Aggressive chicken

[Mggs]

I added a new chicken to my flock 3 wks. agne of the chickens is being especially aggressive with her. I am still isolating the new chicken at night, but allow her to roam during the day. She tries to join the other chickens but the one chicken won’t allow her to do so. I read something about isolating the aggressive chicken for 10 days,than having her rejoin the group to reestablish the pecking order. Is this something I should do? I feel very bad for the new chicken.

 

[deidreg]

Before you separate anyone, how severe is the aggression? Is she chasing around the new chicken and pecking her? Or is she injuring her and drawing blood? If the new hen is not being injured, try to hold your nerve and let them work it out. (It's tough, I know!) If you do separate them, keep in in sight of one another so they get used to each other. Good luck.

 

[aart]

How did you add the new bird?
How many other birds?
How big is coop and run, in feet by feet?
Dimensions and pics would help here.

These tips might help......
Integration Basics:
It's all about territory and resources(space/food/water).
Existing birds will almost always attack new ones to defend their resources.
Understanding chicken behaviors is essential to integrating new birds into your flock.

Confine new birds within sight but physically segregated from older/existing birds for several weeks, so they can see and get used to each other but not physically interact.

In adjacent runs, spread scratch grains along the dividing mesh, best if mesh is just big enough for birds to stick their head thru, so they get used to eating together.

The more space, the better. Birds will peck to establish dominance, the pecked bird needs space to get away. As long as there's no copious blood drawn and/or new bird is not trapped/pinned down and beaten unmercilessly, let them work it out. Every time you interfere or remove new birds, they'll have to start the pecking order thing all over again.

Multiple feed/water stations. Dominance issues are most often carried out over sustenance, more stations lessens the frequency of that issue.

Places for the new birds to hide 'out of line of sight'(but not a dead end trap) and/or up and away from any bully birds. Roosts, pallets or boards leaned up against walls or up on concrete blocks, old chairs tables, branches, logs, stumps out in the run can really help. Lots of diversion and places to 'hide' instead of bare wide open run.
Good ideas for hiding places:
https://www.backyardchickens.com/threads/a-cluttered-run.1323792/

 

[Ridgerunner]

How old are they all? To me it sounds like you are trying to add a juvenile to an adult flock. In addition to Aart's questions what are the ages involved? Knowing what you have to work with can be really important.