The theory a lot of people seem to go with is that it's a diet thing because it doesn't appear to happen in wild ducks....but no one really knows what causes it....at least everything I read seen to say.
That's what I read too, it used to be thought genetic but then diet... I could agree with that, but...
What most breeders breed for doesn't happen in the wild either... especially Calls... so what if it's a genetic defect we caused in our strive for "Perfection"?
