Rooster going after one chicken

[Bhbgl]

My rooster and one of my chickens have been chasing down another chicken for a while and now she’s scared to go out. The rooster gets in front of her and starts shaking her by the neck aggressively and then the other chicken comes and pecks her. She’s even jump up to my arm to get away from them. This morning they’ve chased her all around the yard! I had to put her somewhere where they can’t get to her.
Why are they behaving like that? If they use to be fine in the beginning.

 

[azygous]

Why. Why do children on a playground pick on one kid and make their life miserable? Probably because they sense weakness in that child or something a little "off", and it triggers the bully in them. (I confess to this as a child of ten.) It's similar with chickens.

Read through this and maybe you'll understand better what I'm getting at. https://www.backyardchickens.com/articles/chicken-bully-chicken-victim-a-two-sided-issue.73923/

Victim behavior actually perpetuates their victimhood and stimulates the bullies into behaving as bullies. So you need to interrupt the cycle. I discovered this quite by accident, and the story is in that article. My hen Joycie was a pathetic victim and after several weeks of "vacation" from being bullied and pecked, she emerged as a changed chicken, full of self confidence with the new-found ability to stand up for herself. She was never again a victim until death sneaked up on her a few years later.

You need to remove your bullied hen from the main flock (but keep her still within view of the others), give her a safe place to eat in peace, put on some weight and gain strength, and this will also give you a chance to closely observe her for health problems that could be triggering the attentions of the bullies.

 

[aart]

Why are they behaving like that? If they use to be fine in the beginning.

@azygous has given good advice on how to deal with bullies birds,
but lets get some more info that might help shed light on why the problems exists.
How old are these 3 birds, in weeks or months?
How many other birds..... ages and genders?
How big is their coop and run, in feet by feet?
Dimensions and pics would help here.

Oh, and....Welcome to BYC! @Bhbgl
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