We have 9 Buff Orpington hens. Eight of them have been pecked and are missing lots of tail feathers. The ninth has beautiful, fluffy feathers. There's not a mark on her. We isolated her a few months ago for this same reason, and have her in chicken jail again. I have never actually seen her bully the others, but it seems logical that she would be the culprit. Can a pecky hen be rehabilitated?