Common marmoset
Callithrix jacchus

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TAXONOMY

Suborder: Haplorrhini
Infraorder: Simiiformes
Family: Cebidae
Subfamily: Callitrichinae
Genus: Callithrix
Subgenus: Callithrix
Species: C. jacchus

Other names: true marmoset or white-tufted-ear marmoset; ouistit (French); penseelaapje (Dutch); sagui-comum or sagui-do-nordeste (Portuguese); marmosett, silkesmarmosett, vit silkesapa, or vitörad silkesapa (Swedish)

MORPHOLOGY

Common marmosets are small-bodied New World monkeys that are a mottled brown, grey, and yellow color with white ear tufts and long, banded tails (Rowe 1996). They have pale skin on their faces, which darkens with exposure to sun, and a blaze of white on their foreheads (Groves 2001). Infants are born with a brown and yellow coat and develop the white ear tufts and forehead blaze as they age. Males and females are about the same size, with males measuring, on average, 188 mm (7.40 in) and females having an average height of 185 mm (7.28 in). Males have slightly higher average weights than females at 256 g (9.03 oz) and 236 g (8.32 oz), respectively (Rowe 1996).

Photo: Luiz Claudio Marigo

Members of the genus Callithrix, common marmosets have a few adaptations unique to this group and necessary for their diet and arboreal lifestyle. On all but the hallux (big toe), they have claw-like nails called tegulae instead of the characteristic flat nails (ungulae) of other primates, including humans (Garber et al. 1996). The presence of claw-like nails instead of true nails helps common marmosets in their squirrel-like locomotion patterns. They cling vertically to trees, run quadrupedally across branches, and move between trees by leaping (Rowe 1996; Kinzey 1997). Other rare traits exhibited by callitrichines are their enlarged, chisel-shaped incisors and specialized cecum (part of the large intestine) which are adaptations for a very specialized diet (Rowe 1996; Sussman 2000). Finally, members of this group have a tendency to give birth to non-identical twins, which is unusual for primates (Sussman 2000).

The average lifespan of a wild common marmoset is 12 years (Rowe 1996).

RANGE

Common marmosets are endemic to Brazil. They range in the northeastern and central forests from the Atlantic coast and inland as far west as the Rio Grande and are found in the states of Alagoas, Pernambuco, Paríba, Rio Grande do Norte, Ceará, and Piauí. Common marmosets have been introduced to areas outside of their natural geographic range in Brazil and can be found living within the cities of Rio de Janeiro and Buenos Aires, Argentina (Rylands et al. 1993).

C. jacchus range (in red)

Captive common marmosets have been studied extensively in the lab since the early 1960s (Rylands 1997). Because of their small body size and the habitat in which they are found, marmosets can be difficult to study in the field. Despite these challenges, extensive studies on the behavior and ecology of wild common marmosets have been carried out at sites in Brazil: João Pessoa, Paraíba, Nísia Floresta, near Natal, and Tapcurá, Pernambuco (Rylands & de Faria 1993; Digby 1995; Albuquerque et al. 2001).

HABITAT

Common marmosets inhabit a variety of forest types including the extreme northern Atlantic coastal forest, dry, seasonal, semideciduous inland forests, riverine forests in dry thorn scrub habitat or caatinga, and the savanna forest or cerrado in central Brazil (Rylands & de Faria 1993; Rylands et al. 1996). These forests of the dry central region of South America are markedly different from the humid rainforests of Amazonia and are relatively more hostile environments with shorter canopies (only 65 to 98 ft). They are also less species-dense and species-rich and have more seasonal fluctuations in temperature and rainfall than the rainforest of Brazil (Rylands et al. 1996). Members of the genus Callithrix, including common marmosets, excel in dry secondary and disturbed forests or edge habitats but they also show great elasticity in the type of habitats in which they can live (Kinzey 1997; Sussman 2000).

In the caatinga region, the annual average temperature is 24 to 26° C (75 to 79° F) and the yearly average rainfall is between 300 mm (11.8 in) and 1000 mm (3.28 ft). The dry season is intense and lasts for 7 to 10 months. Irregular rainfall during the rainy season supports semidesert vegetation including spiny shrubs, low trees, and thorn forests (Eiten 1975). The cerrado region has a slightly less harsh dry season and cooler annual temperatures. Cerrado habitat is characterized by yearly average temperatures between 20 and 26° C (68 to 75° F) and rainfall between 750 and 2000 mm (2.46 and 6.56 ft). The dry season only lasts about five months (Eiten 1975). The Brazilian Atlantic forest region has annual average temperatures between 19 and 25° C (66 and 77° F) and rainfall between 1000 and 2000 mm (3.28 and 6.56 ft) per year (Eiten 1975).

ECOLOGY

The specialized morphological adaptations of common marmosets can be best understood by reviewing their specialized diet and arboreal lifestyle. Common marmosets are exudativore-insectivores and their claw-like nails, incisor morphology, and gut specialization reflect this interesting diet. Though all callitrichines feed on plant exudates, common marmosets utilize gum, sap, latex, and resin much more than other species (Rylands & de Faria 1993; Kinzey 1997; Sussman 2000). With lower incisors that are the same length as their canines, common marmosets systematically gnaw the bark of plants to stimulate the flow of edible exudates while vertically clinging with their claw-like nails to the trunks of trees (Stevenson & Rylands 1988; Ferrari & Lopes Ferrari 1989). Once a wound to a tree has been inflicted, the monkey licks or scoops out the exudates with its teeth (Stevenson & Rylands 1988). Gum, sap, latex, and resin are good, non-seasonal food sources in the most extremely seasonal parts of common marmosets' range and make up a significant part of their total diet; anywhere from 20 to 70% of the time spent foraging is devoted to exudativory (Ferrari & Lopes Ferrari 1989; Power 1996; Rowe 1996). Exudate feeding is particularly frequent from January to April, when fruits are scarce (Scanlon et al. 1989; Rylands & de Faria 1993). Marmosets often revisit previously gouged holes and use holes made by other animals and natural injuries to trees to harvest gum and resin. The potential for competition between common marmosets and other frugivorous and exudativorous animals exists and some of the prime potential competitors include birds (parrots and toucans) and woolly opposums (Stevenson & Rylands 1988). Because plant exudate is such an abundant resource, inter- and intraspecies competition may not be important. In fact, the exudativorous behavior exhibited by common marmosets makes it possible for them to live at extremely high population densities, as high as eight animals per hectare (Ferari & Lopes Ferrari 1989).

Photo: Luiz Claudio Marigo

The other important food source for common marmosets is insect prey and they spend between 24 and 30% of their time foraging for insects (Digby & Barreto 1998). Because of their small body size, marmosets are able to utilize insects to fulfill their protein and fat requirements, unlike larger-bodied primates (Sussman 2000). In the understory and middle layers of the forest, small-bodied marmosets can silently stalk and then pounce on large mobile insects (especially orthopterans) (Rylands & de Faria 1993). Common marmosets also include in their diet fruits, seeds, flowers, fungi, nectar, snails, lizards, tree frogs, bird eggs, nestlings, and infant mammals (Stevenson & Rylands 1988; Digby & Barreto 1998).

Home range size varies from .005 to .065 km² (.002 to .03 mi²) and is selected based on densities of gum trees. Common marmosets are found in home ranges with densities of gum trees no less than 50 trees per hectare (124/acre) (Scanlon et al. 1989). Average day range is only between .5 and 1.0 km (.30 and .62 mi) and common marmosets preferentially use areas of their home ranges centered around clusters of gum trees (Stevenson & Rylands 1988). Though they do not travel great distances during the day, common marmosets are active for 11 to 12 hours per day, usually from 30 minutes after sunrise to about 30 minutes before sunset (Stevenson & Rylands 1988; Kinzey 1997). After leaving their sleep site, common marmosets feed intensively for about an hour and then spend the rest of the day alternating between feeding, resting, and socializing (Stevenson & Rylands 1988). They spend about 35% of their time moving and foraging, 10% on social activities, 12% feeding, and 53% of their time is spent stationary (Kinzey 1997). When they rest, common marmosets adopt a sprawling position and can spend long periods of time (over 30 minutes) without moving (Stevenson & Rylands 1988). At the end of the day, common marmosets enter sleeping trees about one hour before sunset; these areas are usually in dense, vine-covered vegetation (Sussman 2000). The group sleeps together in a sleeping site presumably for safety from predators.

Because of their small body size, common marmosets are vulnerable to predation by mammals and birds. Some common predators include mustelids, felids, arboreal snakes, owls, and raptors (Stafford & Ferreira 1995; Kinzey 1997; Sussman 2000). Common marmosets are very vigilant and have specialized alarm calls which elicit certain avoidance responses from other members of the group as well as mobbing behaviors toward potential predators (Kinzey 1997; Sussman 2000).

Content last modified: May 18, 2005

Written by Kristina Cawthon Lang. Reviewed by Toni Ziegler.

Cite this page as:
Cawthon Lang KA. 2005 May 18. Primate Factsheets: Common marmoset (Callithrix jacchus) Taxonomy, Morphology, & Ecology . <http://pin.primate.wisc.edu/factsheets/entry/common_marmoset>. Accessed 2009 November 22.