Common Marmoset

Callithrix jacchus

"Worst Choice" Pet Worst Choice

Common Marmosets, sometimes called Cotton-eared Marmosets because of the large white tufts of hair that surround their ears, are New World monkeys native to the eastern parts of Brazil. Weighing not quite a pound (~14 ounces), these small primates were originally forest dwellers but have been introduced to urban regions and are now commonly seen in large cities such as Rio de Janeiro and Buenos Aires. Common Marmosets typically live in extended family groups. The Common Marmoset is considered a tree-gum specialist; their lower incisor teeth are used to excavate holes in gum-producing trees. In fact, though, they eat a wide variety of foods, including insects, fruits, small animals, eggs, and tree sap.

Did You Know?

Common Marmosets are sometimes called Cotton-eared Marmosets because of the large white tufts of hair that surround their ears.

Source Sustainability Worst Choice

Does the harvest for wildlife trade or captive breeding of this species harm wild populations?

Significant Cause for Concern

Wild Common Marmosets are not believed to be imminently at risk of extinction but they are captured for sale as pets and some populations are declining due to habitat destruction.

Harvesting of individuals for the pet trade is considered a main threat to the species’ survival in the wild. Common Marmosets are captured and traded illegally in Brazil and neighboring countries. The legal international trade for Common Marmosets is highly regulated under CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora).

PetWatch Recommendation:

PetWatch has classified the Common Marmoset as a Worst Choice pet. It is not a recommended pet.

Invasion Threat Worst Choice

Does the release or escape of this species into the wild harm the environment and/or economy?

Significant Cause for Concern

The Common Marmoset can adapt to a variety of diets and can inhabit urbanized areas. In southern Brazil, their range has expanded due to intentional and non-intentional introductions, resulting in harm to native wildlife. This has raised concerns that Common Marmosets could establish self-sustaining populations in the U.S. if they escaped or were released from captivity.

PetWatch Recommendation:

PetWatch has classified the Common Marmoset as a Worst Choice pet. It is not a recommended pet.

Animal Welfare Worst Choice

Does harvest, captive breeding, transport, or being kept as a pet harm individual animals?

Significant Cause for Concern

Common Marmosets are social animals that usually live in pairs or larger family groups. They cannot be kept as solitary pets. They also require a specialized living environment to remain healthy and happy. For example, they need large enclosures — both indoors and outdoors — that have climbing structures, a hiding place where they can retreat for safety, and other items to stimulate their curiosity (e.g., for swinging, gnawing, foraging). They need to be fed a variety of foods (fruits, vegetables, live insects) many times throughout the day. Because of the specialized care that non-human primates (including Marmosets) require, many experts agree that these animals should not be kept as pets.

Common Marmosets are easily infected with human-borne viruses, many of which can kill marmosets. They are particularly vulnerable to the virus HHV-1 (human herpesvirus 1) that causes cold sores in people. Captive breeding of Common Marmosets is also problematic. Research has shown that females bred at a young age have compromised health and a shortened lifespan. Additionally, approximately half of newborns are either rejected or killed by their parents or die from unknown causes.

PetWatch Recommendation:

PetWatch has classified the Common Marmoset as a Worst Choice pet. It is not a recommended pet.

Health Threat Worst Choice

Does this animal pose a health risk to native wildlife, humans, livestock and agriculture?

Significant Cause for Concern

Common Marmosets, like all primate species, are known carriers of numerous serious diseases that can be transmitted to humans. Hepatitis A, yellow fever, Salmonella, and toxoplasmosis are just a few of these diseases.

Mature Common Marmosets can be unpredictable and highly aggressive to humans, including their owners. They will bite and can cause serious injury.

PetWatch Recommendation:

PetWatch has classified the Common Marmoset as a Worst Choice pet. It is not a recommended pet.

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