The Yellow-cheeked Gibbon (Nomascus gabriellae), also called the Yellow-cheeked Crested Gibbon, the Golden-cheeked Crested Gibbon or the Buffed-cheeked Gibbon, is a species of gibbon native to Vietnam, Laos and Cambodia.
The Yellow-cheeked Gibbon is born blond and later turns black, and 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 and turn back to blond at sexual maturity and only have a black cap on the top of their heads. This diurnal and arboreal gibbon lives in primary tropical rainforest, foraging for fruits, using braciation to move through the trees. The Yellow-cheeked Gibbon, like all gibbon species, has a unique song which is usually initiated by the male. The female will then join in and sing with the male to reinforce their bond and announce to other gibbons that they are a pair in a specific territory. The male usually finishes the song after the female has stopped singing. Little is known about this species in the wild, but it is thought that it has a life span of approximately 46 years.
A recent report by the Wildlife Conservation Society counted 2,500 yellow-cheeked crested gibbons in Cambodia’s Seima Biodiversity Conservation Area, an estimate that represents the largest known population of the species in the world.