Bernstein, I. S., Gordon, T. P. 1977. Behavioral research in breeding colonies of Old World monkeys. Laboratory Animal Science 27, 532-540.

The establishment of a breeding colony presents immediate problems of techniques of group formation and animal introductions. In our experience, the simultaneous release of all animals has proven to produce the fewest injuries and the most rapid social integration. The addition of individuals to such a colony results in the mobbing of adults, often with severe consequences. ... Once a group is established, one should avoid adding animals no matter how desirable this might appear. ... One should not retain an excessive number of males in a breeding colony, but a second adult male and some 'understudy' adolescent might be desirable. ... If new groups are to be established, it is far less damaging to the stability of the colony to divide a group along matrilineal lines than to remove any particular age class. ... The remarkable stability of the median birth date in our rhesus colony suggests that removal of neonates will not improve the performance of seasonal colonies. Our individual females did not show some tendency for earlier conception after a birth tragedy.