I have never lived in a situation where I felt confident about letting my birds free range. That said, they are very watchful and alert and quick to respond to something that startles them. I don't think it would be a good idea to leave them free ranging. Supervised though, would be fine. You can train them to come when you want them to with a can of scratch grains or something like that. Put it in an empty metal coffee can and shake it so they can hear it and call them. It would need to be something they don't get all the time. Maybe some Black Oil Sunflower Seeds (BOSS) and then toss them in the litter in their coop, or wherever you want them to go to.