Geographic Distribution and Habitat
Also called cotton-headed tamarin, cotton-top tamarins are only found in a small part of northwestern Colombia. Historically, they were more widespread across Colombian forests. However, today their geographic distribution is limited to the area between the Magdalena and Artato rivers in the east and west and the Atlantic Ocean in the North. The Cauca River marks the south of their current range.
Most of the forest cover in this area is now fragmented, so these tamarins have struggled to maintain territory since they are strictly arboreal—living their entire lives in trees. The Paramillo National Park is an important space for the remaining adults, as this is an unfragmented patch of forest land covering about 208 mi² (540 km²) of land.
Cotton-top tamarins prefer to live in tropical rainforests and other woodlands like secondary forests, which refer to woods that have regrown after being cut down. They’re found across wetlands and dry thorn forests but tend to be very sensitive to habitat changes. Each group of cotton-top tamarins lives in territories of about 5–30 acres (2–12 hectares).
Typically, they’re found up to an elevation of 1,312 feet (400 m), but they may also be found in some areas up to 4,921 feet (1,500 m), like the upper valley of the Sinu River.
Size, Weight, and Lifespan
While cotton-top tamarins aren’t the smallest monkeys in the world (that would be the pygmy marmoset), they are pretty small. There isn’t a lot of sexual dimorphism observed in these monkeys, which means that male and female cotton-top tamarins are not easily visually distinguishable.
When it comes to size, both males and females are about 9.1 inches long on average, with tails that are about 10 inches long. Their fluffy fur and tails make them look heavy, but most cotton-top tamarins weigh around 0.8 pounds (404 gm) if they’re female to about 0.9 pounds (418 gm) if they are male.
In the wild, these tamarins may live to about 13.5 years old, but they may live nearly 26 years in captivity. They reach these ages in captivity since they’re protected from predators and are not dependent on foraging for meals.
The cotton-top tamarin is named for his distinctive shock of white hair that frames his face. This mane runs down to the nape of his neck, making him look like Albert Einstein. In addition to the white hair on his head, he also has fine white hair all over his face, which is black. The hair is mostly invisible, just like the fine hair on the faces of human beings, except where thicker hair outlines the tamarin’s nose, face, and chin. His chest and belly are also white, but along his back and tail, he’s covered in fur that’s a reddish-brown color that deepens to black on the tips.
Like many species of monkeys found across Mexico, Central, and South America, cotton-top tamarins have claws on their fingers, except the big toes, which have flat nails. The tamarins use their claws to cling to branches as they climb, sleep, and live in the trees.
These tamarins have lower canine teeth that are longer than their upper incisors.
As opportunistic foragers, cotton-top tamarins aren’t very picky about what they eat. They scavenge fruit, insects, and nectar from flowers. Cotton-top tamarins supplement their diets with small vertebrates like lizards, eggs, and other vegetation. The variety in their diets helps them keep up with their extremely high energy needs, especially in seasons when fruit is scarce.
Cotton-top tamarins have a high metabolism and must eat high-caloric food frequently. Sometimes, they may eat sap, the thick, nutritious liquid that runs through a tree’s limbs. However, cotton-top tamarins don’t have the teeth to cut through tough bark, so they usually only eat sap when it flows freely.
Behavior and Lifestyle
The average cotton-top tamarin lives in a family group of up to 13, though usually these groups are made of 2–10 individuals. As they age, some individuals may break away from their parental group to find mates in other groups. Sometimes, they may be forced to leave if the group is bigger than their territory can sustain.
These tamarins are a social species and tend to look after each other, including behavior like sharing food and resources, grooming, and helping the breeding pair in the group look after infants. They also tend to have lookouts when the group rests or sleeps to protect them group from predators.
Baby cotton-top tamarins are carried on their parent’s backs by the father until they are old enough to start sharing solid food—usually around the time they’re four months old. The group ensures that foraged solid food like fruits are shared with the children in the group, ensuring that they receive the necessary nutrition as they grow.
Within their groups, cotton-top tamarins are cooperative and share easily with each other. However, if the individual they are sharing with doesn’t reciprocate through sharing food or grooming, they may refuse to share with that monkey again.
Cotton-top tamarins are clever and have demonstrated the capacity to plan a series of actions to achieve a goal, like finding food! Baby cotton-top tamarins learn how to hunt small vertebrates like lizards and mice from their parents. A skill they learn is how to kill and eat them quickly by biting off the head.
These monkeys get the water they need by licking leaves wet with rain, dew, or the fruits they consume. This way, they can avoid climbing down to a water source where a predator can catch them!
While they are diurnal (i.e., awake during the day) cotton-top tamarins wake up about an hour after dawn breaks. They tend to have a lie-in, even if they do wake up early, waiting for the entire group before they start moving. This behavior likely helps them avoid competition when foraging for food.
Throughout the day, the group covers their habitat foraging for food. They climb up and down the forest canopy and call out to each other when they discover a food source. They run, leap, and turn over leaves to look for food and are typically never seen near the forest floor.
There is a clear hierarchy in a cotton-top tamarin group, as only a dominant pair breeds, while all the others in the group work with each other to support the breeding pair and their babies. Throughout the day, these groups play, forage, eat, and rest and groom together. As the sun sets, the group becomes quieter and moves more quickly till they find a sleeping tree for the night.
Incredibly communicative, cotton-top tamarins are known for using over 28 different vocalizations, including chirps, trills, squeaks, and other sounds. They also use scent to mark their territory and use chemical signals to indicate when they’re ready to mate.
Chirps and screams are typically used to warn of predators, as well as for aggressive behavior. Another sound is the rasp, which is often used along with chasing or physically aggressive actions. Long calls are used to maintain contact when group members wander out of sight of each other when they’re foraging. These calls may also be used to communicate with other groups of the same species. Some calls are only used around feeding time and indicate finding a preferred type of food, or gathering and eating the food. Between members of the same group, the monkeys may trill or chirp softly.
Cotton-top tamarins also use their body language to communicate. When alarmed or when trying to woo a potential mate, they may raise the white hair on their heads up to make themselves look bigger. They display aggressive behavior, like showing their genitals or bottoms when competing for food or mates.
The dominant breeding pair in a group of cotton-top tamarins mate for life. Usually, the female will give birth to non-identical twin babies in the monsoon season, when fruit and resources are abundant. This ensures that the babies are able to receive nutrition when they are growing and need it most.
The dominant female will typically use her pheromones, through her behavior and chemical signals, to prevent estrous cycles in the other females in the group. This process is not foolproof, however. If the group becomes unstable, individuals may leave on their own or be forced out to find their own family groups.
If these monkeys are still infants when their parents birth another pair of twins, they will briefly become clingier with their parents, just like human children with new siblings! Soon after the birth of the twins, the younger monkeys demand access to their siblings, and there’s never a loss of parental care for babies of any age within the family group.
With a diet that is predominantly rich in fruits, including fruits with seeds larger than those eaten by other primates of the same size, cotton-top tamarins are essential for seed dispersal. Cotton-top tamarins eat fruits whole, so they can use the seeds to keep their intensities clean. During their movement through the day, they end up dispersing the seeds throughout their territory.
The International Union for Conservation of Nature lists the cotton-top tamarin as Critically Endangered (IUCN, 2020), appearing on the IUCN Red List of Threatened Species. There are fewer than 7,400 individuals remaining in the wild, including only 2,000 mature individuals. Their population is declining as a direct result of habitat loss resulting from human activity, like the conversion of forests into farmland and housing.
Due to deforestation, many cotton-top tamarins must live on the edges of forests rather than in the forest interiors. Because of this, conservation scientists must take “edge effects” into consideration when focusing on what land to protect. Edge effects refer to the differences between the living conditions in forest interiors and forest edges. For instance, forest edges experience more sunlight, more wind, and less humidity. These make forest edges more vulnerable to fire and more accessible to invasive species, and raise the chances of animals coming into contact with humans. Protected areas must not only be large, but also shaped in a way that the forest has few edges (such as a circle or square).
A potential population reduction of 80% or more is suspected over 18 years (or three generations from 2018–2036), due to ongoing, unregulated exploitation of this species for the pet trade, and a continuation of accelerated annual rates of forest loss throughout the species’ range. Studies demonstrate the unsuitability of remaining forest habitat for this species.
Another threat to cotton-top tamarins is the illegal pet trade. The proximity of their habitat to international waters makes them an easy target. It is estimated that over 40,000 tamarins have been caught from the wild and sent abroad to be sold as pets or for scientific research. In the late 1960s and early 1970s, 20,000–30,000 individuals were exported to the United States for biomedical research. Although it is illegal to import cotton-tops into the United States, they are still used for medical research.
The cotton-top tamarin is listed in Appendix I of the Convention on International Trade in Endangered Species (CITES), an international agreement between governments whose goal is to ensure that international trade in specimens of wild animals and plants does not threaten their survival.
Being native to Colombia, cotton-top tamarins have been protected there since 1969. Education efforts are in place to raise awareness about these monkeys and their shrinking habitat, and ensure that people do not try to keep these monkeys as pets. Today, local artisans make plush toys of the cotton-top tamarin to replace the pet trade.
Cotton-top tamarins occur in these protected areas: Paramillo National Natural Park, Los Colorados Fauna and Flora Sanctuary, Los Katios PNN, and Reserva Forestal Cerro de Coraza-Monte de Marja, Reserva Natural Tití Cabeciblanco. They were also introduced to Tayrona National Natural Park in 1974. Additionally, the dry forests are currently protected by the Colombian law, being the most important ecosystem for this species. Proyecto Tití, a conservation programme for the Cotton-top Tamarin in Colombia, was established in 1987 to begin the first long-term field study on this species in collaboration with Colombian biologists, educators, NGOs and government authorities (INDERENA, Ministerio del Medio Ambiente). Initial research focused on understanding the factors influencing reproductive strategies of cotton-top tamarins, but it quickly grew into a comprehensive conservation programme including educational efforts, capacity building, training Colombian students, development of economic alternatives, and the development of an agricultural training programme to decrease the pressure on the forest by local communities.
The regional corporation of the Sinu Valley and Conservation International-Colombia, has been developed since 2008, the programme for the monitoring, assesses and conservation of the cotton-top tamarin in the department of Cordoba in northwest of Colombia. In addition to the studies of cotton-top tamarins in the field, there has been a major and comprehensive assessment of the remaining habitat within the historic distribution of the cotton-top tamarin in Colombia, along with surveys to assess population numbers remaining. This information has provided important insights into the long-term viability of this population given the current rate of habitat destruction.
Written by Caroline Abraham, December 2023