Analysis of the vocal behaviour of adult males from different species of Cercopithecus monkeys in a polyspecific troop shows important species differences, which suggest a superspecific organization upon which the extraordinary stability of certain polyspecific associations can depend. In the community studied, the male Cercopithecus pogonias generally controlled the formation and disbanding of polyspecific troops, coordinated their movements and the spacing between troops, while Cercopithecus cephus seemed to be the ‘follower’ species. However, the roles were divided for defence against predators: male C. pogonias gave warning of aerial predators, while male C. cephus generally gave the alarm against terrestrial predat