The white-cheeked gibbon (Nomascus leucogenys) is a gibbon that inhabits tropical broadleaf forests in southern China, northern Laos, and northwestern Vietnam. Its body length is 45–63 cm and its weight is about 5.7 kg; it has no tail and exhibits marked sexual dimorphism. Males have white hair on the cheeks, while females have a black head and a cream-colored body. Diurnal, it eats fruit, leaves, flowers, young shoots, and insects, lives arboreally, and moves between trees by brachiation. Groups are based on pairs and include offspring; they maintain bonds and defend territory with high-pitched songs called duets. Gestation is about seven months, usually producing a single offspring which is weaned at about two years, but hunting and habitat destruction have caused dramatic population declines and the species is listed as Critically Endangered (CR).