Is this hereditary? (Muscovy)

[princessmama]

I have a muscovy drake that is always soggy, when it rains or he goes for a swim (which he hardly ever does any more actually, he is also *finally* learning to get out of the rain if he's not looking for food or chasing the roo

). I first thought maybe his oil glands don't work correctly? Then I read that it's actually the structure of the feather that keeps the water out. Seems to me it would be both working together.

Anyway, my main question is, is this likely to be a hereditary trait? I'm guessing Yes.

Any thoughts?