The bald eagle may be something to worry about. My neighbor lost his rooster to an immature bald eagle a few years ago, and I've seen YouTube videos of eagle's taking chickens. I live along a river and it seems the eagles come up to the house and gawk at my cats and chickens when the river is flooded, or when the river is frozen. Usually the crows run them off before I can get out there to do it.Also once saw a Bald Eagle.