
Aerial photo taken on Nov. 3, 2021 shows a flock of swans swimming on the lake of the Hongjiannao Wetland Reserve in Shenmu, northwest China's Shaanxi Province. Flocks of wintering wild geese and swans have arrived at the Hongjiannao Wetland Reserve on their route of migration.(Photo: Xinhua)

A flock of wild geese skim over the lake of the Hongjiannao Wetland Reserve in Shenmu, northwest China's Shaanxi Province, Nov. 3, 2021. Flocks of wintering wild geese and swans have arrived at the Hongjiannao Wetland Reserve on their route of migration.(Photo: Xinhua)

Wild geese and swans are seen at the Hongjiannao Wetland Reserve in Shenmu, northwest China's Shaanxi Province, Nov. 3, 2021. Flocks of wintering wild geese and swans have arrived at the Hongjiannao Wetland Reserve on their route of migration. (Photo: Xinhua)

Wild geese and swans are seen at the Hongjiannao Wetland Reserve in Shenmu, northwest China's Shaanxi Province, Nov. 3, 2021. Flocks of wintering wild geese and swans have arrived at the Hongjiannao Wetland Reserve on their route of migration. (Photo: Xinhua)