Photograph by Joel Sartore, National Geographic Photo Ark
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The endangered cotton-top tamarin lives in a small area of northwestern Colombia that is currently threatened by deforestation.

Photograph by Joel Sartore, National Geographic Photo Ark

Cotton-top tamarin


What is the cotton-top tamarin?

Cotton-top tamarins are named for the shock of white hair encircling their heads, a look reminiscent of Albert Einstein. Roughly the size of a squirrel, cotton-top tamarins also have white chests and bellies, while their backs and tails are covered in long black and brown fur. They have claw-like nails, which are critical to jumping from tree to tree in their forest habitat.

Habitat and diet

These diminutive primates are one of three Amazonian species of tamarin. Cotton-top tamarins live in a small forested area of northwestern Colombia. They forage through the middle layer of the canopy for the fruits and insects that make up much of their diet, though they’ve been known to eat larger vertebrates as well.

Cotton-top tamarins also play an important role in spreading seeds in tropical ecosystems. These tamarins commonly eat seeds that are fairly large—bigger even than those consumed by their more sizable fellow primates such as chimpanzees and baboons. Those seeds are eventually digested into feces that has proven an excellent fertilizer with a high success rate for germination.

Behavior

Like their golden lion relatives, cotton-top tamarins form social family groups that include breeding parents, their adult offspring, and even unrelated adults who have migrated to the group. Since tamarin young are commonly born as twins and tend to be disproportionately heavy—they weigh in at about 15 to 20 percent of their mother’s body weight—these adult group members quite literally help tamarin parents shoulder the load. They also work together to defend the group from predators like snakes and large cats.

Since nursing and caring for their young requires so much energy, cotton-top tamarins typically give birth during the early half of the rainy season when fruit is most abundant. Only the dominant female in each group gives birth to young. Though cotton-top tamarins reach sexual maturity between 15 and 18 months of age, researchers have observed that mother tamarins suppress the fertility of their daughters and other adult females in the group. When the mother dies or leaves the group, the oldest and highest-ranking daughter becomes fertile and takes over the dominant role.

Threats to survival

Cotton-top tamarins are critically endangered. In the late 1960s and early 1970s, 20,000 to 30,000 cotton-top tamarins were exported to the United States for biomedical research, specifically as subjects of studies related to colon cancer. Although it is now illegal to import cotton-top tamarins into the U.S., they are still being used for medical research and captive tamarins outnumber those in the wild.

Today, deforestation and human activity pose the most significant threats to the survival of cotton-top tamarins. Colombia is losing its tropical rainforest at a dramatic rate to development and agriculture—in fact, the South American country has recorded the fourth-highest loss of rainforest in the world.

Some of this loss can also be attributed to oil extraction projects as well as the construction of a hydroelectric dam that flooded more than 7,000 hectares of forest in Paramillo National Park, a sanctuary for the tamarin. It’s been estimated that only 5 percent of the cotton-top tamarin’s original geographic range remains. As its habitat shrinks, so too do the cotton-top tamarin’s hopes for survival.