I have 5 Indian Runners, 4 ducks, 1 drake. My drake is chasing some of my bantam chicken girls around and this morning I caught him mounting one and trying to mate with her. I need to separate the ducks, but since they are currently free range, I'm wondering how much space do they need? I'm going to be moving them into their own coop, and fencing off part of the yard for them, but not sure how much space I should give them. Any ideas?