Rowly,
Have you ever thought about wild waterfowl. I keep several species of waterfowl in my pond ie. Wood Ducks, Mallards, Pintail, all of the North American teal (Bluewing, Cinnamon and Greenwing). It is pretty cool to have these birds around and the wild ones visit often. Just this morning I had two wild Wood Duck drakes feeding with mine.
These birds are very hardy and a permit is supplied with the purchase. By the way all of my birds (except the Mallards) are pinioned so they can't fly. Let me know if you are interested I have a few newly hatched Wood Ducks and Mandarins (Chinese Wood Ducks) that are beautiful. These birds give the pond a natural look and I get a lot of compliments.