Time to welcome back the wood duck
It's February. And while lakes and rivers and ponds remain locked in ice, the days are growing longer and winter is more than half over. Indeed, in about a month it will be springtime once again here in the Northland.
Birds will soon be migrating northward. In the prairie country, the harbinger of spring, the horned lark, will arrive first. Soon after, Canada geese, followed by other species of waterfowl, including one of the prettiest species of duck -- the wood duck.
The drake of this marvelous species of waterfowl is perhaps the most beautifully colored bird in North America. Here's an arboreal duck -- as odd as it seems -- that whistles instead of quacks, gulps down acorns with relish, and can fly through flooded timber or an upland forest with ease.
Wood ducks are cavity nesters -- that is, they routinely nest inside holes in trees. But they are not the only species of waterfowl to do so. Buffleheads, common goldeneyes, common mergansers, hooded mergansers and black-bellied whistling ducks are other species of North American waterfowl that nest in tree cavities, too.
And while some of these species of ducks will readily use artificial nest boxes for nesting, it's the wood duck that has benefited the most from these humanmade structures.
At the turn of the 20th century, wood ducks were a species in peril. Unregulated hunting and habitat loss were 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 have made a roaring comeback from those woeful times.
The wood duck's recovery, or mere existence for that matter, could never be possible without adequate nesting and brooding habitat. Indeed, this is the case for any bird. Nevertheless, for this specialized duck, the presence and abundance of trees is essential to their survival.
Wood ducks are just one of the reasons why wildlife managers encourage private landowners to leave dead trees (snags) standing, especially when located near wetlands in prime wood duck nesting habitat. In the Midwest, some 26 species of mammals and 43 species of birds use snags as nesting and perching sites. Snags are also used as food sources and for territorial reasons. The best and most often used snags are large, usually more than 15 feet tall and at least 6 inches in diameter.
After a mated pair of wood ducks has selected a suitable cavity, a hen will begin to lay her eggs, one per day. Wood ducks do not gather nesting material like many birds do to build a nest. Rather, they rely on wood chips and natural woody debris commonly found inside natural cavities 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 can vary from six to 19. I once monitored a nest box where a hen sat on 21 eggs. Curiously, wood ducks will often dump eggs into other cavities for other hens to incubate, a form of brood parasitism. For this reason, it is advised to place wood duck nesting boxes out of sight of one another. Some research indicates that boxes placed in plain view of one another encourage "dump nesting" amongst wood ducks.
After an incubation period of about a month, the ducklings hatch and leap from their nest cavity and either plop into a wetland or bounce on the ground below to join their calling mother. Once all the ducklings have left the nest, the hen will lead her brood to the relative safety of water where they will immediately begin searching for food.
One can easily imagine serious injury occurring to ducklings as they hurdle themselves from cavities high in trees. Surprisingly, the hatchlings have little to worry about. Their down-covered bodies help to cushion any blows they may encounter on the way down. Even their webbed feet, with toes all spread out, act as miniature parachutes to further aid in slowing their descent.
It won't be long and the "hoo-eek, hoo-eek" calls of hen woodies and the high-pitched whistles from drakes will be sounding from river-bottoms and wetlands everywhere. Conditions should be favorable for this year's annual return, too. Runoff from springtime snowmelt ought to fill up those low flowing rivers and dry basins.
If you have nest boxes on your property, now is the time to do a little "housecleaning" by performing any necessary repairs, adding wood shavings or just sprucing them up. The ice is still safe to walk on, sleds filled with gear pull easily on the snow, and the wood ducks are about a month away from returning.
Moreover, there's also plenty of time to construct and install a few nest boxes on your property or on the property of someone you know. Aside from providing this species of duck with much-needed nesting cavities, the activity is great fun. Ice-covered lakes and wetlands offer easier walking to perform nest box activities.
More than 100,000 wood ducks breed in Minnesota each spring. Thanks to significant strides in conservation biology and wildlife management, wood ducks are plentiful once again. And what a good thing it is. The beautiful duck that perches in trees and nests in trees and feeds in trees will be arriving soon as we get out and enjoy the great outdoors.
BLANE KLEMEK is a Minnesota DNR wildlife manager. He can be reached at firstname.lastname@example.org