I just adopted 3 new hens and my other hens and rooster are very mean to the new comers. They are constantly pecking them and keeping them in a corner. Will this behavior change? If so how soon? ( all chickens are the same age if that matters)
Well... It's too late now but you should have first quarentened them for a month so you wouldn't bring in disease or pests into your flock. As for intergration. Usually you want to put the chickens together where they can see each other for a week or so then let them out together. It will take two weeks or so to reach an equilibrium.
I am assuming you didnt' quarinteen them so lets move on. they are together, and will have to establish a NEW pecking order. From the sounds of it the new chicks are gonna be on the botttom of that order, the bullying should subside in a couple of days to a week. If it gets too rough i would reseperate and introduce slowly so new ones have a chance to adjust to old chickens.(put in an adjoining cage for couple of days or longeer) Edited to add: are they the same size too?
Most are the same size. I do have 3 bantams but they seem to stay out of it. It's mostly my 3 ee's picking on the new 3 ee's. Do most chickens carry dieseases?