Mammals
Black-and-White Colobus
Colobus guereza · also called guereza, eastern black-and-white colobus
Draped in a flowing mantle of long white fur, a black-and-white colobus leaps confidently between trees despite having almost no thumbs at all, its multi-chambered, cow-like stomach quietly breaking down the tough rainforest leaves that make up nearly its entire diet.
Overview
The black-and-white colobus, Colobus guereza, is a striking, leaf-eating monkey native to rainforest and forest habitat across parts of East and Central Africa. Its cow-like multi-chambered stomach for digesting tough leaves, dramatic mantle of flowing white fur, and pure-white newborn coat that darkens with age make it one of the most visually distinctive and physiologically specialised monkeys found anywhere in Africa.
A monkey built like a cow, dressed like a cape
Combining a digestive system more reminiscent of a grazing mammal than a typical monkey with one of the most dramatic coats in the primate world, the black-and-white colobus stands out as both a physiological and visual outlier among Africa’s forest primates.
Status
Least Concern, remaining widespread across suitable rainforest and forest habitat throughout parts of East and Central Africa.
Black-and-White Colobus: common questions
Why does the black-and-white colobus have a stomach like a cow's?
This species has a specialised, multi-chambered stomach that uses bacterial fermentation to break down tough, fibrous leaves, an adaptation functionally similar to a cow's digestive system and essential to a diet consisting almost entirely of leaves.
Why are baby black-and-white colobus monkeys white?
This species gives birth to infants with pure white fur, a colouring that gradually darkens over several months into the bold black-and-white pattern seen in adults, a striking transformation that makes newborns easy to spot within a troop.
Why does the black-and-white colobus have such small thumbs?
This species has greatly reduced thumbs, an adaptation believed to aid rapid, efficient movement through the forest canopy, allowing for quick hand-over-hand travel even though it sacrifices some grip strength compared with monkeys that retain a full thumb.
How does the black-and-white colobus move through the forest?
This species can make dramatic leaps between trees, using its long limbs and momentum to cover considerable distance through the canopy despite lacking the strong grip a full thumb would normally provide.