Oh one more thing... do you think all thr birds were attacked through the fence? What if they were all attacked from the in side, and the tracks in pics is the animal just tring to get it's meal back home. It is hard to believe the all of your birds would get close to the fence to get injured after the first one cryed out?...............Could this have been a "inside" job? If so, think Mink or Pine Martin. Do you live near water or big timber?