Introducing new birds to old...any ideas?

[Cedar hill farmer]

I have 4 buff Orpington remaining from original flock of 12 raised 7 years ago.
Have lost 8 due to age and typical chicken issues in last 3 years, otherwise had 12 birds for almost 5 years. In March started 8 new chicks and now they are almost egg bearing age. I built an addition to my coop with a door to separate the different groups and have had them next to each other for over 6 weeks. I have inner mingled them a few times for short periods, it goes well with the exception of one mature bird that systematically chases all eight back to their side. What should I do? Do I bight the bullet and let it fly? The new birds, same breed, seem able to avoid and evade without getting hurt and stand about the same size as mature ones. Their combs are about 1/3 grown in.
Any thoughts or past experiences?View attachment 1870544

 

[cavemanrich]

Typical pecking order activity. Your young birds are already big enough to escape, need be. I would let them free-range for periods out of their run area, so they get used to each others' presence.
I would also suggest there be some hiding places in your run for the lower pecking order chickens to run and hide behind. Miscellaneous chairs or crates work well. After a while, just remove when no longer needed.
As long as there is just chasing,,,, that is just normal. If injuries occur, you can separate the offender from the flock, for about one week. When you return her, she would be the newcomer, and would be chased by the regulars. (for a short while) That may settle things to where pecking order actions are normal, and MILD.
WISHING YOU BEST,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

 

[clembone]

Nice setup.

All is well.

Let them loose.

They have space to move.

They have had time separated to get used to each other thru wire.

It will be fine.

That chasing business should get tiresome soon.

If not, isolate the perp for a week.

In short, I agree completely with cavemanrich.

The suggestion of putting an old chair out there as a structure to hide, dodge with is genius.

 

[Cedar hill farmer]

Sounds good, thanks for the input. Today they become a family........fingers crossed it goes well.

 

[Shamo Hybrid]

Fight! Fight!