The white duck is also an Australian Spotted. We assume that the previously undescribed coloring was a recessive gene being expressed. Maybe a call trait.
We do lose a few to predators. In our area, we believe it is mostly bald eagles and a great horned owl, though we've lost many to raccoons too. To best protect them, we bring them into an enclosed area consisting of a wire run and geodesic dome surrounded by a large area of our yard enclosed in electric fence.
During the day, unless we have seen predators around, we let them out and they fly, walk, and swim wherever they want, ranging up to three miles from home. About half an hour before dusk starts, they start to trickle in in pairs and foursomes on their own.
We'd like to experiment with an automatic door, so we don't always have to be here to open and close the door for them. Despite these measures, we've steadily lost about one quarter of our flock.
With loss, however, we still would not give up our experience with these ducks. We know mallards, eiders, buffleheads, black ducks, and long-tailed ducks fairly well, and the Australian Spotted still beat them all by virtue of their lively and social personalities.
Thanks for the comments.
James