Cercocebus torquatus, the white-collared mangabey, inhabits swamp forests and similar habitats in west-central Africa and has been recorded in countries such as Cameroon and Gabon. Head-and-body length is 45–70 cm; males weigh about 10–11 kg and females 5–6 kg, with males being larger. It is characterized by a white, collar-like ruff of hair and white eyelids, and lives semi-terrestrially, often moving on the ground. Its strong jaws crush hard seeds; it also eats fruit and young leaves. Groups are multi-male/multi-female of 14–25 individuals and show a peaceful social structure. Gestation lasts 5–6 months, and individuals reach maturity in 5–7 years. Populations are declining due to habitat loss and hunting, and the species is listed as Endangered (IUCN category I B).