cockerel being spiteful

Hi i've bought Kevin , my Pekin Frizzle a couple of new wives. Amixed banty from a friend and a Silkie from a show. They are in quarantine at the minute where Kevin and Jenny can see them. However trying to sort it out this morning Kevin got into the new girls and tried to attack them He's so good normally, is he just being territorial over his run, that i've split in 2? Ungrateful little b****r :blink: