Also known as Black Monkey, it belongs to the Pongidae family of Primates order, with the Latin scientific name of Hylobates leucogenys, and English name of White-cheeked Gibbon.    

White-cheeked Gibbon is slender in body form, with wide shoulder and small hips. It has no tail. The length of its body is 40 to 65 centimeters. It can reach the ground with the two hands when standing erect. Body hair of the male is black, with pointed crest hair on the calvaria. Young female is black; it is isabelline or golden yellow when grown up, also with black crest hair on the calvaria. The maximal difference from black gibbon is that White-cheeked Gibbon has distinct white spots on the two cheeks. 

It inhabits in tropical rain forests at an elevation of below 1,500 meters, forming subgroups of an adult couple with 2 to 3 young ones. It lives among trees, feeding on wild fruits, tree buds, young leaves and flowers, especially fond of banyan fruits, as well as some insects. It likes mooing; when the sun rises, the adult apes moo first, then all of them moo together. The sound is euphonious, transmitting to several miles afar.  

It is distributed in southern Yunnan Province. Owing to cultivating wasteland and planting rubber tree in the past, large areas of tropical rain forests have been destroyed, leading to sharp reduction in distribution and number of White-cheeked Gibbon. It is in urgent need of strict protection. 

White-cheeked Gibbon has been listed in Appendix I of International Trade Convention on Endangered Wild Plant and Animal Species.