Ducks and Geese on a vernal pond

I pass this pond every morning on the way home from work. As you can see, it's not really a pond - just low areas in an former corn field that have filled w/ snow melt. Since last Friday, I've seen ducks paddling around here yet not on the natural ponds in the area. Maybe there are a few corn kernels that fell off during harvest last fall left around to eat. Could just be that these vernal ponds are shallow so much warmer than the natural ponds. Will watch to see which disappears first - the ducks or the pond.