Saguinus tripartitus occurs in the upper Amazon rainforest between the Rio Curaray in Ecuador and the Rio Napo in Peru. It can also be found east of the Andes between the right bank of the Rio Napo and the left bank of the Rio Putumayo in Ecuador.

Biogeographic Regions: neotropical (Native )

Saguinus tripartitus can range from 218 to 240 mm in body length and 316 to 341 mm in tail length. They have orange bodies and blackish orange hands. Their heads are covered in black fur with muzzles and faces which are generally white. On their lower back is a patch of cream colored hair. Their tails are generally black with an orange underside.  This species is also closely related to Saguinus fuscicollis. Some investigators consider S. tripartitus to be a subspecies of S. fuscicollis.

Range mass: 290 to 420 g.

Range length: 218 to 240 mm.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: sexes alike

• Terrestrial

Saguinus tripartitus is found in lowland evergreen rainforests, seasonally flooded forests, and terra firma of the Amazon basin. Although typically found at lower elevations, S. tripartitus has been recorded at up to 400 meters above sea level in the western limits of its range, near the Andes Mountains. In general, tamarins are highly arboreal and are rarely seen on the ground.

Range elevation: 0 to 400 m.

Habitat Regions: tropical ; terrestrial

Terrestrial Biomes: rainforest

Saguinus tripartitus is primarily insectivorous and frugivorous. They have also been known to eat small vertebrates, non-insect arthropods, flowers, nectars, gums, and other plant exudates. They may feed less on exudates than some other primates because they lack the dentary adaptations of those species for gouging into plants.

Animal Foods: reptiles; insects; terrestrial non-insect arthropods

Plant Foods: fruit; nectar; flowers; sap or other plant fluids

Primary Diet: carnivore (Insectivore ); herbivore (Frugivore )

In its ecosystem, Saguinus tripartitus is important for its role as prey for larger animals. Most often these are birds of prey. It also has a small role as a predator of insects and very small vertebrates. It is also possible that the diet of S. tripartitus makes them important in seed dispersal and the pollination of flowers.

Ecosystem Impact: disperses seeds; pollinates

Saguinus tripartitus individuals are preyed on by a variety of animals including birds of prey, snakes, ocelots, and tayras. They use several behaviors to protect themselves from these predators. They differentiate between the fecal scents of predators and non-predators in order to avoid areas which may have predators in them. They use specific warning calls which can alert others nearby if the threat is aerial or terrestrial. They sometimes mob predators.

Known Predators:

• hawk-eagles (Spizaetus ornatus)
• crested eagles (Morphnus guianensis)
• snakes (Serpentes)
• tayras (Eira barbara)
• ocelots (Leopardus pardalis)

Saguinus tripartitus primarily uses scents in communication. Individuals use circumgenital marking (marking using glands surrounding the anus) and suprapubic marking (marking using suprapubic glands). Individuals of higher social rank mark more frequently than those of a lower social standing. Saguinus tripartitus individuals can distinguish a large amount of information from scents, such as sex, species, social rank and reproductive status.

Communication Channels: visual ; acoustic ; chemical

Other Communication Modes: scent marks

Perception Channels: visual ; acoustic

Little information is available about the lifespan of Saguinus tripartitus. Rowe (1996) lists lifespan in the wild as 6 years and Hershkovitz (1977) mentions one specimen living five years, nine months, and nineteen days in captivity.

Range lifespan

Status: captivity: 5.75 (high) years.

Average lifespan

Status: wild: 6 years.

Saguinus tripartitus, like other callitrichids, live in groups in which only the dominant female mates, typically with multiple males. There is some evidence of facultative polyandry among tamarins, in which two or more males mate with the female and cooperate in caring for the twin offspring.

Mating System: polyandrous ; cooperative breeder

Saguinus tripartitus, like other callitrichids, live in groups in which only the dominant female mates. As in other callitrichid species, the ovarian cycles of subordinate S. tripartitus females are suppressed while living in groups. In studies involving captive females living in family groups, low and acyclic levels of urinary estradiol (a hormone produced by the ovaries) were recorded while females were living as subordinates. When females were removed from the family group and placed in isolation with a male, their levels of urinary estradiol skyrocketed and immediate onset of their ovarian cycles occurred. The physiological reasons behind this are not known, but it is speculated that pheromones from dominant females may play a part in suppression of ovarian cycles in subordinate females. The length of gestation and lactation periods, breeding seasons and intervals, and time to sexual maturity, are not known. They are believed to be similar to other members of the genus Saguinus in terms of these traits. Gestation periods for Saguinus range from 140 days to 180 days, with most species having gestation periods between 140 and 150 days. Information regarding lactation periods of Saguinus could not be found. No generalizations could be made about the breeding seasons of the whole genus based on the information available. However, Saguinus fuscicollis breeds between April and October, and Saguinus oedipus and Saguinus geoffroyi breed between January and February. The age to sexual maturity varies between 15 and 24 months for Saguinus species.

Like other tamarin species, S. tripartitus gives birth to twins.

Range number of offspring: 1 to 2.

Average number of offspring: 2.

Key Reproductive Features: iteroparous ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization ; viviparous

Patterns and duration of parental investment are not known. Fathers tend to provide and care for the infants more than mothers do after they are born. This may be offset the substantial energy investment of the mother during gestation and lactation. Tamarins give birth to young with large body masses relative to the mother's body mass, so females invest large amounts of energy into the young before they are born. Post-birth care from parents comes in the form of providing food, providing protection, and carrying the young around as they develop. Social groups also help to care for the young, sharing food and generally protecting them.

Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male); pre-independence (Provisioning: Male, Female, Protecting: Male)

Saguinus tripartitus is listed as "Near Threatened" by the International Union for Conservation of Nature and Natural Resources (IUCN). Saguinus tripartitus occurs in remote forests along the Rio Yasuni. Human activities have not greatly impacted these forests to date, with the exception of small petroleum prospecting encampments. However, the recent discovery of petroleum in the area has led to the construction of the Pompeya-Iro highway through the area, which has caused some concern about future deforestation and development in the habitat of S. tripartitus. Due to projected high rates of deforestation, the population of S. tripartitus is expected to decline by twenty-five percent over the next eighteen years (three generations).

US Federal List: no special status

CITES: appendix ii

State of Michigan List: no special status

IUCN Red List of Threatened Species: near threatened

There are no known adverse effects of Saguinus tripartitus on humans.

Saguinus tripartitus individuals are sometimes kept as pets. Because they are small, they are rarely hunted for food. They are also used as models in biomedical research.

Positive Impacts: pet trade ; research and education