Geographic Distribution and Habitat
The cotton-top tamarin, also called the cotton-headed tamarin, is native to a very small region of northwestern Colombia. Its limited distribution stretches from the Atrato River to the Magdalena River. These uniquely colored, clever primates are found in both humid and dry tropical forests. They are arboreal, so they can be seen leaping and scurrying through the canopy.
Size, Weight, and Lifespan
Male and female cotton-top tamarins weigh less than a pound (404-417 g). They are 9.1 in (23.2 cm) tall with a 10.5 inch (26.7 cm) long tail. To put this into perspective, they are about the size of a squirrel. These small primates can live for 13.5 years in the wild, on average.
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Cotton-top tamarins are strikingly colored and appropriately named, with a soft plume of white hair that encircles their small grey and silver faces in a bright halo. Their legs, belly, and chest are also white, and their backs and tail are a beautiful blend of brown and black. Cotton-top tamarins spend a lot of time grooming each other, leaving their coats clean and soft. Most of their body is covered in long fur, with the exception of the very fine, short grey hair that covers their face and ears. They have claw-like nails, which help them leap, climb, and cling to trees.
Due to the small size of their digestive tract, cotton-top tamarins must only consume the highest quality food to stay healthy. Insects and fruits make up the bulk of their diets. Unlike marmosets, who have a long set of lower incisors to chew holes in tree trunks and eat the gum inside, tamarins lack the adaptations to pierce the bark. Therefore, they must rely on other animals or natural processes to open up holes in trees so they can reach the gum.
Cotton-top tamarins have been observed consuming reptiles and amphibians. They can be seen stealthily hunting for insects by scurrying across, up, and down tree trunks, leaping across the canopy, and exploring potential hiding spots for their prey. Like many other primates, cotton-top tamarins choose their feeding site based on the amount of food it provides and usually forage in the middle layer of the canopy.
Behavior and Lifestyle
A day in the life of a cotton-top tamarin consists of foraging for food, resting, grooming, and traveling. Every night, group members sleep in a different tree with a sufficient amount of covering (vines, branches, or leaves) to avoid predators.
The cotton-top’s scientific name, “Oedipus,” translates into “swollen foot.” However, these tamarins do not have large feet. Carl Linnaeus gave them the name simply because he liked the Greek tragedy “Oedipus Rex.”
The oldest cotton-top tamarin lived to be 24 years old.
Locals call cotton-top tamarins “titís.”
When threatened, cotton-top tamarins raise and lower the white fan on their heads to appear larger.
They live in groups of 2-7 individuals, with 1-2 breeding males and females. These primates live in multigenerational groups, meaning that there is often a set of one or two parents; the other group members are their offspring of different ages and a few unrelated adults who have joined the group. The breeding male and female are the dominant members of the group. This is especially true for the breeding female, who takes precedence over the other group members when it comes to food.
Sometimes, individuals leave their group to join another, but usually these “migrators” do not take on a reproductive role. Instead, they become babysitters for the infants.
Overall, cotton-top tamarins are friendly to their fellow group members, with a few exceptions. Most notably, the breeding female can show aggression toward other females. Additionally, cotton-top tamarins are territorial. Males are much more lenient when the intruder is female than when it is male. Females, however, are aggressive to both male and female intruders. It is important to note that when groups of tamarins come in contact, physical contact is quite rare, and aggression is typically just for display.
When predators—such as snakes, large cats, or birds of prey—are in the area, all members of a group work as a team to defend themselves and their fellow group members. Any injured individual is fiercely defended by the group. In addition, during any rest periods throughout the day, one individual stands guard while the others relax, alerting the group to any threats.
This group bond between members is also exemplified in the time they spend grooming each other to create and strengthen relationships.
Cotton-top tamarins primarily communicate through chemical and vocal signals. This is because they live in areas with thick vegetation, which can be difficult for visual communication, except when in close contact with another group member. These up close and personal visual signals can vary from tongue flicking to baring teeth to moving the white fan on their heads to show aggression.
Researchers have identified 38 distinct vocalizations from cotton-top tamarins. These chirps and whistles can be roughly translated to phrases like “I have food,” “I see a stranger,” and “I see a hawk.” There is even a unique call to identify humans. Tamarins also specify the distance and direction of a subject by combining, modulating, and lengthening their calls.
Their chemical communication includes using scent for identification and breeding purposes. Females and males both have glands located near their genitals and anus, but females use theirs more frequently. In addition, the female scent gland is more developed, and is used 10 times more than males to mark their territory and to signal ovulation.
Cotton-top tamarins have been observed in both monogamous (one breeding male and female) and polygamous (several breeding males and females) groups. However, only one female is actively reproducing offspring in each group. Her behavior and chemical signals suppress the other sexually mature females in the group. In some cases, a wandering male may join the group and cause a female to ovulate. As a result, this female may get pregnant, but only one infant will be born.
Females are sexually mature at 15-18 months old, but at this point they do not show regular ovarian cycles. If the dominant female is removed, then the eldest daughter or highest ranking female will begin ovulating and replace the dominant female. She will then suppress the other females in the group. Her ovarian cycle lasts 15.5 days and she shows no physical signs of being in estrus. Mating occurs throughout this time. Her pregnancy lasts 6 months, and once the infants are born, she will have her cycle again within five months after giving birth. On average, 48 weeks lapse between births, which are usually seasonal, with more occurring during the rainy season due to the large amount of fruit available.
In most cases, cotton-top tamarins give birth to twins. Because raising two infants at once can be a daunting task, they raise their young in groups; however, raising young is not an instinctive behavior. Instead, they learn through experience—inexperienced parents may reject or abuse their offspring. Adults carry the infants on their backs, but proportionally they are each quite heavy, weighing 15-20% of their mother’s weight. To put this into perspective, a newborn human weighs only 5% of its mother’s body weight!
During the first week of the infants’ lives, the mother is primarily responsible for their care. Once the first week of life passes, other group members, especially males, help carry the twins and exchange food with the infants. By 10 weeks, the twins can be more independent and are only carried 50% of the time, and at 14 weeks they are no longer carried.
Cotton-top tamarins play an important role as seed dispersers. They can consume and digest large seeds. Once the seeds are discharged, they have a high rate for successful germination. Interestingly, researchers believe that cotton-top tamarins ingest the seeds in part because it helps remove parasites that live in their digestive tracts.
Cotton-top tamarins are classified as Critically Endangered by the International Union for Conservation of Nature (IUCN, 2020), appearing on the IUCN Red List of Threatened Species. Their habitats continue to face rampant deforestation. From 1990-2000, 31% of their habitat was lost to deforestation due to agriculture, logging, and urban expansion. An estimated population of 2,000 mature individuals remained wild as of the the most current surveys in 2010 and 2012, with am estimated total wild population of under 7,000 individuals.
It is estimated that 80% of their population, or more, could be lost by 2036. This decline is due to a combination of factors: a continuation of accelerated annual rates of forest loss throughout the cotton-top tamarin range, studies that demonstrate the unsuitability of remaining forest habitat for this species, and an ongoing, unregulated pet trade of significant proportion.
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.
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).
Parque Nacional Natural Paramillo, Santuarío de Fauna y Flora Los Colorados, and Reserva Forestal de Montes de Maria are protected areas in Colombia that serve as a refuge for cotton-top tamarins. In 1996, Anne Savage and her team began researching the La Reserva Forestal Protectora Serranía de Coraza-Montes de Marìa for conservation. In addition, many local Colombians do not know that cotton-top tamarins are endangered, and a conservation project called Fundacíon Proyecto Tití (PT) is working to inform the public of their endangered status. The foundation is also working with NASA to identify which habitats are best to protect.
- “A Place for Cotton-Tops: Using Satellite Data to Identify Critical Habiat”: https://www.youtube.com/watch?v=QaExd8iA8bs
- “How to speak monkey: The language of cotton-top tamarins – Anne Savage”:https://www.youtube.com/watch?v=4Vfn5CV9juI
- Kareiva, Peter M., and Michelle Marvier. Conservation Science: Balancing the Needs of People and Nature. W.H. Freeman, Macmillan Learning, 2017.
Written by Laura Fern and Eric Starr, March 2018 with 2022 conservation status updates.