Behavioral and adrenocortical responses of male cynomolgus and lion-tailed macaques to social stimulation and group formation (1995)

Clarke, A. S., Czekala, N. M., Lindburg, D. G.

Abstract

Males were exposed to a mirror, then visually exposed to conspecific neighbors in all pairwise combinations, and then formed into conspecific groups [of 3 animals each]. Following group formation [urinary] cortisol values showed a decreasing trend in the cynomolgus, but not in the lion-tails. The cynomolgus rapidly adapted to group living and relations between them were primarily affiliative. In contrast, no affiliative behavior was ever observed in the lion-tail group, which appeared to be highly stressed by group living and was eventually disbanded.