Northern White-cheeked Gibbon

The Northern White-cheeked Gibbon (Nomascus leucogenys) is a species of gibbon native to Vietnam, Laos, and the Yunnan province of China. It is closely related to the Southern White-cheeked Gibbon (Nomascus siki), with which it was previously considered conspecific. The females of the two species are virtually indistinguishable in appearance.