Present on Bioko Island. SIZE Head and body about 61.0 to 76.4cm. Tail length about 5.2 to 7.6cm. Females about 11.5kg. Groups are comprised of single male units of about 20 animals.
Groups range in a fairly restricted area.
From the Cross River in Nigeria to the Sanaga River in southern Cameroon. Extensive selective logging and forest clearance throughout its range in Cameroon. Reafforestation has involved the planting of non-palatable exotic species such as Eucalyptus and Gemlina arborea. The level of hunting in 1975 threatened the survival of the species. The only known protected population occurs within the Korup Reserve in Cameroon.