François's Langur

Francois' langur, also known as Francois' leaf monkey, the Tonkin leaf monkey or the white side-burned black langur, is a species of Old World monkey and the type species of its species group. It is one of the least studied members of the Colobinae. It is a medium-sized primate with black, silky hair and very distinct white sideburns running from the ears to the corners of the cheeks, and a complex four-chambered stomach for digesting its leafy diet (Wikipedia, general species account).

Males have a head-body length of 55–64 cm and females 47–59 cm, with tails of 82–96 cm and 74–89 cm. Infants are born bright orange, fading to black over several months. It is distributed from south-western China to north-eastern Vietnam; fewer than 500 were believed to remain in Vietnam. It prefers limestone cliffs and caves, sleeping on ledges or in caves, which greatly reduces predation.