Infants are pale at birth. Starting at the fingers, toes, and face ring, infants gradually change to a black phase. This genus is characterized by a diploid chromosome number of 52. Northern white-cheeked gibbon. The male cheek patches connect under a black chin and extend up to the top of the ear.
Females can have brown-black genitals and black hairs on the tips of fingers and toes.
A trace of the crown patch can extend between the scapulae. Females are sometimes larger than are males. Nomascus l. leucogenys is nearly extinct in southern Yunnan and northern Vietnam, although they can be found in a small portion of Laos. We currently house two pairs, one of which has two offspring. Southern white-cheeked gibbon.