Callithrix jacchuswhite-tufted-ear marmoset

Geographic Range

Common marmosets are New World primates. Their original range was limited to north eastern Brazil, but habitat destruction in that area is widespread. Wild populations of the common marmoset are now located in south eastern Brazilian coastal rainforest. (Parker, 1990)


Common marmosets can be found around the edges of the forest as opposed to deep within it. They live in many forest types, including plantations. (Parker)

Physical Description

The common marmoset has a body length of about 12 - 15 cm, with a tail length of 29.5 - 35 cm. Distinguishing characteristics of common marmosets include white ear tufts, and a white blaze on the forehead. Their head fur is usually dark brown, while their back fur is a greyish brown color with light transverse striping. They also have very pronounced transverse tail stripes.

(Parker, 1990)

  • Range mass
    300 to 360 g
    10.57 to 12.69 oz
  • Average basal metabolic rate
    0.848 W


It was originally thought that common marmosets were monogamous creatures, forming pair bonds and raising their offspring as a team. This was believed because captive marmosets only bred successfully in a pair situation. However, it has recently been discovered that the common marmoset, along with other species of marmosets and tamarins, is actually polyandrous (one female mates with multiple males). In the wild, groups of two males and a female form in order to mate and rear offspring. The female mates nearly equally with both males while in estrus.

After gestating for approximately 148 days, the female gives birth to the offspring, usually twins (Smuts et al., 1987).

  • Average number of offspring
  • Average number of offspring
  • Average gestation period
    148 days
  • Average gestation period
    144 days
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    477 days
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    382 days

The twins combined can equal up to 40% of the female's body weight. The males assist the female in carrying the infants, and it is generally thought that polyandry in this species is due to the large size of these babies and the energy needed to raise them.

  • Parental Investment
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • male
      • female
  • pre-independence
    • protecting
      • male
      • female



Common marmosets are diurnal, and generally live in groups of 2-13 individuals which may include mated polyandrous groups and their offspring. The most outstanding feature of common marmoset behavior is nonmaternal infant care (also found in other callitrichid primates). Males and siblings are quick to assist mother common marmosets with infant care, and indeed, it seems that this help is necessary for infant survival. (Smuts et al., 1987)

Communication and Perception

Food Habits

While the common marmoset generally feeds on tree sap, this species has also been found to eat insects, spiders, fruit, flowers, and nectar. Less frequently, they have been observed feeding on small lizards, bird's eggs, nestlings, and frogs.

(Parker, 1990)

  • Primary Diet
  • herbivore
    • eats sap or other plant foods
  • Animal Foods
  • birds
  • amphibians
  • reptiles
  • eggs
  • insects
  • terrestrial non-insect arthropods
  • Plant Foods
  • fruit
  • nectar
  • flowers

Economic Importance for Humans: Positive

When zoos are able to obtain these tiny creatures, they are very popular attractions.

Economic Importance for Humans: Negative

Because they have adapted to life on the edge of the forests of south eastern Brazil, common marmosets have also learned to take advantages of the plantations in the area. In greater numbers, they may become pests to human farmers. (Smuts et al., 1987)

Conservation Status

Common marmosets are one of the most endangered callitrichid species. The complete destruction of their habitat in north eastern Brazil has severely threatened the species, but their numbers in reserves in south eastern Brazil seem to be growing.

(Smuts et al., 1987)

Other Comments

It is only very recently that humans have been able to obtain any information about this species at all. Because of their rarity and size, they are difficult to study in the wild, and comparisons between captive and field studies have proved that their behavior varies between the two. (Evans, 1986)


Sarah Cover (author), University of Michigan-Ann Arbor, Phil Myers (editor), Museum of Zoology, University of Michigan-Ann Arbor.



living in the southern part of the New World. In other words, Central and South America.

World Map


Referring to an animal that lives in trees; tree-climbing.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


uses smells or other chemicals to communicate

cooperative breeder

helpers provide assistance in raising young that are not their own

  1. active during the day, 2. lasting for one day.

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.


An animal that eats mainly plants or parts of plants.


offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).


having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.


Referring to a mating system in which a female mates with several males during one breeding season (compare polygynous).


rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.


reproduction that includes combining the genetic contribution of two individuals, a male and a female


associates with others of its species; forms social groups.


uses touch to communicate


reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.


Evans, S. 1986. The Pair Bond of the Common Marmoset (Callithrix jacchus jacchus). Pp. 51-65 in D Taub, F King, eds. Current Perspectives in Primate Social Dynamics. New York: Van Nostrand Reinhold Company.

Parker, S. 1990. Grzimek's Encyclopedia of Mammals Vol 2. New York: McGraw-Hill Inc.

Smuts, B., R. Seyfarth, D. Cheney, R. Wrangham, T. Struhsaker. 1987. Primate Societies. Chicago: The University of Chicago Press.