Male is black in color, while female is light in color. Newborn is also light in color. When it is 4 – 6 months old, its hair at the chest will turn into black in an invert triangular shape at its stomach. Its hair at the head will also turn into black at the center of the head in circle shape. When it is 3 –4 years old, hairs of male will turn into black for entire body except for eyebrows, testis, backhands, back feet, and the circle around its face that the hair is still remain at the same white color. Around the black marking spot on its head, there is distinctively long white hair scattered around. For female, its hair body is not change into black. Its hair color remains the same. At its chest and head, it is black in color, which looks like wearing black bib and crown. Like male, it has distinctively long white hair scattered around its black marking spot on its head.
It is found in Lao, and Cambodia in Western part of Mekong River. In Thailand, it is found in Eastern part such as Surin, Buriram, Prachin Buri, and Trad provinces. It is also found at Hao Yai National Park.
It eats fruits, treetops, bird eggs, and insects.
Its mating behavior is similar to that of any other gibbons. But it is fierce when mature.
It is mature and ready for mating at the age of 7 – 8 years. Gestation period is around 240 days. One litter contains only one young.
Update : 11 April 2017