Wild swans flock to the Bayanbulak National Nature Reserve for nesting, Xinjiang Uyghur Autonomous Region. (Photo/China News Service)

Wild swans migrate to the Bayanbulak National Nature Reserve, China's largest nesting sanctuary for wild swans for breeding from March to April every year. By the end of September, they take their young and leave for warmer climes.

A swan sits on a nest at the Bayanbulak National Nature Reserve for nesting, Xinjiang Uyghur Autonomous Region. (Photo/China News Service)

A swan sits on a nest at the Bayanbulak National Nature Reserve for nesting, Xinjiang Uyghur Autonomous Region. (Photo/China News Service)