Of them, more than 90 percent of the world's spoon-billed sandpipers, a critically endangered sparrow-sized shorebird, make stopovers during their migration route between their breeding grounds in Siberia and their wintering grounds in the south. About 80 percent of the world's wild red-crowned cranes will winter in the Phase I area, according to the administration.

"The bird sanctuaries are truly one of the most important sites for the world's shorebirds," said Wen Cheng, a member of the administration's World Heritage Expert Committee. Wen participated in the entire nomination process of the World Heritage site and made dozens of field trips to the area since 2017.