This is Sunny, my 1 year old buff Orpington hen. I noticed about a month ago her butt feathers were thinning. She is a little broody, but not terribly. Her roommate is a more aggressive RIR, but I've never seen my RIR pick on Sunny, only me. Now, I'm noticing Sunny's feathers are totally gone on her butt and spreading to under her wings. I've read a lot of forums and nothing seems to fit this type of feather loss? Thoughts please! I'm getting ready to introduce new chicks in a few weeks, so I've got to get this figured out first.