No possible way!! We have 100's of crows, turkey vulture's etc etc. I live in the woods. There's just no way. Plus all the damp weather this year hasn't helped anything. But thank god they only effected the big girls and boy. Again, so weird that the growing pen is right next to them and the 17 younger birds don't have a problem.
Plus like I said heavily treed. They get sun but half/half. Can only do what I can do. Better preventive methods and now I know to inspect them a lot more. Actually, I never have. Never had this issue before. My bad this time. Won't do it again.