Established hens won't let newbies on perches

[Boss8]

I added two 20 wk old white leghorns 6 weeks ago...my other 4 ISA Browns(5 months)won't let the leghorns on the perches at night...the leghorn's are still extremely afraid of the Browns(they are still pecking at the leghorn's)....any advice? I'm waiting for two new chickens to be delivered this week and wondering what I'm going to do!?

 

[Pork Pie]

Roost space is important to consider. Around 1.5ft per bird usually allows all to roost. These links may help you

http://www.backyardchickens.com/a/adding-to-your-flock
http://www.backyardchickens.com/a/introducing-new-chickens-using-the-see-but-don-t-touch-method
http://www.backyardchickens.com/t/1098683/introducing-new-chickens-to-old-flock#post_16895615

 

[sawilliams]

My hens don't like to let none layers on the roosts. As none layers are sort of treated like secondary flock members and not full fledged untill maturity.

Roosts are also a big question, as sometimes simple adding 1 more lower or away from the main can provide enough space and distance for new flock members to perch untill they become accepted.