Integrating new chickens into the flock

[Mountaineer]

I have seven chickens that are about 2 years old. I have 5 others that are about 12 weeks old and have been integrated into the flock. The original 7 roost together on the same roost and the 5 do the same on another roost. I allow them to free range all day in my large fenced in backyard. However, the 7 stick together and the 5 younger ones stick together. So, in essence I have two small flocks instead of one large one. Is that normal? I am also getting ready to integrate 4 more chicks that were hatched about 8 weeks ago. I have them in the coop with the others but they are separated by wire. Is there any danger of the older chickens killing the younger ones?

 

[Perris]

I have had the same experience when integrating; the youngster flock merges with the elder flock when the youngsters are ready. And as long as youngsters can run away and hide from elders, they sustain no injuries while learning they're bottom of the pecking order.

 

[Pork Pie]

What you are observing is perfectly normal, and the two flocks will only merge once the younger birds begin to lay, in my experience.

These links on integration should help.
https://www.backyardchickens.com/articles/integrating-new-birds-at-4-weeks-old.72603/

http://www.backyardchickens.com/a/introducing-new-chickens-using-the-see-but-don-t-touch-method

http://www.backyardchickens.com/t/1126547/topic-of-the-week-integrating-chicks-into-an-adult-flock

http://www.backyardchickens.com/t/1069595/introducing-chicks-to-adults#post_16276224

This link on space provisions is equally important
http://www.backyardchickens.com/a/how-much-room-do-chickens-need

 

[RWise]

I put my new hatches in the flock at 5 weeks old, they learn the pecking order in minutes (stay away from that big blue girl).
They need hiding areas, food and water that the big girls cannot get to, and lots of room.

 

[aart]

So, in essence I have two small flocks instead of one large one. Is that normal?

Yeppers! The youngers won't merge into the main flock until they start laying, and even then they may hangout in their respective 'sub-flocks' for much of the day.

 

[aart]

I am also getting ready to integrate 4 more chicks that were hatched about 8 weeks ago. I have them in the coop with the others but they are separated by wire. Is there any danger of the older chickens killing the younger ones?

Probably not killing them, but the 12wo's will be rough on the littlers.
You'll want lots of space, yet another roost, and multiple feed/water stations.
I have 2 groups of chicks this year, one group was broody hatched, then I added 15 incubator chicks 5 weeks younger...but I brooded them in coop and integrated them at 4 weeks old.

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.