A monkey with dense black hair, slightly lighter on the back, and a black beard. They live in groups in the canopy of the Amazonian rainforest.

Statistics
Females 38-41cm with a 37-42cm long tail and weighing 1.9-3.3kg. Males 40-48cm with a 40-42cm long tail and weighing 2.2-4kg.

Physical description
A small monkey with dense, medium-length black fur and a long bushy tail (prehensile in youngsters). The fur on the back and shoulders is paler, from dark brown to yellowish. The face has distinctive swollen temples covered with fur, and a long beard about the same length as the face.

Distribution
An area north of the Amazon from the Rio Negro east and south of the Rio Orinoco into the Guianas, and south of the Amazon from Rio Tocatins east to the Atlantic.

Habitat
Mostly unflooded forests, but also montane savannah and swampy forests.

Diet
Seeds and some fruit.

Behaviour
Sakis are active during the day, mostly in the upper canopy of the forest, where they live in groups of 8-30 individuals including several males.

Reproduction
Little is known about the breeding of sakis, but the gestation period is about 5 months, and only one youngster is born at a time.

Conservation status
Endangered