Squirrel monkeys are not only one of the smallest primates, weighing only 500-1100 g (18-39 oz.), they are also among the smartest! They have the largest brain-to-body mass ratio of all monkeys.
There are seven species of squirrel monkeys. They have short reddish-brown fur with a white mask around their eyes and a dark muzzle.
They have a long tail that is not prehensile, meaning they cannot grip with it. But they do use their tails for balance when they’re running and jumping in the trees.
Life in the Trees
Squirrel monkeys are a type of New World monkey that inhabit the forests and rainforests of southern Central America and South America. Because they spend most of their time in the trees, they are considered arboreal.
They move continuously through the trees on both their hands and feet foraging for food. Squirrel monkeys are excellent climbers and jumpers. They can jump up to 5 m (15 ft.)!
Squirrel monkeys are diurnal, which means they are active during the day. When they sleep, they squat on a branch with their head down and their tail up around them for warmth.
When it’s hot, they stretch out across the branches.
What Squirrel Monkeys Eat
Squirrel monkeys are always on the lookout for food like fruit, flowers, eggs, insects, and small lizards. They have excellent color vision which is useful for spotting fruit among the leaves.
Social Life
Squirrel monkeys typically live in groups, called troops, of about 15-50. But their troops can have as many as 500 members.
They often live with other species of monkeys as well, particularly capuchin monkeys.
Squirrel monkeys have strong communication skills. They communicate with both facial expressions and about 25-30 different calls, including chirps and peeps. They can alert each other of predators, such as birds of prey, snakes and small carnivores.
Squirrel monkeys also communicate with a method called “urine washing”. They pee on their hands and feet and rub the urine all over their bodies. It is thought that squirrel monkeys do this as a way to scent mark their territory, as a way to stay cool, and as a way for others in their group to find them.
Reproduction
Squirrel monkeys breed during the dry season, which is from August to early October.
Usually, male and female squirrel monkeys are close to the same size. However, two months before the breeding season, male squirrel monkeys will put on about 20% more body weight in order to look more attractive to females.
After about 150-170 days gestation, female squirrel monkeys give birth during the rainy season, from February to early April, when food is plentiful. All the babies in the troop are born within one week of each other.
For one month, the baby, called an infant, clings to its mother’s back. After a month, the baby is cared for communally by other females in the group as well.
By 5-6 months, the baby is weaned. And after a year, the young squirrel monkey is independent.
Young squirrel monkeys are curious and playful. They interact not only with members of their troop, they also play with other types of monkeys, such as marmosets and uakaris.
In the wild, squirrel monkeys live around 15 years.
Conservation Status
Four species of squirrel monkey are listed as species of Least Concern by the IUCN Red List. However, the golden-backed squirrel monkey is considered Near Threatened, and the black-crowned Central American squirrel monkey and the black squirrel monkey are considered Endangered.
Threats include being captured for scientific research and the illegal pet trade.
What You Can Do to Help
People often want squirrel monkeys for pets because they are small and cute. However, squirrel monkeys are not suitable pets. Even if they are well-meaning, people cannot provide the appropriate space, care, and enrichment that squirrel monkeys need.
So if you would like to help squirrel monkeys, do not own one as a pet, and speak out against the illegal pet trade.
Squirrel Monkey Resources
- San Francisco Zoo: Squirrel Monkey
- Lincoln Park Zoo: Toto the Squirrel Monkey at Reid Park Zoo
- Sacramento Zoo: Squirrel Monkey
- San Diego Zoo: Guianan Squirrel Monkey
Quick Fact Sheet
Common Name(s): Squirrel Monkey
Scientific Name: Saimiri
Animal Type: mammal
Size: 23-38 cm (9-15 in.) long; Tail: 40 cm (16 in.)
Weight: 500-1100 g (18-39 oz.)
Lifespan: 15 years
About the Author
Abi Cushman is a contributing editor of Animal Fact Guide and My House Rabbit. When she's not writing about weird animal facts, Abi writes and illustrates funny books for kids. Her picture books, Soaked! and Animals Go Vroom!, are available now from Viking Children's Books.
To learn more and to download free activity sheets, visit www.abicushman.com. Follow her on Instagram at @Abi.Cushman.
