West Africa, from the coast of Senegal to Lake Chad and Cameroon's Sanaga River, is home to 60 primate species and subspecies, 46 of which - more than three-quarters - occur nowhere else. They range from the nocturnal angwantibo, pottos, and galagos, to the mangabeys, baboons, and the drill, to an extraordinary diversity of guenons and colobus monkeys. In addition, no less the three of the great apes are restricted to this region, including two chimpanzees and the Cross River gorilla. The savannas and open woodlands in the north are home to baboons, vervets and patas monkey, but the main focus of this guide is the Guinean Forest, ranking high among the world's 35 Biodiversity Hotspots, the richest and most endangered of our planet's terrestrial systems. Forest loss, degradation and fragmentation, and widespread and intensive hunting for bushmeat mean that no less than 30 of the region's primates are now threatened. This comprehensive guide provides a brief introduction to the region, its topography, climate, vegetation, native people and history, and includes as well essays on the classification and evolutionary history of the region's primates, and a review of conservation activities and primate field research projects since the 1960's. The bulk of the book is dedicated to accounts for each primates species and subspecies, providing information not only on their identifying features and geographic distributions, but also on their natural history - their populations and habitats, locomotion, vocalizations, activity patterns, diets and feeding, ranging, and social behaviors. The guide is richly illustrated with full-color plates by Stephen D. Nash, distribution maps for every species and subspecies, and more than 140 color photographs of the primates and their habitats. An appendix describes key sites where these primates can be seen in the wild.