Peru is home to 32 species of primates, distributed in three main families which classify the primates of the New World: Callitrichids, which include species such as pichicos and leoncillos; Callimiconids, represented by a single species (Goeldi's false pichico); and Cebids, the largest family, which includes squirrel monkeys, spider monkeys, howler monkeys, machin, tocon, musmuqui and choro amongst others.
Monkeys found in the Americas stand out from those found in the Old World in a number of physical traits which are the result of adapting to the tropical environments where they live. The most obvious and visible feature is the shape of the nose (monkeys in the Americas have long noses, with wide nasal openings on each side and a curved point pointing downwards, while those in the Old World have flat, broad, egg-shaped noses.
In northern Peru, the white machin blanco inhabits some parts of the western slopes of the northern Andes (departments of Piura and Tumbes), while the Tumbes howler monkey lives exclusively in the Pacific Tropical Rainforest.
