Marmosets, all seventeen named species, live in the New World tropical forests of South America. Callithrix jacchus, the common marmoset, weighs on average 370 gm (.81 lb). C. jacchus is a gray color with a banded tail; it also has distinct, long tufts of white or cream fur around the base of the ears. Marmosets are small, quick, aggressive, territorial, and feed on a variety of insects, fruits, and vegetable matter. The marmoset's lower canine teeth are adapted to perforate tree bark, allowing them to access the tree exudate (tree gum). Male and females share infant care, with males frequently carrying the babies on their backs and giving them to the mothers to nurse.