Plucked tail feathers

[windy014]

We bought 25 chicks this spring and have discovered one possibly two roosters.
I’ve seen one starting pull feathers on some of the hens so I’m assuming it was him but one have my hens had a spot at the top of her tail feathers where they were plucked out. It was a bit bloody and I saw some pecking at it so I took her out, cleaned her up, and am keeping her in the cattle trailer.
At what point can she go back with the others?
Any tips on making sure she isn’t messed with again?
Why would this happen?

 

[GermanKennhuhn]

Welcome to BYC! Are they crowded at all? You could get some blukote at the feed store to cover up the red and the others shouldn’t bother her.

 

[janiedoe]

Welcome to BYC. How old are your chickens?
Do you have pictures, to post, of the suspected males?
Can you give us an idea of how large their coop and run are?
If there was blood it was probably from pecking, not from breeding. While blukote will help prevent her getting pecked, you will need to find the source of the problem.

 

[rjmyooper]

Welcome. Great suggestions. Pictures and their living situation would help a lot.

 

[007Sean]

Howdy, and Welcome to Backyard Chickens.

Happy to have you here with us. Enjoy your time here at BYC!

Thanks for joining our community!

 

[DobieLover]

Hello and welcome to BYC! Glad you joined.
How much space do they have?

 

[Dr Evy]

Welcome to BYC. We’re so glad you joined! Good luck with your pullet!

 

[Tookie]

Hello and welcome to BYC!

 

[chrissynemetz]

Welcome to BYC! We're glad you decided to join us!

 

[rjohns39]

Hi and welcome to BYC We're so happy you've decided to join us