Social hair pulling in captive rhesus macaques (Macaca mulatta)

In this study, we examined social hair pulling, grooming, and aggression within seven groups of rhesus macaques (Macaca mulatta) (N = 319). We took weekly 30‐min behavioral observations on each group for one year to assess the patterns of hair pulling and grooming, which monkeys were receiving and initiating these behaviors, as well as aggression and other behaviors indicating dominance. We also assessed the amount of alopecia on each individual monthly. While grooming tended to be directed “up” the hierarchy (i.e., monkeys were more likely to groom animals of a higher rank than lower rank), most hair pulling was directed “down” the hierarchy. Further, hair pulling seldom co‐occurred with aggressive behaviors, suggesting that it was not a form of aggression. Hair pulling also usually resulted in ingestion of the pulled hair. Hair pulling was correlated with alopecia; monkeys who were frequent recipients of hair pulling scored higher on monthly alopecia ratings than those who were less often observed having hair pulled. Our results suggest that social hair pulling is a behavior distinct from either grooming or aggressive behavior, and that it may contribute to alopecia in socially housed macaques.
Source: American Journal of Primatology - Category: Psychiatry & Psychology Authors: Tags: RESEARCH ARTICLE Source Type: research