Don’t add a single bird. Add a pair. Put one of your birds with the newbie. There will be a dust up, but it is one on one, not 5 to 1. Pick a middle bird, not the top, not the bottom.
Wait till you get back, then add the ‘new’ pair to the flock, pulling out Blackie. Wait a few days, add back blackie and you should be golden.
You might try putting Blackie where you have the new bird, putting the new bird and others out to free range, see how it goes. You might get lucky. If not go with my first idea, I know it will work, or at least did for me.
Mrs K
Wait till you get back, then add the ‘new’ pair to the flock, pulling out Blackie. Wait a few days, add back blackie and you should be golden.
You might try putting Blackie where you have the new bird, putting the new bird and others out to free range, see how it goes. You might get lucky. If not go with my first idea, I know it will work, or at least did for me.
Mrs K