Common Marmoset Facts

Common marmosets are tree-dwelling primates. They are found in the tropical forests of northeastern Brazil in South America. They are New World Monkeys.

Common marmosets, when full-grown, are about 8 inches long, with a tail twice as long as their body and weigh 8–12 ounces.
In the wild, they live in mixed-sex groups of up to 13 individuals with one dominant male and female. Only the dominant male and female produce offspring.

Their diet includes fruit, veggies, gum/sap, and small insects/animals. In captivity, it also includes a specialized marmoset diet to ensure proper nutrition.   Common marmosets can catch colds and other human illnesses easily, like measles, chickenpox, cold sores, and even HIV. In fact, marmosets can contract any illness that affects humans. Thus, one needs to be extraordinarily cautious to prevent cross-contamination. Some of our common illnesses can be a death sentence for a marmoset.

The common marmoset remains an abundant species and is not currently threatened, but its habitat has been degraded at a fast rate. Common marmosets are captured and traded as pets. Though (sadly) popular as pets, they become difficult to control as they age and are often abandoned or killed.

Common marmosets are used for medical experiments. They are used more frequently in Europe than in the United States and are the most common nonhuman primates to be experimented on.

Common marmosets are wild animals and have very specific requirements that are difficult to meet in captivity. Human contact can in no way replace contact with other marmosets. Common marmosets should not be pets or living in captivity. If you want to see a marmoset, please do so by visiting a reputable sanctuary.