The Xiaolinghe River Estuary in Jinzhou is not completely frozen in winter due to its special hydrological conditions. In the reach of about one kilometer upstream from the estuary, there is a large area of water in winter, providing fresh water for wintering migratory birds. The area near the estuary has developed agriculture and various farm produce, which can provide food for these birds. The Xiaolinghe River Estuary is a wintering ground for quantities of anatidae migratory birds, among which the number of ruddy shelducks is the largest with at least ten thousand of them. Others like Chinese spot-billed ducks, mallards, and goosanders also have large numbers.

Rare species include smews, goldeneyes, and white-eyed pochards. These anatidae migratory birds are also food for wintering raptors.

This is an important stopover for migratory birds that mainly comprise storks and cranes, anatidae birds, shorebirds, passerine birds, and raptors. The rare anatidae migratory birds that stop at the Xiaolinghe River Estuary mainly include baer’s pochards, whooper swans, tundra swans, and mute swans.