Native to tropical and subtropical forests of South America,[4] the gray-bellied night monkey faces a significant threat from hunting, harvesting for use in pharmaceutical research and habitat destruction.

[5] Like other members of their genus, this species is nocturnal; its small, round head is striped with black and is dominated by two large, brown eyes.

By day the monkey slumbers in the cavities of trees or in dense thickets; by night, it searches the canopy for a variety of food items.

Primarily a frugivore (fruit-eating), this monkey also eats vegetation, insects, nectar, and even other small mammals and birds when fruit is scarce.

Most active during twilight hours and periods of bright moonlight, the gray-bellied night monkey troop consists of a mated pair and their offspring, up to five individuals in total.

Characteristically vociferous, the monkey produces a range of calls: from soft clicks and low-pitched guttural rumblings to owl-like hoots and high-pitched shrieks when threatened.