I have an acquaintance who swears he saw recently (in PA) a bird roughly "average bird of prey" size with "three black stripes" i.e., bands or bars, on the underside of its wings running parallel with the body and not along the length of the wing. He did not see the head, and acknowledges it might be any type of bird, not necessarily a bird of prey (he was using that to describe the size), but he did say the wings had "fingers" at the end, much like a lot of birds of prey have (the man is not a normal bird-watcher, but he saw this bird and was hoping I could identify it, but I looked a bit in my books to see if I could see anything close (even at shorebirds that might have large wingspans, and owls and still did not find anything that had striped under-wings with just three big dark stripes parallel to the body. Posting this in the hopes that someone could give a suggestion. Clearly seen in PA, whatever it is; since we are getting close to migration though, could be something just passing through. Any help is appreciated. Thanks.