Photo taken on Oct. 18, 2018 shows common cranes at one of the protected areas on Poyang Lake in Duchang County, east China's Jiangxi Province. The Poyang Lake, China's largest freshwater lake, saw a flock of common cranes overwintering in it. From late autumn to early winter each year, hundreds of thousands of migratory birds fly from Russia, Japan and China's northeastern and northwestern regions to settle around Poyang Lake and escape the coming chilly weather. (Xinhua/Fu Jianbin)

Photo taken on Oct. 18, 2018 shows common cranes at one of the protected areas on Poyang Lake in Duchang County, east China's Jiangxi Province. The Poyang Lake, China's largest freshwater lake, saw a flock of common cranes overwintering in it. From late autumn to early winter each year, hundreds of thousands of migratory birds fly from Russia, Japan and China's northeastern and northwestern regions to settle around Poyang Lake and escape the coming chilly weather. (Xinhua/Fu Jianbin)

Photo taken on Oct. 18, 2018 shows common cranes at one of the protected areas on Poyang Lake in Duchang County, east China's Jiangxi Province. The Poyang Lake, China's largest freshwater lake, saw a flock of common cranes overwintering in it. From late autumn to early winter each year, hundreds of thousands of migratory birds fly from Russia, Japan and China's northeastern and northwestern regions to settle around Poyang Lake and escape the coming chilly weather. (Xinhua/Fu Jianbin)

Photo taken on Oct. 18, 2018 shows common cranes at one of the protected areas on Poyang Lake in Duchang County, east China's Jiangxi Province. The Poyang Lake, China's largest freshwater lake, saw a flock of common cranes overwintering in it. From late autumn to early winter each year, hundreds of thousands of migratory birds fly from Russia, Japan and China's northeastern and northwestern regions to settle around Poyang Lake and escape the coming chilly weather. (Xinhua/Fu Jianbin)

Photo taken on Oct. 18, 2018 shows common cranes at one of the protected areas on Poyang Lake in Duchang County, east China's Jiangxi Province. The Poyang Lake, China's largest freshwater lake, saw a flock of common cranes overwintering in it. From late autumn to early winter each year, hundreds of thousands of migratory birds fly from Russia, Japan and China's northeastern and northwestern regions to settle around Poyang Lake and escape the coming chilly weather. (Xinhua/Fu Jianbin)