Woolly Monkey

Common Woolly Monkey

Common, or Humboldt’s, woolly monkeys are the largest of all monkeys. (Only the muriqui, or woolly spider monkey, is appreciably bigger.) These monkeys live in high forests on the slopes of the Andes Mountains and Mato Grosso in Brazil. They spend time at the top of the tallest trees, which protrude from the forest canopy. On the ground, they may walk on their hind legs, using their heavy tails to keep them upright. They are diurnal animals and eat mainly fruit and insects, but they can survive on leaves and seeds if necessary.

Heavier in build than the spider monkeys, the common woolly monkey has short, thick hair. Its head is rounded, its body robust, and it has a prominent belly. Fast and agile in the trees, it moves on all fours and by swinging hand over hand, but it is less graceful than the spider monkeys. Its thumbs and toes are well developed for grasping branches, and it has a strong, prehensile tail with a sensitive naked area near the tip.

The fur is thick and black, and the body is very heavyset compared to other tree-dwelling monkeys. Older monkeys grow a fringe of long hair on the backs of their arms and legs.

Common woolly monkeys live in groups of about eight individuals. They communicate using a range of facial expressions and calls. Males, which are heavier than females, often display their long canine teeth with wide yawns to warn off rivals.

The female gives birth to 1 offspring after a gestation period of 18 to 20 weeks. The young monkey holds on to the fur of its mother’s belly or back at first and is carried around, but after a few weeks it is able to clamber about the branches unaided. The female suckles her young for 12 months or more. Common woolly monkeys become sexually mature at about 4 years old.

Distribution: Northern South America.

Habitat: Tropical forest.

Food: Fruits, leaves, seeds and insects.

Size: 40 - 70 cm (16 - 28 in); 5 - 10 kg (11 - 22 lb).

Maturity: 5-8 years. Breeding: 1 young produced every 2 years.

Life span: Unknown.

Status: Vulnerable.

Brown Woolly Monkey

These noisy primates are very playful by nature, and juvenile monkeys in particular spend a lot of time playing around with each other.

Active during the daytime, these woolly monkeys live in groups numbering between 10 and 45 individuals, although they will split up and head off separately when foraging. Wild figs are their favoured food. Although there is a hierarchy within the troop, all males will mate with receptive females, but it is the dominant male that assumes precedence. Their territory may overlap with neighbouring groups, which can be joined by young females as they mature and leave their natal troop.

Distribution: Found in South America, in parts of Colombia, Venezuela, Peru and Ecuador, as well as Bolivia and Brazil, favouring different areas of habitat throughout its range.

Weight: 3.5 - 10 kg (7.7 - 22 lb); males are bigger.

Length: 99 - 140 cm (39 - 55 in) overall; the tail is slightly longer than the body.

Maturity: Females 6 - 8 years; males 5 years.

Gestation Period: About 225 days.

Breeding: 1; weaning occurs at 9 - 11 months; females give birth every 1.5 - 2 years.

Diet: Frugivorous, eating fruit, as well as vegetation an invertebrates.

Lifespan: Nearly 26 years in captivity.


Long and prehensile, the tail helps the woolly monkey hold on to branches securely.


The head is rounded, with very small ears on the side.


The frontal location of the eyes helps the monkey land safely when jumping.

Tail in close-up

There is no fur on the underside of the tail, near the tip, making it easier for the monkey to grip branches.


The colour varies from a relatively light to a very dark, blackish-brown shade.


The huge harpy eagle represents a serious danger to woolly monkeys, who utter a warning call on sighting an eagle, then hide under the leaves in the hope of escaping detection.