Aggressive chicken seriously harming other chicken

[PBlanck]

I have 3 chickens; Dotty (a barred rock), Buffy (Buff Orrington
) and Gertrude (a dirty white colored chicken that I can't identify).

Gertrude is extremely smart and can be fairly aggressive. Lately she has been picking on Buffy and doing serious harm. Buffy got to the point where she would just hide in a corner and stick her head in a hole in a cement block. When I finally rescued her (I had been out of town) her right leg was so damaged that she could not put any wait on it. I isolated Gertrude for 5 days. Buffy now walks with a limp. I reintroduced Gertrude and she went after Buffy again.

These two had lived peacefully together for a couple of years prior to this.

Does anybody have a solution? Does one of them have to go?

 

[duckets]

Good Morning PBlank,

Sometimes birds and all animals for that fact, can become fixated on acting aggressive toward or 'bullying' a cage mate, you might have to segregate Gertrude indefinitely from Buffy and the rest of your flock. Are they penned or do they free range, either way you shouldn't have to get rid of anyone, just build some additional accommodations.

An extra pen and hutch, although not as big, is always beneficial, ie, new chicks, etc.