Very noisy, with constant squeals and high-pitched birdlike whistles and chirps, they are considered the most vocal of the New World primates. This monkey has 26 separate calls which are different combinations of a few basic sounds. The vocalizations probably serve to maintain contact within the group, as well as, to provide information among individuals. The core of the group is adult females and their offspring. The large group breaks up into subgroups of 5-8 as they forage for insects and fruit.
Females receive no help from adult males in caring for their young.
A newborn squirrel monkey weighs 3 ounces. It rides on the mother's back by gripping her fur. A young squirrel monkey becomes independent at one year of age. Squirrel monkeys can live 15-20 years.