Wintering whooper swans are pictured in a lake in Rongcheng, east China's Shandong Province, Jan. 5, 2026. Over 6,000 migratory whooper swans have flocked to Rongcheng to spend the winter. (Xinhua/Xu Suhui)

Wintering whooper swans are pictured at a national nature reserve in Rongcheng, east China's Shandong Province, Jan. 5, 2026. Over 6,000 migratory whooper swans have flocked to Rongcheng to spend the winter. (Xinhua/Xu Suhui)

Wintering whooper swans are pictured in a lake in Rongcheng, east China's Shandong Province, Jan. 5, 2026. Over 6,000 migratory whooper swans have flocked to Rongcheng to spend the winter. (Xinhua/Xu Suhui)

Wintering whooper swans are pictured in the waters of Lidao Town in Rongcheng City, east China's Shandong Province, Jan. 5, 2026. Over 6,000 migratory whooper swans have flocked to Rongcheng to spend the winter. (Xinhua/Xu Suhui)

Wintering whooper swans are pictured at a national nature reserve in Rongcheng, east China's Shandong Province, Jan. 5, 2026. Over 6,000 migratory whooper swans have flocked to Rongcheng to spend the winter. (Xinhua/Xu Suhui)

Wintering whooper swans are pictured in the waters of Lidao Town in Rongcheng City, east China's Shandong Province, Jan. 5, 2026. Over 6,000 migratory whooper swans have flocked to Rongcheng to spend the winter. (Xinhua/Xu Suhui)

Wintering whooper swans are pictured at a national nature reserve in Rongcheng, east China's Shandong Province, Jan. 5, 2026. Over 6,000 migratory whooper swans have flocked to Rongcheng to spend the winter. (Xinhua/Xu Suhui)

Wintering whooper swans are pictured at a national nature reserve in Rongcheng, east China's Shandong Province, Jan. 5, 2026. Over 6,000 migratory whooper swans have flocked to Rongcheng to spend the winter. (Xinhua/Xu Suhui)

A wintering whooper swan flies at a national nature reserve in Rongcheng, east China's Shandong Province, Jan. 5, 2026. Over 6,000 migratory whooper swans have flocked to Rongcheng to spend the winter. (Xinhua/Xu Suhui)