To the OP, do your chickens and ducks share a coop? While I have ducks, geese, and chickens that share orchard, creek, and pasture space, they do have their own coops. Ducks and nice dry coops don't exactly mix. The ducks shouldn't be allowed into the chicken coop, at least that's how i roll.
Oh, I am also in favor of getting rid of one of those drakes. I once had 16 duck hens, and 2 drakes. They killed a hen fighting over her, so the worst one lost his head. I absolutely don't tolerate drakes like that any more. My hens are of much higher value to me.