Migrant birds fly over Momoge National Nature Reserve in Zhenlai County, Baicheng City of northeast China's Jilin Province, Oct. 20, 2020. (Xinhua/Zhang Nan)

White cranes fly over Momoge National Nature Reserve in Zhenlai County, Baicheng City of northeast China's Jilin Province, Oct. 20, 2020. (Xinhua/Zhang Nan)

Migrant birds fly over Momoge National Nature Reserve in Zhenlai County, Baicheng City of northeast China's Jilin Province, Oct. 20, 2020. (Xinhua/Zhang Nan)

Migrant birds fly over Momoge National Nature Reserve in Zhenlai County, Baicheng City of northeast China's Jilin Province, Oct. 20, 2020. (Xinhua/Zhang Nan)

Migrant birds fly over Momoge National Nature Reserve in Zhenlai County, Baicheng City of northeast China's Jilin Province, Oct. 20, 2020. (Xinhua/Zhang Nan)

White cranes fly over Momoge National Nature Reserve in Zhenlai County, Baicheng City of northeast China's Jilin Province, Oct. 20, 2020. (Xinhua/Zhang Nan)

White cranes fly over Momoge National Nature Reserve in Zhenlai County, Baicheng City of northeast China's Jilin Province, Oct. 20, 2020. (Xinhua/Zhang Nan)

White cranes fly over Momoge National Nature Reserve in Zhenlai County, Baicheng City of northeast China's Jilin Province, Oct. 20, 2020. (Xinhua/Zhang Nan)

Migrant birds fly over Momoge National Nature Reserve in Zhenlai County, Baicheng City of northeast China's Jilin Province, Oct. 20, 2020. (Xinhua/Zhang Nan)

Migrant birds forage at Momoge National Nature Reserve in Zhenlai County, Baicheng City of northeast China's Jilin Province, Oct. 20, 2020. (Xinhua/Zhang Nan)