My full time profession is that of wildlife biologist. I am also a former falconer (too much time), and do many, many raptor surveys each year, so I know a little about them.
Let me reiterate, not only is it against federal law, it is against international treatys to kill, injure, or harrass any migratory bird including all raptors. Yes, all migratory birds--nor just raptors. Some exceptions to the laws include exotics (English house sparrows, starlings etc.). This is outlined in the Migratory Bird Treaty Act and was originally signed in 1918. We have treatys with Canada, Britain, Mexico, Japan, and Russia to protect migratory birds.
Hawk/falcon/eagle/harrier etc issues are difficult. Other nuisence wildlife issues (like elk in a hay pile), are easier. It's just tough to lure raptors away like it is other animals. Fortunately, I have only lost one chicken--to a Cooper's Hawk 1.5 years ago. I however, have great horned owls nesting on our property (about 600 feet from the coop), and there are tons of red tails, barn owls, bald eagles (in winter), harriers, and other raptors in the area and fly over often.
I would suggest trying some of the good ideas presented here that are passive (tinsel, mirrors etc). You can call your local fish and game department, but my guess is that they are not going to come out and trap a single bird. This is just one of the many times where rural living has a challenge that has to have a creative solution that doesn't break laws and international treaties. Sorry I haven't been much help.