raising ducks protected from predators

just wondering if anyone has raised ducks in an enclosure that is completely predator proof. I love baked duck, mandarin duck, duck soup, bar-b-que duck, smoked duck, but don't have any critters because there is so much pressure from predators here, coyotes, raptors, feral cats and dogs, bobcats and even a family of black bears were spotted less than 1/2 mile away a few weeks ago.
I have been thinking of making an A frame  about 6-8 ft wide and 10 or 12ft long  maybe 4' tall at the peak out of large straight branches with corrugated tin for the top and hardware cloth on the ends and hardware cloth floor, built on a couple cedar logs. Is that enough space for some ducks.

I think that depends on how many 'some' is, to you. If, like us, you are ordering from TSC, you're kinda stuck with their minimum. Even at the smaller end, 6x10 should be plenty of room for 10, especially if they'll also have space outdoors. We're noticing they pretty much clump together, so far - so for Pekins, anyway, that size would probably be more than sufficient, even for 20, as long as they have plenty of time & space to roam, outdoors.