Cuo’e island is the world’s highest-lying bird island with an altitude of 4,500 meters in China's Tibet Autonomous Region. The diversity of birds spending the summer months on the small island has significantly increased during the past ten years, said Taqi, a local wildlife ranger. When he started back in 2009, there were only bar-headed gooses and a few brown-headed gulls. By providing those birds a safe habitat, more and more species of birds come to the reserve.