This widespread African species ranges from Angola and the Democratic Republic of Congo eastwards to the Indian Ocean coastline and Zanzibar Island (Tanzania); in the eastern part of its range it is found from Ethiopia in the north to eastern South Africa in the south (Colyn and Verheyen 1987; Lawes 1990; Colyn 1991; Gautier-Hion et al. 1999; Butynski 2002a, b). It is found from sea level up to 3,800 m asl (Rwenzori Mountains).

There are 17 subspecies:

1). C. m. albotorquatus. In Kenya, present in Kipini Conservancy, Witu Forest, Tana River forests west as far as Meru and Kora National Parks. C. m. phylax, a synonym of C. m. albotorquatus, is present on Patta and Witu Islands, Lamu Archipelago, Kenya. Reported to be present in the coastal forest of southern Somalia, but this requires confirmation (T. Butynski and Y. de Jong pers. comm.).
2). C. m. kolbi is restricted to the highlands of Kenya, east of the Rift Valley (including Nairobi). There is no evidence that C. m. kolbi occurs in Marsabit (T. Butynski and Y. de Jong, pers comm. 2007).
3). C. m. albogularis is present from Kilifi Creek south to northern Tanzania, and from here west to Mount Kilimanjaro and Mount Meru, Tanzania; it also occurs on the island of Zanzibar, Tanzania. This subspecies is possibly the subspecies that occurs from Kilifi Creek to Malindi (T. Butynski and Y. de Jong pers. comm.).
4). C. m. francescae is known only from Mount Waller and the Vipya Plateau of Malawi.
5). C. m. moloneyi is present from Zambia west of the Luangwa River, northern-most Malawi, the Southern Highlands of Tanzania to the Udzungwa Mountains (T. Butynski pers. comm.).
6). C. m. erythrarchus ranges from the Mlanje Plateau in southern Malawi, to Zimbabwe, much of Mozambique (althought the coastal limits are uncertain) to Limpopo Province and northern KwaZulu-Natal in South Africa in the south.
7). C. m. labiatus is restricted to South Africa where it is found in the Limpopo Province, Mpumalanga, KwaZulu-Natal and the Eastern Cape.
8). C. m. heymansi ranges between the Lualaba and Lomami Rivers in the Democratic Republic of Congo.
9). C. m. opisthostictus ranges from the Province of Katanga (= Shaba) in the Democratic Republic of Congo, north to approximately 6°N on the left bank of the River Lualaba to the western shores of Lake Tanganyika, it is found in north-western Zambia west of the Luangwa River.
10). The nominate subspecies C. m. mitis is known only from the Dundo region of Angola.
11). C. m. boutourlinii is present in southern Ethiopia, where it is found from Lake Tana southwards along the western side of the Ethiopian Rift, but does not reach Lake Turkana.
12). C. m. stuhlmanni is widespread occurring in the Democratic Republic of Congo from the region between the Uele River and the Congo River, east of the Itimbiri River to the Ituri and Semliki Forests (Democratic Republic of Congo and Uganda), and from here south to about 6°S and east of the Lualaba River, into southern Sudan, northern Uganda and parts of Kenya west of the Rift Valley, including Mount Elgon and the Kakamega Forest.
13). C. m. schoutedeni is present in the Democratic Republic of Congo on the islands of Idjwi and Shushu in Lake Kivu, and from the Virunga Volcanoes and south-west as far as Bobandana.
14). C. m. doggetti is found in the highlands of eastern Democratic Republic of Congo, northern Burundi, north-western Tanzania, through Rwanda and parts of southern Uganda (there is uncertainty in the distribution of this subspecies and the degree of overlap with neighbouring subspecies).
15). C. m. kandti has an unclear distribution, but is generally found in the area of Virunga Volcanoes, the contiguous Gishwati Forest, and higher part of Nyungwe.
16). C. m. zammaranoi (treated by some as a synonym of C. m. albotorquatus) has a very restricted distribution in southern Somalia along the Jubba and Webi-Shebeli Rivers. See Gippoliti (2006) for a review.
17) C. m. monoides ranges through the Selous Game Reserve and Kichi Hills west to the foot of the Udzungwa Mountains, south into Newala District.

Cercopithecus mitis is found in rain forests of central, eastern, and southern Africa. The species can also be found in the Congo basin.

Biogeographic Regions: ethiopian (Native )

Blue monkeys are small (ranging in weight from 4 to 6 kg) and arboreal. The face is nearly naked, usually dark in color (infrequently blue), and has well-developed musculature (Lawlor, 1979). Cercopithecus mitis is also known as the diademed monkey because it has a prominent row of forward pointing white fur just above its brow line (Rudran, 1978).

White whiskers are well developed in males. Males are larger than females. Male canines are also slightly larger than the female canines (Rudran,1978).

These monkeys are catarrhine; the nostrils are close together and they face downward. They have cheek pouches to carry food while foraging (Rudran, 1978).

The dental formula of C. mitis is 2/2 1/1 3/3 2/2=32.

The nail on each digit is flattened, and the pollex is opposable (Lawlor, 1979).

The upper parts of the body are gray and the limbs are darker in appearance. Some young have indistinct russet-colored rump patches, which has not been seen in adults (Dorst and Dandelot, 1970).

Range mass: 4 to 6 kg.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: male larger

Average basal metabolic rate: 19.276 W.

Habitat and Ecology

Systems

• Terrestrial

Cercopithecus mitis is found in a variety of habitats. They are very dependent upon humid, shaded areas with abundant water and tall trees which provide both food and shelter.

Habitat Regions: tropical ; terrestrial

Terrestrial Biomes: forest ; rainforest ; scrub forest

Blue monkeys are frugivorous and folivorous in nature, eating mainly fruits and leaves. In addition, blue monkeys tend to concentrate their invetebrate feeding on slow-moving slugs and worms (Rudran, 1978).

Animal Foods: mollusks; terrestrial worms

Plant Foods: leaves; fruit

Primary Diet: herbivore (Folivore , Frugivore )

As a prey species, these monkeys probably have some impact on predator populations. In addition, they are likely to be important in seed dispersal because of their frugivory.

As is true for other forest dwelling monkeys, C. mitis likely falls prey to leopards. Other potential predators include snakes and birds of prey.

Known Predators:

• leopards

Cercopithecus or guenon monkeys such as this species, the Blue Monkey (Cercopithecus mitis), have been studied in some depth across their range. Guenon monkeys have cheek pouches in which they store fruits, which they feed on and process after moving away from fruiting trees (Lambert 2001), probably to avoid predation and reduce competition between conspecifics. As they forage in the canopy, they swallow fleshy pulp and spit out seeds, many of which get scattered across the forest floor at low densities, thus potentially avoiding high risk of mortality and increasing the odds for survival and subsequent germination and establishment.

As in other species of primates, communication in these monkeys is likely to be complex and varied. Because of their facial markings, facial expressions are extremely marked. Body postures add to the visual signals used in communication. Vocalizations are common in primates and are probably used by diademed monkeys. Tactile communication occurs between mates and rivals, as well as between mothers and their offspring. Grooming is an important physical activity which helps to solidify social bonds.

Communication Channels: visual ; tactile ; acoustic

Perception Channels: visual ; acoustic

Longevity for this species has not been reported, but if C. mitis is like other members of the genus Cercopithecus, the maximum lifespan is probably around 20 years.

Average lifespan

Sex: female

Status: captivity: 25.0 years.

Average lifespan

Sex: female

Status: captivity: 27.1 years.

Maximum longevity: 37.8 years (captivity) Observations: One 37.8 year old specimen was still alive in captivity (Richard Weigl 2005).

Blue monkeys have a polygynous mating system, although promiscuous mating has been known to occur (Estes, 1991). Females solicit copulation from the males using body language (Estes, 1991). Females present their hindquarters to a male to indicate that they are ready to copulate. During copulation, females pout, looking over their shoulder at the male.

Mating System: polygynous ; polygynandrous (promiscuous)

Breeding occurs throughout the year. The gestation period lasts 5 months (Rudran, 1978). The female gives birth to a single offspring. The young are weaned at about six months and reach sexual maturity at about three years (Grzimck, 1990).

Breeding interval: Females are capable of producing young annually if food is available.

Breeding season: Breeding occurs throughout the year.

Average number of offspring: 1.

Average gestation period: 5 months.

Average weaning age: 6 months.

Average age at sexual or reproductive maturity (female): 3 years.

Average age at sexual or reproductive maturity (male): 3 years.

Key Reproductive Features: iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization ; viviparous

Average birth mass: 366.4 g.

Average gestation period: 132 days.

Average number of offspring: 1.

Average age at sexual or reproductive maturity (male)

Sex: male: 1673 days.

Average age at sexual or reproductive maturity (female)

Sex: female: 1673 days.

The young are relatively well developed at birth, with open eyes and the capability to grasp their mother and support their own weight (Macdonald, 1984). Females provide their young with milk for about six months. Allomaternal care does occur amongst the female troup members (Bourliere and Bertrand, 1970).

Parental Investment: precocial ; 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); extended period of juvenile learning

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Species: 1
Species With Barcodes: 1

Survival threats to blue monkeys include habitat destruction, such as the clearing of rain forests. Blue monkeys are also destroyed for eating cultivated crops or destroying exotic trees (Fleagle, 1988).

US Federal List: threatened

CITES: appendix ii

IUCN Red List of Threatened Species: least concern

Population

Population Trend

Major Threats

Conservation Actions

Blue monkeys eat cultivated crops and destroy exotic trees.

Negative Impacts: crop pest

In Uganda, blue monkeys are hunted for their meat (Fleagle, 1988).

Positive Impacts: food