Common Marmoset

The common marmoset (Callithrix jacchus) is a New World monkey. It originally lived on the Northeastern coast of Brazil, in the states of Piaui, Paraiba, Ceará, Rio Grande do Norte, Pernambuco, Alagoas and Bahia. Through release (both intentional and unintentional) of captive individuals, it has expanded its range since the 1920s to Southeast Brazil (its first sighting in the wild for Rio de Janeiro was in 1929) and became there an invasive species, raising concerns about genetic pollution of similar species such as the buffy-tufted marmoset (Callithrix aurita) and predation upon bird nestlings and eggs.

http://en.wikipedia.org/wiki/Common_marmoset