Well, there is a thread going on here about quail that are sick b/c of being with chickens, but........ I have a very small barn, 20x24--12x 20 being used by horses the other 12x20 for my rabbits, chickens, ducks and quail who all share the same small space. Rabbits three high on one wall, quail three high on the other wall, with a common area for ducks and chickens. I have not had any problems.
someone will probably be along shortly to chastise me for keeping themm all together.