What I've done before is take the victim and the gentlest of the others and put those 2 together for a week elsewhere, then add another hen to those 3 for another week. Then put the group of 3 together into the main group and they should stick together. A group of 3 seldom gets picked on, they should stick together and the other hens think they have 'back-up' and tend not to push the issue. It probably doesn't *always work, but it's always worked for me.
