Callithrix kuhlii
Weid's black-tufted-ear marmoset

Callithrix kuhlii (Weid’s black-tufted-ear marmoset) lives in Southwest Brazil, mainly in the coastal regions. (Rylands, 1993)

Weid’s black-tufted-ear marmosets live in a variety of forest types, particularly tropical and subtropical forests. These marmosets inhabit the lower part of the trees. It thrives in areas of dense vegetation and new growth. (Mittermeier et al., 1988)

Weid’s marmosets are relatively small, weighing between 350 and 400 grams, or about 13 ounces. They are generally black with gray head pelage and have a distinctly ringed tail. There is an area of white around their cheeks and forehead, and they have black tufts of hair around their ears. They have nails that are claw-like and lack opposable thumbs. ("Marmosets and Tamarins", 2001; "Singapore Zoological Gardens Docents", 2000; Mittermeier et al., 1988)

These marmosets live about 10 years in the wild and have been known to live up to 16 years in captivity. ("Singapore Zoological Gardens Docents", 2000; "The Primata", 2003)

Weid’s black-tufted-ear marmosets live in groups of about seven composed of many females and a few males, in an approximate ratio of two females for every one male. They are highly social and spend most of the day foraging and grooming. Everyone in the group helps to care for the infants that are born twice a year. Female babies grow up and become a part of the group while males generally leave when they reach sexual maturity, around a year after birth.

Callithrix kuhlii has a distinct "voice" much the same way that humans do. It uses specific vocalizations known as "phee calls" to identify itself to others in its group and to intruders.

Callithrix kuhlii moves through its area quadrupedally, but can leap from tree to tree. It travels between 830 and 1200m a day in search of food. These marmosets are sympatric with the tamarin Leontopithecus chysomelas, which travels with it and forages as well. These two species do not fight with one another because the marmosets forage in the middle and lower parts of the forest, while the tamarins forage in the upper canopy. Both of theses groups gain from this mutualism by having additional eyes above and below to watch for predators and receive early warning.

Weid’s marmosets mark their territory by rubbing secretions from their suprapubic gland onto an area. They do this by pressing the suprapubic pad on the object and pulling themselves along it with their arms. ("Singapore Zoological Gardens Docents", 2000; "The Primata", 2003; Mittermeier et al., 1988; Nunes et al., 2001; Ruskalis, Fite, and French, 2003; Rylands, 1993)

Home Range

The territory of C. kuhlii is approximately 100 square meters, however, these marmosets can move up to 1200 m a day to forage. ("Singapore Zoological Gardens Docents", 2000; Mittermeier et al., 1988)

Callithrix kuhlii communicate with one another using visual, tactile, olfactory and acoustic signals. These marmosets use visual signals to try to mate, they touch one another while they groom to form bonds, they leave scent trails to mark their territory and they call to one another, especially if danger is perceived. ("The Primata", 2003; Marroig, Cropp, and Cheverud, 2004; Mittermeier et al., 1988; Rylands, 1993)

Callithrix kuhlii feeds on fruit, flowers, nectar, seeds, insects, and spiders. Sap is a main staple in its diet and it has specialized teeth for gouging holes in tree bark.

The main predators of marmosets are harpy eagles: Harpia harpyja, hawks: Buteo albicaudatus, Asturina nitida, Buteo magnirostris, jaguar: Panthera onca, jaguarundi: Felis yagouaroundi, ocelot: Leopardus pardalis, and snakes: suborder Serpentes. Their main means of defense is speed or they may gang up on smaller predators and try to intimidate them into going away. ("Singapore Zoological Gardens Docents", 2000; "The Primata", 2003)

The holes made by gouging out tree bark provide sap for other animals. Marmosets play a role in pollination and seed dispersal as fruit and nectar are common components of their diet. They may travel extensively throughout their home range every day, pollinating many plants and dispersing seeds. They are also prey for many other species. ("Singapore Zoological Gardens Docents", 2000; Mittermeier et al., 1988; Rylands, 1993)

There are no known adverse affects of C. khulii on humans.

Weid’s marmosets have been a large commodity in the pet trade, especially in the United States until the U.S. prohibited its importation. It also can be used in biological and medical laboratories because it breeds easily and can be affected by some human diseases such as rubella and herpes. ("The Primata", 2003; Rylands, 1993)

Callithrix kuhlii are not endangered, but their numbers are dwindling due to habitat destruction. ("Singapore Zoological Gardens Docents", 2000; Mittermeier et al., 1988; Rylands, 1993)

Callithrix kuhlii was previously hypothesized to come from hybridization of Callithrix geoffroyi and Callithrix penicillata, however, new evidence shows that it is morphologically distinct from other marmosets. (Marroig, Cropp, and Cheverud, 2004)