

The benefits to nonhuman primates living in social groupings are well established. However, when certain research that requires housing subjects singly is performed, there are no guidelines as to how paired nonhuman primates should best be separated from one another. Two social separation techniques were assessed to determine whether one was more beneficial to primate wellbeing than the other. Twelve pairs of mother-reared, adolescent male rhesus macaques were randomly assigned to an experimental or control group. After an initial period of baseline observation for each group, the control pairs were separated with a solid divider, and the experimental pairs were separated first by a perforated divider (that is, social panel) providing limited social access for 1 wk, and then were separated with a solid divider. Thirty-minute focal animal scans were collected when animals were paired, socially paneled (experimental only), and separated, totaling 114 h. Drawing from social separation literature, the ethogram focused on behaviors indicating tension, despair, agitation, and protest. We hypothesized that the transitional week of limited social access would minimize the stress response following separation. Social separation resulted in a significant change in behavior (rMANOVA, F(4,19) = 6.6, P = 0.002). Monkeys displayed more despair behaviors (for example, inactivity, huddling, self-directed stereotypic behaviors, P = 0.004) and agitation (for example, manipulating their cages, performing stereotypic locomotor behaviors, P = 0.02) when they were separated compared with when they were paired. However, there was no significant influence of whether or not the animals received the transitional social panel housing prior to full separation. There was no evidence that applying a social panel eased the transition to single housing. Our results illustrate the negative impact of social separation and add to the limited literature on the effects of adolescent peer separation on laboratory primates’ psychologic wellbeing. Future work should focus on ways to minimize these adverse effects using other behavioral management techniques.