Date January 19, 2024
Location Garden Prairie, IL
This bird was seen while driving on US highway 20 between Garden Prairie and Marengo, IL. Here is how I came to this conclusion.
First, Rough-legged Hawks are often sighted in this area of northern Illinois in the winter. I had even chased one the prior winter that was reported on eBird in a park preserve in nearby Crystal Lake. In other words, the range is correct.
Second, the habitat was right. A corn field in a rural area.
Third, the behavior was typical. It was hovering over the field. The Cornell entry reads: "Winter is the time to see this large, open-country hawk in southern Canada and the U.S., where it may be perched on a pole or hovering over a marsh or pasture on the hunt for small rodents." The Audubon app has similar language: "Spends the winter in open country . . . Often hunts by hovering over fields, watching for movement below."
Fourth: I noted the dark leading edge and white trailing edge of the wings. Obviously, I did not have a lot of time for observation while driving, but I had sufficient time to lock in this observation.
Fifth: Northern Harrier was a possibility, but it was ruled out. The wing coloration and the behavior don't fit harrier. While it's certainly possible that a harrier could be flying this high, I almost always see them gliding over the field within 20 feet or so of the ground. This bird was higher up.
Sixth: There is dashcam footage of this bird. Below is screen shot which is obviously very blurry because, well, it's from a dash cam in fairly low light, late afternoon, cloudy day, going 50 mph. But it does confirm some details if in a vague fashion. Compare this image to the image above:
The dark trail on the trailing edge is distorted/amplified by the poor quality, but otherwise the wings are consistent. There is a very small impression of the white portion of the under tail as well. Also note the posture: that of hovering, not gliding or soaring. Here is a screen shot of bird in context, with no cropping:
