we have almost all Rouen ducks and 26 acres - they roam farther than I would like - often times across the street, so we have to constantly keep an eye on them and herd them back towards the pastures and paddock areas. They have plenty of food & water, a paddock area with kiddie pools and their barn, plus a pond but seem to love to free range. Might be the breed, but we also have a couple Blue Swedish, a Cayaga and they are roamers too! They are trained to come back in at 5 for locking up at night though - I just call them all and they come running up, and go in the barn. They may go in at dusk on their own, but I haven't been brave enough to test that as I don't want to have to hunt for ducks in low light. It would break my heart worrying if one or two were left out unsafe.