Genus Saimiri - Squirrel Monkeys

Squirrel monkeys are New World monkeys of the genus Saimiri. Saimiri is the only genus in the subfamily Saimirinae. The name of the genus is of Tupi origin (sai-mirím or çai-mbirín, with sai meaning 'monkey' and mirím meaning 'small') and was also used as an English name by early researchers.

Squirrel monkeys live in the tropical forests of Central and South America in the canopy layer. Most species have parapatric or allopatric ranges in the Amazon, while S. oerstedii is found disjunctly in Costa Rica and Panama.

There are two main groups of squirrel monkeys recognized. They are differentiated based on the shape of the white coloration above the eyes. In total there are 5 recognized species. Squirrel monkeys have short and close fur colored black at the shoulders, yellow or orange fur along the back and extremities, and white on the face.

Squirrel monkeys have determined breeding seasons which involve large fluctuations in hormones and there is evidence of sexual dimorphism in males.

Squirrel monkeys can only sweat through the palms of their hands and feet. This can have the effect of making their hands and feet feel damp to the touch. Squirrel monkeys must make use of other thermoregulation techniques such as behavioral changes and urine washing. These monkeys live in habitats of high temperatures and high humidity, making it essential for them to maintain proper osmoregulation if conditions pass certain thresholds. Color vision studies have also been performed on squirrel monkeys for the purpose of better understanding vision ailments in humans.

The common squirrel monkey is commonly captured for the pet trade and for medical research, but it is not threatened. Two squirrel monkey species are endangered: the Central American squirrel monkey and the black squirrel monkey are listed as vulnerable by the IUCN.



The Black-capped Squirrel M(Saimiri boliviensis) is a species of New-World monkey native to the upper Amazon basin in Bolivia, western Brazil and eastern Peru. They weigh between 365 and 1135 grams and measure, from the head to the base of the tail, between 225 and 370mm. Black-capped squirrel monkeys are primarily tree-dwelling and are found in both native and plantation forests as well as some farmed areas near running water. Their diet is omnivorous and mostly consists of flowers, fruit, leaves, nuts, seeds, insects, arachnids, eggs and small vertebrates. They mostly live in female-dominated troops of around 40 to 75 monkeys, with males having been observed to disperse to live in all-male troops after reaching sexual maturation. Their current conservation status according to the IUCN is 'Least Concern'. The species belongs to the genus Saimiri and has two subspecies, S. b. boliviensis (the Bolivian squirrel monkey) and S. b. peruviensis (the Peruvian squirrel monkey).

Black-capped Squirrel Monkey (Saimiri boliviensis) Manu Peru

Humboldt Squirrel Monkey (Saimiri cassiquiarensis) Captive at Shanghai Zoo