Cercopithecus mona
mona monkey

Mona monkeys, Cercopithecus mona, are found in southwest Africa. These countries include Nigeria, Ghana, Cameroon, Senegal, Congo, Angola, Kasai, Gambia, Kwango, and West Uganda. The species was also introduced to Grenada around the late 1600s.

(Estes 1991, Glenn 1997, Grzimek 1990, MacDonald 1985, Meester 1968, Nowak 1999, Zoo Atlanta 1998)

Cercopithecus mona is an arboreal creature and can be found primarily in rainforests, toward the middle and top of the trees. This species is also found in mangrove swamps, gallery forests, and woodlands. Rarely, mona monkeys are seen in farmlands. The territory of a typical group ranges from 5 to 50 acres.

(Grzimek 1990, MacDonald 1985, Nowak 1999, Zoo Atlanta 1998)

Cercopithecus mona is a small Old World guenon monkey with a body length of 32 to 53 cm and a long tail of 67 to 90 cm. Individuals are colorful. The dorsal fur is red-brown to brown-agouti. Theventral surface and buttocks are white. The upper half of the face is bluish-gray with a white band on the forehead. Eyebrows are dark, and the snout is pinkish. Around the face, the hair is yellow with a dark stripe running from between the eyes to the ears. The cheeks are greyish-yellow and the lips are white. Other prominent features are the long thick sideburns and white long tufts on the ears. The tail is near black on top with grey underneath. the tail tip is black.

Males are typically larger than females, so there is sexual dimorphism in size. Other than size, however, males and females are similar. Males usually weigh around 5 kg, whereas females usually weigh around 4 kg.

Albinism is known to occur in this species, but it is rare

(Grzimek 1990, Hill 1966, Kingdon 1974, MacDonald 1985, Nowak 1999, Zoo Atlanta 1998)

Longevity of this species has been estimated at a maximum of around 30 years.

Mona monkeys live in large packs ranging from 5 to 50 individuals. There is usually only one adult male in a social group, but if the group gets large enough, there may be several adult males. Large groups such as these tend to be only temporary arrangements which result from several small groups combining together. Large groups provide the benefit of keeping a more attentive watch for predators and other dangers. All-male groups are also known to exist, but are much smaller in size. Male groups usually consist of two to four males ranging in all age groups.

Mona monkeys are very social and active. They are diurnal and active mostly during the early morning or late afternoon. They sometimes travel in troups when moving across trees quickly. They "fly" across trees by running to the outer end of a tree branch and leaping across to another tree branch. They securely land on all four limbs in a vertical posture. However, they are also known to sometimes miss their landing and fall to the ground or in the water. This does not usually injure them severely for they have been seen to just climb up the nearest tree to join the troup again.

When they feel like they are in danger, they freeze and remain still until the danger passes.

(Estes 1991, Glenn 1997, Grzimek 1990, Hill 1966, Kingdon 1971, MacDonald 1985, Nowak 1999)

These monkeys are known to be loud and noisy, with calls that sound like expressive moans. Their alarm calls sound like little sneezes. The males make boom and hack calls in order to show territory and rank. Although it is commonly thought that their moan is the origin of their name "mona", their common name actually refers to their long tails and the Moorish root of the word.

In addition to vocal communication, the complex facial markings of this species indicate that there is also visual communication. Facial expressions and body postures probably figure prominently in the communication of this diurnal species.

Tactile communication occurs in all primates, as grooming, mating, caring for young, and aggressive confrontations all involve physical contact between individuals.

Because this species does not show a prominent sexual swelling to display estrus, it is likely that in addition to behavioral cues, males can detect the presence of sexual receptivity in females through olfactory information.

Mona monkeys are omnivorous. Most of their diet consists of fruits. In addition to eating fruit, they may also feed on sprouts, young leaves, and invertebrates. Of all species in the genus Cercopithecus, C. mona eats the greatest proportion of insects and least of leaves.

An interesting aspect of the feeding habits of these animals is how they store their food in cheek pouches. The capacity of these pouches is almost as large as that of the stomach. The pouches extend from the lower teeth to both sides of the neck.

The cusps on the teeth are good for grinding food, which suits the diverse diet of this species.

(Grzimek 1990, MacDonald 1978, Nowak 1999, Zoo Atlanta 1998)

Details on predation of this species are not widespread in the literature. However, these monkeys apparently fall prey to the same predators that complicate the lives of other forest primates in Africa. It is likely that leopards, golden cats, pythons, and raptors (like crested eagles) all present threats to mona monkeys.

To the extent that these monkeys serve as food for other species, they may have an impact on predator populations. Because of their frugivory and their cheek pouches, mona monkeys are undoubtedly important in seed dispersal.

Perhaps because their habitat is disappearing, mona monkeys are sometimes know to raid crops.

(Kingdon, 1974)

Although not of great economic importance in modern days, these monkeys were historically traded as pets. During the peak of the slave trade period (late 1600s to 1700s), mona monkeys were introduced to Grenada in Central America. At that time, introducing small African animals as pets was common. However, because only a few were transported at a time, the number of animals involved was small. Some of these animals escaped and founded a wild population.

(Benson & Glenn, 1998)

Overall, this species is still considered to be abundant. It is not listed by either IUCN or U.S. ESA.

This species has been bred in captivity, where the maximum life span is 26 years. The have been known to hybridize successfully with other species in captivity. These include Cercopithecus neglectus, Cercopithecus mitis, and Cercopithecus atheiops.

(Grzimek 1990, Kingdon 1974, Nowak 1999, Zoo Atlanta 1989)

Mona monkeys are also sometimes referred to as Dent's Monkeys. The maximum lifespan of a mona monkey in the wild is around 30 years. Their lifespan is affected by variables such as predators and disease. Their predators include the crested eagle, python, leopard, and golden cat. With respect to diseases, they are naturally immune to yellow fever and the Semliki Forest virus.

In contrast to their condition in their native region in Africa, mona monkeys that were introduced to Grenada have lower muscle tone and poorer health yet higher weight measurements relative to the wild African monkeys. This contrast could be due to the fact that the mona monkeys of Grenada have no predators. Nevertheless, It is currently believed that wild mona monkeys today no longer survive in Grenada.

(Bensen & Glenn 1998, Grzimek 1990, Kingdon 1974, Nowak 1999)