Got 4 day-old chicks in April, when ready moved them to outside tractor and fenced yard inside my garden where my 3 4-year-old ladies spend their days. First surprise, my new beautiful black Americauna, Pandora quickly became Pan when he started crowning at three weeks. At 6 months, they were allowed into the garden. My older ladies spent alot of time in a overgrown patch of lemon balm, after a couple of months they accepted the fact that they were not the 'only' chickens in the entire world and they had a 'boy' in the yard. But after they all adjusted to each other or so it seemed, Pan started attacking Edda, a RIR, the dominant hen in the younger group and up till then his favorite lady and the other hens have followed Pan's behavior. To prevent injury, I keep Edda in the fenced yard inside the garden so they still see and interact with her but cannot do any harm and put her in the house at night after everyone has settled in, then remove her early in the morning. If anyone has any possible explanation for this behavior or a solution it would be greatly appreciated.