The black-shanked douc (Pygathrix nigripes) is an endangered species of douc found mostly in the forests of eastern Cambodia, with some smaller populations in Vietnam. This species is unique among the doucs in having a largely greyish-blue face. No global population estimate exists, although the Wildlife Conservation Society reports a almost 25,000 individuals present in Cambodia's Keo Seima Wildlife Sanctuary, a population that has remained stable over the last decade. Prior to the discovery of the significance of this population, the largest populations were believed to be in adjacent Vietnam, where the largest known population is around 500-600 individuals. They are primarily arboreal and their diet consists of leaves, from which they obtain most of their water.
