Vocalizations of Wolf’s monkeys includes 2 contact calls, 2 travel calls, and 3 alarm calls. The most common contact call is used while foraging. These monkeys let out an occasional grunting sound to maintain vocal contact and know the positions of other members of the group. These calls are made more often when foraging in large groups or in areas of low visibility, such as the upper areas of the canopy. Vocal communication is also more common while hunting for insects than foraging for fruits and leaves. To communicate territoriality, males let out a boom call, which is a low, short tone that can be carried long distances due to resonating air sacs. A common alarm call is the sneeze call. It is a short call resembling a the sound of a sneeze.
This species also uses visual communication to convey threats and aggression. Males fix their eyes on the target, move back their ears to stretch out the facial skin, and retract their scalp. This is called staring. Along with staring, they will sometimes open their mouths, but keep the teeth hidden. To present an even greater threat, they will stare with their mouth open, but begin bobbing their head. A fear grimace is used as an appeasement signal to reduce aggression in aggressive encounters. This is accomplished by retracting the lips to show the teeth, but keeping the teeth closed together. Males also perform a visual cue that resembles yawning. The mouth is opened and the canines are revealed to convey tension or aggression.
Like other primates, Wolf's monkeys also extensively use grooming for tactile social communication. The use of chemical cues, such as pheromones, is likely, but undocumented.
Communication Channels: visual ; tactile ; acoustic ; chemical
Perception Channels: visual ; tactile ; acoustic ; chemical
Cercopithecus wolfi has not been evaluated by the IUCN. As a primate, C. wolfi is on appendix II in CITES.
US Federal List: no special status
CITES: appendix ii
IUCN Red List of Threatened Species: least concern
Wolf's monkeys occasionally raid local agricultural crops and have a potential for carrying diseases that can be contagious to humans.
Negative Impacts: injures humans (carries human disease); crop pest
Wolf's monkeys are one of the species hunted in the bushmeat market. Their meat provides food to local inhabitants and a product to trade for other goods. They are also likely to play a role in the regeneration of healthy forests through seed dispersal.
Positive Impacts: food
Wolf's monkeys are probably important in seed dispersal of food trees and they may contribute to pollination when they drink nectar.
Ecosystem Impact: disperses seeds
Wolf's monkeys are frugivorous, but they supplement their diet heavily with leaves, seeds, and flowers. At Salonga National Park in the Democratic Republic of Congo, Wolf's monkeys have been recorded consuming 32% fruit (4% fleshy and 27% arils), 27% seeds, 29% leaves, and 11% flowers. Though not a primary means of sustenance, Wolf’s monkeys will occasionally feed on nectars and insects if they are readily available. The principal feeding time for this species is during the early morning and early afternoon.
Animal Foods: insects
Plant Foods: leaves; seeds, grains, and nuts; fruit; nectar; flowers
Primary Diet: herbivore (Frugivore )
Cercopithecus wolfi is most commonly found in the Democratic Republic of Congo and areas in Uganda. There are three subspecies of Wolf’s monkey: Cercopithecus wolfi wolfi occurs between the Congo and Sankuru Rivers, Cercopithecus wolfi pyrogaster is found between the Kwango and Kasai-Lulua Rivers, and Cercopithecus wolfi elegans is found between the Lomami and Lualaba Rivers.
Biogeographic Regions: ethiopian (Native )
Cercopithecus wolfi occupies primary and secondary lowland rainforest habitats. Wolf's monkeys are commonly found in swamp forests and secondary forests along riverbanks. They spend a majority of their time between 15 and 25 meters high in the canopy where they forage and sleep.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: rainforest
Other Habitat Features: riparian
The average lifespan is reported to be 20 to 26 years.
Typical lifespan
Status: wild: 20 to 26 years.
Wolf's monkeys have dark grey fur dorsally with a reddish patch in the center of the back. The ventral fur is usually white or pale yellow. The forelimbs are dark grey to black while the hindlimbs are a light reddish-brown color. The distal half of the tail is black while the proximal half is a grayish coloration. The face is characterized by a black patch extending from ear to ear, from below the eyes to the top of the head. Within this black area is a patch of white fur that grows from the brow. The cheeks and chin are the same whitish-yellow as the ventral fur and the ear tufts are often white or slightly reddish. The scrotum is blue, which may be important in mate selection. Blue scrotal color is common in many Cercopithecus species and related genera. Wolf's monkeys have ischial callosities (callus-like areas of skin on the buttocks). This provides a degree of comfort while sitting on branches and night resting. These callosities are typical of the family Cercopithecidae.
Being an arboreal quadruped, Wolf's monkeys have forelimbs and hindlimbs that are fairly equal in length giving it an intermembral index number close to 100. The head and body length of males varies from 445 to 511 mm with an average of 485 mm. The length of the tail in males ranges from 695 to 822 mm with an average of 779 mm. There has not been enough data collected from females to adaquetely determine these measurements. Cercopithecus wolfi is a sexually dimorphic species. The weight of males ranges from 3.8 to 4.2 kg, females are considerably smaller, ranging from 2.4 to 3.1 kg. Males also have larger canine teeth than females.
Range mass: 2.4 to 4.2 kg.
Range length: 445 to 511 mm.
Average length: 485 mm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
Since this species is arboreal, its main predators are avian, primarily crowned hawk eagles (Stephanoaetus coronatus). When these birds are spotted by Wolf's monkeys, they will sound an alarm call and retreat to the ground. Though less common, leopards also pose a threat to this species. More recently, humans have become a major predator of this species for the bush meat market. In addition, their primary habitat is being destroyed at an extremely rapid pace for lumber.
Known Predators:
The mating system is a single-male, multi-female polygynous system. There is usually one dominant male and sometimes several less dominant males that mate with a larger number of females. In groups with many females and a single male, males from nearby bachelor groups will often come into the group to mate with females and then retreat to their bachelor group. Copulation is usually initiated by females. They will often present their genitals to a male as a way of enticing him. Though it seems to serve no reproductive function, females will often engage in “pouting” during copulation. This means that the female will look back over her shoulder and pout out her bottom lip at the male.
Mating System: polygynous
Wolf's monkeys give birth to one offspring at a time, though twins occur rarely. Most births occur from June to December when there is the greatest abundance of food. Gestation length is from 160 to 170 days and the young are nursed for 3 months after birth. Females produce their first young at 4 to 5 years old.
Breeding interval: Interbirth interval in Wolf's monkeys is not documented. Other Cercopithecus species generally give birth every year, although interbirth intervals can be as high as 5 years in some populations.
Breeding season: There is no fixed breeding season, although most births occur from June to December.
Range number of offspring: 1 to 2.
Average number of offspring: 1.
Range gestation period: 160 to 170 days.
Average weaning age: 180 days.
Average time to independence: 180 days.
Average age at sexual or reproductive maturity (female): 4.5 years.
Average age at sexual or reproductive maturity (male): 4.5 years.
Key Reproductive Features: iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Not much information is known about the parental investment of Wolf's monkeys, though it has been observed that infants will ride on the backs of their mothers for the first few months after birth. Female young stay in their natal group, male young disperse from their natal group when they become independent.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); post-independence association with parents
Wolf's mona monkey (Cercopithecus wolfi), also called Wolf's guenon, is a colourful Old World monkey in the family Cercopithecidae. It is found in central Africa, primarily between the Democratic Republic of the Congo and Uganda. It lives in primary and secondary lowland rainforest and swamp forest.
The species was first described from a living specimen in the Zoological Garden at Dresden. It was brought in 1887 by Dr Ludwig Wolf from somewhere in central west Africa. The species was described in 1891 and named after the collector. This specimen died in October 1891 and the skeletal characteristics were described in 1894.[3][4]
Wolf's mona monkey is in the C. mona grouping within the genus Cercopithecus along with Campbell's mona monkey, Dent's mona monkey, Lowe's mona monkey, the mona monkey, and the crested mona monkey.[1] Wolf's mona monkey was previously considered a subspecies of the crested mona monkey.[1][5] The genus Cercopithecus is part of the subfamily Cercopithecinae along with baboons, mangabeys, and macaques. This subfamily shares several common traits such as cheek pouches, low and rounded molar cusps, and simple stomachs; all adaptations to a frugivorous diet.
Wolf's mona monkey has two subspecies[1] which are separated by a large area of swamp forest:[6]
Guenons, the largest group of African primates, are very colorful. Their color is used in intraspecific communication for recognizing individuals, species, and potential mates. Wolf's mona monkey is dark grey with a red "saddle" on its back. The pelage depends on the subspecies. C. wolfi wolfi has a chestnut-colored patch on the middle of its back. Its arms are black and legs are red. It has a yellow underside, occasionally with an orange stripe down its flanks. Its cheek whiskers are yellow, speckled with black, and its ear tufts are red. C. wolfi elegans has a back which is gradually browner towards the rump. Its forearms are black, and its upper arms have a pale speckling. Its legs are light gray, while its underside is white. Its cheek whiskers are white, with dark speckling that increases near the base. Its ear tufts are white. The male's scrotum is blue.[6] Wolf's mona monkey is also sexually dimorphic in size. Males weigh, on average, almost twice as much as females, 4.5 kilograms (10 lb) and 2.5 kilograms (5.5 lb) respectively.[7] Its small size makes it susceptible to predators, especially the crowned eagle and the leopard.
The diet of Wolf's mona monkey differs depending on location. Although predominantly a frugivore, it may also forage for seeds and insects for protein. Since it has no adaptations for leaf eating, its leaf diet mainly consists of young and easily digestible leaves.[8][9]
The birth season for Wolf's mona monkey is from June through December due to rainfall and resource availability. It lives in a single male/multi-female group. It is female philopatric, with males dispersing from the group at sexual maturity. Because one male controls several females there is extreme competition for the alpha male position. Females, on the other hand, are generally amicable and participate in grooming and allomothering. Unlike macaques there are no strong linear dominance hierarchies.
Conspecific groups are generally intolerant of each other. Both males and females behave aggressively in intergroup encounters. They are very territorial, using calling and aggression (if needed). Females play an important role in territory defense; when they call it prompts the male to call as well.
Among cercopithecines, forest guenons such as Wolf's mona monkey have very developed cheek pouches. These cheek pouches are second only to macaques. The evolution of these cheek pouches in both genera may be a response to the increased potential for interspecific competition in the mixed-species associations which these monkeys frequently form.[10]
Wolf's mona monkey is known to associate with several guenon and non-guenon species such as the black crested mangabey, the red-tailed monkey, the Angola colobus, Allen's swamp monkey, and the bonobo. No viable offspring or interspecific mating occurs during its associations with other primates.
In one study, Wolf's mona monkeys were found associating with bonobos within 20 metres for an average time of 20 minutes (although sometimes for over an hour). These interactions were mainly initiated by, and departed by, the guenons; this indicates that the guenons most benefited from these associations. Although the common chimpanzee is known to hunt sympatric primates, this is not the case with the bonobo. No aggressive interactions occurred during the study period. The red-tailed monkey (C. ascanius) was also found to associate with bonobos, and on five occasions the association was initiated by a mixed group of guenons (C. ascanius and C. wolfi). When a mixed group was involved in the association, it always lasted for over an hour. Interactions occurred once every seven hours. Associations mainly occurred while the bonobos were feeding or resting. Wolf's mona monkey was found to feed in the trees while the bonobo fed or rested.[11] Another study has shown that bonobos will prey on monkey species, including Wolf's mona monkey. A five-year study in Salonga National Park witnessed five incidents where bonobos preyed on groups of monkeys. The research indicates it was deliberate hunting, where a group of bonobos would coordinate their actions—contrary to their normal hunting behaviour, which is quite solitary and less purposeful. In three occasions the hunt was successful and infant monkeys were captured, once a red-tailed monkey and twice a Wolf's mona monkey.[12]
When forming associations with other primates it is necessary that there is a difference in diet or feeding height between the species to reduce competition. When in a mixed group, Wolf's mona monkey will move and forage at a mean height of 17 metres. Wolf's mona monkey is mainly found in association with the red-tailed monkey (which forages at 12 m) and the black crested mangabey (which forages at 21.5 m), two species with similar diets to Wolf's mona monkey. These mixed groups most likely form for predator detection.[7]
Wolf's mona monkey (Cercopithecus wolfi), also called Wolf's guenon, is a colourful Old World monkey in the family Cercopithecidae. It is found in central Africa, primarily between the Democratic Republic of the Congo and Uganda. It lives in primary and secondary lowland rainforest and swamp forest.
