Behavioral effects of changing group membership among captive lowland gorillas (1996)

Hoff, M. P., Hoff, K. T., Horton, C. et al.

Abstract

After visual and limited-contact familiarization new members were introduced to an existing group. Seven adult females were moved among four breeding groups. The order in which new members were introduced was determined by knowledge that the zoo staff had of individual behavioral styles among the animals and of the gorilla's previous dominance interactions. Despite the expected increase in aggression, the animals adapted to the changes in group membership such that there was a minimal amount of contact aggression, and the aggressive displays, which did occur at substantial levels, declined to approximate premovement levels within four weeks of the group changes.