Rehrig, A., DiVincenti, L., Schery, L. A. 2014. Social housing of non-human primates in a research facility: socialisation across macaque species and sexes. Animal Welfare 23(4), 387-389.

Refinement of social housing practices is paramount to improving animal welfare in laboratory environments, especially with regard to non-human primates. Even though social housing of the same species should be considered the optimal paradigm, cynomolgus (Macaca fascicularis) and rhesus macaques (Macaca mulatta) share similar communication styles making inter-species, opposite sex socialisation a viable approach to providing social enrichment. This paper describes social housing a male cynomolgus macaque, which underwent a routine orchiectomy prior to pairing, with a female rhesus macaque for the purpose of providing social interaction for animals that otherwise would have been single housed. Once paired, the primates exhibited behaviours indicative of compatibility, including mounting, lip smacking, grooming, co-threatening and choosing to remain in close proximity. Social housing also ameliorated abnormal behaviour (eg pacing, self-directed fur-plucking) in the female macaque. Neutering male macaques, mixed-species pairing and opposite sex socialisation are all valid options for reducing the number of individually housed primates in research facilities.