Based on 4,175 research-grade iNaturalist observations in Illinois, Brown-headed Cowbird is most often recorded in April; in Illinois it behaves like a seasonal. It ranks #27 among birds recorded in the state in our data.
Molothrus ater
Brown-headed Cowbird in Illinois by month
Bars show research-grade observations per month. They mix true seasonality with how often people are outdoors, so treat small numbers with caution.
Also seen in Illinois in April
American Robin
Canada Goose
Red-winged Blackbird
Mallard
Northern Cardinal
House Sparrow
Common Grackle
Mourning Dove
Places to look in Illinois
State ParkCahokia
Botanical GardenMorton Arboretum
National ForestShawnee National Forest
Botanical GardenChicago Botanic Garden
Botanical GardenLadd Arboretum
State ParkStarved Rock State Park
FAQ
When does Brown-headed Cowbird appear in Illinois?
Mainly April–June, with the most records in April.
How common is Brown-headed Cowbird in Illinois?
It ranks #27 by number of iNaturalist observations among birds in Illinois (4,175 records in our sample).