Older flock ganging up on new comers - even after 10 weeks

[rosiethechicken]

I have 4 chickens from original flock (2010).
Recently added two more pullets.
Its been about 10 weeks since pullets are here, but the old group
is still ganging up on the pullets. They are terrorized,
afraid to get into coop, trying to sleep outside etc.

Recently a broody member of the flock hatched 2 chicks and were killed. I suspect the the killer
is one of the original flock.

Anything I can do ? I originally built my coop just big enough for them to sleep.
They free range during the day. Is small coop creating the problems ?

 

[hcppam]

How small is the coop, and I know you probably did this but did you keep the girls separated at first where they could all see each other without contact.

 

[Hangin Wit My Peeps]

Are they the same size? It's always good to wait until they are the same size so they have a fighting chance. If they are not then they will continue to pick on them I would for sure seperate them or they will not eat most likley. The others will bully them away

Put up a fence so they can all see each other and let them get to know each other until the others are the same size as the bullies. I hate adding newbies

It's horrible to watch. When I waited it out until they were the same size it went much better

 

[rosiethechicken]

When the little ones came in, they were 7 weeks. I kept the little one in a wire enclosure where the year
olds can see and get used to. That went on two weeks. Now the little ones are 16 weeks, but the year olds are terrorizing them
to a point where they don't want to get into the coop in the evening.

May be I am imagining, but few times I felt like the older ones strategically move on open field and corner the little ones.