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Geoffroy's Marmoset

(Callithrix geoffroyi)

Conservation status:

Marmosets are classified as vulnerable due to habitat loss and threat of disease. The main threat today is the loss of the habitat.

Amazing Facts:

Marmosets are one of only a few species who have perfected the art of eating sap from trees. They have teeth that are specialized to eat the gum from the trees, but they also eat fruits and some insects. Another unique trait of these animals is that the females, when giving birth, almost always have twins. These twins are each about 20 percent of her body weight, which would be like a human giving birth to two 11 lb. babies. Labor lasts only about an hour and the babies come at 2-3 minute intervals.


Most of the sounds listed below are described from the young marmosets. Adult calls are very similar to the juvenile ones, but are more stereotyped and specific in function.
  • Phee: a high-pitched distress call usually made as a juvenile's response to being forcibly removed from the back of an adult carrier. This is a fundamental vocalization that develops into the adult contact call.
  • Tsik, tsik, tsik: a sharp, loud distress call usually made as a juvenile's response to an extremely rough dismount by an adult carrier. It develops into the adult alarm call.
  • Nga: a distress squeal. A contact call which stimulates adults to nursing response.
  • Twitter: a rapid sequence of short, high-pitched notes. A contact call. The number of notes in the twitter varies according to age, infants giving 2-12 notes, adults 2-20 notes.


Marmosets sleep at night and roam around looking for their favorite gum tree during the day. They move around through the trees with both arms and legs, but have also been known to leap from tree to tree. Marmosets are a family oriented species, living in groups of 8-10. When the females have the infants, the entire family, including the father, takes turns caring for the young and carrying it around.

General Description:

Looking like squirrels, they have a long tail, and typically have black tufts from their ears.

Here at Knoxville Zoo we have four marmosets, one adult male and female. They have two offspring.

Order: Primate
Family: Callitrichidae
Genus: Callithrix
Species: geoffroyi

Gestation: About 4.5 months
Range: Rainforests of Southeastern Brazil
Longevity: About 10 years
Weight: Females: 190 grams, Males: 230-350 g