Control Role of an Adult Male in a Captive Group of Lowland Gorillas

Abstract
An adult male gorilla was removed from the social group in which it had resided for 27 months. There was an immediate increase in aggressive behaviors among the remaining adult females, as well as an intensification of mother-infant social behaviors. The return of the male resulted in an immediate rise in male aggression and a decline in female aggression, with a gradual return to baseline levels in most behaviors. The control role of the male in the group through aggressive behaviors is suggested.