The agile mangabey (Cercocebus agilis) is an Old World monkey of the white-eyelid mangabey group found in swampy forests of Central Africa in Equatorial Guinea, Cameroon, Gabon, Central African Republic, Republic of Congo, and DR Congo. Until 1978, it was considered a subspecies of the Tana River mangabey (C. galeritus).[1] More recently, the golden-bellied mangabey (C. chrysogaster) has been considered a separate species instead of a subspecies of the agile mangabey.
The agile mangabey has a short, overall dull olive-grey pelage.[2] The bare skin of the face and feet is blackish.[3] Males are 51– in length and weigh about 7kg–13kgkg (15lb–29lbkg), while the smaller females are 44– and weigh 5kg–7kgkg (11lb–15lbkg).[2]
Similar to other mangabeys, they are diurnal.[1] Although generally arboreal, they do spend a significant portion of their time (12–22%) on the ground,[3] especially during the dry season. It is typically more commonly heard than seen,[2] and males have a loud, species-specific call that is believed to be used to space themselves out.[1] Other calls are also used to maintain group cohesion and warn of predators.[3] Group size can be as high as 18 members, led by a single adult male. Group meetings can be friendly and may involve exchange of members. Adult males not in groups often travel singly.[2]
Fruit makes up a major portion of the agile mangabey diet. They are known to eat at least 42 different species of fruit.[3] Their tooth structure and powerful jaws allows them to open tough pods and fruits that many other monkeys can not access.[3] Agile mangabeys eat from a number of dominant swamp-forest trees, including dika nuts and sugar plums, when they are fruiting.[2] They also eat fresh leaf shoots from raffia palms when fruits are scarce. Grasses and mushrooms,[2] as well as insects, other invertebrates, bird's eggs and some vertebrate prey, such as rodents, are also eaten.[3]
Agile mangabeys are known to contract T-cell leukemia virus, similar to the leukemia virus that infects humans.[4] There is also evidence that they contract Simian immunodeficiency virus (SIV), a virus related to human HIV that infects certain apes and monkeys.[5] They have rarely been kept in captivity,[3] with only three individuals held in Species360 registered institutions in July 2008.[6]