Cotton-top Tamarin

Cotton-top tamarins are very small monkeys, about the size of a squirrel. They are named for the mane of long, white hair on their heads and the fine white hair covering the black skin on their faces. Tamarins are generally characterized by their facial appearances and are divided into three groups: the hairy-face, mottled-face, and bare-face groups. While they have white hairs on their face it is fine and thin enough that cotton-top tamarins are categorized in the bare-face group. These small monkeys have fur varying from brown to black to red, except for their stomach, arms, and legs which are white. These tamarins are not sexually dimorphic and the average height of both males and females is 9.13 in. Wild males and females weigh a little under a pound.

Tamarins primarily rely on quadrupedal locomotion to get around. They run along small branches and leap between trees. They have claw-like nails rather than flat nails characteristic of other primates. These claw-like nails aid in clinging, running, and leaping through trees.

Cotton-top tamarins are found in the Northwest region of Colombia, in a range bound by the Cauca and Magdalena Rivers and the Atlantic coast. They reside in humid tropical forest, dry deciduous forest, and secondary growth forest. Tropical forests have multiple vertical layers of growth, from the short understory (less than 5 meters) to the tallest trees in the canopy (over 20 meters). Cotton-top tamarins use multiple layers of the tropical forests in which they are found, moving vertically between the understory and canopy, but preferentially utilizing the lower vertical levels of the forest. Occasionally they can be spotted foraging among the leaf litter on the ground.

The primary components of the cotton-top tamarin diet are insects, fruit, plant exudates like gum and resin, and nectar, but they have also been recorded eating reptiles and amphibians. It is important for tamarins to have a high-quality, high-energy diet because of their small-body size, limited gut volume, and rapid rate of food passage.

Foraging occurs in the middle layer of the canopy from five to fifteen meters (16 to 49 ft). Cotton-top tamarins select a feeding site because of its fruit availability but they also hunt for insects and utilize gum in the vicinity. Some insect-hunting techniques employed by cotton-top tamarins include stealth, turning over leaves, exploring crevices, pouncing, and moving rapidly to the ground to seize prey. As with foraging for other foods, hunting for insects is an individualistic behavior among tamarins.

Plant exudates are carbon-rich secretions such as gums and resins. This is an important source of minerals, water, and other nutrients. Although tamarins do not have the same specialized adaptations to fully digest and metabolize gum, sap, resin, and latex as their relatives, the marmosets (Callithrix species) do. Instead, they rely on more indirect means to obtain exudates like natural weathering of bark, the holes left by wood-boring insects or rodents, and re-gouging of hardened gum holes to stimulate flow.

Cotton-top tamarins typically live in groups ranging from 3-9 individuals. These groups consist of a dominant mated pair, their young of the year, and a few subordinate or young animals of both sexes. These subordinate members tend to form small groups and migrate in and out of the home range of the main group. They are territorial and scent mark their territory. When coming into contact with other groups, they will threaten them with the showing of their rear and genital area as a territorial display.

Tamarins sleep in a group and start their day about an hour and twenty minutes after dawn when the entire party leaves the sleeping tree at the same time. Cotton-top tamarins follow established routes to find available foods. After about an hour of foraging, they begin to rest for a few minutes at a time, either stretching out on a branch or grooming within the social group. They continue to travel and forage throughout the day, taking increasingly longer resting periods, the longest being around midday. In late afternoon, they begin to travel more quickly and more cohesively with limited foraging stops until they reach a sleeping tree. They have a few favored sleeping trees in their territory with plenty of foliage cover and will alternate between them.

Tamarins are monogamous breeders and only the dominant pair breeds. Breeding typically takes place in the initial half of the year. They exhibit a form of cooperative breeding that includes adult ‘helpers’ staying with the family unit to gain breeding experience. These helpers gain breeding experience that could potentially make them more successful parents when they finally disperse to join or make their own groups.

Gestation lasts 4 and a half months, at which point 2 infants are born. Each infant weighs 15-20% of the mother’s weight. A unique feature among tamarins is that males put more effort in caring for the young than the females. The father assists at birth and carries the young all of the time except when the mother is feeding. This results in the males losing a significant amount of their pre-birth body weight.

Cotton top tamarins are listed as Critically Endangered on the IUCN Red List. They are among the most endangered species of primate in the world due to their limited and encroached upon habitat. They are hunted, poached for the illegal pet trade, and used for animal testing by humans. There are only roughly 300-1000 individuals in the wild, 1800 in captivity, and 64% of those in captivity are being tested on in research laboratories.

The largest threat to cotton top tamarins is habitat loss. Deforestation as a result of land use for expanded agriculture, mining, logging, slash and burn farming, as well increased urbanization is greatly impacting the availability of suitable habitat. From 2013 to 2018, 98% of Colombia’s rainforest area was deforested for these purposes, accounting for 5% of the global forest decrease since 2000.

The reason so many are in research facilities is because tamarins were found to contract colonic adenocarcinoma (cancer of the colon, as well as other gastrointestinal diseases such as colitis, etc.) and thus began the practice of removing them from the wild for scientific testing.

• Tamarin dads put in an unrivaled amount of effort into caring for their young. These diminutive monkeys will carry both of their children on their back to the point of losing as much as 11% of their body weight!
• In the wild, when the group rests during the day, one group member separates itself from the resting animals and remains vigilant, alarming the group through vocalizations if it detects danger.
• Dominant female tamarins possess the ability to suppress the fertility of their daughters and other adult females in the group so that only they can become pregnant.

The Oakland Zoo has two cotton-top tamarins, Alberto and Ash. Alberto came to us in 2019 at the age of 6. He enjoys the sun the most as well as his favorite treat, waxworms! Ash is a newer resident who joined us in March 2025, from Idaho Falls. She is 3 years old.

Since cotton-top tamarins are critically endangered, Alberto and Ash are recommended to breed by their Species Survival Plan. While neither of them has been a parent, they were both raised by their parents in family groups. Cotton-top tamarins learn to raise babies by watching their parents, so our hope is that they will pick up on how to be parents quickly!

Our partner Proyecto Titi works to save habitat, curb the illegal pet trade, and educate the community. They are currently working to create a wildlife corridor to connect some remaining tamarin habitats. Here are some ways you can help:

• Support Proyecto Titi by donating or shopping in their online store.
• Look for sustainable products, especially those that come from the rainforest, like coffee and chocolate. Look into shade grown varieties.
• You can help stop the illegal pet trade by getting responsibly bred animals as pets and educating those around you about the plight of wild-caught exotic pets