This video from Vietnam is called Chà vá chân xám (Grey Shanked Douc).
From Animal Science Blog:
Endangered Grey-Shanked Doucs in Vietnam
A team of researchers from WWF and Conservation International (CI) has discovered the world’s largest known population of grey-shanked doucs (Pygathrix cinerea), increasing chances that the Endangered monkey can be saved from extinction.
The grey-shanked douc is one of the world’s 25 most endangered primates and has only been recorded in the five central Vietnamese provinces of Quang Nam, Kon Tum, Quang Ngai, Binh Dinh, and Gia Lai. Fewer than 1,000 individuals are believed to still exist, and until now, only one other population with more than 100 animals was known.
“This is an exciting and important discovery because of the large size of the population,” said Barney Long, Central Truong Son Conservation Landscape Coordinator for WWF Greater Mekong – Vietnam Program. “It’s very rare to discover a population of this size with such high numbers in a small area, particularly for a species on the brink of extinction. This indicates that the population has not been impacted by hunting like all other known populations of the species”.