Colobus guerezaguereza

Geographic Range

Colobus guereza is found in diverse regions of equatorial Africa. This species is found in the lowland tropical rainforest to the upper reaches of the Montane forests of the upper Donga river and tributaries, as well as Acacia-dominated riverine galleries and evergreen thicket forests. Guerezas are also found in the equatorial areas of Africa including Nigeria, east and west of the Niger river, and locally distributed in relic forests north of the rainforest zone. They are also found along the Donga river, Gashaka, Ngelnyaki, Cameroon, Ethiopia, Gojjam, Kulla, Kenya, Uganda, Tanzania, N Congo, E Gabon, Central African Republic, NE Zaire, W Kenya, NW Rwanda, and S Sudan.

(Bateman, 1984; Grzimek, 1988; Happold, 1987; Honacki, 1982; Kingdon, 1987; MacDonald, 1984; Nowak, 1991)


Guerezas live in forest, woodlands, or wooded grasslands. They can also survive in dry, moist, or riparian forests that are either in lowlands or up to 3,300 m. They are most abundant in secondary forests or along rivers. They tend to live in the lower part of the trees if their area does not overlap with that of any other group of monkeys. When trees are not densely spaced, guerezas feed and travel on the ground.

(Bateman, 1984; Grzimek, 1988; Happold, 1987; MacDonald, 1995; Nowak, 1991)

  • Range elevation
    3,300 (high) m

Physical Description

Colobus guereza is a heavy bodied animal with a long tail. The head and body length is 45 to 72 cm and the tail length is 52 to 100 cm. Guerezas are slightly sexually dimorphic in that the males can weigh up to 1.19 times more than females. Guerezas have only four digits on each hand; the thumb is absent or represented by a small phalangeal tubercle that sometimes bears a nail. The loss of the thumb may be an adaptation for quick movements through the trees.

Members of the genus Colobus, which are in the subfamily Colobinae, are distinguished from members of the other subfamily, Cercopithecinae, by the absence of cheek pouches and the presence of prominent ischial callosities that are separate in females and contiguous in males.

The stomach of C. guereza is complex. It is subdivided by a partition into 2 subregions. The upper region contains a neutral medium, which is necessary for the fermentation of foliage by anaerobic bacteria. The black and white monkeys' large salivary glands provide a buffer fluid between the two regions of the stomach.

The coloration of fur is distinctly black and white. The face is gray and has no fur. The coat is glossy black, and the face and callosities are surrounded by white. A U-shaped white mantle of varying length is found on the sides. The outside of the thigh is variably whitish, and the tail is either a whitish or yellowish color from tip to base. There is also a large white tuft at the end of the tail.

The skull is prognathous, that is, the lower jaw projects beyond the upper. The orbits are relatively small and oval with narrow superciliary ridges. A postorbital bar forms a plate on the side of the skull separating the orbit from the temporal fossa. The nostrils are more or less lengthened by an extension of nasal skin, and the nose nearly touches the mouth.

The molar teeth have high pointed cusps, and the inside of the upper molars and the outside of the lower molars are slightly convexly buttressed. The enamel on the inside of the lower incisors is thick, and there is a lateral process on the lower second incisor.

The young of the C. guereza do not share the black and white coloration, but instead have pure white fur for the first weeks of their life.

(Bateman, 1984; Grzimek, 1972; Grzimek, 1988; Happold, 1987; Honacki, 1982; Kingdon, 1987; MacDonald, 1984; Nowak, 1991)

  • Sexual Dimorphism
  • male larger
  • Range mass
    5 to 14 kg
    11.01 to 30.84 lb
  • Range length
    45 to 72 cm
    17.72 to 28.35 in
  • Average basal metabolic rate
    17.037 W


Guerezas have a polygynous mating system.

There seems to be little or no reproductive seasonality in most populations of Colobus monkeys that have been studied, but there tends to be a birth peak, timed so that weaning coincides with the greatest seasonal abundance of solid food. The age of full sexual maturity in the guerezas is at least 6 years in males and 4 years in females. Each adult female produces one young every 20 months after a gestation period of about 6 months.

Sexual behavior is usually initiated by the female by tongue smacking. During copulation, the female remains prone.

(Bateman, 1984; Grzimek, 1988; Metro Washington Park Zoo, 1995)

  • Breeding interval
    Guerezas breed once every two years.
  • Breeding season
    Breeding is not strictly seasonal, although births are timed so that weaning occurs at the time of greatest food availability.
  • Average number of offspring
  • Average number of offspring
  • Average gestation period
    6 months
  • Average gestation period
    175 days
  • Average age at sexual or reproductive maturity (female)
    4 years
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    1461 days
  • Average age at sexual or reproductive maturity (male)
    6 years
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    2192 days

At birth, the infants are about 20 cm in head-body length and weigh about 0.4 kg. The eyes are open and the infant clings to the mother's or father's stomach. The weaning age is not known. Both the female and the male take part in the parenting of the child. Female guerezas remain in their natal group. This means that mothers and daughters have life-long relationships.

  • Parental Investment
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • male
      • female
  • pre-independence
    • provisioning
      • female
    • protecting
      • male
      • female
  • post-independence association with parents
  • extended period of juvenile learning
  • inherits maternal/paternal territory


A member of the related species Colobus polykomos is reported to have lived 23.5 years in captivity. The lifespan of C. guereza is similar, throught to be about 29 years in captivity and about 20 years in the wild.

(Bateman, 1984; Grzimek, 1988; Nowak, 1991)


Guerezas are generally diurnal. They are highly arboreal residents of deep forest. However, when the trees are not densely packed, guerezas will feed and travel on the ground.

Guerezas live in sexually mixed groups averaging 8 to 15 individuals, with usually only one fully adult male and three or four reproducing females, adolescents and infants. Sometimes several males are present in mixed groups, but only temporarily. The fixed core of the mixed group consists of the females, who remain in the group of their birth for life. These females are thought to be close relatives that display their friendly intragroup relationships, marked by mutual grooming and well-developed "infant transfer." This latter phenomenon consists of an infant being handled by several females soon after birth and carried as far as 25 m from its mother. A mother may even suckle the infant of another female and her own simultaneously.

Black and white colobus monkeys spend most of their time sitting in the tops of trees; and they take turns sleeping at night so that at least one individual is awake at all times to watch for predators.

Unlike females, young males leave the group of their birth before they are fully mature. The adolescent guereza males leave their birth group either voluntarily or due to force from the adult male of the birth group. Upon leaving their natal group, young males lead a solitary life or temporarily associate with other solitary males. Some black and white monkey males eventually take over their own harem and create a new group.

There is no true leader of a group, but strong males usually take leadership roles. There are definite indications of infanticide in consequence of the threat of male replacements within mixed groups.

Intergroup relationships are not friendly among mixed groups of guerezas, which live in well-defined territories of about 32 to 40 acres. Territories may overlap marginally; they are vigorously defended by males with leaps and cries, hand-to-hand communication, roars, and occasional chasing and fighting. Additionally, displays of the white fringe fur flapping up and down serve as warning to other monkeys. Some groups, however, do share water holes and other essential resources.

(Bateman, 1984; Grzimek, 1972; Grzimek, 1988; Happold, 1987; Nowak, 1991; The Phoenix Zoo)

Home Range

Colobus guereza groups live in well-defined territories of about 32 to 40 acres.

Communication and Perception

Male guerezas roar loud nocturnal and dawn choruses as a means of spacing groups. Five vocal sounds have been recorded: roars, snorts, purrs, honks, and screams.

In addition to vocal communication, visual signals, such as flapping of fringe fur, facial expression, and body posture are used in aggressive communication between groups.

Tactile communication in this species includes grooming, playing, and fighting.

(Bateman, 1984; Grzimek, 1972; Grzimek, 1988; Happold, 1987; Nowak, 1991; The Phoenix Zoo)

Food Habits

Guereza are the second most folivorous of the Colobus species. Their diet consists primarily of leaves (especially from Celtis durandii, or Hackeberry Tree) with about 58% of young unripe leaves, 12.5% mature leaves, 13.5% fruits, 4% leaf buds, and 2% blossoms. However, this distribution is highly varied seasonally and geographically; thus at times mature leaves may account up to 34% of the diet. Guerezas seem to prefer leaves that are less susceptible to seasonal fluctuations. Guereza get water from dew and the moisture content of their diet, or rainwater held in the tree trunk hollows. In captivity C. guereza is fed monkey chow, fruits and vegetables.

Natural enemies of the guereza are crowned hawk eagles, leopards, and sometimes chimpanzees.

(Bateman, 1984; Grzimek, 1988; Kingdon, 1987; Metro Washington Park Zoo, 1995; Nowak 1991,

  • Plant Foods
  • leaves
  • fruit
  • flowers


Natural enemies of guerezas are crowned hawk eagles, leopards, and sometimes chimpanzees.

(Bateman, 1984; Grzimek, 1988; Kingdon, 1987; Metro Washington Park Zoo, 1995; Nowak 1991,

Ecosystem Roles

As herbivores which serve as prey for several other species, these monkeys may play an important role in food webs.

Economic Importance for Humans: Positive

Guerezas are used in animal testing concerning human diseases, behavior, and physiology. For example, studies have been performed that test for certain behavioral responses when the territory of a guereza group is threatened. Another study tested the effects of rickets (vitamin-D deficiency) on guerezas. Other studies deal with how phenotypic variability is inversely related to selection intensity. A final example is a study dealing with the effects of an experimental serum for Mycobacterium bovis. The data collected in these studies has proved invaluable.

Colobus guereza is one of many monkey species that is sacred to the Hindu and Buddhist religions. They play a major role in these religions as icons of sacred gods.

Colobus guereza fur has been a luxury for people in some cultures and has brought in large amounts of money to trade and fur companies.

(Grzimek, 1988; Morrisey, 1995; Stetter, 1995; Suedmeyer, 1996; Von-Hippel, 1996)

Economic Importance for Humans: Negative

These monkeys do not really initiate contact with humans. Therefore, the only negative effects from these black and white monkeys are the few instances when guerezas eat agricultural crops, probably due to inhospitable environmental conditions.

(Grzimek, 1988)

  • Negative Impacts
  • crop pest

Conservation Status

There has been a drastic decline in Colubus populations over the last 100 years. Guerezas are noted in Appendix II of the Concentration in International Trade of Endangered Species (CITES). Population sizes of black and white monkeys are currently declining in many localities due to hunting and deforestation by humans. Nevertheless, since 1934 it has been reported that guerezas are "not uncommon" in suitable protected habitats. For example, guerezas are still abundant in most parts of their lowland ranges in Cameroon and the Nigerian border, and in East African reserves and parks. Although guerezas are still abundant, there is the potential for extinction of eastern populations from unrestricted skin trading.

(Honacki, 1982; Happold, 1987; Kingdon, 1987; Metro Washington Park Zoo, 1995; 1996)

Other Comments

First seen by Ruppell in 1835, black and white monkeys have been widely studied. When the range of guerezas overlaps with that of red colobus monkeys, guerezas feed from fewer species of trees (usually less than half of the usual number) and choose different plant parts. Their tolerance of a less varied diet allows them to occupy forests or thickets with impoverished or specialized flora. Their sacculated stomachs and highly efficient extraction of nutrients from their food allow them to survive on a less nutritious diet than monkeys lacking bacterial fermentation. Natural enemies of the guereza are crowned hawk eagles, leopards, and sometimes chimpanzees. If guerezas are able to live a life absent of predator threat, longevity is about 20 years (29 years in captivity).

An interesting fact about Kenyan guerezas living in high altitudes is that albinism is frequent, but for unknown reasons.

Colobus means "mutilated one". The name was given to these monkeys because they have no thumbs.

(Bateman, 1984; Grzimek, 1988; Happold, 1987; Nowak, 1991)


Nancy Shefferly (editor), Animal Diversity Web.

Kenneth Kim (author), University of Michigan-Ann Arbor.



living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

World Map


uses sound to communicate


Referring to an animal that lives in trees; tree-climbing.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


uses smells or other chemicals to communicate

  1. active during the day, 2. lasting for one day.
dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates


animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.


an animal that mainly eats leaves.


forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.


An animal that eats mainly plants or parts of plants.


offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).


having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.


having more than one female as a mate at one time


rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.


Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).

scrub forest

scrub forests develop in areas that experience dry seasons.


remains in the same area


reproduction that includes combining the genetic contribution of two individuals, a male and a female


associates with others of its species; forms social groups.


uses touch to communicate


Living on the ground.


defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement


the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.


uses sight to communicate


reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year


Bateman, G. 1984. Encyclopedia of Mammals. Facts on File, Inc. New York, NY. 389-405.

Grzimek, B.. 1972. Grzimek's Animal Life Encyclopedia v.10 Van Nostrand Reinhold Company, NY, Cincinnati, Toronto, London, Melborne.

Grzimek, B. 1988. Grzimek's Encyclopedia of Mammals. McGraw-Hill, Inc. Muncher, West Germany. 2:318-24.

Happold, D.C.D. 1987. Mammals of Nigeria. Clanrendon Press and Oxford University Press. New York, NY. 13, 89, 97-8.

Honacki, J. 1982. Mammal Species of the World. Allen Press Lawrence, Kansas. 233

Kingdon, J.1987. The Kingdon Field Guide to African Mammals. Academic Press. San Diego, CA. 29-30.

MacDonald, David. 1984. The Encyclopedia of Mammals. Facts on File Publications, NY.

Metro Washington Park Zoo.1995.

Morrisey, J. 1995. Vitamin-D-deficiency rickets in three colobus monkeys (Colobus guereza kikuyuensis) at the Toledo Zoo. Journal of Zoo and Wildlife Medicine. 26(4): 564-568.

Nowak, R. 1991. Mammals of the World. Johns Hopkins University Press. Baltimore, MD. 1: 490-91.

Phoenix Zoo 1996.

Stetter, M. 1995. Isoniazed and rifampin serum levels in a colobus monkey (Colobus guereza caudatus) infected with Mycobacterium bovis. Journal of Zoo and Wildlife Medicine. 26(1): 152-154.

Suedmeyer, W. 1996. Forelimb tremor in two colobus monkeys (Colobus guereza kikuyuensis). Journal of Zoo and Wildlife Medicine. 27(3): 421-425.

Von-Hippel, F. 1996. Interactions between overlapping multimale groups of black and white colobus monkeys (Colobus guereza) in the Kakamega Forest, Kenya. American Journal of Primatology. 38(3): 193-209.