Hooded cranes fly over a wetland in Qiqihar, northeast China's Heilongjiang Province, March 31, 2026. (Photo by Wang Yonggang/Xinhua)

An aerial drone photo taken on March 28, 2026 shows migratory birds at the Fujin National Wetland Park in Fujin City of northeast China's Heilongjiang Province. (Photo by Qu Yubao/Xinhua)

An aerial drone photo taken on April 1, 2026 shows herons resting on trees in Tongjiang, northeast China's Heilongjiang Province. (Photo by Liu Wanping/Xinhua)

An aerial drone photo taken on April 1, 2026 shows an oriental white stork resting in a nest in Zhaodong, northeast China's Heilongjiang Province. (Photo by Liu Dapeng/Xinhua)

An aerial drone photo taken on March 30, 2026 shows migratory birds resting on the Harbin section of Songhua River in northeast China's Heilongjiang Province. (Photo by Zhang Shu/Xinhua)

Mandarin ducks are pictured at Zhaolin Park in Harbin, northeast China's Heilongjiang Province, March 30, 2026. (Photo by Zhang Shu/Xinhua)