I free range my flock of 29 daily; they mostly stay in the forest/underbrush, but thy do also wander to a grassy area near my back field. I came home this evening to find my flock in an uproar... As I went out to see what was going on, I see a very large (standing at least 24 inches) bird looking at me over a pile of feathers. The bird was primarily white, with grey speckled wings and breast. I live in southeastern Wisconsin and have NEVER seen a bird of prey like this, or this size. Any idea?