Introduction to flock

[Shawneeinwa]

Hello all, thank you in advance for your help.
I recently realized out of our 5 chicks we got at the end of march we had a rooster. I swapped him back to the friend I had got them from and I got a new (younger) hen. The problem is this little hen is significantly smaller than our other 4. The original 4 are roughly 16 weeks old, while the new chicken in approx 8 weeks I'm guessing, a large difference in size, and introducing a new 1 into existing 4. I hung out in the coop with them all and its clear they all (but one) want to chase her and gang up. For now I have divided one of the coop rooms with a clear screen divider so they are together but separated. They don't all have day access to the run with this setup, I am just alternating them back and forth.

My question is, how long should I expect to keep them this way? Out of our original 4 one of them couldn't care less about the new chicken, can I put the 2 of them together, and keep the bossy 3 separate? My thought are if the one takes to her now, and they start roosting together etc the new one will be accepted quicker?

 

[oldhenlikesdogs]

I would try bonding the two as well. All you can do is try, but keep an eye out for any pecking.

 

[aart]

Out of our original 4 one of them couldn't care less about the new chicken, can I put the 2 of them together, and keep the bossy 3 separate? My thought are if the one takes to her now, and they start roosting together etc the new one will be accepted quicker?

It might work....it might not....give it a try
You might also try 'mix and match', keeping adding one or two of the olders with the newbie.
See how it goes, switch them out again if trouble arise.
Put all the olders(except maybe the 'nice' one) in the newbie space let the newbie explore the main coop and run without harassment.
Chicken Juggling!!

How big is your coop and run, in feet by feet?
Dimensions and pics would help here.

This might help:
https://www.backyardchickens.com/articles/introducing-a-single-hen-to-an-existing-flock.71997/

As might there tips about.....
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/