Role Behavior of an Agonadal Alpha-Male Rhesus Monkey in a Heterosexual Group

Abstract

An agonadal male rhesus monkey became the alpha male in a heterosexual group of rhesus monkeys, including 4 other fully adult intact males. As the breeding season began, the agonadal alpha male showed the same seasonal changes in behavior as did the intact males. He interacted with females much as do intact alpha males save that he never completed a copulatory sequence. He did mount females, groomed them and maintained consort relationships appropriate to the female’s hormonal condition. His interference in the sexual activities of the other males and his defense of group members was indistinguishable from that of intact alpha males but his behavior in no way delayed conception on the part of the females. Both the fertility and timing of births in this group were similar to those of other normal groups maintained at the same location. Testosterone levels for the intact males reflected normal seasonal values whereas the alpha male showed levels equivalent to those of a young juvenile.