Francois' monkey (Trachypithecus francoisi) is a langur that inhabits limestone karsts and tropical monsoon forests from northern Vietnam to southern China. It is folivorous and adapted to a leaf-based diet; a compartmentalized stomach and symbiotic bacteria allow it to break down cellulose. Fur can differ among individuals, sometimes standing up as it grows; infants are orange and darken to black as they mature. They typically live in groups of 3–10 individuals with one male and multiple females. Its conservation status is Endangered (IUCN Category I B).