00:39

Spring is the time when many migratory birds fly north. More than 500 wild swans have made a stop in the wetland along the Huliu River in the Guanglin County in north China's Shanxi Province. They stay here for a month every spring. Local officials say the improved ecological conditions in the wetland have attracted an increasing number of migratory birds in recent years. Black storks, white-tailed sea eagles and great bustards are also often seen in the area.