Common marmosets live on the edges of tropical forests in north-eastern Brazil. The species is also known as the white-tufted-ear marmoset. However, the destruction of their forest habitat means that they are less common than they once were.
Common marmosets are diurnal and live in small troops of up to 12 monkeys. Within each troop a female teams up with two or more males to form a breeding group. The female mates with all of these males. All the breeding males help the female to carry the young and find food for them. It is thought that the babies need multiple "fathers" to help them survive, because the babies are too heavy for just the mother to carry. The other members of the troop are the offspring of the adults, and these also help to raise the young. Only one female in each troop breeds at a given time. Common marmosets teed mainly on tree sap and other exudates (such as gums and resins). Exudates are such an abundant resource that the marmosets can live in relatively high-density populations.
Common marmoset is easily recognized by the white tufts on its ears and the white patch on the otherwise brown forehead. It also has stripes on its back and tail. In common with most marmosets, the tail is a little longer than the body.
Insects are another important food, and the diet also includes fruits, nectar, flowers, spiders, and sometimes birds’ eggs, lizards and frogs. In addition, common marmosets have learned to exploit the food potential of plantations that grow near the forest edge.
Distribution: Eastern Brazil.
Habitat: Edge of forests.
Food: Sap, nectar, insects, spiders, fruit and flowers.
Size: 12 - 15 cm (4.75 - 6 in); 300 - 360 g (10.5 - 12.75 oz).
Maturity: 2 years. Breeding: Twins born at all times of the year.
Life span: 10 years.
Status: Lower risk.