This species is found from the south and east of the Congo-Oubangui River system in central Africa, through Uganda to the Rift Valley in Kenya and western Tanzania; it ranges as far south as northern Angola to north-western Zambia Gautier-Hion et al. 1999; Butynski 2002). It is known to occur up to 2,000 m.

There are five recognized subspecies:

The subspecies C. a. ascanius is present in Angola and south-western Democratic Republic of the Congo, south of the Congo and Kasai Rivers, generally below 500 m asl. North of this, some animals between the Kasai and Lukenie rivers may be attributable to this form (Sarmiento et al. 2001).

C. a. atrinasus is restricted to the vicinity of the type locality of Zovo, Angola on the Lunda Plateau at about 850 m asl. Although the type locality is near DR Congo, this subspecies has never been recorded from this country (Sarmiento et al. 2001).

The southern subspecies C. a. katangae is present mainly in southern Democratic Republic of the Congo and Angola, between the Kasai and Lualaba Rivers at 500-1,300 m asl (see Sarmiento et al. 2001 for details). It is also reported in north-western Mwinilunga District (Ansell 1978).

C. a. whitesidei is present in the Democratic Republic of Congo where it ranges mostly south and east of the Congo River and west of the Lomami. The Lukenie marks the southern boundary, although monkeys that are similar to this taxon are known from south of the river (Sarmiento et al. 2001).

The eastern subspecies C. a. schmidti has the widest distribution of the five subspecies and occurs from east of the Lualaba River, Democratic Republic of Congo, into Uganda, Rwanda, Tanzania and Kenya, and also occurs north of the Congo River where it is found north of Bangui, Central African Republic to southern Sudan in the east (see Sarmiento et al. 2001). It ranges between 400 and 2,500 m asl, mainly at elevations about 1,300 m in the eastern part of its range (Sarmiento et al. 2001).

Transitional forms are said to occur between whitesidei and katangae, katangae and ascanius, and katangae and atrinasus. There is a wide transitional zone between ascanius and atrinasus (Lernoud 1988; Sarmiento et al. 2001).

Redtail monkeys (Cercopithecus ascanius) are found in Africa from the Central African Republic eastwards through Kenya and south into Angola and Zambia. Populations are most dense in Uganda.

Biogeographic Regions: ethiopian (Native )

This relatively small primate exhibits some sexual dimorphism in weight and body length. Males have an average mass of 4.1 kg and a length of approximately 46 cm. Redtail monkey females, in contrast, average 2.9 kg in mass and about 38 cm in length (Torstar Books 1984; Smuts et al. 1987).

Other than size differences, males and females of this species are very similar. The recognizable markings of adult redtail monkeys include a black face, bluish skin around the eyes, a white spot on the nose, and white cheek fur. The name 'redtail' comes from the chestnut-colored fur on the underside of the tail. The rest of the body is covered with a speckled brown coat and gray or black limbs, depending on the subspecies (Torstar Books 1984).

Redtail monkey infants have woolly gray fur at birth. Although they are born with a visible nose spot, young redtail monkeys have a brown tail and no cheek whiskers. As they mature, their markings begins to resemble those of adults (Kingdon, 1984).

Range mass: 2 to 6 kg.

Average mass: males: 4.1 kg; females: 2.9 kg.

Average length: males: 46 cm; females 38 cm.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: male larger

Habitat and Ecology

Systems

• Terrestrial

Redtail monkeys can live in a rather large variety of habitats. They are mainly found in the middle canopy of tropical rain forest habitats. However, they have also been observed in swamp forests, secondary forests, riverine gallery forest, and other woodlands (Smuts et al. 1987).

Habitat Regions: tropical ; terrestrial

Terrestrial Biomes: forest ; rainforest

Redtail monkeys are primarily frugivorous, but supplement their diet with leaves, insects, flowers, buds, and gum (Torstar Books, 1984; Chapman and Chapman, 2000).

It is common for adults to store fruit in their large cheek pouches in order to take their meal to an area free from the threat of theft by other monkeys (Torstar Books, 1984).

Animal Foods: insects

Plant Foods: leaves; fruit; flowers; sap or other plant fluids

Primary Diet: herbivore (Frugivore )

Because these monkeys are frugivorous, and can transport fruits in their cheek pouches, it is likely that they play some role in seed dispersal. In addition, as a prey species, they probably have some effect on predator populations.

Ecosystem Impact: disperses seeds

Cercopithecus ascanius is potential prey for chimpanzees, crowned hawk-eagles, wild cats, and humans (Kingdon, 1984; Leland and Struhsaker, 1993). It is also likely that these monkeys fall victim to the same predators that trouble other small, arboreal primates in African forests. These include leopards, snakes, and a variety of avian predators.

Known Predators:

• Humans
• Chimpanzees
• Crowned hawk-eagles
• Leopards

As in all primates, communication in this species is complex, and includes chemical, visual, auditory, and tactile components. The visual communication system consists of eyebrow raising, facial skin stretching, and head-bobbing (Estes, 1991). These signals are commonly used to warn potential predators or unwanted intruders. Vocal communication consists of birdlike chirps between members of a group (Kingdon, 1984). This form of communication is mainly used socially among members of the same unit. These associated individuals may also identify one another by nose-to-nose greeting, in which two individuals press their muzzles together. After this greeting they will commonly practice reciprocal social grooming or play (Estes, 1991).

Communication Channels: visual ; tactile ; acoustic ; chemical

Perception Channels: visual ; acoustic

Although data are not available for this species, other members of the genus Cercopithecus are known to live in captivity for more than 30 years. It is likely that C. ascanius is similar to other members of the genus in lifespan. Lifespan in the wild is likely to be somewhat shorter than it is in captivity.

Average lifespan

Status: wild: 30 years.

Average lifespan

Sex: female

Status: captivity: 25.9 years.

Average lifespan

Sex: female

Status: captivity: 28.3 years.

Maximum longevity: 31.2 years (captivity)

Cercopithecus ascanius displays a polygynous-promiscuous mating system (Cords et al., 1984). This type of mating characterizes populations in which one male mates promiscuously with the females of the group. Since females show no outward signs of receptiveness they frequently elicit matings with males from their own group or from wandering male groups through a behavior known as presenting (Estes, 1991).

Mating System: polygynous ; polygynandrous (promiscuous)

Redtail monkeys generally breed throughout the year, although the peak season is from November to February (Smuts et al., 1987). The majority of pregnancies produce a single infant.

Although data are lacking for C. ascanius, in general, species in the genus Cercopithecus have gestations ranging in duration from around 5 months to a maximun of 7 months. Newborns typically weigh around 400 g, and are entirely dependent upon the mother for transportation and nourishment (Nowak, 1999). It is reasonable to assume that C. ascanius is similar in these respects to other members of the genus.

Males generally reach sexual maturity at the age of six, females mature at four or five years of age (Smuts et al., 1987).

Breeding interval: It is likely that females are capable of producing young each year.

Breeding season: Redtail monkeys generally breed throughout the year, although the peak season is from November to February

Average number of offspring: 1.

Average gestation period: 6 months.

Range age at sexual or reproductive maturity (female): 4 to 5 years.

Average age at sexual or reproductive maturity (male): 6 years.

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

Average birth mass: 371 g.

Average gestation period: 147 days.

Average number of offspring: 1.

As in most primates, parental care is mainly the responsibility of females. Young are altricial, and must be carried for the first several weeks of life. Mothers provide food (milk) for their young, as well as transportation and grooming.

Female guenons typically have life-long associations with their kin. The dominance rank of a female within her social group will affect the dominance rank of her daughters.

Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Protecting: Female); post-independence association with parents; extended period of juvenile learning; maternal position in the dominance hierarchy affects status of young

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

Although redtail monkey populations are currently healthy, there is some concern about their future status. As is the case with many rainforest dwelling animals, the threat of habitat loss by deforestation is a major concern. Since C. ascanius inhabits a relatively small area on the African continent, loss of habitat could be detrimental for the future of this primate species.

Redtail monkeys are also threatened by predation. They are potential prey for chimpanzees, crowned hawk-eagles, wild cats, and humans (Kingdon, 1984; Leland and Struhsaker, 1993).

Redtail monkey populations are depleted by distraught farmers that view them as pests and shoot them on sight (Leland and Struhsaker, 1993).

US Federal List: no special status

CITES: appendix ii

IUCN Red List of Threatened Species: least concern

Population

Population Trend

Major Threats

Conservation Actions

Cercopithecus ascanius regularly practices crop raiding of nearby agricultural gardens containing maize, banana, millet, bean, pumpkin, pineapple, or passion fruit crops (Kingdon, 1984). In regions of low productivity this behavior has become a serious problem for neighboring human villages.

Redtail monkeys are also one of the major carriers of yellow fever in Africa (Kingdon, 1984). When the monkeys venture into human villages to raid their crops, there is a greater chance that an infected individual could spread this disease to the villagers.

Negative Impacts: injures humans (causes disease in humans ); crop pest

Redtail monkeys have been instrumental in the regeneration of Strychnos mitis, a tree species found in the Kibale Forest. Redtail monkeys feed heavily on the fruit of this tree. As they eat the fruit, they spit the intact seeds, which fall to the rainforest floor where the seeds can successfully germinate. This method of seed sowing produces more saplings annually than the fruit would normally produce without the help of redtail monkeys (Lambert 1995).

 Redtail monkeys have also been useful as laboratory animals in studies on various viral diseases (Kingdon 1984).