The Collared mangabey is a largest species of its genus with a slate-grey overall coloration. This primate exhibits a dark grey, considerably long and white-tipped tail (longer than the body), which is often held high over the head. The body is slender, having white under-part. The Collared mangabey is so called due to displaying a white collar around its chestnut-red cap. The Collared mangabey has large, prominent and blackish ears. The black colored face contrasts with white eyelids, giving this animal its alternative name - the four-eyed monkey.
These primates are endemic to the Atlantic coast of West Africa, found from Guinea to Gabon. Preferred types of habitat are generally swamps, mangroves and valley forests. However, during the dry season, fruits are often hard to find and the Collared mangabeys may occur in various other habitats.
The Collared mangabeys are basically arboreal creatures, mainly found in the lower levels of the understory. However, as opposed to other mangabeys, these animals occasionally descend to the ground, where they forage on the forest floor in groups, typically moving around in a single-file order. These primates are very social animals, forming groups of 14 - 60 mangabeys, consisting of multiple individuals of both sexes. All-male units don't seem to occur. Instead, males can occasionally found solitarily. The Collared mangabeys are diurnal animals that are active during the daytime hours. They are peaceful and generally non-territorial primates. However, males of this species are known to emit a loud two-note bark, which brings the community members together and serve as an alert signal, announcing the position of their group so as that other troops keep away. This is a very important call, helping control group spacing and avoid conflict with other groups of conspecifics.
The Collared mangabeys are omnivores, their diet consists of various fruits, nuts, seeds, grasses, mushrooms and young leaves, supplemented with occasional invertebrates.
The reproductive system of this species is insufficiently explored. Groups of these primates contain multiple individuals of both genders, which means than they may have either polygynous (each male has numerous mates) or polygynandrous (promiscuous) (both males and females have numerous mates) reproductive systems. The Collared mangabeys don't exhibit a certain breeding season. However, females generally produce offspring between March and August. A single infant is born after 170 days of gestation. The baby will become mature at 5 - 7 years old.
The Collared mangabeys currently face habitat destruction in many parts of their forest range. Due to raiding crops, the Collared mangabeys are considered pest species and are thus commonly persecuted and hunted. Additionally, localized threats include hunting for food.
According to IUCN, the Collared mangabey seems to be widespread and sometimes locally abundant, but no overall population estimate is available. According to the Website of everything resource, the total population of the Collared mangabeys’ was 1,000 individuals or less, when the animals were listed as Near Threatened on the IUCN Red List. Currently, this species is classified as Vulnerable (VU) and its numbers continue to decrease.