Common marmoset

Special features

In addition to their small body size, the little monkeys are particularly known for their long gray-black ringed tail and the white tufts on their ears. The face is brightly colored, sparsely haired and a white spot is located on the forehead. Like all monkeys in the family to which the common marmosets belong, they have claw like nails on their fingers and toes. Only the big toe has the typical primate flat nail. With their claws, they can literally “hook” onto the bark of the trees and unlike other primates, they are capable of climbing up and down trees in a vertical position.

Habitat and lifestyle

Marmosets can be found in a number of different types of forests. Since they are very adaptable, they can be found in the rainforest and coastal forests of Brazil as well as in the dry thorn savanna (Caatinga). They can also be encountered in suburban gardens, agricultural plantations and even in the public parks of Rio de Janeiro. The marmosets spend most of their day foraging. At night they sleep in lianas and in forked branches of treetops. The size of their home range is largely determined by the amount of the exudate-producing trees and is usually only two to six hectares. For their daily foraging, the marmosets cover between 500 meters and one kilometer.

Social behavior and reproduction

Marmosets usually live in groups of three to 15 individuals, where the group mostly consists of up to four adult males and females and their offspring. If the group becomes too big, migration that includes both sexes takes place. However, females leave the group more frequently than males. One breeding pair that is usually responsible for reproduction dominates the group. All the other members of the group are organized in an age dependent hierarchy after the breeding pair. The mating system of marmosets is very complex and variable. Previous studies with common marmosets have indicated an exclusively monogamous reproductive system. In the wild, additional mating systems such as polyandrous (one dominant female mates with multiple males) and polygynous (a dominant male mates with several females) were observed.

Births occur throughout the year but are more frequent from October to December (dry season) and from April to July (rainy season). The gestation period is approximately 145 days. Usually, common marmosets give birth to twins. Taking care of the infants (carrying and feeding) spells a higher energy input for the female. Thus, the rearing of the young is not solely left to the mother. All the other group members, especially adult males, help intensively in raising the young (cooperative rearing). After approximately ten weeks, the infants are weaned but they do take solid food to them from the age of four weeks. After three to four months the young animals are largely independent and they are fully grown after approximately 15 months.

Source: Handbook of the Mammals of the World: Primates (edited by Mittermeier, R.A., Ryland, A.B., Wilson D.E., published by Lynx Edicions, Conservation International, IUCN, 2013)