Pairing rhesus macaques (Macaca mulatta): methodology and outcomes at four national primate research centers (2014)

Baker, K. C., Coleman, K., Bloomsmith, M. A. et al.

Abstract

Pairing laboratory macaques is a high priority goal for many behavioral management programs. There are numerous methodological differences in introduction procedures across facilities, including the intermediate stages used between single housing and full contact. A retrospective database of 4325 isosexual rhesus macaque pairs (2973 female, 1351 male) housed at four National Primate Research Centers was compiled. All subjects were over 4 y; mean ages at each center ranged from 8.4 to 11.1 y. One facility employed one intermediate phase consisting of a barrier allowing physical contact (?P facility?). Another used this method with the addition of an initial clear panel phase (?C-P facility?). Two other facilities employed mesh panels providing minimal contact (?M facilities?). The proportion of full contact pairings deemed successful (co-housed for a minimum of 14 days without problematic agonism/wounding) ranged from 52%-65% (females) and 32-69% (males). In comparison to the P facility, the C-P facility saw less success among females (?2=9.87; p<.005), but not males. In comparison to the C-P facility, one M facility saw more success among females (?2=8.14, p<.005), but not males. The other M facility required observation of grooming as an additional criteria for success and saw significantly less success in all comparisons (p<.0001) except female introductions at the C-P facility. Comparisons within facilities are needed to evaluate changes to introduction procedures and possible tailoring of methodology to sex.