Have no idea what will happen but, it would be an interesting experiment. When two hens go broody together in the same place they tend to share the chicks and watch over them. I think you might have a problem if the duck hatches chick eggs and is trying to encourage them to go to a pond and swim. Likewise a chicken mother hatching duck eggs but, have a stroke when her "perceived" babies run into water. Hope you have a video cam to record all this.
I believe I read a book like that to my grandkids some years back
gander007
