BLACK LION TAMARIN

Leontopithecus chrysopygus

Geographic Distribution and Habitat
The black lion tamarin is a member of the tamarin family of monkeys that is found throughout South America. The black lion tamarin is one of the four subspecies of lion tamarins, which also include the golden-lion tamarin, the golden-headed lion tamarin, and the black-faced lion tamarin. All lion tamarins receive their common names from their colorful characteristics; as their names suggest, lion tamarins are recognized by their lion-like manes and thick coats. The black lion tamarin, also called the golden-rumped tamarin, is unmistakable due to its bright gold rump.

All lion tamarins live throughout the Atlantic Rainforest of southeastern Brazil. The Atlantic Rainforest straddles the Atlantic Ocean from the Rio Grande do Norte state to the Rio Grande do Sul state of Brazil, and stretches inland as far as Paraguay and Argentina. It is a seasonal tropical moist forest, which means that it receives high amounts of rain seasonally rather than continuously. The Atlantic Rainforest is characterized by high biodiversity, with nearly 52% of its trees being endemic to the region. While the Atlantic forest has some of the richest tree and amphibian diversity in the world, over 85% of it has been deforested over the past four decades. Black lion tamarins occupy the canopy level of this forest.

Black lion tamarins are mostly found in an extremely isolated region inside the protected borders of Morro do Diabo State Park, located in the state of São Paulo. Their habitat range inside this park only encompasses roughly 189 sq mi (490 sq km). This population is the most stable and least fragmented. There are other small isolated pockets of black lion tamarins within close proximity to the park. However, these small populations of black lion tamarins located outside the park are extremely fragmented and are rarely observed.

Black lion tamarins geographic range. Map: IUCN, 2008, 2020 (click to enlarge)

Size, Weight, and Lifespan
Black lion tamarins are small primates that weigh in at anywhere between 1.18 and 1.51 lb (0.54-0.68 kg). There is little to no weight discrepancy between males and females. From their head to base of their tail, they measure an average of 11.3 in (28.7 cm). Tail length exceeds body length and typically measures about 14.3 in (36.3 cm). While their tail is impressively longer than their body length, it is not prehensile, meaning it is not capable of grasping branches. They have long arms and legs, and thick curled claw-like fingers and toes. They do not have opposable thumbs.

Lifespan of the black lion tamarin has not been specifically studied, as researchers have not been able to regularly track populations. However, other related species of lion tamarin have an average lifespan of about 14 years.

Appearance
The black lion tamarin, or golden-rumped tamarin, is named after its most obvious features: its large lion-like mane and its colorfully golden rump. A luxurious coat of black fur surrounds the tamarin’s head, giving it a regal, mane-like appearance. Their faces are mostly free of hair, with dark brown skin and large amber-brown eyes.

Their thick black coat runs down their back and under their belly. While they are called golden-rumped tamarins, the color that surrounds their rump can vary between lighter gold and an amber brownish-gold. This color starts at the base of the rump and runs slightly underneath their belly, stopping around the genitalia. Their long bushy tails are black. Their hands are also black and their fingers have patches of black fur on top.

What Does It Mean?

Biodiversity:
​The level of variation of life in an ecosystem, biome, or the entire planet. Biodiversity is a measure of the health and function of an ecosystem.

Diurnal:
Active during daylight hours.

Endemic:
Native or restricted to a certain area or country.

Gestation:
The time of pregnancy from conception until birth. 

Prehensile:
Able to grasp or hold objects.

Visit the Glossary for more definitions

Photo credit: Roger Smith/Flickr/Creative Commons

Diet
Black lion tamarins are omnivorous. They rely on small insects and arthropods for some of their diet, and seasonal tree fruits and tree gum for the rest. Typical fruits of their region include small berries and are usually found at the tops of the canopy, underneath palm leaves, and under the bark of trees.

Their long fingers facilitate reaching small berries and digging beneath tree bark for gum, both of which are usually found at about 33 ft (10 m). More importantly, they are able to dig underneath rocks and small plants for insects. Foraging for insects—which are located either higher in the canopy or on the forest floor—proves to be much harder than finding fruits and nectar; it requires keen digging and quick responses to quick camouflaged insects, and leaves the tamarins exposed to possible predators that lurk on the forest floor. However, insects offer more nutritional value and protein than fruits and tree gums, so consuming insects is vital to the black lion tamarin’s nutritional health. 

Depending on which part of the forest they find themselves in (drier vs. swampier), their diet lean towards the foods that are more readily available. These small primates are very resourceful foragers. Because they live in such a small area of forest, and are not able to travel to other areas when food sources become scarce, they have become adept at foraging for the limited amount of foods that occupies their small surface area. The smaller the area of forest a primate occupies, the fewer the food sources that are available.

Black lion tamarins display a shared foraging pattern when insect prey is available—when looking for insects they typically forage alone or in pairs, but when a source of insect prey is found in larger quantity they come together as a group. Researchers have observed unusual or uncharacteristic aggression towards each other when tough-to-reach insects are found. This means that while they forage as a group and often share with each other and with their young, when the food is scarce they adopt an “every man for himself” attitude and do not share. Black lion tamarins adapt their diet and food sources to monthly, weekly, and even daily patterns that rely on seasonal weather conditions. All of this means that they have an extremely complex and specific diet and food schedule.

Behavior and Lifestyle
Black lions tamarins are diurnal and aboreal (they are active in the daytime and live in trees). Daily life is mostly comprised of foraging, which can take up a large portion of the day depending on the food source and where they need to travel for it. Within the Morro do Diabo State Park, they sometimes travel relatively far distances for food.

Black lion tamarins are not territorial. For safety and protection, they occupy tree holes during the night, and sometimes during the hottest part of the day. Tree nooks are a safe distance from the forest floor, are concealed, are the perfect size for their small bodies, and are often reused.

Fun Facts

The black lion tamarin was thought to be extinct for over six decades.

Black lion tamarins have a higher chance of surviving in the wild than in captivity.

The entire social group participates in rearing babies.

Their lion-like manes give them their name.

Daily Life and Group Dynamics 
Black lion tamarins live in extended family groups of 4-8 individuals. Male to female ratios depend on group size. Only one female in each group breeds each breeding season, which occurs three times per year. Males and females may migrate between troops, which means that both genders may enter and leave different groups. This especially occurs when juveniles approach adulthood and search for groups of their own.

Tamarins, in general, are social primates. Grooming is a common social activity that bonds them together. Males typically carry the young when foraging or traveling. Social play is common in juveniles and youths.

Communication
Black lion tamarins exhibit complex forms of communication, including verbal and nonverbal cues, and scent marking. They communicate while foraging for food, both to relay location and to keep the troop together.

Communication related to food is extremely important within the group. When large food sources are found, there is little competition within the group; the group may communicate through a series of “clucks,” or nonverbal cues like touches or gestures.

Alarm calls include short small screams that alert danger or possible predators within striking distance. Because they can be susceptible to larger predators that lurk on the forest floor or in the mid-canopy, this alarm call is an important form of communication that could mean the difference between life and death.

The most common forms of communication are mating calls between males and females.

Reproduction and Family
Despite their small groups sizes, family life and reproduction cycles for black lion tamarins can be very complex. They live in groups of 4-8 individuals, yet only one female reproduces per season, and there are only three seasons per year. Males use mating calls to lure females, and the two that match will be the only pair that produce offspring in that troop. The breeding female then emits pheromones that suppress reproduction in the other females. This balances group life and population, as the group cannot support offspring from every female.

Gestation lasts approximately 130 days. She typically gives birth once per year, with each birth producing 1-2 infants. Twins are very common in all lion tamarin species. Typically, most mammals give birth to an equal number of females and males, but black lion tamarins almost always give birth to more males, at a rate of about 60:40.

The whole group takes a role in raising the young. This is called alloparenting. Activities such as hunting and scavenging are socially learned behaviors taught by the entire group, but especially by the mothers and fathers. Offspring are nursed and provided with food in their early weeks of life. After reaching about 25 weeks they are considered ready to fend for themselves. Males typically carry the infants when traveling.

Photo credit: Miguel Rangel Jr/Creative Commons

Ecological Role
Black lion tamarins play an important role within the food web. The Atlantic Rainforest has a fragile ecosystem, and every animal that plays its part in the food web and cycle of life is an important piece. Tamarins are seed dispersers throughout their areas of the forest.

Conservation Status and Threats
The black lion tamarin is considered to be one of the rarest and most endangered primate species on the planet. The International Union for Conservation of Nature Red List of Endangered Species lists the black lion tamarin as Endangered (IUCN, 2020). The species was listed as Critically Endangered in 2000 and 2003, but its threat was down-listed to Endangered in 2008 and 2020 to Endangered due to intense conservation efforts.

The species was believed to be extinct for nearly 50 years until they were spotted in 1972. Since their rediscovery, population numbers have never been entirely agreed upon. This makes classifying the population a difficult task. However, the IUCN’s 2020 census lists 1,600 individuals in wild populations.

Since the early 1970s, the forest that the black lion tamarin calls home has lost 85% of its primary forest. This staggering number has most likely had a drastic effect on the wild numbers of black lion tamarins. It has isolated and fragmented their populations to a dangerous degree.

It is anticipated that the population will further decline by 50% or more within the next three generations (2019-2040) due to continued habitat loss within its range, the possible loss of several subpopulations that are believed to be non-viable over the mid- to long-term, and the potential for significant losses due to unforeseen catastrophic events (e.g., a recent yellow fever outbreak that has caused significant mortality in golden lion tamarin populations).

Logging is still the primary threat to the black lion tamarin, and while national parks have been created to protect what little is left of the Atlantic Forest, it still faces threats from commercial timber companies. The black lion tamarin is not typically seen in the illegal pet trade. Like all species, especially those in the Amazonian region, they face further environmental threats due to climate change and global warming.

Conservation Efforts
Conservation efforts are mostly supported through zoological societies and field stations inside the national parks of Brazil. Caetetus Ecological Station is a long-standing field research station inside the Atlantic Forest in the state of Sao Paulo, Brazil. The station is home to a considerable portion of the population of black lion tamarins, and when researchers are able to find them they conduct critical population estimates and other research that aims at protecting the species.

Captive breeding programs are a useful way to keep the population of endangered species viable. However, it is a difficult task and the success rate of releasing animals bred in captivity is still very slim. The Jersey Zoo (Island of Jersey, UK) has a well-managed breeding program that has successfully released a captive-bred family of black lion tamarins into the wild. This model of success is a positive sign for the wild population. However, this all depends on whether or not the black lion tamarin has a habitat to be released into. In order to have any success in repopulation, what’s left of the Atlantic Forest must be protected from commercial logging.

References:

  • French, Jeffrey A.; Pissinatti, Alcides; Coimbra-Filho, Adelmar F. (1 January 1996). “Reproduction in captive lion tamarins (Leontopithecus): Seasonality, infant survival, and sex ratios”. American Journal of Primatology. 39 (1): 17–33. doi:10.1002/(SICI)1098-2345(1996)39:1<17::AID-AJP2>3.0.CO;2-V.
  • Albernaz, Ana L. K. M. (1 January 1997). “Home Range Size and Habitat Use in the Black Lion Tamarin (Leontopithecus chrysopygus)”. International Journal of Primatology. 18 (6): 877–887. doi:10.1023/A:1026387912013.
  • Camargo Passos, Fernando De; Keuroghlian, Alexine (1999). “Foraging Behavior and Microhabitats Used by Black Lion Tamarins, Leontopithecus Chrysopygus” (PDF). Revista Brasileira De Zoologia. 16: 219–222. doi:10.1590/s0101-81751999000600022.
  • Kierulff, M.C.M., Rylands, A.B., Mendes. S.L. & de Oliveira, M.M. 2008.  Leontopithecus chrysopygus. The IUCN Red List of Threatened Species 2008: e.T11505A3290864. http://dx.doi.org/10.2305/IUCN.UK.2008.RLTS.T11505A3290864.en.

Written by John DeVreese, July 2018. Population data updated November 2020.