I have 2 runs and 2 flocks that free range together in a fenced yard when I'm home.
When I was out of town for a week, my DH took care of the chickens. The last night (I got home about 9 that evening) one of the older hens from the original flock and run got put in the run with the younger Orpingtons. Over night she was pecked pretty badly on the head and neck. There was a fair amount of blood in several places in the coop and she was a mess. I brought her in the house for the day and treated her (cleaned and blu-kote) and put her back with the hens in the original run that night after dark. No more problems, but having her trapped with the newer chickens made her a victim. She is quite alpha and the oldest of my hens.
Chickens hate change, and change can cause their behaviors to adapt. Little raptors they are.
When I was out of town for a week, my DH took care of the chickens. The last night (I got home about 9 that evening) one of the older hens from the original flock and run got put in the run with the younger Orpingtons. Over night she was pecked pretty badly on the head and neck. There was a fair amount of blood in several places in the coop and she was a mess. I brought her in the house for the day and treated her (cleaned and blu-kote) and put her back with the hens in the original run that night after dark. No more problems, but having her trapped with the newer chickens made her a victim. She is quite alpha and the oldest of my hens.
Chickens hate change, and change can cause their behaviors to adapt. Little raptors they are.