Southern Yellow-cheeked Gibbon, Cat Tien National Park, Vietnam

Male. Only males have the golden cheeks. Black fur alone is no reliable indicater of the species' sex. Females are born blonde, then turn black, then turn blonde again at sexual maturity.

Photographed from the Rescue Center inside Cat Tien National Park. This species can also be found in the wild in the park. It is easily heard because of its loud vocalization.