Thanks!
We actually have ducks visiting the pond even without using tame ducks to lure them in. We have had hooded mergansers out on the pond, but they are very spooky. We aren't going to shoot them or anything, but they are just very very spooky. On the other side of the pond's dam, there is a swampy area with a bunch of trees and we hear the ducks back in there calling. We are pretty sure they are sleeping back in there at night as we see them fly back there late in the day and hear their calls. I just can't get much of a glimpse of them, but luckily we do have ducks visiting!
The small island in the middle of the pond has a tree growing on it so that is neat. I am not sure if the ducks will perch in the tree once it is big, but I thought perhaps it would be a nice place for them to sleep. We are not at the pond a lot so they have lots of privacy.