It is a rare primate species found only in the Peruvian Andes, in the departments of Amazonas and San Martin, as well as bordering areas of La Libertad, Huánuco, and Loreto.

A recent extensive study suggests that the yellow-tailed woolly monkey indeed belongs in Lagothrix, which has been followed by the American Society of Mammalogists and the IUCN Red List.

[4][5][2][6] The species was first described by Alexander von Humboldt in 1812 under the name Simia flavicauda, based on a skin found 10 years earlier, used by a local man as a horse saddle.

Humboldt had never seen a live animal of this species nor a preserved specimen, and believed it belonged to the genus Alouatta.

[8] The rediscovery attracted the attention of national and international press, as well as conservation organizations that saw the need to know quickly the status of this species.

In the summer of 2004, scientists searched for yellow-tailed woolly monkeys in a remote area of San Martin, where the forest is tropical, humid, and quite mountainous.

The balance between avoiding the extinction of the species and maintaining the livelihood of the farmers of Peru is a major issue in the struggle for conservation efforts toward the yellow-tailed woolly monkey.

They are known to express aggressive behaviors upon initial encounters such as branch shaking, "mooning" of the scrotal tuft, and short barking calls.

The monkey's color is deep mahogany and copper with a whitish patch on its snout extending from the chin to between its eyes.

[10] The yellow-tailed woolly monkey lives in the montane cloud forests of the Peruvian Andes at elevations of 1,500–2,700 m (4,900–8,900 ft) above sea level in the departments of Amazonas and San Martin, as well as bordering areas of La Libertad, Huánuco, and Loreto.

However, the construction of new roads, habitat loss and fragmentation from agriculture, logging and cattle ranching, and subsistence hunting, together with the monkey's naturally low population densities, slow maturation, and low reproductive rate, have led to a predicted decline of at least 80% over the next three generations.

Conservation efforts led by ASPROCOT have been made recently to help protect the endangered monkeys by turning to alternative forms of agriculture to preserve the remnants of the Amazonas forests.

[13] Several communities in Peru have made conservation efforts to preserve the yellow-tailed woolly monkeys through various ways.

Efforts include preventing further immigration into areas home to the monkeys and beginning ecosystem protection initiatives.