We let ours out every now and then in the yard. They will fly very short distances but always come back. When they know where dinner is they will stay right there. The only problem is with their size they are easy pickings for predators.
I let mine all free range. When I first get them I cut the wing feathers so they can't fly and by the time they grow back they realize how good they have it and stick around. They do fly around in the yard once in awhile. Especially if they are running for some scratch the ones in the back will fly to the front. Or if the group breaks into a few small groups they will fly between the groups. I have never had one fly away.
Mine have free-ranged ever since they were 6 weeks old and were feathered enough to stay outdoors. They don't leave. They will fly around some but generally stay near the small pond and barn. They know where home is.
I wouldn't ever clip their wings, as size IS a problem with predators always on the look-out, and I feel better when they at least have some protection. My ducks free-range every day (expect when there is lots of snow on the ground) though predators have never bothered them yet. And we hope that this does not change.
Yes, I have 5 extra males that are out 24/7. At night they all go back down to the pond to sleep in the water. Then during the day they fly back up to the other pens.
The woman that I got my Call eggs from allows all 140 of hers to free range. In the morning she opens the barn doors and they fly to the 4 ponds that she has on her property. Before dusk, she whistles for them and they all fly back to the barn. She said in all the years she's done this she has only lost 2 Calls.
Wow! Thanks for all the responses. Great information. If I get some, I didn't want to clip their wings. I want them to be able to get away from my large male ducks if they try to breed them. I am still concerned about them flying into the dog's lot and getting eaten. That's what happened to several mallards I raised last year. I'll have to give it some more thought. Thanks everyone.