After reading all the potential problems that could arise, we were able to successfully bring a new rooster to our flock. I think it helped that he was the third rooster in the pecking order at his old home. He's a sweet, docile, and very well-mannered, 22 week BO. Our flock consists of 9, 14 week BO pullets. We wanted a rooster closer to their age, but he popped up, local, for free, and the owner had to get rid of two roosters asap. After his time in quarantine, we fenced off a section of the run for him to see but not touch. Every day, we let him out for a little while, supervised. The night before last, we let them all out to free range, while I was in the back yard. He watched over them, kept them together, and brought them all in at night. He was even very patient when they lightly pecked his big, red waddles. He put them in their place when they pecked too hard, but nothing overly aggressive. After two days with them, he appears well mannered, and has not tried to mount them, since they're a little young. We couldn't be happier with his transition to new flock leader. I know this is not always the case with roosters, but I wanted to let people know that with the right rooster, and integration method, it can work.
