Saguinus mystax

Geographic Distribution and Habitat

Moustached tamarins, also called Spyx’s moustached tamarins and black-chested mustached tamarins, are native to Brazil and Peru, where they are found in all layers of the Amazonian lowland rainforest, with the exception of flooded forests. They can persist in disturbed forests close to human settlements. 

There are three recognized subspecies:

  • Spix’ moustached tamarin, Saguinus mystax mystax, is distributed in Peru and Brazil
  • The red-cap moustached tamarin, Saguinus mystax pileatus, is endemic to the Brazilian Amazon, west of the Rio Purus, south at least as far as the Rio Pauini or Rio Mamoria.
  • The white-rumped moustached tamarin, Saguinus mystax pluto, is endemic to Brazilian Amazonia. The borders of its range are disputed.
Moustached tamarin range, IUCN 2008

Size, Weight, and Lifespan

Small primates, the head to body length of moustached tamarins is 9 to 9.7 inches (24.2-24.7 cm), with an added tail length of 15 inches (38 cm). They weigh, on average, between 1 and 1.3 pounds (500–600 g). Adult females are slightly larger than adult males.

They are known to live up to 18 years in captivity. Due to predation and other factors, wild lifespans are likely less. 

What Does It Mean?

The killing of young offspring by a mature animal of the same species.

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

Visit the Glossary for more definitions


The white facial hair surrounding their mouths is the distinctive characteristic that gives the moustached tamarin its name. Their face is rather flat, with almond-shaped eyes and large furry ears. The black hair on their body is long and silky. These small creatures have claw-like nails on their hands and feet, except on the hallux (or big toe). This helps them cling to trees as they feed on fruit or saps.

Photo credit: Photo credit: MarvinCZ/Creative Commons

Tamarins forage in the upper and middle layers of the forest and feed on fruit, nectar, invertebrates, and small vertebrates. They also eat plant exudates, such as gums and sap, which add calcium to their diet. Gums are a great staple, especially during the dry season. Stick grasshoppers and spiders are also on the menu. On rare occasions, mustached tamarins have been observed feeding on nestling birds.

Only 60% of females have trichromatic vision, seeing in three colors, which enables them to better detect ripe fruit; the other females and males have dichromatic vision, seeing primarily in two colors. All moustached tamarins have great spatial memory and are able to quickly identify and remember the locations of fruiting trees.

Behavior and Lifestyle

Moustached tamarins are diurnal (active during daylight hours) and arboreal (tree-dwelling). Much like squirrels, they walk and run on all fours with their bellies close to the surface beneath them, especially when climbing on slanted branches. They use their claws to dig into the bark and remain stable. 

Their mode of locomotion varies depending on which layer of the forest they find themselves in. When they are in the lower canopy, tamarins perform what is known as “trunk-to-trunk” leaps. These jumps are quick and short in length, between 3 and 6 feet (1–2 m). While standing on a medium or large trunk, the tamarins powerfully and rapidly extend their hind limbs to propel themselves into the air, turning their body in mid-air to land securely on another trunk. When they cross between discontiguous trees, they extend their legs further out in order to perform “bounding” leaps, which are up to 6 feet (2 m) in length.

While high in the canopy, tamarins perform what scientists referred to as an “acrobatic” leap, which is a long leap of 16 feet (5 m) or more, to travel between the crowns of trees. As they jump, they use their tail to decelerate their descent before landing on their front limbs.

Daily Life and Group Dynamics 

Moustached tamarins live in groups of 2–8 individuals (most often 5–6), not including infants. Each group is usually composed of 1 or 2 adult females. Solitary individuals of both genders are occasionally encountered, but it is not clear how long they remain alone before joining a group.

Moustached tamarins depart in the early morning as a group to forage for food. The group’s home range covers a territory between 60 and 124 acres (25–50 ha). At night they retire together in areas with lots of foliage to hide from predators while they sleep.

They are territorial, yet they have been observed associating with groups of saddleback tamarins (Leontocebus fuscicollis). Sharing territory with another species increases the survival chances of both groups. When larger troops travel together—with more eyes and ears watching and listening—predator avoidance is facilitated.

Moustached and saddleback tamarins avoid competition for food because they only consume three of the same insect species; they also use different hunting techniques and forage in different strata of the forest. Moustached tamarins thrive in the middle and upper layers, whereas saddleback tamarins prefer the lower layers.

Tamarins don’t usually all feed at the same time. One adult, positioned near the feeding site, scans the surroundings and alerts the group if predators are nearby. Although not specifically documented for moustached tamarins, it is reasonable to think this behavior applies to them as well.

Tamarins generally flee from predators; however, on one occasion at least, scientists observed a group of moustached tamarins successfully rescuing one of their group mates from a boa constrictor.


Like all primates, moustached tamarins use vocalizations, facial expressions, gestures, grooming, and scent marketing to communicate. Upon waking, they vocalize to coordinate the groups’ movement toward foraging sites. When two groups inevitably encounter each other, conflict arises. Adult males erupt in a fight, punctuated by aggressive and loud vocalizations, while subadults of both genders chase each other. The fights are followed by periods of calm when both groups forage for food and subadults check each other out for future mating opportunities. If they become separated while foraging, individuals of the same group produce calls that last 2 to 3 seconds to indicate their location.

Moustached tamarins spend time grooming each other to develop friendships. They untangle and comb each other’s hair with their claws and use their teeth and tongue to clear any parasites or gunk off each other. Depending on their social position in the group and what they expect from the breeding female, some individuals may offer more grooming services than others.

Finally, they use scent-marking to define the boundaries of the territory they occupy and to communicate with one another. Females practice scent-marking more than males so it is possible that scent-marking is their way of seeking out mates.

Reproduction and Family

Female moustached tamarins become fertile between 15 and 17 months of age, while males become mature at 18 months. Both males and females migrate to different groups in adulthood. It is not known which gender transfers more often. This migration avoids the risks of inbreeding.

For a long time, it was thought that these little primates were monogamous, but research indicates that they have several mating models. In some groups, one male mates with several females; in others, one female mates with multiple males; and in others still, both males and females have multiple partners.

The reproductive season spans the months of November through February. When a group includes two adult females, only one (usually the oldest of the two) breeds during that time.

Females go into estrus for about 17 days. After a gestation period of roughly five months (140–150 days), females give birth to twins. The interval between births is approximately one year in the wild; in captivity, the same female may give birth twice a year. Mothers carry their infants during the first four months of life, but considering the fact that, at birth, the twins are up to a quarter of her size, Mom needs all the help she can get. In fact, mothers do best when they can rely on 4 to 5 helpers. This may explain why in polyandrous groups, the alpha male tolerates the presence of other males who can provide infant care.

Infanticide by mothers occasionally occurs when a group does not include enough helpers to rear the babies. When that happens, the inter-birth interval is shortened. Infanticide of unrelated babies by male moustached tamarins has never been documented.

Young tamarins play by running and chasing each other while vocalizing. These play sessions are always monitored by adults who surround the “playground” in order to protect the young from predators.

Ecological Role

In their travels, moustached tamarins disperse the seeds of the fruits they ingest and therefore play an important role in the regeneration of the rainforest. 

Conservation Status and Threats

Although the overall population of moustached tamarins is decreasing, the species is classified as Least Concern by the International Union for Conservation of Nature (IUCN, 2015). They adapt to both disturbed forest patches and proximity to human settlements.

Natural predators include eagles, snakes, ocelots, and other wild cats.

Conservation Efforts

No special programs are dedicated to the moustached tamarins. Efforts to protect the rainforest, of course, would benefit all its inhabitants, including this little monkey.

  • IUCN Red List
  • Comparative study of positional behavior in three species of tamarin monkeys (DOI: 10.1007/BF02381179) – April 1991 – Paul A. Garber
  • Primate Societies – Tamarins and Marmosets: Communal Care of Offspring – Anne Wilson Goldizen
  • Primates – The Amazing World of Lemurs, Monkeys and Apes – Art Wolfe
  • Folia Primatologica 73(2-3):146-8, March 2002 – Boa constrictor Attack and Successful Group Defense in Moustached Tamarins, Sanguinus mystax – Eckhard W. Heymann
  • Primate Behavioral Ecology – Karen B Strier

Written by Sylvie Abrams, August 2019