Delacour's langur lives in remnant forests among the limestone mountains of northern Vietnam. Its black-and-white coat, crest, and long tail stand out, and leaves form most of its diet.
Its black-and-white coat has sharply contrasting areas, with a conspicuous crest and a long, bushy tail. The white lower-body markings can look like a pair of white trousers.
It moves along steep limestone cliffs by gripping the rock and making long leaps. Leaves are its main food, along with fruit, flowers, and bark.
An extinction-risk assessment has not been added yet.