An aerial drone photo taken on Oct. 13, 2025 shows migratory birds foraging in a wetland of a national natural reserve in Mishan City, northeast China's Heilongjiang Province. Migratory birds are about to fly south in the migratory season in Heilongjiang Province. (Photo by Sun Haiqi/Xinhua)

An aerial drone photo taken on Oct. 9, 2025 shows red-crowned cranes at a wetland of Naoli River national natural reserve in northeast China's Heilongjiang Province. Migratory birds are about to fly south in the migratory season in Heilongjiang Province. (Photo by Han Yang/Xinhua)

An aerial drone photo taken on Oct. 12, 2025 shows migratory birds at a wetland of Naoli River national natural reserve in northeast China's Heilongjiang Province. Migratory birds are about to fly south in the migratory season in Heilongjiang Province. (Photo by Sheng Jingli/Xinhua)

An aerial drone photo taken on Oct. 14, 2025 shows oriental white storks and wild ducks in Sanjiangkou national wetland park in Tongjiang City, northeast China's Heilongjiang Province. Migratory birds are about to fly south in the migratory season in Heilongjiang Province. (Photo by Liu Wanping/Xinhua)

This photo taken on Oct. 14, 2025 shows herons and egrets in Sanjiangkou national wetland park in Tongjiang City, northeast China's Heilongjiang Province. Migratory birds are about to fly south in the migratory season in Heilongjiang Province. (Photo by Liu Wanping/Xinhua)