Abney, D. M., Poor, L. L., Reuther, K. J. 2011. Socialization of adult male cynomolgus macaques: benefits vs. costs. American Journal of Primatology 73(S1), 41. (34th Meeting of the American Society of Primatologists Scientific Program, Abstract #27)

At Charles River Laboratories (Reno, NV), we have a high rate of success when socializing juvenile and sub-adult cynomolgus macaques (Macaca fascicularis). Until recently, we would rarely attempt to introduce adult males through progressive contact panels due to previous unsuccessful experiences. With the recent USDA focus on socialization, we have attempted to increase the number of socialized adult males in our population. Over three months, we attempted to socialize 1,418 cynos. Of that population, 174 were categorized as adult males. In the non-adult male population, the success rate was almost 100% [n=1241/1244]. In the adult male population, only 51% were successfully socialized [N=89] with a 33% [N=28] incidence of severe injury. While there are certainly well-being benefits for the 51% that are socialized, there is also a large cost for the 49% of unsuccessful socializations in which moderate aggression was noted. The mean time in minutes per animal for an adult male socialization is 39.77 ± 0.1957 compared to 5.995 ± 0.003135 for a non-adult male [Unpaired t-test, P<0.0001 two tailed]. If the animal is injured during the socialization attempt, the average amount of time caring for the animal jumps to 522.4 minutes per animal. This data suggests adult male socialization attempts are potentially costly to the animal in terms of injury and costly to the institution in terms of labor to support the socialization.