I took a second trip around the Wildlife Drive at Montezuma NWR this day and was rewarded with a view of this duck family at Millenium Marsh.

Two of the ducklings are not Wood Ducks. I am guessing that they are Hooded Mergansers. Probably a Hoodie dropped some eggs in the Wood Duck's nest. Both Wood Ducks and Hooded Mergansers are cavity nesters.