There are no negative effects of Debrazza's monkeys on human economies.
Like other small forest monkeys, it is likely that Debrazza's monkeys fall prey to chimpanzees, leopards, various avian predators, and snakes.
This species shows marked sexual dimorphism in size. Male Debrazza's monkeys weigh up to 7 kg, three more than the average female, which weighs 4 kg. Lengths range from 40 to 63.5 cm. Females and males are gray with black extremities and tail. The shape of the head is round, with a long white beard, white muzzle, and an orange crown. The thighs and rumps have white stripes. Legs are long, and the tail is non-prehensile.
Male Debrazza's monkeys have a distinct blue scrotum. In addition, both males and females have well-developed cheek pouches and the most robust feet of all of the guenons.
Range mass: 4 to 7 kg.
Range length: 40 to 63.5 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
The longevity of C. neglectus has not been reported, but other species within the genus Cercopithecus have been reported to live in excess of 30 years in captivity. Lifespans in the wild are likely to be somewhat shorter. It is reasonable to assume that Debrazza's monkeys are like the other members of their genus in regard to lifespan.
Average lifespan
Status: captivity: 30 years.
Average lifespan
Sex: female
Status: captivity: 23.0 years.
Average lifespan
Sex: female
Status: captivity: 26.3 years.
Debrazza's monkeys are found in forests, swamps, and seasonally flooded areas. They exist predominantly in the closed canopy, preferring dense vegetation, and are generally found within 1 km (.62 miles) of rivers in humid forests.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: forest ; rainforest
The range of Debrazza's monkey, Cercopithecus neglectus, is a large triangle bordered by southern Ethiopia to the Northeast, Cameroon to the Northwest, and northern Angola to the south. This species is more common in easten Africa and less regularly observed on the continent's western side.
Biogeographic Regions: ethiopian (Native )
Debrazza's monkeys are omnivorous, but primarily eat fruit. Other items in their diet include leaves, flowers, mushrooms, beetles, termites, and worms.
Animal Foods: insects; terrestrial worms
Plant Foods: leaves; fruit; flowers
Other Foods: fungus
Primary Diet: omnivore
As a prey species, it is likely that these small primates have some impact on predator populations. In addition, because they are largely frugivorous, they probably play some role in seed dispersal.
Ecosystem Impact: disperses seeds
Debrazza's monkeys are hunted for their flesh in Zaire and Cameroon. They have also been widely collected for zoos, mainly from areas of Uganda and Kenya. From 1968 to 1973, 152 Debrazza's monkeys were imported into the United States and from 1965 to 1975, 373 were imported into the British Isles.
Positive Impacts: pet trade ; food ; research and education
Debrazza's monkeys are neither endangered nor threatened. However, in 1975, Ethiopia started protecting them from being hunted and trapped. Threats to these monkeys include the pet trade, habitat destruction from deforestation, range fragmentation from increasing human populations, and cultivation, mainly of coffee plantations in Ethiopia. These monkeys can also be found protected on the Dja Reserve in Cameroon.
US Federal List: no special status
CITES: appendix ii
IUCN Red List of Threatened Species: least concern
Communication between Debrazza's monkeys is both vocal and visual. Visual communication includes staring as a threat, sometimes with the mouth open but the lips covering the teeth. Another threat display is bobbing the head up and down. To reduce aggression in certain situations the lips are retracted showing clenched teeth. As an expression of tension or as another threat display, yawning by adult males is performed to show the canines.
Vocal communication consists of low boom calls to communicate territorialiy, and isolation calls often given by infant or juvenile monkeys when they become separated from the troop.
In addition to these, there is communication through tactile signals. These are likely to be especially important during mating, as well as between mothers and their offspring.
Communication Channels: visual ; tactile ; acoustic ; chemical
Perception Channels: visual ; tactile ; acoustic ; chemical
Sometimes lone males are found outside the unimale social systems that the monkeys establish. Researchers believe the males disperse to create new troops. Research is now being done to see if females leave as well, to create new troops. (Riverbanks 2001)
The sexual dimporphism in size of this species suggests that breeding is probably polygynous. In most guenons, females remain in their natal group all of their lives, whereas males disperse around the time they reach sexual maturity. Males typically compete to control access to a group of females (Nowak, 1999). However, this species is reported to sometimes be found in pairs with young, indicating that there may be some monogamy (Oregon Zoo, 2005).
When it is time to mate, females solicit copulation by presenting themselves. During copulation, the female pouts by sticking her lower lip forward while keeping her lips closed.
Mating System: polygynous
Debrazza's monkeys reach sexual maturity at 5 to 6 years of age. The breedng interval is long, but the gestation period is 5 to 6 months. Single births are normal, although twins are produced on rare occasions. The known breeding season in the equatorial rain forest is from February to March. Otherwise, breeding occurs when food is available.
Becuase females nurse their young for a year, it is unlikey that females are able to produce more than one young per year, even under good conditions. Young begin to eat solid food around the age of 2 months.
Breeding interval: The exact breeding interval is not known.
Breeding season: The known breeding season in the equatorial rain forest is from February to March.
Range number of offspring: 1 to 2.
Range gestation period: 5 to 6 months.
Average weaning age: 12 months.
Range age at sexual or reproductive maturity (female): 5 to 6 years.
Range age at sexual or reproductive maturity (male): 5 to 6 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Average birth mass: 260 g.
Average number of offspring: 1.
When born, the young are furred with eyes open. Newborns are able to cling to their mother's fur, but are comletely dependent upon her for food, comfort, grooming, and protection. Females nurse and care for their young until they become independent, sometime around the age of 1 year. Young females stay with their mothers a long as they live, whereas males leave when they are sexually mature.
The role of males in parental care has not been described. Although most parental care is clearly the responsibility of the mother, fathers may aid in protecting the young born to them in the social group from predators or from infanticidal males. Although infanticide has not been reported for this species, it does occur in other guenons.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Provisioning: Female, Protecting: Female); post-independence association with parents; extended period of juvenile learning
De Brazza's monkey (Cercopithecus neglectus) is an Old World monkey endemic to the riverine and swamp forests of central Africa. The largest species in the guenon family, it is one of the most widespread arboreal African primates. Aside from size, it can be differentiated from other cercopithecus monkeys by its orange diadem and white beard. Due to its cryptic nature, the species is not well documented in all of its habitats but has shown unique traits such as pair-bonding and aggressive behavior towards other guenons.
Locally known as swamp monkeys, these primates are named after the Italian naturalist and explorer Jacques Savorgnan de Brazza.[3][4] Their scientific species name, neglectus, which means to pay no attention to, was given to them because of their ability to hide from both humans and predators.[5]
The De Brazza's monkey is the most sexually dimorphic species of guenon; males weigh around 7 kilograms, while females weigh around 4 kilograms. Adults have grey agouti fur with a reddish-brown back, black limbs and tail, and a white rump. Both sexes have cheek pouches they use to carry food while they forage.[6][7] Males have a distinct blue scrotum, while females have a red perianal region and visible nipples. Juveniles lack the darker colors on the extremities that is characteristic of adults, but retain the whites stripes and red rump while infants are a uniform brown agouti with only a small beard. The white muzzle and beard, along with an orange crescent on its forehead and white stripes on its thighs distinguish it from other guenons.[6][8] Due to this distinctive appearance, the monkey is sometimes referred to as the "Ayatollah Monkey" after the similarly bearded Grand Ayatollah Ruhollah Khomeini.
De Brazza's monkeys range across the swamps, bamboo and dry mountain forests of Angola, Cameroon, Central African Republic, Congo, Democratic Republic of the Congo, Equatorial Guinea, Ethiopia, Gabon, Kenya, South Sudan, Nigeria and Uganda and possibly Tanzania though reports have not been confirmed.[9][2][10] Troops are found almost exclusively near water, rarely venturing farther than 1 km away from a river or tributary. As a result, they can sometimes be seen swimming.[6][7] The monkeys prefer dense forest and vegetation, only venturing into more open forest to feed. They are mainly arboreal, but descends to the ground to feed on herbaceous plants.[6][2] Due to its cryptic nature there is no accurate population estimate for the species over its entire range.[8]
The diet of De Brazza's monkeys consists mostly of herbaceous plants found on the forest floor, and fruits when available. These are supplemented with insects, seeds, and other food sources when primary foods are scarce.[7]
Predators of the De Brazza's monkey include the crowned eagle, leopard, humans, and common chimpanzees. Though rare, dogs and pythons may also predate on juvenile De Brazza's. The typical predator response is to curl up in a tight ball against the side of a tree with the orange crown and white stripes on the thighs hidden and wait silently for the predator to leave. Individuals will only move if the predator approaches their position, and even then they move quietly and slowly to try and escape notice.[7]
The lifespan of the De Brazza's monkey is thought to correspond similarly to other members of Cercopithecus which live up to 22 years in the wild and 30 years in captivity.[8] Its cryptic nature makes the De Brazza's monkey hard to observe in the wild. Troop sizes are small for a guenon, ranging from 2-10 individuals on average.[11] In some areas of Western Africa, such as Gabon and Cameroon, small pair-bonded groups of a male, female, and infants and juveniles have been observed. In Eastern Africa, the DeBrazza's monkeys live in single male, multi-female groups. Solitary males do not create bachelor groups and will occasionally depose an alpha male to take over access to the females.[7]
Male De Brazza's monkey communicates with booming sounds. These are usually heard early in the morning when the male calls out to establish his territory, though he will also use this call to bring the group back together if they get separated.[6][7] When attacked by predators, males will give an alarm call. In the case of crowned eagles, males will emit a short bark before attacking the eagle to scare it off. Females have also been observed to give alarms calls and growl at humans. Otherwise, female vocalizations are limited to quiet croaks given when feeding or resting. Infants and juveniles will give shrill squeals of distress when separated from their mothers or the group.[7] Given the cryptic nature of this species, hearing their calls is sometimes the only way to know they are present.[12] Unlike other guenons, which often form polyspecific associations to decrease predation and increase foraging, DeBrazza's monkeys will be aggressive towards other species and have only been known to tolerate some colobine species which do not compete with them for resources.[7]
Female De Brazza's monkeys reach sexual maturity around 5 years of age, while males do not reach maturity until closer to 6 years of age.[13] Most juveniles males will leave their natal group before they reach maturity.[7] The breeding season lasts from February to March, but females can also go into estrous during times of high food availability.[6] Gestation lasts between 5 and 6 months, and an infant stays close to its mother for the first year of its life at which point it is weaned.[6][13] Females usually have one infant at a time, though twins have been born on rare occasions, with a year long inter-birth interval.[13]
The De Brazza's monkey is listed as least concern by the IUCN Red List.[8] The main threats to DeBrazza's monkeys are deforestation due to logging and agriculture, and bushmeat hunting.[14][15] There are several captive population housed in zoos across Europe and North America. The Association of Zoos and Aquariums (AZA) manages captive population under a species survival plan. This is unique because the species is not listed as vulnerable or endangered, but has been sponsored by the AZA to proactively prevent need for reactive conservation in the future.[16] More data is needed to fully assess the conservation needs of this species.[8]
{{cite book}}: CS1 maint: others (link) De Brazza's monkey (Cercopithecus neglectus) is an Old World monkey endemic to the riverine and swamp forests of central Africa. The largest species in the guenon family, it is one of the most widespread arboreal African primates. Aside from size, it can be differentiated from other cercopithecus monkeys by its orange diadem and white beard. Due to its cryptic nature, the species is not well documented in all of its habitats but has shown unique traits such as pair-bonding and aggressive behavior towards other guenons.
