Migratory birds are pictured at the Hailiu Reservoir in Tumd Left Banner in Hohhot, capital city of North China's Inner Mongolia autonomous region. Over the past few days, the number of migratory birds passing through the reservoir has reached the tens of thousands, with a wide variety of species – including swans, gray cranes, wild ducks and red-billed gulls. [Photo/Tumd Left Banner Convergence Media]

A flock of ruddy shelducks rest in the Hailiu Reservoir. Since 2018, every year 4,000-5,000 of them settle in the reservoir permanently, thanks to the banner's continuous efforts in environmental protection and ecological governance. [Photo/Tumd Left Banner Convergence Media]

Migratory birds stroll about the reservoir in Tumd Left Banner. Its main water source is the incoming water from the Xiaohei River, with a drainage area of 44.3 square kilometers and a total irrigation area of 90,000 mu (6,000 hectares). It is an important supply area for migratory birds. [Photo/Tumd Left Banner Convergence Media]