Uakaris mainly feed on fruit, but will also eat leaves, insects and small vertebrates. Although they are quite agile, uakaris rarely jump from branch to branch. They almost never come down to the ground. The distinctive faces of these monkeys have a purpose. Females select males with the reddish faces, as they are regarded as the strongest in the troop.
Uakaris live in large troops of 12 - 33 individuals. In areas where forests have not been damaged by human activity, groups of over 100 have been reported. Uakari troops often get mixed in with those of other monkeys, such as squirrel monkeys, during daytime feeding forays.
Bald uakaris have hairless, red faces fringed with shaggy fur, hence their name. The long fur on the body is pale but looks reddish-brown, and a few have white fur. Their clubbed tails are proportionally shorter than those of other New World monkeys.
Each troop has a hierarchical structure, which is maintained by fighting among both , sexes. The dominant males control access to females in a troop during the breeding season. Females give birth to a single young every two years.
Part of the difficulty in studying these monkeys is that they occur in areas of forest that tend to be flooded for much of the year. Uakaris live high up in the canopy, where they are hard to observe due to their generally quiet nature. In fact, the existence of a new species in Brazil was confirmed in 2008. If they do descend to the ground, other members of the troop serve as look-outs, warning of approaching danger.
Distribution: Occurs in northern South America, but its precise distribution is unclear. Concentrated in the central Amazon basin, from Colombia and Venezuela down to Peru and Brazil.
Habitat: Beside rivers in flooded forests.
Weight: 2.3 - 3.5 kg (5.1 - 7.7 lb)
Length: 54 - 56 cm (21 - 22 in) overall; tail is a third of the body length
Maturity: Females about 3.5 years; males 5.5 years
Gestation Period: About 135 days
Breeding: 1; weaning occurs at 15 - 21 months
Diet: Strong teeth allow these monkeys to crack tough-cased fruit, nuts and invertebrates
Lifespan: Up to 20 years in the wild.
The face is hairless up to the top of the head and is bright red.
Females release a chemical messenger when ready to mate so males require a good sense of smell.
These monkeys have the shortest tails of all New World monkeys.
This race (C. c. calvus) is characterized by its silver-white fur.
Young bald uakaris are carried on their mother’s backs at first, gripping on to the sides of her body. They have dark fur.
Bald uakaris with this orange-red fur belong to the subspecies C.c. rubicundus, rather than being a separate species.
Size: 30 - 50 cm (12 - 19.5 in); 2.4 - 4 kg (5.25 - 8.75 lb).
This more common relative of the bald uakari lives east of the Japura River up to the Negro and Branco Rivers (all tributaries of the Amazon). It lives in flooded forests as well as highland forests. There is black fur on its head and back, but the tail is paler, even yellow in some individuals. Black ukaris eat mainly seeds, which they collect when the fruits are still on the trees. They climb down to the ground to feed on fallen nuts if other food is scarce.