Guenons

views updated May 29 2018

Guenons

General characteristics

Breeding

Habitat

Activity

Guenon relatives

In captivity

Resources

Guenons are small to medium-sized monkeys widespread throughout sub-Saharan Africa. These primates are classified in the infraorder of Old World simian primates (Cataffhina) and the family Cercopithecidae. Their genus, Cercopithecus, is large, very diverse, and successful.

The Cercopithecidae family consists of two subfamilies: the omnivorous Cercopithecinae (including guenons, talapoin, and baboons from Africa) and the vegetarian Colobinae. There are approximately 19 species of monkeys in the genus Cercopithecus and more than 70 subspecies. These species are: LHoests monkey (C. lhoesti ), the diana monkey (C. diana ), DeBrazzas monkey (C. neglectus ), the mona monkey (C. mona), the crowned guenon (C. pogonias ), the lesser white-nosed guenon (C. petaurista), the red-bellied guenon (C. erythrogaster ), the white-nosed guenon (C. nic-titans), the mustached guenon (C. cephus ), the owl-faced guenon (C. hamlyni), Campbells monkey (C. campbelli ), Dryas monkey (C. dryas ), the red-eared monkey (C. erythrotis ), the blue monkey (C. mitis), Preusss guenon (C. preussi ), Sclaters guenon (C. sclateri ), the sun-tailed monkey (C. solatus ), the black-cheeked white-nosed monkey (C. ascanius ), and Wolfs monkey (C. wolfi ).

General characteristics

While guenons vary greatly in coloring and facial characteristics, there are certain characteristics that they have in common. Generally, the guenon is a medium to large monkey, slender in build, measuring (head and body) 13-27.5 in (32.5-70 cm). Its tail is considerably longer than its body, ranging in length from 19.5-34 in (50-87.5 cm). Guenons are most active during the day, can be either terrestrial or arboreal, and walk on four feet, sometimes with slightly lifted wrists and ankles. While their jaws are short, they have well-developed cheek pouches. These pouches allow them to forage for food in open areas and then return to shelter to chew and swallow their food.

All guenons are easily recognized by their colorful fur. They are usually grayish green on their backs and the tops of their heads, and get much lighter down their sides and on their stomachs and undersidesusually light gray to white. However, as many of their common names indicate, their coloring varies a great deal between species. Many species have ornamentation around their heads, such as white noses, white mustaches, white beards, prominent side whiskers, white throats, and/or white or brown brow bands. Their legs can also be decorated, sometimes with white or beige stripes on their thighs or bright coloring on the insides of their legs. Furthermore, the coloring of the young is occasionally different from that of adults.

The size and territory of guenon troops varies from species to species. Some species, such as the mustached guenons, stay within fairly strict territorial boundaries. Other species do not observe these boundaries at all, and roam freely. Within guenon troops, the ranking system found with baboons is only very loosely established.

The manner in which guenons feed is closely related to their habitat. For example, arboreal guenons primarily eat leaves and tree fruit. Reportedly, guenons in the wild will also eat eggs, although this has not been verified. In their natural habitats, they eat a wide variety of foods, such as fruits and vegetables, nuts, insects, birds, lizards, and other small animals.

Breeding

While guenons breed throughout the year, in some species, the births of the young are concentrated during specific times of the year. Pregnant for about seven months, guenon mothers usually bear one baby, although twins sometime occur. The newborn clings to the mothers stomachs, supported by the mothers hand. According to scientists, some species of guenon newborns can walk after only a few days. At one or two months, they are active, and eat their first solid food. At four months, they can take care of themselves. Guenons mature sexually at the age of four years.

Habitat

While some guenons stray into the temperate climates found in southern Africa or high altitudes, they mostly thrive in tropical conditions. To survive, these monkeys need a temperature of at least 70°F (21°C). They are most comfortable when the temperature is between 75-85°F (24-29°C).

Guenons live primarily in the tropical rainforest belt in Africa to the south of the Sahara Desert, but a few species have adapted to the forests along principle African rivers. Overall, the forest-dwelling species prefer to live deep within the shelter of forests. However, they often prefer to inhabit different types of forests. For example, some species like to live high in the canopy and rarely come down to the lower branches or the forest floor. Other species are very active near the ground and commonly leave the trees. Interestingly, guenon distribution is heavily influenced by varying conditions. Population shifts sometimes cause migrations to areas previously uninhabited by guenons.

Activity

Like most monkeys, guenons are most active during the daytime. During the hottest part of the day, around noon, they rest, and groom themselves and each other. This is their only form of social contact. In the morning and late afternoon, they spend their time looking for food. While foraging, they communicate with each other through a series of peaceful calls. If a member of the troop encounters a dangerous situation, he emits a sharp barking sound, which is repeated by the troop members. On these occasions, all of the monkeys in the troop climb higher to get a better view of the danger. After doing so, the monkeys flee by running and jumping through the tree canopy. By extending their bodies vertically, guenons can leap very long distances from branch to branch.

Guenon relatives

The genus Cercopithecus has three offshoots that have adapted to other environmental conditions and evolved morphological traits that distinguish them from other guenons. Consequently, some scientists have assigned them separate generic status. The first of these relatives, is the dwarf guenon. Known formally as Cercopithecus talapoin, the dwarf monkey has been classified by some scientists in a separate genus called Miopithecus. Other scientists place these guenons in a subgenus by the same name. This monkey is significantly smaller than all other guenons and has morphological traits (in body structure) are directly related to its reduced size. It is found is swampy forests and mangrove swamps near the coast. It eats plants, nuts, insects, and, on occasion, small animals.

The second of these relatives is the swamp guenon (Cercopithecus nigroviridis ). Like the dwarf guenon, it prefers to live in swampy forests. This monkeys skull and other anatomical characteristics are similar to those of baboons. These differences, combined with significant behavioral and vocal differences, have caused some scientists to classify them in a separate genus (Allenopithecus ). Other scientists, who allow a wide range of guenon characteristics, classify swamp guenons in the subgenus Allenopithecus within the genus Cercopithecus. Very little is known about these monkeys in the wild. In captivity, they are very agile and tireless. It is believed that they live in small groups and eat a vegetarian diet.

The third relative of the guenon is the red guenon or dancing monkey, classified by taxonomists in the separate genus Erythrocebus. It is the only species of guenon that lives primarily in semi-arid savanna, avoiding forests even when threatened. Thus, it has made several adaptations distinguishing it from all of its relatives. These characteristics are: a rough coat, long and slender arms and legs, short hands and feet, and whiskers and mustaches on adult males. These guenons live in troops of 7-15, containing only one male. The male acts as a sentry, and is always looking for potential enemies. If something threatens the troop, the male red guenon distracts the animal while the others flee. Red guenons feed on plants, insects, and small animals.

In captivity

Often referred to as organ grinders monkeys, young guenons make gentle, trusting pets. If treated well, they usually have pleasing dispositions and like attention. However, as they mature or if they are mistreated, they are large enough to become a threat. The dispositions of adult guenons can be unpredictable, sometimes bordering on aggressive. The males can inflict serious bites with their sharp canine teeth. Therefore, it is inadvisable to keep them as house pets.

In zoos, guenons are generally a public favorite. They are kept in family groups or pairs, and are fed a mixed diet of fruits, nuts, and vegetables. While guenons do not breed in captivity as readily as some other types of monkeys, breeding is not impossible. In fact, some zoos have been successful at interbreeding various guenon species.

Rhesus monkeys have long been the staple to most scientist performing animal experiments. However, these monkeys have been getting more and more difficult to secure. Consequently, guenons have increasingly been used for medical and pharmaceutical experiments.

Guenons live a long time in captivity; some guenons have reportedly lived to be more than 20 years old in zoos. Indeed, one mona monkey lived to be 26 years old in a United States zoo. While their life span may be as high as 25-30 years, guenons in the wild probably do not live to such an old age.

Resources

BOOKS

Glenn, Mary E., and Marina Cords, eds. The Guenons: Diversity and Adaptation in African Monkeys. New York: Springer, 2003.

Hill, W.C. Osman. Evolutionary Biology of the Primates. New York: Academic Press, 1972.

Jolly, Alison. The Evolution of Primate Behavior. New York: Maccmillan, 1972.

Nowak, Ronald M. Walkers Mammals of the World. 6th ed. Baltimore: The Johns Hopkins University Press, 1999.

Preston-Mafham, Rod, and Ken Preston Mafham. Primates of the World. London: Blanford, 1992.

Kathryn Snavely

Guenons

views updated Jun 27 2018

Guenons

Guenons are small to medium-sized monkeys widespread throughout sub-Saharan Africa . These primates are classified in the infraorder of Old World simian primates (Cataffhina) and the family Cercopithecidae. Their genus, Cercopithecus, is large, very diverse, and successful.

The Cercopithecidae family consists of two subfamilies: the omnivorous Cercopithecinae (including guenons, talapoin, and baboons from Africa) and the vegetarian Colobinae. There are approximately 14 species of monkeys in the genus Cercopithecus and a total of over 70 subspecies. These species are: the grass monkey, L'Hoest's monkey, the diademed guenon, the diana monkey, De-Brazza's monkey, the mona monkey, the crowned guenon, the lesser white-nosed guenon, the red-bellied guenon, the greater white-nosed guenon, the mustached guenon, the owl-faced guenon, the dwarf guenon, and the swamp guenon. The red guenon has been classified in another genus altogether, Erythrocebus.


General characteristics

While guenons vary greatly in coloring and facial characteristics, there are certain characteristics that they have in common. Generally, the guenon is a medium to large monkey, slender in build, measuring (head and body) 13-27.5 in (32.5-70 cm). Its tail is considerably longer than its body, ranging in length from 19.5-34 in (50-87.5 cm). Guenons are most active during the day, can be either terrestrial or arboreal, and walk on four feet, sometimes with slightly lifted wrists and ankles. While their jaws are short, they have well-developed cheek pouches. These pouches allow them to forage for food in open areas and then return to shelter to chew and swallow their food.

All guenons are easily recognized by their colorful fur. They are usually grayish green on their backs and the tops of their heads, and get much lighter down their sides and on their stomachs and undersides—usually light gray to white. However, as many of their species' names indicate, their coloring varies a great deal between species. Many species have ornamentation around their heads, such as white noses, white mustaches, white beards, prominent side whiskers, white throats, and/or white or brown brow bands. Their legs can also be decorated, sometimes with white or beige stripes on their thighs or bright coloring on the insides of their legs. Furthermore, the coloring of the young is occasionally different from that of adults.

The size and territory of guenon troops varies from species to species. Some species, such as the mustached guenons, stay within fairly strict territorial boundaries. Other species do not observe these boundaries at all, and roam freely. Within guenon troops, the ranking system found with baboons is only very loosely established.

The manner in which guenons feed is closely related to their habitat . For example, arboreal guenons primarily eat leaves and tree fruit. Reportedly, guenons in the wild will also eat eggs, although this has not been verified. In their natural habitats, they eat a wide variety of foods, such as fruits and vegetables , nuts, insects , birds , lizards, and other small animals.


Breeding

While guenons breed throughout the year, in some species, the births of the young are concentrated during specific times of the year. Pregnant for about seven months, guenon mothers, usually bear one baby, although twins sometime occur. The newborn clings to the mother's stomachs, supported by the mother's hand. According to scientists, some species of guenon newborns can walk after only a few days. At one or two months, they are active, and eat their first solid food. At four months, they can take care of themselves. Guenons mature sexually at the age of four years.


Habitat

While some guenons stray into the temperate climates found in southern Africa or high altitudes, they mostly thrive in tropical conditions. To survive, these monkeys need a temperature of at least 70°F (21°C). They are most comfortable when the temperature is between 75–85°F (24–29°C).

Guenons live primarily in the tropical rainforest belt in Africa to the south of the Sahara Desert, but a few species have adapted to the forests along principle African rivers . Furthermore, one species—the grass-monkey-thrives in the open savanna and spends a significant amount of time on the ground.

Overall, the forest-dwelling species prefer to live deep within the shelter of forests. However, they often prefer to inhabit different types of forests. For example, some species like to live high in the canopy and rarely come down to the lower branches or the forest floor. Other species are very active near the ground and commonly leave the trees. Interestingly, guenon distribution is heavily influenced by varying conditions. Population shifts sometimes cause migrations to areas previously uninhabited by guenons.

The savanna-dwelling species of guenon, the grass monkey, inhabits areas near the boundaries of rain-forests. They live only near running water and tend to avoid open areas and forest interiors. They prefer certain trees, and are reportedly fond of the fruit of the wild fig tree. When they are pursued, they have been seen pressing themselves against tree branches for camouflage. Typically, they live in groups of 20-50, each group usually limiting its activities to a specific territory.

Activity

Like most monkeys, guenons are most active during the daytime. During the hottest part of the day, around noon, they rest, and groom themselves and each other. This is their only form of social contact. In the morning and late afternoon, they spend their time looking for food. While foraging, they communicate with each other through a series of peaceful calls. If a member of the troop encounters a dangerous situation, he emits a sharp barking sound, which is repeated by the troop members. On these occasions, all of the monkeys in the troop climb higher to get a better view of the danger. After doing so, the monkeys flee by running and jumping through the tree canopy. By extending their bodies vertically, guenons can leap very long distances from branch to branch.


Guenon relatives

The genus Cercopithecus has three offshoots that have adapted to other environmental conditions and evolved morphological traits that distinguish them from other guenons. Consequently, some scientists have assigned them separate generic status. The first of these relatives, is the dwarf guenon. Known formally as Cercopithecus talapoin, the dwarf monkey has been classified by some scientists in a separate genus called Miopithecus. Other scientists place these guenons in a subgenus by the same name. This monkey is significantly smaller than all other guenons and has morphological traits (in body structure) are directly related to its reduced size. It is found is swampy forests and mangrove swamps near the coast. It eats plants, nuts, insects, and, on occasion, small animals.

The second of these relatives is the swamp guenon (Cercopithecus nigroviridis). Like the dwarf guenon, it prefers to live in swampy forests. This monkey's skull and other anatomical characteristics are similar to those of baboons. These differences, combined with significant behavioral and vocal differences, have caused some scientists to classify them in a separate genus (Allenopithecus). Other scientists, who allow a wide range of guenon characteristics, classify swamp guenons in the subgenus Allenopithecus within the genus Cercopithecus. Very little is known about these monkeys in the wild. In captivity, they are very agile and tireless. It is believed that they live in small groups and eat a vegetarian diet.

The third relative of the guenon is the red guenon or dancing monkey, classified by all in a completely separate genus (Erythrocebus). It is the only species of guenon that lives primarily in semi-arid savanna, avoiding forests even when threatened. Thus, it has made several adaptations distinguishing it from all of its relatives. These characteristics are: a rough coat, long and slender arms and legs, short hands and feet, and whiskers and mustaches on adult males. These guenons live in troops of 7-15, containing only one male. The male acts as a sentry, and is always looking for potential enemies. If something threatens the troop, the male red guenon distracts the animal while the others flee. Red guenons feed on plants, insects, and small animals. There are two subspecies of red guenon: the patas monkey and the Nisnas monkey.


In captivity

Often referred to as "organ grinder's" monkeys," young guenons make gentle, trusting pets. If treated well, they usually have pleasing dispositions and like attention. However, as they mature or if they are mistreated, they are large enough to become a threat. The dispositions of adult guenons can be unpredictable, sometimes bordering on aggressive. The males can inflict serious bites with their sharp canine teeth. Therefore, it is inadvisable to keep them as house pets.

In zoos, guenons are generally a public favorite. They are kept in family groups or pairs, and are fed a mixed diet of fruits, nuts, and vegetables. While guenons do not breed in captivity as readily as some other types of monkeys, breeding is not impossible. In fact, some zoos have been successful at interbreeding various guenon species.

Rhesus monkeys have long been the staple to most scientist performing animal experiments. However, these monkeys have been getting more and more difficult to secure. Consequently, guenons have increasingly been used for medical and pharmaceutical experiments.

Guenons live a long time in captivity; some guenons have reportedly lived to be more than 20 years old in zoos. Indeed, one mona monkey lived to be 26 years old in a United States zoo. While their life span may be as high as 25-30 years, guenons in the wild probably do not live to such an old age.


Resources

books

Hill, W.C. Osman. Evolutionary Biology of the Primates. New York: Academic Press, 1972.

Jolly, Alison. The Evolution of Primate Behavior. New York: Maccmillan, 1972.

Preston-Mafham, Rod, and Ken Preston Mafham. Primates of the World. London: Blanford, 1992.

Walker, Ernest P. The Monkey Book. New York: Macmillan, 1954.


Kathryn Snavely

Cercopithecus

views updated May 21 2018

Cercopithecus (guenon) See CERCOPITHECIDAE.