Loosing neck feathers/looking dull

[Diedie]

I have a two austrolope hens and a rooster. Both the hens are loosing their feathers and they look very dull. They should not loose their feathers as it is winter.

 

[Quail Keeper]

Actually, some chickens do go through a molt during the winter, but it doesn't sound like that is the case to me. It sounds like it may be caused from the rooster mounting the hens and grabbing at their necks. Maybe get some other opinions?