My black sex link has some weird feather loss. It's only on one wing and her head. Her head feathers look like the ends have been broken off. I have 3 chickens total and only she is showing this. She is still laying daily and eating well. This just started happening a few weeks ago. They aren't any worse the when I first noticed. I had to start keeping them in their house more because they were escaping my yard. Any help would be great.