World Migratory Bird Day Highlights Spring Bird Migration Through Chicago

Every spring, millions of birds pass over the Chicago region, most traveling at night, unseen as they move along the Mississippi Flyway. World Migratory Bird Day, observed May 9 this year, is a reminder that our area sits directly in the path of one of nature’s great seasonal journeys. In Chicago, spring migration typically runs from mid-March into early June, with peak movement building from mid-April into mid-May.

Some of these travelers become familiar summer residents. The return of Chicago’s beloved piping plovers to Montrose Beach drew headlines again this April, a visible reminder that even our most celebrated local birds are part of a much larger migration story. Many of the birds we see each summer have returned from wintering grounds in Central and South America, Mexico and the southern United States to breed here before heading south again.

World Migratory Bird Day focuses on awareness and action. The 2026 theme, Every Bird Counts – Your Observations Matter, highlights the role of everyday sightings in tracking migration patterns and population changes. Tools like BirdCast allow residents to see nightly migration estimates, often showing hundreds of thousands, sometimes millions, of birds moving over Illinois in a single evening.

A 2019 study published in Science found that North America has lost about 2.9 billion breeding birds since 1970, roughly 29 percent of its bird population, with habitat loss, development, pesticides and other environmental pressures all contributing to the decline. According to the Cornell Lab of Ornithology, nighttime lighting remains a major migration hazard worldwide, because artificial light can disorient birds flying overhead and draw them toward buildings and glass, increasing the risk of deadly collisions.

Simple actions can help. Turning off nonessential lights during peak migration, supporting habitat restoration, creating a bird-friendly yard, participating in a spring bird count and simply noticing the birds passing through are small but meaningful ways to participate. 

Find Local Birding Resources and Events

BirdCast (migration maps & forecasts): 

BirdCast.info

Chicago Bird Alliance:
ChicagoBirdAlliance.org

Chicago Bird Collision Monitors:
BirdMonitors.net

Forest Preserves of Cook County:
fpdcc.com

Lake County Forest Preserves:
lcfpd.org

Forest Preserve District of DuPage County:
DuPageForest.org

McHenry County Conservation:
District: mccDistrict.org

Forest Preserve District of Will County:
ReconnectWithNature.org