SCIENCE with Ms Lun
Black & white colobus monkey
Species
There are 6 species of black and white colobus and several subspecies. The species I saw was the guereza (also known as the Eastern black and white colobus, mantled guereza or Abyssinian black and white colobus. The guereza is distinguished by the U-shaped mantle of white hair from its shoulder down the back and a black tail with a white, fluffy tuft at the end.
Colobus guereza
: Colobus guereza occidentalis
: Colobus guereza guereza
: Colobus guereza gallarum
: Colobus guereza dodingae
: Colobus guereza matschiei
: Colobus guereza percivali
: Colobus guereza kikuyuensis
: Colobus guereza caudatus
Colobus angolensis
Colobus satanas
Colobus polykonus
Colobus vellerosus
Eastern black and white colobus (8 subspecies)
: Western guereza
: Omo River guereza; Abyssinian black & white colobus
: Djaffa Mountains guereza ; Neumann's black & white colobus
: Dodinga Hills guereza
: Mau Forest guereza
: Mt Uaraguess guereza; Percival's black & white colobus,
: Eastern black-and-white colobus
: Mt Kilimanjaro guereza
Angolan black and white colobus (8 subspecies)
Black colobus
King or Western black and white colobus
White thighed (or ursine) colobus
Population
As a species, the guereza is classified as of Least Concern but numbers are declining. However, most other black and white colobus species and subspecies are vulnerable, endangered or critically endangered with decreasing numbers.
Size
Black and white colobus monkeys are around 54.3 to 70 cm long plus a tail that is longer than their body (around 76 cm in males). Females are slightly smaller (around 52 and 67.3 cm with a tail length of around 67.8 cm). Males weigh 13.5 kg and females weigh 7.9 - 9.2 kg.
Habitat & distribution
Forests - lowland, montane (mountainous) and gallery (forest restricted to the banks of a river or stream). They can also be found in bamboo stands.
No thumb and special stomachs
Colobus monkeys get their name from the Greek word 'kolobus' meaning 'mutilated' because they lack a thumb. Most primate have a thumb (except colobus and spider monkeys).
Colobus monkeys also have a sacculated stomach. This is a bit like a cow's 4 chambered stomach. Most primates, like humans, have a single chambered stomach. Colobines have three or four chambered stomachs. The forestomach allows leaves to be fermented, breaking down the tough cellulose found in mature leaves.
Diet
Colobus are strictly leaf eaters. While they prefer young leaves, they can eat mature leaves that other monkeys can't eat (see yellow box for more info).
Interesting facts
~ Colobus monkeys are the most arboreal of Africa's monkeys. They jump from tree to tree using branches as trampolines (they jump up an down on them to get the lift they need to jump up to 15 metres!). Their long, white mantle hair and long tail hair is used as a makeshift parachute to help them glide between the trees.
~ While the differences in appearance between the subspecies of guezera is subtle, the differences between the species is more marked. Angolan black and white colobus appears most similar to the guereza but the white hair around the face shoulders is longer and there is no white mantle. The tail fades from black to white in the lower half. The black colobus does not have the white mantle hair; the Western black and white colobus is mainly black but has white hair on its chest and white whiskers and the White thighed colobus is also mainly black with silvery thighs. Their tail is also white and only slightly tufted.
Group
Black and white colobus monkeys live in troops of 8-15 individuals. Usually there is a dominant male with several females and their offspring. They are territorial.
Breeding & lifespan
Gestation is about 6 months. Babies are born with pink faces and white fur, which starts to change at about one month old. By three months old, they have developed adult colouration. Other members of the troop help care for the younger members. Unfortunately, infant mortality rate is high.
The lifespan of a guereza is around 20 years in the wild.
Predators & threats
Natural predators include leopards, large eagles and chimpanzees.
Humans once hunted blacks and white colobus monkeys for their skins (for dance costumes, hats and capes). Humans still pose a threat through deforestation, clearing land for agriculture and settlements.