A friend of our has two pairs of ducks, one pair of Pekin and one pair of Black runners. He just (2 days ago) hatched some ducklings I am wanting to get one or some. He is not sure if the ducklings are pure bred or if they are mixed. His Pekin drake is quite dominate. I am wondering A) what will they look like if they are mixed? B) is it okay to just get 1 duckling and keep it with my chickens after it is fully grown or should I get 2?