These small monkeys, about a foot long and weighing two pounds, are the most common monkeys found in South America. They are known for hopping from branch to branch like squirrels. Their tails are longer than their bodies but are not prehensile and cannot grasp objects or hold onto branches. Instead, they are used for balance. Squirrel monkeys use their hands and feet to move deftly through the middle canopy and can jump more than six feet from a standing position. Because of their small size, they can easily access fruit at the ends of branches. In squirrel monkeys, only females are able to see red; males are red-green color blind.

Squirrel monkeys live in large multi-male, multi-female groups of 20 to 75 individuals. Sometimes several groups join together for a period of time, creating troops of 300 or more. Large groups often split off into smaller groups during the day to forage. Sub-groups may be adult males, juveniles, or mothers and young. They forage alongside capuchin monkeys to whom they are related. More eyes mean a better chance of spotting predators and sounding the alarm. Squirrel monkeys are noisy, using squeals, whistles, and chirps to communicate with other members of their group. When threatened, they can defend themselves with a nasty bite. Predators include eagles, boas, anacondas, ocelots, and jaguars.

Breeding is seasonal and synchronized within the group, so all babies are usually born within a week of each other. Births are timed to coincide with the rainy season when food is most abundant. Males breed with multiple females. After a five month gestation, a female will give birth to a single offspring. Males do not help raise infants, but other females may step in to help (a behavior known as allomothering).


Tropical rainforests of Central and South America.


Squirrel monkeys are omnivorous, but they prefer fruit, nuts, and insects. Water is obtained from the food they eat, and water-filled holes in trees.

Physical Characteristics

Body length averages 12 inches and weight is about two pounds. Lifespan in the wild is 10 to 15 years; in human care it can be 20 years or more.