GOLDEN-HEADED LION TAMARIN

Leontopithecus chrysomelas

Geographic Distribution and Habitat
Golden-headed lion tamarins (Leontopithecus chrysomelas)—also called golden-headed tamarins and not to be confused with the closely related golden lion tamarins—are endemic to the Atlantic Forest of coastal Brazil. Their preferred habitat is evergreen broadleaf tropical forests and semi-deciduous forests, and they live 10–33 feet (3–10 m) up in trees. Habitat destruction has limited their range to the southern portion of the state of Bahia, Brazil. Golden-headed lion tamarins are members of the family Callitrichidae, which include marmosets and tamarins.

While they thrive in primary forests, golden-headed lion tamarins are able to live in disturbed and secondary forests as long as there are sufficient food and sleeping sites. One study found that the body condition and reproductive success of a population of golden-headed lion tamarins living in a cabruca, an agroforest of cultivated cocoa trees shaded by native forest trees, was better than those living in some natural forest types.

Golden-headed lion tamarin range, IUCN 2008

Size, Weight, and Lifespan
​Golden-headed lion tamarins weigh 17–25 oz (500–700 g). Their head-to-body length is 8–13 inches (20–34 cm) long, with their tails adding an additional 12–15 inches (32–40 cm) in length. They are known to live about 15 years in captivity.

Appearance
​Taking after their namesake in appearance, golden-headed lion tamarins have a striking mane of golden-orange hair, in stark contrast to their mostly black bodies. Their legs and tails also have this golden-orange coloring. They have long fingers and hands, which they use to forage for prey in the small nooks and crannies of epiphytic tank bromeliads, an important foraging source. Like their Callitrichidae cousins, they have claws instead of nails on all but their big toe, a rarity in the primate world. Their canine teeth are relatively large, and help them to bite into tough fruit. There is very little sexual dimorphism among golden-headed lion tamarins, although females are often slightly larger than males.

In a palm tree in Una, Bahia, Brazil

Diet
As omnivores, golden-headed lion tamarins consume fruit, flowers, nectar, insects, exudates, and small invertebrates. Occasionally they eat lizards, small snakes, bird eggs, and even small birds. One part of the tree they do not eat is leaves.

Epiphytic tank bromeliads are an important foraging source for golden-headed lion tamarins. Epiphytic plants are those that grow on another plant, such as on a tree trunk, but are not parasitic. Tank bromeliads are a taxon of plants that trap water in their crowns. These pools (or “tanks”) provide important habitat for salamanders, frogs, and aquatic insects where you might least expect themin tree canopies! This makes them an ideal foraging spot for golden-headed lion tamarins and other arboreal animals.

Behavior and Lifestyle
Golden-headed lion tamarins are arboreal, diurnal, and quadrupedal, moving about using all four limbs. When they are traveling down a tree trunk, they can climb down either head-first or tail-first. At night, they usually find a tree hole to sleep in, and they will use the same hole for up to six nights in a row. They sometimes spend their nights in a tank bromeliad or a thicket of vines.

Daily Life and Group Dynamics 
Golden-headed lion tamarins live in extended family groups of four to eight individuals, composed of a mated pair and their offspring. They defend a home range of 99–247 acres (40–100 ha). A higher availability of food usually lends itself to a smaller home range, and thus less energy spent on defending it. Same-sex adults are very aggressive toward one another when defending their territories.​

Communication
Long calls are used by golden-headed lion tamarins to signal a group’s presence in the area and to maintain relationships between bonded pairs. They cluck while foraging and trill when they are alone. When two individuals meet, they often let out a whine. Golden-headed lion tamarins also rely on scent communication. They can use pubic and throat scent glands to mark surfaces, leaving olfactory communication signals to other golden-headed lion tamarins. They signal aggression by raising their hairs, which makes them appear bigger and can help to ward off predators.​

What Does It Mean?

Arboreal:
Physically adapted to living primarily or exclusively in trees.

​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.

Canopy:
Beneath the emergent layer, the canopy layer is the primary layer of the forest and forms a roof over the two remaining layers (the understory and forest floor). Many animals live in this maze of leaves and branches, where food is abundant.

Deforestation:
The permanent cutting, clearing, and removal of trees to convert forest land for other use, such as pasture, cropland, or plantations.

Disturbed Habitat:
A temporary change in environmental conditions that causes a pronounced change in an ecosystem.

Diurnal:
Active during daylight hours.

Exudate:
A substance, such as gum, sap, or resin, which flows from the vascular system of a plant.

Inbreeding:
The breeding of closely related individuals, especially over many generations.

Inbreeding depression:
A reduction in the overall health and reproductive fitness of a population due to inbreeding.

Primary forest:
Also termed old-growth forest, virgin forest, or primeval forest—a forest that has attained great age without significant disturbance and thereby exhibits unique ecological features and might be classified as a climax community, an ecological community in which populations of plants or animals remain stable and exist in balance with each other and their environment.

​Quadrupedal:
Using four limbs to move about. This word comes from the Latin meaning “four feet.”

Secondary forest:
A forest that has regrown after a major disturbance, such as fire or timber harvest, but has not yet reached the mature state of primary forest.

Semi-deciduous:
A botanical term referring to plants that lose their foliage for a short period of time; as leaves fall, new ones start growing.

Visit the Glossary for more definitions

Reproduction and Family
Adult golden-headed lion tamarins typically mate for life and take equal responsibility in rearing offspring. Typically, only one female in each group breeds during the breeding season, which is the warm and wet season of September through March. They breed once per year, which is relatively infrequently and results in slow population growth. After a four month gestation, they almost always give birth to twins, something very rare among other primates but normal for marmosets and tamarins. Females become sexually mature at about 1.5 years of age, and males slightly later at about 2 years of age.​

Fun Facts

Golden-headed lion tamarins can stand their hairs up on end to make themselves look bigger—a useful skill for these squirrel-sized monkeys to have to ward off predators!

Ecological Role
Golden-headed lion tamarins play an important role in the ecosystem as seed dispersers. The seeds in the fruit they eat pass through their digestive system and are dispersed well away from the parent plant. One study found that 89% of almost 600 fecal samples contained seeds, and that golden-headed lion tamarins perform an important function to the persistence and regeneration of many rainforest plants.

Golden-headed lion tamarins sometimes form mixed-species groups with Wied’s black-tufted-ear marmosets. These two species do not directly compete with each other because golden-headed lion tamarins forage higher in the canopy than Wied’s black-tufted-ear marmosets.

Conservation Status and Threats
Golden-headed lion tamarins are listed as Endangered by the International Union for Conservation of Nature (IUCN, 2020), primarily due to population loss of over 50% over the past two decades. The populations that remain are severely fragmented. Information about the total population in the wild is dated, but in 1994–1997, estimates ranged from 6,000 to 15,000 animals in the wild. The current population is likely lower than it was when those estimates were created.

While this population loss is dramatic, it’s sadly not surprising. Golden-headed lion tamarins have undergone startling habitat loss over the past several decades, with an estimated 2–5% of their original habitat remaining as a result of deforestation. This deforestation has occurred largely to clear space for timber, charcoal, and agriculture industries. Even altered habitat types are being lost. Cabrucas, cultivated cocoa plantations that are shaded with native trees, cover about 18% of the total range of golden-headed lion tamarins, and can serve as suitable habitat for the species. However, this type of high biodiversity value agriculture is being threatened due to low cocoa prices and fungal epidemics that make it more profitable for farmers to convert their agroforests to cattle pastures, which have very low biodiversity value.

Not only is habitat loss an issue for population numbers, it has also resulted in extremely fragmented populations. The remaining forest is patchy, and individual golden-headed lion tamarins can’t easily, or ever, cross in between “islands” of habitat. This means that the genetic diversity of the remaining populations is decreasing, leaving them susceptible to inbreeding, depression, and other consequences of low genetic diversity.

Illegal collection of golden-headed lion tamarins for the pet trade was a significant problem for the species in the 1980s. Luckily, recovery of these illegally exported animals was made a priority of the Brazilian government, and these individuals went on to help form genetically diverse captive breeding populations. Although the international demand for golden-headed lion tamarins for the pet trade is not as high as it once was, it is still present and it is only weakening an already extremely stressed population.

Conservation Efforts
There are several ongoing conservation projects in effect to help protect golden-headed lion tamarin habitat and bolster their population numbers. The Una Biological Reserve is a protected 17,000 acre (7,000 ha) preserve that was established in 1980 for the protection of golden-headed lion tamarin habitat. However, this area is not large enough to support a self-sustaining population of golden-headed lion tamarins. It is estimated to contain a population between 240 and 460 individuals, while the minimum number of individuals necessary to maintain genetic diversity over the long term is believed to be about 500. Currently, golden-headed lion tamarins within Una are monitored regularly, and even receive veterinary care. However, this is only a short-term solution as the issues caused by inbreeding depression will only make the animals sicker—it’s treating the symptoms but not the cause. The only long-term solution is to connect patches of forest to the reserve and allow new golden-headed lion tamarins in to bring genetic diversity to the population.

To help support this goal, a Landowner’s Environmental Education Program was created in 1979 to help teach the community about the importance of protecting both the reserve and the forests that connect to it. As of 2001, over 70% of the farms in the area have begun using conservation practices to help preserve golden-headed lion tamarin habitat. The program focuses on conservation, property rights, and land use, and targets school children, farm workers, hunters, and forest guards.

Resources

  • Catenacci, L.S., K.M. De Vleeschouwer, S. L. G. Nogueira-Filho. 2009. Seed Dispersal by Golden‐headed Lion Tamarins Leontopithecus chrysomelas in Southern Bahian Atlantic Forest, Brazil. Biotropica 41(6). Accessed 8 July 2020: https://doi.org/10.1111/j.1744-7429.2009.00530.x
  • Mallinson, J. 2001. Saving Brazil’s Atlantic Rainforest: Using the golden-headed lion tamarin (Leontopithecus chrysomelas) as a flagship for a biodiversity hotspot. Dodo 37: 9-20.
  • Pinto, L. and A. B. Rylands. 1997. Geographic Distribution of the Golden-Headed Lion Tamarin, Leontopithecus chrysomelas: Implications for Its Management and Conservation. Folia Primatologica 68: 161-180. Accessed 8 July 2020: https://doi.org/10.1159/000157244
  • Zeigler, S. L., W. F. Fagan, R. DeFries, et. al. 2010. Identifying Important Forest Patches for the Long-Term Persistence of the Endangered Golden-Headed Lion Tamarin (Leontopithecus Chrysomelas). Tropical Conservation Science 3(1): 63-77. Accessed 8 July 2020: https://doi.org/10.1177/194008291000300106
  • https://www.britannica.com/plant/tank-bromeliad
  • https://www.britannica.com/plant/epiphyte
  • https://www.iucnredlist.org/species/40643/10347712
  • https://nationalzoo.si.edu/animals/golden-headed-lion-tamarin
  • https://www.worldlandtrust.org/species/mammals/golden-headed-lion-tamarin/
  • https://www.nybg.org/bsci/res/bahia/Una/
  • http://pin.primate.wisc.edu/factsheets/entry/golden-headed_lion_tamarin/cons

Written by K. Clare Quinlan, July 2020