Chicago Bird Migration 2025. Migratory bird movement is in full swing, and experts are urging chicagoans to turn off their lights at night to help protect the birds over the next few days from fatal window collisions. More than 377 million birds have crossed over illinois during the fall migration so far, according to estimates.

The live data feed runs from march 1 to june 15 during spring migration and from august 1 to. As millions of birds migrate over illinois during peak migration season, volunteers with the chicago bird collision monitors are especially busy tending to injured birds.