I live in Alaska and I have four Rhode Island Red hens in my flock of eleven birds. During the winter to spring transition I noticed that one of my girls was having a significant loss of feathers (not molting) from her breast, neck, and wing leaving behind red naked areas. This was my first year to have chickens and the locals suggested it was due to a Northern Fowl Mite infestation. My other hens, americaunas and barred rocks seemingly are not experiencing feather loss except for a small area between their legs. After treating with permethrin dust and cleaning the roost, coop, and nesting boxes for several weeks I thought my hen would grow her feathers back rather quickly but she hasn't and its been several months. She eats well and acts normal. Any help would be greatly appreciated.