Typically, adequate nesting cavities for wood ducks are somewhat limited, with a variety of natural and artificial cavities available. Naturally, wood ducks locate cavities in dead snags near or over water. They will invade cavities already created by birds such as pileated woodpecker for their nests. While natural wood duck nests are productive for producing healthy ducklings, the artificial nest cavity provides ducks with an ideal place to lay and set, with predator protection and easy fledgling exit. Man-made duck boxes are highly attractive to wood ducks, and few erected will be unused if properly placed and maintained effectively.
Even if un-maintained, hen wood ducks will lay and attempt to set on eggs in dilapidated nest cavities. In fact, a shabby duck box is still probably in better condition than most natural cavities. But fledglings will have a better survival rate if the predator guards on the pole and the exiting wire mesh on the inside of the box are both intact. Additionally, the old nesting material, shavings, and debris should be tossed and replaced with clean shavings to provide a conducive environment for incubating eggs.
Some wood ducks will begin nesting as early as late January in the Carolinas, and duck box rehabilitation can start anytime this month through the beginning of January.