A phased process to reintroduce a hand-reared infant Tonkean macaque to her natal group

Reintroduction of separated individuals into their social group is a major problem in the management of captive group of non-human primates. Here we report a case in captive Tonkean macaques in which a female infant was abandoned by her mother after birth, then removed, hand-reared, and reintroduced after weaning to her original group in several stages. After the initial phase of separation, a period of habituation to group members followed during which the infant was brought to the front of the group enclosure daily for two months. We then started a phased reintroduction process that lasted a year. Because the biological mother was the group member most attracted to the infant, the process began by allowing the two individuals to interact. In the next stages, we introduced the infant to the other individuals one after the other, starting with the females. Females then acted as protectors against potential male aggression. At the age of one year and two months, the introduced individual had fully integrated her original group. Two years later, she appeared to behave like the other group members. This report shows that a phased process can be used to reintroduce an infant to a macaque group containing several adult females and males.