I didn’t think that I had captured a reasonably focused image of one of the ducks in the swamp, but this one is alright. The log in front of the duck is what is focused, so the duck is just beyond the focus zone. When I enlarged the photo, I figured out why the duck was out of focus: a dragonfly flew in front of it as the camera was focusing.
That actually looks like a duckling; here is a photo of the presumed parent:
I haven’t seen this type of duck before; the neck markings look like they should be diagnostic but I came up empty. Edited to add: finally figured it out; female wood duck.
Speaking of dragonflies, I managed to get one a little bit closer to the camera, too:
Apparently, my camera likes to focus on dragonflies—should keep some in a jar for difficult focus situations.