My hen has huge bald spot, what can I do?

[Cardia]

i have a hen, she should have beautiful feathers and was so fluffy but I moved her into a new coop with a new flock including two roosters. Soon after I moved her I noticed she began loosing feathers in her back but I though it was from the roosters but today I saw her and basically her back feathers are gone! So maybe it not the roosters, but I’m not sure why she suddenly lost all her feathers. She’s not being bullied or anything like that. So I’m not sure what’s going on and what I should do to help her. I left some photos below.

 

[Rose the Legbar]

It looks like rooster damage and/or damage by being picked on by the other hens. How many roosters do you have and how many hens do you have? How much run space do you have?

 

[-Shade-]

Sometimes if they are low in calcium this can happen as well, especially around molting seasons. Oyster shells help with sufficient calcium intake, and you can buy/make her a chicken saddle/apron if it’s damage from a naughty hen or overbearing rooster

 

[Crazy Maizie]

How many hens to roosters are in that flock? How much space do they have? This looks like rooster damage, but it could be others picking on her. How was she integrated?