Abney, D. M., Moomaw, H. A. 2015. Strategies for successfully social housing incompatible cynomolgus macaque trios. American Journal of Primatology 77(S1), 59-60. (38th Meeting of the American Society of Primatologists Scientific Program, Abstract #65)

At Charles River, we are committed to ensuring all animals have the highest level of care and welfare. At our facility, the typical study design requires primates to be housed in groups of 3 (or triads). While we have a near 100% socialization success with the majority of our cynomolgus macaques (Macaca fascicularis), aggressive behavior can occur within the triads, leaving 1 or more animals singly housed. If the social unit breaks down mid-study, regrouping is rarely possible due to study design constraints. We adopted a round-robin system within the triad to facilitate continued social housing and minimize single housing. This social housing schedule has been successfully implemented in all of the triads in which it has been attempted (n= 5 triads). The behavior staff identifies the animal who is most compatible with the other animals in the triad, typically the dominant or submissive, and that animal spends 3 – 4 days fully socially housed with one partner and then switches partners. Meanwhile, the less compatible partners remain at grooming access on days when they are not fully socialized. We have found this minimizes aggression and injuries within the triad and leads to greater social success. Overall, this system eliminated the need for a singly housed animal to have a behavioral exemption due to incompatibility, and has improved welfare for many animals in our facility.