RED-CHESTED MUSTACHED TAMARIN

Saguinus labiatus

Geographic Distribution and Habitat
The red-chested mustached tamarin (Saguinus labiatus), also known as the red-bellied tamarin and the white-lipped tamarin, makes its home in the middle canopy of trees predominantly in the Amazon rainforest of Brazil and connecting regions of Peru and Bolivia. Some populations also have been found living north of the Amazon basin in Brazil.

In the dense layer of vegetation up to 100 feet (30 m) high, and 20 feet (6 m) thick, these distinctive tamarins are an essential part of the diversity unique to this region. They are arboreal and, while they may venture to the lower canopy for food, they can live out their many years without ever coming to the level of earth where humans walk. There are three recognized subspecies: Saguinus labiatus labiatusSaguinus labiatus rufiventer, and Saguinas labiatus thomasi.

Red-chested mustached tamarin range, IUCN 2008

Size, Weight, and Lifespan
Average size for this species is under a foot in length—between 9 and 11.5 inches (23–29 cm)—and their average weight is about 1.1 pound (498.95 g), with females being generally larger than the males, the only example of sexual dimorphism in the species.

In the wild, scientists estimate the lifespan of this tamarin, based on the wear of their teeth, to be up to 8 years. In captivity, the lifespan averages 8–10 years, but some of these tamarins live to be much older—more than 20 years old!

Appearance
Red-chested mustached tamarins are contenders for the “best dressed” of the tamarin family with their suits of reddish-orange in front, dark brown or black in back, and distinctive white around the nose and mouth—an apparent mustache that flatters male and female alike. This stylish look is actually all about function, for in the forests where these little tamarins live, the white around the mouth and red around the belly actually work as camouflage in their world of verdant shadow and light.

They have hard nails that cover all their fingers and toes (except the hallux) that are essential to their arboreal lifestyle, and non-opposable thumbs. They have longer canine teeth than incisors, and longer hind limbs than forelimbs, and some individuals have a white patch on their head to go with their mustache.

Their ears have a distinctive shape and point, which resembles a combination of Spock (from Star Trek) and a baby bat.

Diet
While they are technically omnivores, more than half of the red-chested mustached tamarin’s diet is fruit. They eat figs and mulberries (the morcaceae family), Amazon grapes, and all types of tropical fruit. When the dry season comes (July and August) and fruit is harder to find, they eat nectar and insects like grasshoppers and crickets. They don’t gnaw on bark—they don’t have the teeth for it—but instead eat plant exudates when available.

What Does It Mean?

Altricial:
Infants of a species who are still not fully developed, and must be cared for by their parents.

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

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.

Diurnal:
Active during daylight hours.  

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

Fraternal Twins:
Twins that develop from two different eggs.

Frugivore:
An animal who feeds on fruits.

Gestation Period:
The time of pregnancy from conception until birth.

Hallux: 
The innermost digit of the foot, known for humans as “the big toe.”

Incisors:
Narrow-edged teeth at the front of the mouth, adapted for cutting.

Monogamous:
Having only one sexual partner.

Omnivore:
An animal or person who eats food of both plant and animal origin.

Opposable thumb:
A thumb that can be placed opposite the fingers of the same hand. Opposable thumbs allow the digits to grasp and handle objects and are a characteristic of primates.

Polyandry:
A pattern of mating in which a female animal has more than one male mate

Sexual dimorphism:
Distinct difference in size or appearance between the sexes of an animal in addition to difference between the reproductive organs themselves.

Visit the Glossary for more definitions

Behavior and Lifestyle
Amid a wash of bird song and insect hums, red-chested mustached tamarins spend their time with a small social and familial group, high in the trees.

They are diurnal and keep very busy all day. They call to each other in long, distinctive phrases, telling of whereabouts. They run on all fours (quadrupedally) through layers of canopy when it is continuous, but are able, to paraphrase Superman, to make long leaps in a single bound across trees when necessary. Constantly scanning the area—on visual alert for predators—they can also be patient hunters of insects. They have a “home range” of about a tenth of mile (.17 sq km), where they frequent favorite feeding, social, and sleeping sites. They sleep near the others in their group, in tall trees 40–65 feet from the ground (12–20 m). They like to sleep in trees that help to obscure them from sight—trees with forks, holes, and even termite mounds or holes that help hide them from potential predators. They sleep with their heads tucked to hide the white of their faces (which might be seen in the dark by a night hunter) and their tails wrapped around them. During the rainy season, they have their go-to places, where they like to seek shelter and wait out the rain.

They are always on the lookout for potential predators—just how alert and how long they have to visually scan an area depends on the size of their group.

Daily Life and Group Dynamics 
Red-chested mustached tamarins are very social and live in groups, the sizes of which vary. On average, a group consists of five members, but it may be as small as two or as large as ten or more. They travel about a mile every day (1.3–1.7 km).

A common grouping includes a mother and father, plus family members who help raise the young. Usually, the groupings are only one breeding female (the mother) and one breeding male (the father), with a support team of others. There is a main male helper, or helpers, generally a male sibling or half-sibling of the breeding pair—an uncle or half-uncle. A group may also have other male or female siblings (but not generally if they are sexually mature) who also help with child rearing. In this way, the breeding couple is the dominant unit of the group.

Groups can change, however. For example, if one group encounters another, non-breeding males may leave to join with a female to become a dominant, bonded pair. A mother whose children have become independent may leave the group for another male. It seems that any aggression within the species is between an outside male and a breeding male who is trying to keep the female from leaving. Some couples stay bonded for life, and some groups seem to stick together. 

Red-chested mustached tamarins frequently group with other species of tamarins and marmosets as well, forming cooperative groups to help protect from predators without competing for food or mates. Studies of red-chested mustached tamarins in these types of inter-species groupings demonstrated better watch for predators with less individual effort. Cooperation between species—it just makes sense!

Fun Facts

Red-chested tamarins can twist their chin up in a vertical arc as they look at something, with a “huh?” type of expression.

Communication
These tamarins have a very high, almost bird-like voice and communicate in distinctive syllables. Their long calls have different dynamics and meanings. When they wake, they call loud and clear to each other in other groups, and then often meet up together. During the day, they call out to tell each other their whereabouts. They also have alerts of different sounds that let the others know what type of predator is near—telling each other to beware, and of what creature, with different calls.

They also use scent to communicate. They have glands on their chest, throat, and genitals, and use these to scent mark. Females rub on an external area like a branch (substrate), especially when they are fertile, to communicate their interest and availability. Males may scent mark a territory and each other in a ritual where they all face the other and the breeding male marks the head and back of the helper male and other males who then scent mark the territory. This is thought to be a ritual of group male solidarity, marking their territory and each other against males outside the group.

While scent and vocalizations are the primary ways they communicate, body language also sends a message. For example, a lunge with a wide-open mouth showing their canines means what one would assume it would mean: “Back off, man! Don’t make me use these teeth!”

Reproduction and Family
Reaching sexual maturity at 2–4 years of age (there is no difference between the genders in who reaches sexual maturity first), these tamarins may be polyandrous or monogamous—or serial monogamists, meaning they are only with one partner through the raising of a set of young but may form other breeding pairs in a lifetime. As noted above, when a couple become bonded, a male and female red-chested mustached tamarin become the sole breeding couple in their group while the others in the group help in the process of raising the young.

After a gestation period of a little over five months, the mother usually gives birth to fraternal twins. The babies are altricial, and while they may be mostly in the care of the mother for the first five weeks—until they are able to eat solid food—the entire group of this species are part of the support team. The father plays a huge role in caring for the children, as do other male members in the group. The babies are not independent until 1–2 or years, but all red-chested mustached tamarins in the group carry, feed, and care for the children, successfully demonstrating that “it takes a village to raise a child.”

Photo credit: Nils Axel Braathen/ Creative Commons

Ecological Role
Like all animals that are primarily frugivores, the red-chested mustached tamarin is a key component in distributing seeds and fertilizer throughout the forest—the magic of pooping and running. And like all the animals of this region, they are an integral part of the chain of life, which sustains the health of the forest, and of our planet.

Conservation Status and Threats
The red-chested mustached tamarin is categorized as Least Concern by the International Union for Conservation of Nature (IUCN, 2015). Habitat loss due to deforestation is impacting the species and their populations are decreasing. Their natural predators are birds of prey, ocelots, jaguars, many snakes, and even certain other primates—but the continued loss of all of these creatures’ homes is the greatest threat to their lives and their future.

Conservation Efforts
The red-chested mustached tamarin is listed in Appendix II 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.

The IUCN has listed that more research is needed for the red-chested mustached tamarin, as their population is decreasing. Most of the research for these tamarins is over a decade old, and habitat loss has increased exponentially in that time. When we as humans work together to quell deforestation, we are helping to protect these handsome, vocal, and social tamarins.

References:

  • Kristofik, N. 2011. “Saguinus labiatus” (On-line), Animal Diversity Web. Accessed March, 2020 at https://animaldiversity.org/accounts/Saguinus_labiatus/
  • https://www.iucnredlist.org/species/41524/17931345
  • https://eol.org/pages/323903
  • https://www.nationalgeographic.org/encyclopedia/rain-forest/print/
  • https://kids.mongabay.com/elementary/004/
  • http://www.theprimata.com/saguinus_labiatus/
  • https://www.monaconatureencyclopedia.com/saguinus-labiatus/?lang=en
  • https://animalcorner.org/animals/tamarin-monkeys/
  • https://thewebsiteofeverything.com/animals/mammals/Primates/Callitrichidae/Saguinus/Saguinus-labiatus/
  • http://www.departments.bucknell.edu/biology/resources/msw3/browse.asp?id=12100235

Written by Laura Lee Bahr, April 2020