Autumn and early winter are great times of year to look for migrating raptors. With raptors, if no obvious plumage characteristic jumps out at us, it is best to start with structure. And by raptor structure I mean tail and wing proportions. If you compare the proportions of this bird to the buteo or accipitor species that is most common in your area, we can start making progress. The wings, for example, even though not held completely outstretched, still appear longer and narrower than a typical buteo such as Red-tailed Hawk, and are much longer and narrower than accipitors or falcons that utilize shorter wings for maneuverability. The tail is much longer than that of a buteo, and closer to the proportions expected for an accipitor. So where does that leave us? The tail is more accipitor-like but the wings seem too long and narrow for that group. Well, there are other raptors besides the main hawk groups of buteos and accipitors. Could it be one of them? Osprey has long narrow wings often held in a crooked or ‘M’ shape, but the plumage of this bird is all wrong for Osprey. The wings are not pointed enough for kites, and the overall shape is not right for eagles. That leaves us with one option…Northern Harrier. Do the plumage characteristics fit Harrier? A banded tail with relatively even widths of black and white bands, darkly patterned secondaries, and a dark face all are good for an adult female Northern Harrier.
I’m more used to seeing Northern Harriers hunting low over meadows or marshes, seeing their white rump, which is not visible in this view. But during migration you can see them in non-hunting flight. Keep Northern Harrier in mind when you spot a migrating bird that is not quite accipitor-like and not quite buteo-like.
My thanks to Jim Sutherland for submission of the photos for this BirdQuiz.