Some of mine look like that and i thought that maybe the feathers are just getting worn out. They are almost a year and a half and haven't had a big molt . Dust baths , the feathers rubbing up against the sides of the nest boxes etc... could that be a possibility?
Hi, I am looking at your pics from some time ago and it looks similar to something on my chicks. I am not sure if it is their first moult or mites. Did you sort your problem out, and if so how please?