Usually quiet but utters loud cries when alarmed. Arboreal although occasionally descends to ground. Associate in bands of 12-100. Squirrel monkey groups are subdivided into adult male bands, mother-infant bands, and juvenile bands. Adult females with their young form the core of the group.
Adult males intermingle with the females only during the several months of mating season.
Single young born after 6 months gestation. Mother is not particularly attentive. Life span is 15 years. Squirrel monkeys move through the trees by leaping. This odor turns away hunters who might otherwise kill them for food.