Squirrel Monkeys and Capuchins: Cebidae

Physical characteristics: Common squirrel monkeys weigh 1.5 to 2.75 pounds (0.6 to 1.2 kilograms), with the males being larger than the females. They measure about 12 inches (30 centimeters), with a tail length of about 16 inches (41 centimeters). The fur is short and dense. The round head is gray to black on top, with a white face mask and a black snout surrounded by black fur. Eyes are large and ears are small. The back is olive-gray, and the underparts are light yellow. The forearms, hands, and feet are yellow-orange. The long tail tipped with black is non-prehensile, or incapable of grasping things such as tree branches.

Common squirrel monkeys feed mainly on soft fruits and insects. (Norman Owen Tomalin/Bruce Coleman Inc. Reproduced by permission.)

Geographic range: Common squirrel monkeys are found in Brazil, Colombia, French Guiana, Guyana, Suriname, and Venezuela.

Habitat: Common squirrel monkeys occupy the middle layers of the forest with abundant vines and other vegetation. They also inhabit mangroves and forests along rivers and streams.

Diet: Common squirrel monkeys feed mainly on soft fruits and insects. They also eat frogs, spiders, snails, crabs, and occasionally bats.

Behavior and reproduction: Depending on available habitat, common squirrel monkeys live in groups of twenty to 300. Subgroups of males, mothers with offspring, and juveniles are formed within the main group. They are active during the day, foraging together in small groups. They are mostly arboreal but are sometimes found on the ground. They normally walk on all fours, but can move on their hind legs.

Males and females have several partners. Before the mating season, adult males gain weight on the upper body and in the genital organs in what is known as the "fatted male" condition. They also fight with one another to determine who will mate with the females. One large offspring is born during the rainfall season when food is plentiful. The young stay with the mother for about a year. Males do not share in parenting.

Common squirrel monkeys and people: Common squirrel monkeys are sometimes hunted for food. They are sold as pets and used for medical research.

Conservation status: Common squirrel monkeys are not considered a threatened species. ∎