Exudates, such as gum and sap, fruit, nectar and fungus make up the bulk of Callthrix species' diet, but it also eats animal prey such as arthropods, young birds, small lizards and frogs. They are specialized for exploiting exudates by their elongated, chisel-like lower incisors and a wide jaw gape that allows them to gouge bark of trees that produce gums. Their intestines also have an enlarged, complex cecum that allows them to digest gums more efficiently than most other animals.