Class: Mammalia (Mammals)
Species: more than 50 species and subspecies
Body length: 16 to 22 inches (425 to 560 millimeters), depending on species
Weight: 5 to 15 pounds (2.27 to 6.8 kilograms), depending on species
Life span: 20 to 30 years
Gestation: 135 to 200 days, depending on species
Number of young: 1
Weight at birth: unknown
Age of maturity: 2 to 6 years, depending on species and gender
Conservation status: due to the illegal bushmeat trade, most guenon species are at critical risk.
• The first scientific symposium devoted to guenons took place in 1985.
• There are natural hybrid zones where some guenon species have been found to breed with other guenon species. More research is needed to confirm whether this has always happened or is a result of modern-day pressures caused by loss of habitat.
• If you hear a guenon sneeze, it's probably the "sneeze call" that guenons pass through the group as an alarm.
The San Diego Zoo was the first facility in the world to welcome a Diana guenon baby Cercopithecus diana.
Guenons (GWEN nons) are medium-sized African monkeys with long tails and large cheek pouches. They are some of the most colorful, graceful, and lively monkeys. Unlike other tree-dwelling and leaf-eating monkeys, guenons have more varied diets including fruits, seeds, and young leaves. They use their cheek pouches to store extra food in as they forage. The pouches can hold almost as much as their stomachs!
Guenons also prey on insects, some reptiles, and occasionally small mammals. At the San Diego Zoo the guenons are offered nutritionally complete primate biscuits, assorted fruits (such as apples, grapes, melons), vegetables (green beans, corn, eggplant), and greens (cabbage, lettuce, kale). Enrichment treats can include raisins, popcorn, and peanuts.
Plays well with others
Many guenon species are often found hanging out with other guenon species and other kinds of monkeys such as mangabeys, colobus monkeys, and Allen’s swamp monkeys. This may help all the monkeys improve their diets and be better able to spot predators—safety in numbers! While guenons make a variety of sounds, they also communicate with several gestures and facial expressions: an open mouth showing sharp teeth, closed eyelids, or a movement of the head or tail can get different messages across to other monkeys loud and clear!
The goods on guenons
A few guenon species spend their time on the ground, but most guenons live in large groups, traveling and foraging in the forest canopy. Different guenon species often mix together. They understand each other's alarm calls and know how to react. Danger for guenons can come from chimpanzees, leopards, or eagles. And as logging roads open a way into the forests of equatorial Africa, guenons are one of the primary targets being hunted by humans for the illegal bushmeat trade. A number of species of guenons are critically endangered.
Most guenon species live in large groups of females and at least one resident male, with groups of "outsider" males drifting in and out of the territory. Sometimes males live separately or in small bachelor groups. And some, such as the De Brazza's guenon Cercopithecus neglectus, live in male/female pairs.
Schmidt's spot-nosed guenon: friendly neighbors
Known to scientists as Cercopithecus ascanius schmidti, this guenon is known by several common names: red-tailed monkey, white spot-nosed monkey, and Schmidt's spot-nosed guenon. All together they give a pretty good description of this charming, sociable monkey. They have white noses and long red tails. Their tails help them balance as they move through the trees where they spend most of their time looking for fruits, leaves, and insects. Schmidt's spot-nosed guenons can live in large groups of up to 50 monkeys, but when things get too crowded for the amount of food available, the troop may split into smaller groups.
Wolf's guenons: tufted ears and much to hear!
Wolf's guenons Cercopithecus wolfi are tree dwellers found south of Africa's Congo River. This colorful species of monkey has nothing to do with a wolf: it was named after the last name of the person who first described it for science. They have pale foreheads and a black stripe above their eyes, stretching from tufted ear to tufted ear. This gives them a rather grim appearance, but they are social and make a lot of sounds! Scientists have recorded seven different sounds the Wolf's guenons make, including a grunting call they use to keep in contact while foraging. It appears that this grunting increases when they're foraging for insects: could this be their favorite food? Because they also feed on nectar, Wolf's guenons are pollinators of certain rain forest trees.
L'Hoest's guenon: togetherness...
...is a lifestyle for the L'Hoest's (le WESTS) guenon Cercopithecus lhoesti. These monkeys travel in family groups of several females and youngsters with one male, who is in charge. But if the group is threatened, it's often the females who are the most aggressive! L'Hoest's guenons rarely hang out with other monkey species. That's fine with them, though, because they have each other and will curl up together for security. They are dark gray in color with "bibs" of white fur under their chins. Young L'Hoest's guenons have semiprehensile tails that are strong enough to support their weight when they are small: this is very rare in Old World (Asian and African) monkeys. They lose this ability as they grow up, using their tails only for balance as adults.
Lesser spot-nosed guenons: talking with tails
Furry white beards and a bright white mark on the nose make the lesser spot-nosed guenon Cercopithecus petaurista easy to identify. These energetic and curious monkeys use their expressive tails to "talk" to others and indicate their mood. Spot-nosed guenons also communicate by jerking their heads in different positions, each of which means something specific. That may be why they have those white whiskers and nose spots: the white can be seen shining in the dark rain forests of western Africa where they live.
De Brazza's guenons: colorful loners
De Brazza's guenons are a little bit different than most other guenon species. They are often paired for life, or may live in one-male troops. They have never been seen around other primate species, even other guenons in the wild. Among the largest of the guenons, De Brazza's guenons have a distinctive, beautiful coloration. Their bodies are grayish, with a reddish brown back and black arms, legs, and tail. Their rumps are white and they have a white stripe on their thighs. The rumps of young De Brazza's guenons are yellow, and adult males have a bright blue display during mating season!
De Brazza's guenons have a large "boom" call, made even louder by inflating a vocal sac, which they use as a warning. They also use their lush, white beards for visual displays. Groups of De Brazza's have been known to sit completely still for up to five hours and then creep silently away into the forest.