Silvery marmosets, Callithrix argentata, are found south and east of the Amazon River in eastern Brazil. Silvery marmosets are isolated from other marmosets, except south of the Amazon delta where they co-occur with common marmosets, Callithrix jacchus. (Preston-Mafham 1992)
Within the tropical rain forest silvery marmosets take advantage of tree hollows, dense vegetation, and vine tangles for sleeping sites.
About the size of a squirrel, silvery marmosets are one of the smallest New World monkeys. Head and body length averages 21.59 cm and tail length averages 29.21 cm. Silvery marmosets vary in color from silvery white to dark brown. Dark brown marmosets have hairless ears and faces and are sometimes referred to as bare-ear marmosets. Because of their dark tails, silvery marmosets are also referred to as black-tailed monkeys. A unique feature of the silvery marmoset is that their jaw narrows to a sharp point. This pointed jaw, along with short canine teeth, are believed to be an adaption for their unique feeding habit. While other New World monkeys posess nails on all of their toes, marmosets have claws on all of their toes except the big toe. (Preston-Mafham 1992; Napier 1985)
Females usually give birth to twins twice a year after a gestation time of 145 days. Ten to twenty days after giving birth females ovulate, at the same time they are nursing current young. Subordinate females within the family group are prevented from ovulating by exposure to pheromones released by dominant females.(Napier 1985)
Silvery marmosets live in extended families of about twelve where all the members help care for the young. Silvery marmoset fathers carry their infants and return them to the mother to be fed every two to three hours. Infants are weaned from their mother's milk at about six months and are considered adults at one to two years old.
Silvery marmosets are arboreal and diurnal. Their long, curved claws enable them to climb trees and escape predators. Both males and females engage in scent marking to claim territories and communicate with others. They also communicate vocally when excited, alarmed, or at play.
When confronted with a possible threat, silvery marmosets will lower their eyebrows and smack their lips.
(Swindler 1998; Rowe 1996)
Silvery marmosets are gumivores, their diet consists mainly of the sap and gum of trees. With canines and incisors of equal length they are able to gouge holes in trees and lap up the exudate. They supplement their diet with fruit, insects, and leaves. (Swindler 1998)
Because of their small size and mild disposition marmosets are used regularly in medical research. Studying the fertilization, placental development, and embryonic stem cells of marmosets may reveal causes of developmental problems and genetic disorders in humans. (WRPRC, 1997)
By feeding on newly planted crops that replace rain forests silvery marmosets have become pests. As a result humans in these areas carry out active extermination campaigns.
The destruction of forests has resulted in the endangerment of many rainforest animals, including many monkey species. However, silvery marmosets have been able to survive by taking advantage of human food crops and living in secondary forest habitats. It remains to be seen whether this trend continues.
Rhonda Garza (author), Fresno City College, Carl Johansson (editor), Fresno City College.
living in the southern part of the New World. In other words, Central and South America.
Referring to an animal that lives in trees; tree-climbing.
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
ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates
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.
the area in which the animal is naturally found, the region in which it is endemic.
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
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
1997. "Wisconsin Regional Primate Research Center”" (On-line). Accessed November 6, 2000 at http://www.primate.wisc.edu/WRPRC/Centerline/spring97/Cenmar.html.
Napier, J., P. Napier. 1985. The Natural History of the Primates. Cambdridge, Massachusetts: MIT Press.
Preston-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.