How long have you had these birds?
How big is their coop and run, in feet by feet?
Dimensions and pics would help immensely here.
A
wire crate would be a big help, to isolate the injured and the bully in rotation.
Time for some Chicken Juggling.
Put the bully in the crate and see how the other 3 get along.
If that doesn't go well, might have to isolate the injured to protect and heal and reassess for the next step.
Oh, and...
Welcome to BYC! @kattfink
Where in this world are you located?
Climate, and time of year, is almost always a factor.
Please add your general geographical location to your profile.
It's easy to do, and then it's always there!
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