As summer-like temperatures quickly turned into seasonal fall weather, the change in conditions has kicked off the peak of migratory season for many birds.
This year's migration has already proven to be particularly treacherous for some birds, with officials of McCormick Place confirming the deaths of hundreds of birds near the campus due to collisions with windows.
That migration is expected to be particularly pronounced tonight, with over 600 million birds expected to pass through Illinois overnight.
With the large migration expected, Illinois Gov. J.B. Pritzker encouraged Illinois residents to turn their lights off tonight to aid the birds in their travels.
Buildings along Chicago's lakefront are a particular hazard to birds, where numerous collisions have been reported in recent days.
Chicago proves to be particularly treacherous due to the Great Lakes region being a hotspot of migration for many species of birds, with the city's majestic skyline proving to be an abrupt change for birds traveling over the water.
Local
Large buildings and residences with high windows are also known to be exceptionally dangerous for birds, who are much less likely to collide with windows when lights are off.
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