Samiri boliviensis




Scientific name: Samiri boliviensis

English names: Bolivian Squirrel Monkey

Spanish and local names: Chichilo, Mono ardilla

Size: 225 to 370 mm (8.86 to 14.57 in)

Weight: 365 to 1135 g (12.86 to 40.00 oz)


Kingdom Phylum Class Order Family
Animalia Chordata Mammalia Primates Cebidae


Taxonomy and name

Until 1984 the squirrel monkey was considered a single, widespread species. Currently, two main groups are known with five different species total. The scientific name of the genus Samiri comes from the Tupi language words Sai which means monkey and mirim which means small.


Squirrel monkeys are small and have short dense fur that covers most of their bodies, mostly of a yellowish colour. Their heads are elongated and egg-shaped, and it has been suggested they have comprised a larger snout for a larger brain case. Their heads are covered in a grey or black colour and have a distinctive white mask-like fur colour in front of their heads around their eyes. This species can be identified from other Samiri species by the arched eyebrows.

Females are somewhat smaller than males and can be distinguished by the black on their heads, males are grey. Squirrel monkeys are very agile and have a tail that comprises half its total body length. The tips of the tails are black and are used for balance as they are not prehensile.

Habitat & Range

Squirrel monkeys are arboreal and occur more in gallery forest, although they also live in forest edges. Their range is quite large and covers a great part of the amazon basin, they occur below the elevation line of 1,500 meters into the Andean slopes.

Life & Behaviour

Squirrel monkeys are highly social and live in groups of 10-550 individuals with an average group size of 40-50 members. They are not territorial and depending on the size of the group they can move from 0.6 to 1.1 kilometres per day, with a nomadic range of up to 3 square kilometres.

Squirrel monkey troops have a very hierarchical behaviour; males establish their dominance through fierce fighting and assert their dominance through urine-washing and forced subjugation of an inferior. Urine-washing is a behaviour by which the individual urinates on its hands, feet, and body, thus ensuring that wherever it travels it will leave its trace. Through penile display, males assert their dominance over subservient males. In this behaviour, the dominant male will display its penis to the other male, often urinating on him.

Their sociability also includes lots of playing and it’s one of the few monkey species that will raise their offspring amongst different members of the group, it’s not only the parents that carry, feed and play with the juveniles, other members also participate.

Squirrel monkey diet includes insects and fruits which they forage mostly in the tree branches, coming down to the ground only occasionally. Their main predator is the harpy eagle and to protect themselves they have complex forms of communication. Samiri boliviensis is one of the most vocal squirrel monkeys, with 26 different identified calls, consisting of chirps and peeps (used when alarmed), squawks and purrs (used during mating and birthing seasons), barks of aggression, and screams of pain.

Conservation & Threats

Squirrel monkeys at La Senda Verde have arrived because of the wildlife pet trade, that along with habitat destruction are their main threats and causes of a decrease in their population. However, large numbers, high adaptability to habitat degradation and low hunting pressure from humans are the reason this species is catalogued as “Least Concern” or LC by the IUCN which means they are not considered an endangered species.

View conservation assessment on this species



SPACE TRAVELER- A squirrel monkey “Miss Baker” was sent into space and returned safely as part of the United States Space program.

THREE LEGS- Bolivian squirrel monkeys recur from time to time to bipedal walking (on two legs) and to assist themselves they use their tails as a third leg.

SHOW OFFS- Female squirrel monkeys have pseudo-penises, which they use to display dominance over smaller monkeys, in much the same way that the male squirrel monkeys display their dominance.

Squirrel monkeys at La Senda Verde

There are 27 squirrel monkeys at La Senda Verde in total. They roam freely in the premises.


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