The douc langurs are amongst the most beautiful primates in the world. All 3 species are endemic to Indochina.
The 3 species are the red-shanked douc langur (Pygathrix nemaeus), black-shanked douc langur (Pygathix nigripes) and gray-shanked douc langur (Pygathix cinereus).
The red-shanked douc is distinguished by its bright maroon/red “stockings” which run from its knees to its ankles. Otherwise it is similar in appearance to the grey-shanked douc, with a golden face, white chin and dark grey to black hands and feet. The black-shanked douc has a largely greyish blue face. The tail of all 3 species is as long as the body.
Description Source: WWF