Callithrix argentata - Silvery Marmoset

Description:

Silvery marmosets, Callithrix argentata, are among one of the smallest “New World” monkeys.  Their total body length averages about 18 cm to 28 cm, their tail length averages about 26 to 38 cm, and weigh between 300 and 360 grams.  The species vary in color from silvery white to dark brown, with the dark brown marmosets having hairless ears and faces, also called bare-eared marmosets. The silvery white marmosets are white in color with pink ears and face and a black tail.  The silvery marmoset differs from most of the other New World monkeys by possessing claws on all their toes except their big toe (Napier, 1985).

Distribution:

Silvery marmosets are found south and east of the Amazon River in Brazil and tend to be isolated from other marmosets with the exception of the Amazon delta; there they co-occur with Callithrix jacchus.

Marmoset activity is mostly concentrated in areas where there are many gum-producing trees.  Range size is positively correlated with fruit availability and appears to be limited by the size of the main patch of contiguous forest available to the group (Rowe, 1996).

Ontogeny and Reproduction:

Marmosets begin to breed after they are between 15 and 18 months old.  There is typically only one breeding pair in a group where all members of the family care for the young and from time to time they pass the babies back to their mothers for feeding.

The gestation period varies from 140-146 days.  A few weeks before they give birth their activity slows down considerably.  They usually give birth to twins but sometimes 1 or 3 young are born (Napier, 1985).

Ecology and Behavior:

Silvery marmosets are mainly gumivores; their diets consist mostly of the sap and gum of trees.  They have very large canine teeth and incisors so they are able to scrape large openings into the bark to get at the sap and liquids of the trees.  They also eat some fruit, insects, and leaves.

Silvery marmosets use their large claws to climb trees, forage for food, and to escape from predators.  Males and females mark their paths in trees with urine so other marmosets can follow, and to claim territory.  Like other New World monkeys, marmosets communicate somewhat vocally with a few general calls for warning and play.

Silvery marmosets also have a unique behavior that they display when they feel threatened: they stand tall and lower their eyebrows and smack their lips (Swindler, 1998).

Marmosets are being threatened by the destruction of forests, but unlike many other species, marmosets have found a way to cope with their declining food sources. They feed off human food crops and live in smaller secondary forests.  It is not known how long this surviving strategy will continue to allow them to survive (Mafham, 1992).

Literature Cited:

Napier, J., P. Napier. 1985. The Natural History of the Primates. Cambdridge, Massachusetts: MIT Press.

Mafham, R. 1992. Primates of the World. London, UK: Blandford Publishing.

Rowe, N. 1996. The Pictorial Guide to Living Primates. East Hampton, New York: Pogonias Press.

Swindler, D. 1998. Introduction to the Primates. Seattle, Washington: University of Washington Press.

Reference written by Jennifer McMonagle, Biol 378 (Mammalogy), University of Wisconsin – Stevens Point:  Edited by Christopher Luddington. Page last updated March 4, 2005.