Deep in the forests of south China’s Hainan, park rangers are working tirelessly to safeguard one of the world’s rarest primates – the Hainan gibbon.

Today, around 42 individuals survive, all within the trees of the Hainan Tropical Rainforest National Park. In the Bawangling area, rangers trek through dense woodland without marked trails, guided not by sight but by the gibbons’ ringing calls overhead. Agile and swift, the animals can swing nearly a kilometre through the canopy in just a minute.

Though the population remains fragile, the current figure marks a remarkable rebound. In the late 1970s, numbers had plunged to as few as seven after years of habitat loss and hunting.

Protection efforts have since intensified, combining habitat restoration with cutting-edge science. Researchers at Sun Yat-sen University have developed an acoustic AI system capable of identifying individual gibbons through their unique vocal patterns, analysing more than 1,800 hours of recordings.

With sustained fieldwork, scientific innovation and stronger conservation frameworks, hope is steadily growing for the future of this critically endangered species.