Behavioral changes associated with introducing new group members in orangutans (2001)

Vickers-Smith, A., Stoinski, T., Maple, T.

Abstract

Three of the introductions involved one male and one female, while the remaining three involved introducing a female to a male-female pair. .. Aggressive behaviors were very low during both the introduction and the post-introduction periods. Surprisingly, although the animals spent a significant percentage of their time in close proximity, affiliative behaviors were not frequent in the post-introduction period.