The Black-tufted marmoset, also known as Mico-estrela in Portuguese, is a species of New World monkey. They are characterized by black tufts of hair around their ears and typically have some sparse white hairs on the face. Black-tufted marmosets have a brown or black head and their limbs and upper body are gray, as well as their abdomen. Their rump and underside are usually black. The tail of these monkeys is ringed with black and white and is not prehensile, but is used for balance. Black-tufted marmosets do not have an opposable thumb and their nails tend to have a claw-like appearance.
Black-tufted marmosets are found in Brazil ranging from Bahia to Paraná, and as far inland as Goiás, and can commonly be seen in the City of Rio de Janeiro where they were introduced. These marmosets typically live in gallery rainforests.
Black-tufted marmosets live an arboreal life high in the trees, but below the canopy. They are only rarely can be seen near the ground. They have a lifestyle very similar to other marmosets. Black-tufted marmosets live in family groups of 2 to 14. These groups usually consist of a reproductive couple and their offspring. Though these marmosets live in small family groups, they can share their food source, sap trees, with other marmoset groups. Scent marking does occur within these groups, but it is believed that the marking is to deter other species rather than other Black-tufted marmoset groups, because other groups typically ignore these markings. They also appear to be migratory, often moving in relation to the wet or dry seasons, however, the extent of their migration is unknown. Though communication between Black-tufted marmosets has not been studied thoroughly, it is believed that they communicate through vocalizations. They produce predator-specific cries when they are threatened and also frequently use other vocalizations.
Black-tufted marmosets are herbivores. Their diet consists primarily of tree sap. In periods of drought, they will also consume fruit and insects. In periods of serious drought, they may eat small arthropods, mollusks, bird eggs, baby birds and small vertebrates.
Black-tufted marmosets are monogamous creatures and mate for life. They breed twice a year, producing 1 to 4 infants, though most often just twins. The gestation period is 150 days and offspring are weaned after 8 weeks. Both parents take care of newly born offspring, as well as older juveniles also help to raise them. The infants are extremely dependent on their parents. They become reproductively mature at 18 months but typically do not mate until much later, staying with their family group until they do.
Main threats to Black-tufted marmosets include deforestation and fragmented habitat, hunting for pets, and hybridisation. In Rio de Janeiro State, where they were introduced alongside the Common marmoset, Black-tufted marmosets are considered as an invasive species posing a danger to the survival of the endangered Golden lion tamarin through competition.
According to the IUCN Red List, the total population size of Black-tufted marmosets is more than 10,000 mature individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List but its numbers today are decreasing.
Due to their choice of diet, Black-tufted marmosets may impact the health of trees that they are feeding on and disperse seeds of the fruit that they consume. They are also prey items for such local predators as large birds of prey, snakes and wild cats.