A heron is seen on the bank of the Yellow River in Pinglu County, north China's Shanxi Province on April 6, 2020. As the weather turns warm, hundreds of herons build nests and reproduce at a wetland of the Yellow River here in spring time. (Photos: Xinhua)

Two herons are seen on the bank of the Yellow River in Pinglu County, north China's Shanxi Province on April 6, 2020. As the weather turns warm, hundreds of herons build nests and reproduce at a wetland of the Yellow River here in spring time.

A heron hatches eggs in the nest on the bank of the Yellow River in Pinglu County, north China's Shanxi Province on April 6, 2020. As the weather turns warm, hundreds of herons build nests and reproduce at a wetland of the Yellow River here in spring time.

Two herons are seen on the bank of the Yellow River in Pinglu County, north China's Shanxi Province on April 6, 2020. As the weather turns warm, hundreds of herons build nests and reproduce at a wetland of the Yellow River here in spring time.

A heron rests on a branch at the bank of the Yellow River in Pinglu County, north China's Shanxi Province on April 6, 2020. As the weather turns warm, hundreds of herons build nests and reproduce at a wetland of the Yellow River here in spring time.