my four big girls five months old are one each of barred rock, black australorp, buff orp, and silver laced w. the babies are about 8 wks old. two production reds (they were supposed to be BO), two black aust, and one delaware.
i strung chicken wire across part of the run. i put the babies in a temp coop (rabbit hutch). they stayed like that for a couple of weeks. then i cut a little hole in the bottom of the chicken wire in a couple of spots so the little ones could pass through but the big ones couldn't. the little ones began venturing into the main run. whenever the big ones got too rough, they would run back into their own territory. they spent more & more time w/ the big ones. after about 3 wks i took the chicken wire down. then in about a week i put the babies in the coop after the big girls had gone up onto the roost. i stayed there for quite awhile to supervise. i did this for a couple of nights. then the babies started going in the coop themselves ( i had taken their temp coop away). they would huddle in a corner & raise heck. the big ones would watch from their roost, but made no attempt to go after them.
the past few nights the two young black aust got themselves up on the roost. the big ones made no effort to do anything about it. after two nights of this, the whole young pack are up on the roost with the big girls.