It's funny that I got that right because I thought I knew kestrels well enough to easily recognize them, but I recently posted a photo of a hawk eating a vole because I didn't
think it was a kestrel. Turns out it was after all. So, honestly, I'm
not sure what looked kestrel-y about it to me. The
wings are roughly kestrel shaped, and if that's a red-tail, then it's about the right size, and kestrels mob other hawks, but I didn't put that much thought into it. I guess I didn't see anything to make me think it wasn't a kestrel.
I'm glad I got it right. Now I don't feel so silly about not recognizing the kestrel I posted the other day. :)