Introducing Mature Birds To Established Flock

[EmilyRobb]

I decided to purchase some relatively mature birds to add to my flock. The birds are just 2 pullets and a cockerel, and they're all about 4 months old so they're pretty developed. I've only ever added chicks to my flock after brooding and at about 6 weeks of age, but I've had no issues with adding chicks and everyone establishes the pecking order once again. How should I go about introducing the new birds to my own flock?

 

[aart]

Below are some basics,
knowing more about your flock ...
-your flock size(numbers, ages, genders),
-your coop(size in feet by feet with pics),
might garner specific suggestions.


Consider biological/medical quarantine:
BYC Medical Quarantine Article

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/