Southern Yellow-cheeked Gibbon

The yellow-cheeked gibbon (Nomascus gabriellae), also called the golden-cheeked gibbon, the yellow-cheeked crested gibbon, the golden-cheeked crested gibbon, the red-cheeked gibbon, or the buffed-cheeked gibbon, is a species of gibbon native to Vietnam, Laos, and Cambodia. The species was discovered and named after the British naturalist Gabrielle Maud Vassal.

The yellow-cheeked gibbon is born blond and later turns black. Males carry this colouring through their lifespan and have the distinguishing golden cheeks. Females are born blonde to blend into their mother's fur but they later turn black. Females turn back to blond at sexual maturity, keeping only a black cap on the top of their heads.