A flock of swans takes wing above the Nanhaizi Wetland Nature Reserve in Baotou, in North China's Inner Mongolia autonomous region, on March 1. As the weather gradually warms up, the population and species of migratory birds passing through the wetland are reaching peak levels. The number of swans at Nanhaizi has reached more than 3,000 and there are various kinds including whooper swans and mute swans. After staying in the reserve, they are expected to continue their trek northwards around mid-March. [Photo by Li Qiang/Baotou Evening News] 

Swans take off at the Nanhaizi Wetland Nature Reserve in Baotou, in North China's Inner Mongolia autonomous region, on March 1. Flocks of swans have been spotted around Baotou city as spring approaches. The swans feed on the straw and grain around the shoals and will leave for Mongolia and Russia around a month later. [Photo by Li Qiang/Baotou Evening News]