I know about that lethal gene cresteds carry. Never breed crested to crested. And some say not to breed crested to non-crested because the 50/50 babies will have the lethal gene and it's risky. Then... Where does the common white crested duck fall into this? Also! I have 13 ducks, 2 drakes and the rest hens. I have a white crested drake and a rouen drake, one crested hen, 6 rouen hens, and 4 runner hens. When the runners start to lay will the drakes start hopping on them? I may have to get rid of the rouen if so. I get could get pure rouens yeah, but the crested drake was one of my first ducks. Got him and the hen at 2 weeks old. I'm attached to them more than the rouens.