I have a coop for my chickens and a tractor for the ducks. Tractors are better free-ranging, coops for when that is impractical. My chickens can not not free range due to dogs and chickenhawks, but I have a large run netted over with fishing net for them. The ducks don't free range regularly, but I only have a few so a tractor was easier to build for them and I do let them out into the lake occasionally.