First the duck flew up to the entrance of the nest box. This is the same box that has had a red morph Eastern Screech-Owl in it for the past week or so. I wasn't able to see if it was still inside, but as we'll see in a moment, I'm guessing maybe it was.
Most of the time the duck clung to the front of the box below the entrance hole, looking in.
Finally she poked her head entirely in the box to check it out.
A second later she fluttered down, leaving a big wet belly mark on the nest box. I saw her do this routine twice, but she never seemed to go totally inside the box, making me suspect that our owl friend may have already been in there. At one point I thought I saw the owl face in the box entrance hole, but it was too quick and through my binoculars so not a great look.
There were at least 8 Wood Ducks at the marsh this morning, and there are at least 3 other duck boxes there, so it will be interesting to see how the Wood Duck breeding season goes.