Mittermeier, R.A. & Rylands, A.B. (Primate Red List Authority)
Listed as Vulnerable as the species is expected to have undergone a decline of more than 30% across its range over the past three generations (27 years), particularly in the C. a. lunlulatus subspecies.
This species is restricted to the Upper Guinea area. It is known from coastal Senegal and Guinea-Bissau, and is widespread in Guinea, Sierra Leone, Liberia and Côte d'Ivoire to Ghana. It ranges from sea level up to at least 1,000 m asl and possibly higher in the Lome Moutains in Sierra Leone. There are two subspecies:
The subspecies C. a. atys ranges in Senegal, Guinea Bissau, Guinea, Sierra Leone, Liberia and Côte d'Ivoire to the Nzo-Sassandra system.
C. a. lunulatus ranges through the eastern part of the range from the Nzo-Sassandra system to the Volta River. It has recently been recorded from Burkina Faso (Galat and Galat-Luong 2006).
There have been very few recent surveys for C. a. atys in Senegal and Guinea-Bissau, but it is not thought to be common. In the absence of hunting, this species used to be relatively widespread in farm/bush and secondary forest in Sierra Leone.
C. a. lunlulatus has a more restricted range, patchy distribution and is not known to be abundant anywhere.
It is found in primary and secondary forests, gallery forest, swamp forest including mangrove and mosaic habitats in the Guinean Forest Zone. This species is largely terrestrial but will also use the forest canopy. In Guinea it is known from woodland savanna. This species is known to raid farms. They are tolerant of some degree of habitat degradation in the absence of hunting.
This species is presumably threatened by habitat loss caused by deforestation for timber and firewood. The species is locally hunted for meat, and this is an increasingly important threat with ongoing forest fragmentation. Although they are tolerant of a wide range of habitats, hunting of this species for meat and persecution from crop raiding are major threats. However, in the muslim populations in the northern and western parts of its range, hunting is not thought to be a major threat.
This species is listed on Appendix II of CITES and on Class B of the African Convention on the Conservation of Nature and Natural Resources. European Union listed in Appendix I.
The nominate subspecies occurs in a number of protected areas including Tai National Park and Sapo National Park. C. a. lunulatus occurs in Comoe National Park but it is threatened by civil conflict and hunting; it has also been recorded from Ankasa Resource Reserve, Dadieso Forest Reserve and Yoyo Forest Reserves in Ghana, and Marahoué National Park, Dassioko Forest Reserve and Niegre Forest Reserve in Côte d’Ivoire. Many of these protected areas should be elevated to national park status.
There are captive-breeding programmes for this species in European zoos.