Mona monkeys belong to the Old World monkey family. These monkey have brown agouti fur with a white rump. They have a brown crown on their head, broad whitish brow band, grey mask of bare skin and bushy pale cheek fur. The upper parts of the body and the outer sides of the limbs are deep brown while the underparts and the insides of the limbs are creamy-white.
Mona monkeys are found in western Africa. Their range extends from Ghana, Togo, Benin, Nigeria and to western Cameroon. They have also been introduced into Grenada, Saint Kitts and Nevis and São Tomé and Príncipe. These monkeys live mainly in moist forests. They are also able to adapt to heavily degraded forest, gallery forest in savannah regions, and mangrove forest in the delta region of the Niger River. They are generally the commonest monkey near rivers.
Mona monkeys are very social and live in groups of about twelve individuals. There is usually one mature male, but in larger groups, there may be several adult males. Mona monkeys are diurnal. They are active usually during the early morning or late afternoon. Mona monkeys forage high in canopy and often carry their food in cheek pouches. When moving quickly across trees they may travel in groups. They move across trees by leaping across one tree branch to another. They easily land on all four limbs in a vertical posture. Sometimes they may miss their landing and fall to the ground or in the water. This does not injure them much and they will just climb up the nearest tree to join the group again. When threatened Mona monkeys usually freeze and remain motionless until the danger passes. They are vocal species with a harsh grating call, and males produce an "ooer" alarm call.
Little is known about the mating system in Mona monkeys. However, it is suggested that they are polygynous as they live in mostly female groups with very few males. Females give birth every two years to a single infant. The gestation period lasts around 5-6 months. The mother nurses and takes care of her infant around a year. Young Mona monkeys become reproductively mature at around 2-5 years of age.
The main threat to Mona monkeys is the destruction of their habitat. These monkeys also suffer from being hunted for food.
The IUCN Red List and other sources don’t provide the number of the Mona monkey total population size. Currently, this species is classified as Least Concern (LC) on the IUCN Red List.
Mona monkeys are important in seed dispersing due to their frugivorous diet and due to storing food in their cheek pouches. They are also prey items for some local predators.