Huang Songhe, a photographer from Guangxi Zhuang autonomous region, has taken a number of pictures of the Cao-vit crested gibbons along the China-Vietnam border. At the moment, there are only 140 Cao-vit crested gibbons estimated in the world. They all live in a narrow, primitive karst monsoon forest which sits on the border between Jingxi city, Guangxi Zhuang autonomous region, China and Huyện Trùng Khánh, Cao Bang province, Vietnam.