Delacour’s langur is a critically endangered monkey, confined to small pockets of forest amid the jagged limestone karst mountains of northern Vietnam.
Named in honour of ornithologist Jean Théodore Delacour, the first western scientist to encounter the species, this elegant primate is characterised by its distinctive black-and-white fur coloration, a long, bushy tail and a conspicuous crest.
Its local name – voọc quần đùi trắng (loosely translated as ‘langur with white pants’) – derives from the sharply delineated markings, which give the visual impression of a predominantly black monkey wearing a pair of knee-length white shorts or an unnecessarily large nappy.
Groups of Delacour’s langur average around ten individuals and typically comprise a single adult male, several females and their offspring.
These monkeys are equipped with specially adapted pads on their hands, feet and rump that enable them to run, jump and sit on the razor-sharp limestone. They moves through their steep, treacherous and rugged habitat with supreme confidence, clinging to precipitous cliffs and making death-defying leaps.
Delacour’s langurs eat mainly leaves, with a small number of plant varieties making up the vast majority of their diet, along with fruit, flowers and bark.