We coasted along with our 22 pet chickens for 6 months and no problems. Now it seems like one after another. Now our head rooster is getting a bald butt. I watch the hens walk by him and grab those small downy feathers. He NEVER drops his tail feathers as he is always on guard, and has the feathers more erect than erect. And he doesn't ever object to their peck. Is this normal?