backl feather loss

[vancouver chicks]

hi - I have 8 girls of various breeds. My Red Copper Maran, is loosing feathers from her tail up along her spine. This is not happening with the other 7 or the other Maran. She is about 1 year old.
I can see no evidence of the others picking at her. It has gotten to the point where her spine bones are showing.
Other than the feather loss she seems healthy, she has lots of energy and eats/drinks normally, and is a consistent layer.
This has been going on over a month and does not look anything like normal molting. It is slowly spreading up her back.
Any suggestions or ideas of cause?
Thanks
Elaine in Vancouver Canada

 

[shmccarthy]

Do you have a rooster?

 

[vancouver chicks]

No rooster. We are not allowed to keep roosters in Vancouver.

 

[donrae]

Sounds like mites?

 

[Cindy in PA]

That's exactly where my girls peck each other. Most are fine, but a few are bald & I've seen them sit there while others pull out their feathers.