Black-and-white Colobus

The name colobus means mutilated in Greek, referring to the absent thumb. The adaptation turns the hand into a streamlined hook that locks onto branches during fast canopy travel. Without a protruding thumb catching on twigs, they move through dense forest faster than any other African primate their size.

They are specialist leaf eaters. A multi-chambered stomach with bacterial colonies ferments cellulose the way a ruminant's gut does. This allows colobus to digest mature, tough and even mildly toxic leaves that other primates cannot process. They supplement with unripe fruit, seeds and flowers.

Newborn colobus are born with entirely white fur that gradually darkens over the first three to four months. The high-contrast colouring may encourage allomothering, where other females in the troop carry, groom and protect the infant. It could also help the mother locate the baby quickly in dim forest light.

Arusha National Park has the most accessible population on the northern safari circuit. The montane forest along the crater rim and around the Momella Lakes supports several troops that are habituated to foot traffic. Lake Manyara's groundwater forest and the forested slopes around Ngorongoro also hold populations.

Males produce a deep, resonant roaring chorus that carries over a kilometre through forest. The call is typically given before dawn and serves as a territorial declaration to neighbouring troops. Multiple males in a troop join in, creating a rolling sound that is one of the most distinctive noises in East African montane forest.

Black-and-white colobus are listed as Least Concern by the IUCN. However, populations are fragmented by deforestation across much of their range. In Tanzania, protected montane forests in the northern highlands remain strongholds. The species historically suffered heavy hunting for its fur, which was used in ceremonial garments and exported as fashion trim.