Goeldi's Marmoset

Goeldi's Marmoset or Goeldi's Monkey (Callimico goeldii) is a small, South American monkey that lives in the upper Amazon Basin region of Bolivia, Brazil, Colombia, Ecuador, and Peru. It is the only species classified in the genus Callimico.

Goeldi's monkeys are blackish or blackish-brown in color. Their bodies are around 8 to 9 inches long (about 22 cm), and their tails are 10-12 inches long (25-30 cm).

Goeldi's monkey was first described in 1904, making it one of the last monkey genera to be described. In older classification schemes it was sometimes placed in its own family Callimiconidae and sometimes in the (now abandoned) family Callitrichidae, the family containing marmosets and tamarins. More recently, it has been classified into Cebidae, which now contains all the marmosets and tamarins, as well as the capuchins and squirrel monkeys.

Females reach sexual maturity at 8.5 months, males at 16.5 months. The gestation period lasts from 140 to 180 days. The mother carries a single baby monkey per pregnancy. The infant is weaned after about 65 days.

Goeldi's monkeys prefer to forage in dense scrubby undergrowth; perhaps because of this, they are rare, with groups living in separate patches of suitable habitat, separated by miles of unsuitable flora. Their diet consists of fruit, insects, spiders, lizards, frogs, and snakes. They live in small social groups (approximately six individuals) that stay within a few feet of one another most of the time, staying in contact via high-pitched calls.

The life expectancy in captivity is about 10 years.