Im still new to chickens, but the pictures look just like one of my BOs a month or so ago. She went broody and the other chickens all picked on her. I didnt know what it was for a couple of weeks though. I never saw them picking or anything so I was a little worried. One Sunday I camped out at the coop all day and finally saw that it was the other chickens picking at her neck and wing(she has a small deformed wing). They would peck at her and pull her feathers trying to get her out of the nest so they could lay. Her neck wasnt red or anything, just bare. When I finally broke her and she got off the nest they slowly started growing back. Funny how she is normally the top dog, but when broody shes the low man on the totem pole.
So my guess would be feather picking. But Im not 100% sure.
So my guess would be feather picking. But Im not 100% sure.