Isosexual social group formation for environmental enrichment in adult male Macaca mulatta (2003)

Alexander, S. N., Fontenot, M. B.

Abstract

Isosexual groups [averag group size: 4.2 animals] of 80, previously single-caged 4-10 years old male rhesus macaques were formed [group formation protocol is not outlined]. Thirty-one [38.8%] of these animals had at least one prior incidence of SIB [self-injurious biting]. .. During the year prior to group formation, the clinical history of the subjects included a 20% incidence of diarrhea, 1.0% incidence of wound infection and 12.5% incidence of severe SIB requiring pharmacological intervention and wound care. Animals with severe SIB were treated pharmacologically for 2-11 months prior to group formation. All of these cases were removed from treatment prior to group formation. Over the 4-month period post formations <5.0% of the animals were removed for treatment of minor fight wounds. Less than 2.0% of the animals were removed for clinical purpose (e.g., diarrhea, dehydration). No occurrence of severe SIB was noted. We concluded that the formation of isosexual social groups is a suitable alternative to individual housing of adult male rhesus monkeys and may decrease the occurrence of SIB in a susceptible population.