Swans are seen at the Wuxing white crane conservation area by the Poyang Lake in Nanchang, east China's Jiangxi Province, Nov. 30, 2021. Numerous migratory birds including white cranes and swans have arrived in the wetland by the Poyang Lake, taking it as their winter habitat. (Photos: Xinhua)

A swan flies over the Wuxing white crane conservation area by the Poyang Lake in Nanchang, east China's Jiangxi Province, Nov. 30, 2021.

Two swans fly over the Wuxing white crane conservation area by the Poyang Lake in Nanchang, east China's Jiangxi Province, Nov. 30, 2021.

A flock of white cranes fly over the Wuxing white crane conservation area by the Poyang Lake in Nanchang, east China's Jiangxi Province, Nov. 30, 2021.

Swans are seen at the Wuxing white crane conservation area by the Poyang Lake in Nanchang, east China's Jiangxi Province, Nov. 30, 2021.

Two swans fly over the Wuxing white crane conservation area by the Poyang Lake in Nanchang, east China's Jiangxi Province, Nov. 30, 2021.

A swan is seen at the Wuxing white crane conservation area by the Poyang Lake in Nanchang, east China's Jiangxi Province, Nov. 30, 2021.

Migrant birds fly over the Wuxing white crane conservation area by the Poyang Lake in Nanchang, east China's Jiangxi Province, Nov. 30, 2021.

A white crane is seen at the Wuxing white crane conservation area by the Poyang Lake in Nanchang, east China's Jiangxi Province, Nov. 30, 2021.

White cranes are seen at the Wuxing white crane conservation area by the Poyang Lake in Nanchang, east China's Jiangxi Province, Nov. 30, 2021.