Jorgensen, M. J., Lambert, K. R., Breaux, S. D. et al. 2017. Pair housing of vervets/African green monkeys for biomedical research. American Journal of Primatology 79(1), e22501.

Vervets, also known as African green monkeys, are a nonhuman primate species widely used in biomedical research. However, there are currently few references available describing techniques and rates of success for pair‐housing this species. We present data from four cohorts of vervets from three different facilities: (i) the Wake Forest Vervet Research Colony (VRC; n = 72 female pairs, n= 52 male pairs), (ii) the University of Louisiana at Lafayette—New Iberia Research Center (UL‐NIRC; n = 57 female pairs, n = 54 male pairs), (iii) the Tulane National Primate Research Center (TNRPC; n = 18 male pairs), and (iv) a cohort of imported males (n = 18 pairs) at Wake Forest. Compatibility was measured at 14, 30, and 60 days following introduction. Success rates for pair‐housing at 14 days ranged from 96% to 98% for females and 96% to 100% for males at the VRC and UL‐NIRC but were lower in the smaller imported male cohorts (TNPRC: 50%; WF: 28%). Among the UL‐NIRC cohort and VRC male cohort, most of the pair separations after 14 days were due to reasons unrelated to social incompatibility. In contrast, a large proportion of TNPRC and imported male pairs successful at 14 days required separation within 60 days due to incompatibility. Multiple logistic regressions were performed using cohort, mean age of pair and weight difference between pair‐mates as potential predictors of compatibility at 14 days. All three predicted the 14‐day outcome in males but not females. A separate analysis in the VRC cohort found no evidence that prior familiarity in a group setting influenced outcomes. Variations in success rates across cohorts may have been influenced by introduction methodology. Behavioral differences between vervets and macaques, coupled with our findings, lead us to theorize that the gradual introduction techniques commonly implemented to pair house macaques may not be beneficial or suitable for this species.