The rarest primate on Earth
On a single forested ridge in China's Hainan Tropical Rainforest National Park is the entire world population of the Hainan gibbon (Nomascus hainanus). As of early 2024, the population stands at just 42 individuals, making it the world's rarest primate. This is a fragile recovery from a low point of fewer than 10 individuals in the 1970s. In the 1950s, more than 2,000 Hainan gibbons lived across the island, but their numbers plummeted due to habitat destruction from logging and the expansion of rubber plantations, as well as poaching. Today, they are confined to the Bawangling National Nature Reserve, a mountainous area that became their last refuge as lowland forests disappeared.
The Hainan gibbon is a species of lesser ape, meaning it is smaller and distinct from great apes like gorillas and chimpanzees. They have striking sexual dichromatism: adult males are entirely black, while adult females are a golden-buff color with a black patch on their head. Infants are born a golden color and turn black within a few months. Females revert to the golden hue upon reaching sexual maturity. These apes are almost exclusively arboreal, spending their lives in the treetops and moving with incredible speed and agility by swinging between branches, a method of locomotion called brachiation. They rarely, if ever, descend to the ground. Their diet consists mainly of ripe, sugar-rich fruits like figs, supplemented with leaves, flowers, and insects.