Mystery hawk

Identifying hawks in flight is always difficult for me, even with the aid of Jerry Ligouri's information-packed book, Hawks at a Distance, which I reviewed at my blog The Nature of Things a couple of years ago. I can easily identify the ones that I see most often - Red-tailed, Red-shouldered, Cooper's, Sharp-shinned, and the kites that visit here. But others give me more trouble. I'm never sure of my identification and there's been one circling over my yard this week that has me a bit flummoxed.

The bird is a Buteo, no doubt about that - broad wings and short tail. It is very light underneath, but then many hawks are. The wings and the tail have dark tips. I'm not really able to identify other field marks.

The bird flies very high as he slowly circles over the yard and he calls constantly as he goes. The call is not that of a Red-tailed or Red-shouldered. I'm very familiar with their sounds. This bird has a piercing one-note (to my ears) cry that is most like that of the Red-tailed, but isn't quite the keee-yar of that hawk, and the pitch is slightly different.

Since I haven't been able to see any marks that would absolutely identify the bird, I have concentrated on its call. I've been listening to hawk voices from Cornell Lab of Ornithology and the closest that I can find is the call of the Broad-winged Hawk.  (Click on the link to listen to the sound.)

Broad-winged Hawks do summer just to the east of us, but we are a little beyond their normal range as shown on the maps in my field guides. As I've noted before though, birds don't read maps and they have these wonderful things called wings that frequently take them into areas where they are not "supposed" to be.

I'll keep looking to try to see more field marks and maybe even get a picture, but my best guess at this point is that my mystery hawk is a Broad-winged who is exploring new territory. Perhaps this is just another bird that is expanding its range.