Here in NJ the annual hawk migration has started already. I'm guessing it started early this year because of the drought. A lot of the birds moving through are immature and very hungry. They may have been raised in the wilds of Canada and know nothing about humans. I have had Coopers hawks fly against my pigeon aviaries while I am standing there feeding. Redtails and other hawks can kill larger prey. They will simply eat it where they have killed.