A group of black swans are pictured at a lake in Changbai Island Forest Park, in Shenyang, Liaoning province. [Photo/Xinhua]

A black swan swims in the lake at Changbai Island Forest Park, Shenyang. [Photo/Xinhua]

A mandarin duck plays with a black swan in the lake at Changbai Island Forest Park, Shenyang. [Photo/Xinhua]