I have a year old male Ruen duck, all females have been killed by predators. I'd like to add three female Ruens ducklings to my duck flock, but I'm not sure how well the drake will accept them. What age is a good to put them in the coop and run with the drake ? What issues are there to consider? My other option is to butcher the drake and add a new male duckling with the females so they will all grow up together. Any advice ?-Thanks