All threads concerning hawks and their control mention the Migratory Bird Treaty Act and the maximum penalties imposed. The thing to remember is different areas of North America apply the act differently based on the perceived importance of the predator/chicken within a certain community. Some Authorities may never issue kill permits, some may readily issue them, and some (as in my case) only require notification of a kill on my property. It's important to obtain a LOCAL interpretation of need. If the hawks are not rare, if the adults don't actually seem to migrate, and if you raise chickens for income, you are more likely to be let off lightly for blowing one away. That said, it's best to first obtain a ruling based on your individual circumstances. I recently lost a chicken to a pair of resident red tail hawks, but the flock (especially a rooster) learned from the experience. The hens quickly hide, the roosters strut their stuff, and the circling hawks now move on without conflict. The fact is the hawks are important for rodent control and I'm glad to have them around, even if I lose an occasional chicken.