This male had a central role in the group and was the only member to emit loud calls, but it was not strongly dominant over the other animals. Younger males seemed to leave the group willingly at about 3-4 years and to take females of the same age with them. In contrast with what was observed in some other investigations, the adult males seemed peripheral to the group and may even have moved between groups. The nucleus of a group was formed by the adult females and their young. In an investigation of an introduced population of C. sabaeus on St. Kitts Island in the West Indies, however, McGuire et al.
Guenons apparently are territorial but generally avoid serious conflicts.
Vocalizations in Cercopithecus are highly varied. C. aethiops has a creaking cry and a staccato bark that enable the members of a troop to keep in touch with one another. Other calls of this species express alarm, excitement, pain, rage, and melancholy. The subspecies C. ascanius schmidti emits birdlike chirps and twitters, interspersed with whistles, when alarmed or disturbed. Different species of guenons may travel together.