Chickens are very easily stressed and moving to a new home is one of the most stressful events a chicken can experience. Stress can have negative behavioral and physical manifestations in chickens, including, pecking, picking and bullying. When chickens of any age bully other chickens, the behavior must be interrupted and the bully, reformed. This is how I reformed a brooder bully, but the technique works with chickens of all ages.
There is a difference between establishing or maintaining one's place in the pecking order and true bullying. Enforcement of the social hierarchy with the occasional peck or nudge is to be expected, but repeated aggressive behavior causing injury is not. If feathers are being picked or blood is being drawn, the behavior should be stopped. Any time a chicken is injured, they must be physically separated from the other birds for their own protection until the wound is 100% healed. Failure to do so can result in cannibalism and death.
I had just bought three adorable, 6 week old Frizzle
chickens: Monica, Rachel and Phoebe, when conflict erupted in the brooder. Rachel, the red Frizzle, was mercilessly pecking at the other two chicks. Poor Phoebe took the brunt of Rachel's aggression and was often found cowering underneath Monica. I needed to find a solution to end to the pecking and help them become friends again. The breeder from whom we purchased the Frizzles assured me that Rachel had not been a bully prior to the move, so it was fair to deduce that stress from moving was the cause of her aggressive behavior. Cochin
Reforming a bully is fairly simple. I physically segregate the problem chicken from others, but allow the birds to be near one another so they can still see and hear each other without danger of further injury. The Frizzles were in a simple, cardboard box brooder, which was ideally suited to making a chick condo. To make the chick condo, I took a second large box and connected it to the first with duct tape. I then cut out a window in between the two boxes and secured window screening to the openings with a stapler. Hardware cloth could be used instead of window screening. Since the Frizzles were old enough to fly, I put some window screening on the top of the boxes to contain them.
Rachel clearly wanted to get back to her brooder buddies and I feel awful about separating them, but it was necessary. In 4-5 days, the Frizzles were reunited without further incident. They have been inseparable ever since. If the separation is not successful in the first few days, a few more days in segregation should do the trick.