Eurasian tree sparrow
Winter populations of bald eagles are found along the Mississippi River around the Chain of Rocks Bridge. The city is on the Mississippi Flyway, used by migrating birds, and has a large variety of small bird species, common to the eastern US. The Eurasian tree sparrow, an introduced species, is limited in North America to the counties surrounding St. Louis. The city has special sites for birdwatching of migratory species, including Tower Grove Park.