Leghorn chicken issue

[Mamachuck]

My female Leghorn is missing some feathers on the back of her neck. I have not heard or seen any fighting. I have 4 chickens and 1 White peeking duck, all females. Also she has not laid an egg in over a month.
When they free range she stays with the flock. I see her eating and drinking like normal. Wondering if she was beat up for sitting on someone else’s egg? My Orpington can be a bitch. Could she be sick and the others know it? Thank you for any suggestions and help!

 

[cavemanrich]

It does look like feathers being pecked. Another thing you did mention, is she has not layed for over a month. It is a possibility she is going thru molt. I know leghorns are prolific layers, so the stop just seems odd. She is most-likely not broody, and sitting on other hens eggs. Leghorns are seldom broody.
One last thought,,,,, your Orpington may be acting Tras-gender, and acting like a rooster. I had a RIR that acted that way, She would mount other hens. and pluck their neck, and back feathers.
Also do check for mites. Those are also a possibility to feather loss.
WISHING YOU BEST,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,