Southern White-cheeked Crested Gibbon

The southern white-cheeked gibbon is a species of gibbon native to Vietnam and Laos, closely related to the northern white-cheeked gibbon and the yellow-cheeked gibbon, of which it has previously been treated as a subspecies. Unweaned juveniles are light brown, turning to black after weaning; adult males remain black while adult females are brown (Wikipedia, general species account).

The species is named for the male's facial markings, a large patch of white fur around the edge of the mouth, which distinguishes it from a male northern white-cheeked gibbon, where the white is a streak along the cheeks. Females have a thin edging of white around the face. It lives in lowland broadleaf forest, with some populations in forested mountainous areas, and like all gibbons it is arboreal and frugivorous. Its original distribution covered central Vietnam and central Laos.