A large number of migratory birds on their journey north are resting and recharging at the Baotou Yellow River National Wetland Park in Baotou, Inner Mongolia autonomous region.

A video clip captured thousands of swans playing there.

"When I was shooting the clip, there were more than 5,000 birds, including swans, wild ducks and gray cranes," said Guo Liming, the photographer. "They are expected to stay in the wetlands for about half a month before flying farther north."

Covering an area of 122 square kilometers, the wetland in Baotou is an important transition station for migratory birds, both on the migration route between East Asia and Australia and between Northwest China's Qinghai Lake to the wetlands of Northeast China's Sanjiang Plain.

With the continuous strengthening of ecological protection in the Yellow River Basin in recent years, the Baotou Yellow River National Wetland Park attracts dozens of rare species of migratory birds every year during their migration.

Video by Guo Liming.