Pygmy Marmoset (Finger Monkey)

“Also known as a finger monkey, a pygmy marmoset can leap a distance of 16 feet to get from one tree branch to another.”

Pygmy marmosets (also called pigmy monkeys) live in the Amazon forests of South America. These cute creatures are the world’s tiniest monkeys weighing about 4 ounces in adulthood. Finger monkeys are omnivores that really like to eat tree sap! These monkeys live to be about 12 years old in the wild.

5 Amazing Pygmy Marmoset Facts

• Pygmy marmosets (also called finger monkeys and pigmy monkeys) live in the tops of trees in the rainforests of South America.
• Finger monkeys have fingernails they use as claws to climb trees.
• Butterflies, fruits, berries, and tree sap are all favorite foods of this small omnivore.
• One male and one female pygmy marmoset breed and live together for a lifetime.
• Pygmy marmosets groom each other’s fur just like other monkeys.

Scientific Name

While pygmy monkey or pygmy marmoset is this animal’s common name, its scientific name is Cebuella pygmaea. It belongs to the Callitrichidae family, and its class is Mammalia. Marmoset comes from the French word marmouset.

2 Kinds of Pygmy Marmosets

The pygmy marmoset has two subspecies that are mostly divided by natural terrain barriers. They both prefer lowland forests within floodplains of rivers.

• Eastern pygmy marmoset – The Eastern pygmy marmoset can be found in Amazona (the Brazilian state) and surrounding areas, including north Bolivia, and eastern Peru.
• Western pygmy marmoset – The Western pygmy marmoset is located in an area that covers northern Ecuador and Bolivia, parts of southern Columbia, the eastern part of Peru, and in Brazil north of Rio Solimões.

Appearance and Behavior

These marmosets have a coat of orangish brown fur with a mixture of brown and black stripes. The dark fur of this small animal helps to hide it as it moves across tree branches. The fingernails of this monkey serve as claws that can grasp the bark of a tree as it climbs. The way this marmoset moves and climbs is similar to that of a squirrel you might see in your local park.

It has a small nose, small eyes, and an ear on each side of the top of its head. These marmosets have extra flexibility in its neck allowing them to turn its head to look backward. This helps the animal to be on high alert for predators in the area.

A pygmy marmoset’s tail is longer than its body. It uses its tail for balance as it moves along tree limbs high up in the Amazon forest.

The body of an adult pygmy marmoset measures about 4 to 6 inches long. Plus, its squirrel-like tail is 6 to 9 inches long. A pygmy marmoset’s 9-inch tail is equal in length to an average size fork in a silverware drawer. An adult weighs a little over 4 ounces. This means it weighs about the same as one stick of butter from your fridge at home.

This marmoset claims the title of the smallest monkey in the world. But, it’s not the smallest primate in the world. That title belongs to a pygmy mouse lemur that weighs around 1.1 ounces! Learn more about the world’s smallest animals here.

These marmosets live in groups called troops, with about 5 to 9 members. Living in groups provides these small animals with some level of protection against predators. If one member spots an ocelot, it would alert the rest of the troop to take cover in the trees. These marmosets are shy animals that stay with their own troop while remaining hidden in the trees much of the time.

The members of the marmoset troop communicate with one another using squeaks and chirps that only they can understand. One sound may mean there is danger near, while another may be a male calling a female. The sounds these animals make are somewhat similar to the sounds made by brown and gray squirrels.

Evolution and History

This diminutive monkey evolved from larger ancestors to allow it to flourish in the canopies of trees and move about the thin and weakest of branches with ease, much like a squirrel does. Unlike other primates with flat nails, the pygmy marmoset developed long, very sharp nails over time that allowed it to grasp trees and branches. They essentially function as claws for climbing purposes.

Furthermore, this tiny primate adapted to life in the trees by evolving bottom teeth that are exceptional at penetrating bark and accessing tree sap. Their digestive systems have also developed in such a way as to break down tree gum and sap.

Habitat

These marmosets live in Peru, Ecuador, Brazil, and Columbia in South America. They live in the Amazon rainforests or in thickets growing near rivers. These animals live in a tropical climate that’s humid and rainy. Pygmy marmosets live in the rainforests of South America throughout the year.

You’ll find these marmosets living in forests where trees grow close together. This allows them to jump easily to the branches of different trees. Plus, it’s easy to stay hidden from predators when the branches of trees are crisscrossing one another. The marmoset’s orange/brown fur also helps it stay hidden among the rainforest’s dark branches and tree trunks. Generally, these marmosets remain in a territory of less than an acre of forest.

Diet

What do pygmy marmosets eat? The main food source of this animal is tree sap. These marmosets use their bottom row of sharp teeth to dig holes into the bark of a tree. They dig until they find sap, then drink it like a dog drinks water from its bowl.

Oftentimes, a pygmy marmoset chooses just one tree to dig into for sap every time it wants food. This tree is located somewhere in the specific territory of the monkey. Some trees can have up to 1300 holes made over time by one hungry marmoset!

These animals are omnivores, so they certainly eat more than tree sap. They eat fruit, butterflies, leaves, small spiders, and nectar. They are quick and can grab insects that live on the branches around them. The type of food these monkeys eat depends on what is most plentiful in the area.

Since these marmosets are so little, they don’t need to eat very much to survive. They may drink as much as a tablespoon of tree sap at one time. These monkeys like to look for food in the morning and late afternoon.

Pygmy marmosets that are kept in zoos are fed vegetables and fruits along with a special food mixture that’s easy for them to digest. The amount and type of food they are given are carefully monitored. Feeding this marmoset processed food would be harmful to this little animal.

Predators and Threats

As you may have guessed, these marmosets have many predators due to the fact that these monkeys are so small. Some of their predators include hawks, snakes, ocelots, and eagles, specifically the harpy eagle.

Since these marmosets stay high up in the trees, they are especially vulnerable to eagles, hawks, and other birds. Plus, there are many snakes that climb trees such as the pit viper. The pygmy marmoset’s speed and ability to hide are its only defenses against these predators.

The habitat of these marmosets is threatened when trees in the rainforest are cut down and cleared. This takes away their home as well as their food source.

Humans are a threat to these animals in another way. Sometimes these animals are caught and sold as exotic pets throughout the world. This is another thing that reduces their population.

The official conservation status of the pygmy marmoset is Threatened. Their habitat is threatened when trees are cleared, but if this could be slowed it would help increase the population of this monkey.

There are laws against buying and selling wild animals as pets. This includes the pygmy marmoset. Enforcement of these laws can contribute to keeping the pygmy marmosets safe in their natural habitat.

Reproduction, Babies, and Lifespan

Breeding season for these marmosets happens throughout the year. While looking for a mate, a male will mark the area with his scent and follow one female around the territory. One male and one female in a troop breed and the rest of the members of the group help to take care of the young. This male and female stay together for their lifetime. The gestation period of a pygmy marmoset is about 20 weeks. Generally, there are two live babies in a litter. More rarely, a female will have one or three babies.

A newborn pygmy marmoset weighs .4 ounces. Imagine a newborn pygmy as being about the size of an adult human’s thumb!

During the first couple weeks of a newborn pygmy marmoset’s life, it rides around on the back of its father. It’s the father who is the main caretaker of pygmy marmoset babies. When it’s time to eat, the father takes the babies to their mother so she can nurse them.

Baby pygmy marmosets start to eat insects and tree sap at about 3 months old. Others in the troop teach the babies how to find food. Once a baby pygmy marmoset is about 1 and a half or 2 years old, it may strike out on its own as an adult. But, in some cases, the young stay with the troop to help raise other babies. This means there may be several siblings in a troop.

The average lifespan of a pygmy marmoset is 12 years. Of course, the number of predators in the area where a pygmy marmoset lives can definitely have an effect on its lifespan. These small monkeys can suffer from malnutrition as they age if there is a decrease in the foods they eat in their environment.

Population

The conservation status of the pygmy marmoset is Threatened. The exact population of pygmy marmosets is unclear due to their size and ability to hide in inaccessible areas. But, scientists believe the largest concentration of these animals lives near the Amazon and Rio Negro Rivers in South America. Their population seems to be holding steady as some efforts are being made to reduce the clearing of the Amazon rainforest.