La communauté de primates diurnes de la forêt de Taï, Côte-d’Ivoire

Résumé En

The community of diurnal primates living in the Taï Forest National Park, Western Ivory Coast is described. Besides the Chimpanzee, it includes four species of genus Cercopithecus (C. campbelli, C. diana, C. nictitans, C. petaurista), three species of Colobus (C. badius, C. polykomos, C. verus) and one Cercocebus (C. atys) Details are given on the relative abundance of the seven species found on a 2 km² study area which was closely studied from 1977 to 1983, together with their population density, age and sex ratios, and sizes of home-ranges. The ecological niche of every species is defined, based upon three major parameters : diet, vertical stratification within the forest structure, and the usual supports for locomotion. The Taï forest Cercopithecids are more often observed in polyspecific groups than in monospecific groups. However, all the species do not display the same tendency to associate with the others. It is the Olive Colobus Colobus verus which lives the more often in mixed groups (in 92 per cent of the cases !). It also associates preferentially with the three sympatric species of Cercopithecus, rather than with the other Colobines. The polyspecific troops of Cercopithecids of the Taï Forest can include as many as 6 different species of monkeys. Adaptive relationships between abundance and distribution of food resources, on the one hand, and group size, home range size, and strength of territorial behaviour on the other hand, are stressed. Scarse and patchy food resources favour large multimale groups exploiting large undefended ranges. Conversely, abundant and evenly distributed resources favors small unimale groups living on permanent territories. Information is given in an appendix on some behavioural idiosyncrasies of the Olive Colobus.