Oh my gosh,
I had to laugh when I read that. You won't get fertile eggs from that pairing. I don't know if it's normal, but I have a Muskovy drake that (until I clipped BOTH wings) kept flying the fence to fight with the roosters and try to breed with the hens. He wants nothing to do with the ducks, just the chickens. I tell everyone he has an identity crisis. Is he hurting the ducks or just being a pain?
Re-read my post and wanted to clarify--not laughing at you wondering about mixed chicks, laughing because you have a roo in love with ducks and I have a drake in love with chickens.