Oates, J.F.

Collectively, Cercocebus and Mandrillus include nine species and two subspecies of African monkeys: seven species of Cercocebus and two of Mandrillus, including two drill subspecies. Together, they represent some of the least studied and hence least known of the Afro-Eurasian Primates.

Ranging from forests in Senegal to the Zanzibar Archipelago, red colobus monkeys (Piliocolobus spp.) are the most threatened group of African monkeys. According to the IUCN Red List of Threatened SpeciesTM in 2020, every form of red colobus monkey is threatened with extinction, and 14 of the 18 taxa (>75%) are listed as Critically Endangered or Endangered.

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 occur nowhere else. They range from the nocturnal angwantibo, pottos, and galagos, to the mangabeys, baboons, and the drill, to guenons and colobus monkeys. In addition, no less than three of the great apes are restricted to this region, including two chimpanzees and the Cross River gorilla.

This report, compiled by 85 experts from across the world, reveals that nearly half of all primate species are now in danger of becoming extinct from destruction of tropical forests, illegal wildlife trade and commercial bushmeat hunting. The list includes five primate species from Madagascar, six from Africa, 11 from Asia, and three from Central and South America, all of which are the most in need of urgent conservation action.

The Cross River gorilla (Gorilla gorilla diehli) is recognized by IUCN as Critically Endangered, and is the most threatened taxon of ape in Africa. Work during the last two decades has revealed that fewer than 300 Cross River gorillas may remain, spread across an area of about 12,000 km2. The outlook for these apes is far from hopeless, but a concerted and sustained effort will be required if their long-term survival is to be assured.

Effective habitat conservation is essential if wild populations of primates are to survive. This revised edition of the African Primate Action Plan (1986) provides a summary review of progress on projects originally recommended and gives recommendations for new projects in areas and on populations not previously included