I had to put my ducks and geese into my chicken house this spring as they had outgrown their brooder boxes in my house. I have an 18' x 16' chicken house that is divided up into rooms and pens.
Pros; I got them out of my house. They had a lot more room in their pen. They kept the other chickens, housed in that part of the building, entertained.
Cons; Ducks need lots of water. Even with a tray made to go under a hot water tank with a hose draining outside the building, there is still a lot of wet shavings and this can and will get into other pens. I was emptying pens every other day, top dressing did not work. And this just their drinking water.
My building is heavily insulated. I had a problem with moisture and I ended up having to treat my meat birds with an antibiotic because they got sick. Even with windows open.
If it is just the run they will share and there is no signs of aggression between them, you may be able to do this. I also want to tell you that I have read on BYC that some people have lost their chickens because the ducks hurt them or drowned them. It would be something you'd have to watch closely. My ducks and geese have shown some territorial aggression towards my chickens while they are ranging and a couple of times I had to step in because it was developing into more than a quick grabbing of feathers. Maybe you could put up a divider between them in the run. They could still se each other but not be able to get at each other. That way you wouldn't have to worry while you were gone.
