of steep mountain sides and deep river gorges, with canopy heights of 20–25 m. Cloud forest, the habitat of this monkey, are in high altitudes and often have cloud coverage near or in them. The last estimated population count was less than 250 individuals. The current habitat of the yellow-tailed monkey is fragmented due to deforestation, as is the population. This can hinder reproduction, as it limits an already limited population. The Yellow-Tailed monkey has never been subject to a full census so exact numbers vary. A study was done to exam the population however the terrain and fragmented populations made this difficult. The yellow-tailed woolly monkey lives in the montane cloud forests of the Peruvian Andes at elevations of above sea level in the departments of Amazonas and San Martin, as well as bordering areas of La Libertad, Huánuco, and Loreto. Its habitat is characterized by steep gorges and ravines. The original extent of its habitat is estimated to be around , but recent estimates put the remaining habitat at between . Diet and natural history Its diet is primarily frugivorous, but leaves, flowers, insects and other invertebrates are also eaten. The species is arboreal and diurnal. It has a multiple-male group social system and a polygamous mating system. They have a variety of vocalisations, including a loud, "puppy-like" bark which they use as a territorial or alarm call. Yellow-tailed woolly monkeys participate in geophagy, the consumption of soil. Geophagy is a rare biological behavior, but the species benefits since it results in trace mineral intake of minerals and reduction of intestinal parasites; they tend to suffer from an iron-deficient diet. Their consumption of soil allows them to intake iron that they do not get from their regular diet. Conservation The inaccessibility of its habitat protected the species until the 1950s. 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. This and its restricted geographic distribution have led to this species' current critically endangered status. Conservation work started soon after the species was rediscovered in the mid-1970s. This pioneering work by the Peruvian NGO APECO led to the creation of three protected areas, Rio Abiseo National Park, Alto Mayo Protected