We've got a Sharp-shinned hawk haunting ours and our neighbors, but so far it doesn't appear to have put a serious damper on things. Couple years ago we had some kind of large hawk haunting them. Never got a good look at it. Not a redtail, but it never hung around long enough to get a solid look at its markings to really TELL what it was. We'd get a glimpse of 'big and brown" coming IN, as everything at the feeders scattered for cover, and then it would be gone again.