During spring and fall, migrant birds begin their journeys. Across the United States, birds travel corridors of travel, called flyways. One of the routes, the Mississippi Flyway, brings thousands of birds through the Chicago area during migratory seasons. The Chicago Bird Collision Monitors is a volunteer conservation group committed to saving migrant birds which have collided with Chicago’s skyscrapers. The group has partnered with the Forest Preserve District of DuPage County’s Willowbrook Wildlife Center in Glen Ellyn to rehabilitate the injured birds.

source