Illinois Duck Migration Report 2026

Duck observations in Illinois usually climb from the week of Nov 9 and reach their fall high around the week of Dec 14, and the share stays that high into January; they stay above the halfway mark between their July level and that high through the week of Apr 6. That is from ten years of research grade iNaturalist observations, 2016 to 2025, counted as a share of all bird observations so the growth of the app does not skew it.

Illinois Natural History Survey (Forbes Biological Station) runs the INHS Waterfowl Aerial Inventory, Illinois River, last counted on September 23, 2026 (11,915 ducks, 810 mallards). Illinois Natural History Survey (Forbes Biological Station) runs the INHS Waterfowl Aerial Inventory, Central Mississippi River, last counted on September 23, 2026 (4,275 ducks, 395 mallards). Each count links to the agency's own report.

In Illinois, blue-winged teal climb first, from around the week of Aug 17, and common goldeneye come last, from around the week of Dec 7. That is the week each species' share of bird observations first passes the halfway mark between its July level and its fall high; the species chart shows all of them week by week.

Illinois is in the Mississippi Flyway. The continent's busiest duck corridor, following the Mississippi River system. The freeze watch for Illinois reads forecast lows at the Mississippi Flyway's northern staging areas: Bemidji, Fergus Falls, Green Bay, Alpena, Saginaw Bay.

The 2026 U.S. Fish and Wildlife Service breeding survey estimated 33.4 ± 0.6 million birds, 6% below the long-term average of 35.4 ± 0.09 million. That is the fall flight's starting point for every state, Illinois included.

Season dates, zones and bag limits for Illinois are set by the state wildlife agency inside the federal frameworks and are listed on the Illinois waterfowl season page, linked below.