Wood ducks and a handful of other species of waterfowl are cavity nesters. Buffleheads, common goldeneyes, common mergansers and hooded mergansers are other duck species that nest in tree cavities, too.

And what’s more, all these species of ducks will use artificial nesting boxes as well. But it’s the wood duck that has benefited the most from artificial nest boxes, also called “wood duck houses.”

Wood ducks were a species in trouble at the turn of the 20th century. Unregulated hunting and habitat loss were primary reasons for their population decline.

However, with timely legislation designed to protect migratory species, along with regulated hunting, habitat management, and the placement of nesting boxes throughout the birds’ breeding range, wood ducks are plentiful once again throughout the continent.

That said, the wood duck’s survival, let alone their recovery, would not be possible without adequate nesting and brooding habitat, which is thankfully abundant throughout much of Minnesota. To be sure, this is the case for any bird.

Yet for this specialized duck, the presence of water and trees is essential — be it flooded timber in the backwater areas of the Headwaters of the Mississippi River, the cottonwood-lined oxbows of the Red and Red Lake rivers, or the plentiful lakes and wetlands everywhere else in the state — wood ducks and other cavity nesting waterfowl flourish in these environments.

Wood ducks are just one of the many reasons why wildlife managers encourage private landowners not to cut down standing dead trees (snags), especially when located near wetlands in prime wood duck nesting habitat.

The best and most often used snags are large, usually over 15 feet tall and are at least six inches in diameter. After a mated pair of wood ducks has selected a suitable tree cavity or nest box, a hen will begin to lay her eggs, one per day.

Unlike what most other nest-building birds do, wood ducks don’t gather nesting material for their nests. Rather, they rely on wood chips and woody debris commonly found inside natural cavities, including soft feathers that the hen plucks from herself, for their nest bowls. This is why one needs to add wood chips or shavings to artificial nesting boxes.

The average clutch size is 10 to 12 eggs, but it can vary from six to 19. Curiously, wood ducks will often lay eggs in different cavities for other hens to incubate, a form of “brood parasitism,” as it’s called. For this reason, it is best to place wood duck nesting boxes out of sight from each other.

Some research indicates that boxes placed in plain view from one another encourage “dump nesting” amongst wood ducks.

After an incubation period of around a month, the ducklings hatch and spend about a day inside the tree cavity or wood duck house. Hen wood ducks and other species of cavity-nesting ducks will then call softly to her brood from the ground to encourage her ducklings to jump from the cavity’s entrance.

Motivated by their mother’s familiar voice, but also by their own hunger and thirst, the ducklings will, one by one, leap from their nest cavity to join their calling mother. As it usually goes, once all the ducklings have left the nest, the hen leads her brood to the relative safety of water, where they immediately begin searching for food.

It’s easy to imagine that ducklings tumbling a dozen or more feet through the air to the hard earth below would be injurious. Surprisingly, however, the ducklings have little to worry about.

Their fluffy, down-covered bodies help to cushion any blows they encounter on the way down. Even their webbed feet, with toes all spread out, act as miniature parachutes to slow their descent.

Indeed, at this moment, wood ducks and other cavity-nesting ducks are busy laying and incubating eggs inside the confines of natural tree cavities and artificial nest boxes.

The handsome wood duck that whistles instead of quacks, gulps down acorns, and can fly through woodlands with ease and perch on tree limbs, is just one of the many species of wonderful wild waterfowl to observe and appreciate as we get out and enjoy the great outdoors.