Stahl, D., Herrmann, F., Kaumanns, W. 2001. Group formation of a captive all-male group of lion-tailed macaques (Macaca silenus). Primate Report 59, 93-108.

The [6 adult (5 years and older)] individuals were brought together simultaneously. .. .. The individuals showed no fights or other serious aggression during the first encounter on the first day. Aggression rates were high only during the first hour after introduction of the animals. Afterwards, the aggression level remained within a similar low level during the whole observation period. .. Affiliative behavior was highest during the first hours. .. The development of the social relationships within the first days suggests that there is a certain degree of social compatibility between male lion-tailed macaques.. .. After four days, the zoo decided to remove Heiner from the group. The animal did not show conspicuous aggressive behaviour but it was thought that he was not compatible with the other animals in the group. Four weeks after the group establishment Nepomuk died because of a chronic, subacute gastritis. Two months later, another monkey, Smokie, died because of a bacterial infection. To prevent further risks the group was disbanded at the end of December 1995.