I have six chickens (2 New Hampshires, 2 Wyandottes, and 2 Ameracaunas). One of my Ameracaunas is being bullied by the other chickens. They have been pulling out her tail feathers and have started to draw blood. Since this is a group behavior, I can't separate out the bully. I'm worried about my Ameracauna. What should I do?