They are so beautiful!!!!
I feed my free range ducks of a mix of unmedicated chick starter and uncooked dry rice.
Make sure they have plenty of water at all times. They will a lot of food on their own.
To tell males from females is easy.
The females will quack
The males sort of make a hissing rasping sound....much quieter.
I have Pekin ducks, but now I want some mallards after seeing you photos!