In the early 1900s, wood ducks (Aix sponsa) nearly became extinct due to unregulated market hunting for their meat and feathers, and also due to destruction of nesting and brood habitat. But thanks to the passage of the Migratory Bird Treaty Act in 1918 and the discovery of the wood duck nest box, the wood duck is now one of Mississippi’s most abundant duck species. In fact, Mississippi has one of the densest populations of breeding wood ducks in North America.
To many people, the drake woody is one of the most beautiful ducks in North America. Wood ducks are small ducks, weighing from 1.0 to 1.5 pounds each. The male has beautiful long green feathers on its crest, a large bright red eye and a short red bill with a black tip. The feathers of the wings and body are composed of a variety of colors and patterns. The female is predominantly a dull gray color, with a characteristic tear-shaped white streak around the eye.
Woodies can be observed in a variety of habitats but prefer wooded sloughs, creeks and beaver swamps. Their small size, broad wings and tail make them quite adept at twisting and winding as they fly through the trees. Mississippi is fortunate in that many of the state’s wood ducks are non-migratory and live here throughout the year.
Wood ducks are cavity nesting birds – hens naturally nest in the cavities of trees. A hen and a drake will “pair off” on the wintering grounds to breed. In Mississippi, hens have been observed initiating nests as early as the second week of January; however, most nesting begins in March and April. Weather has a great influence on when nesting begins in the spring and how late hens will continue to nest in the summer. During a cool summer hens will nest into July and early August. The nesting peak in Mississippi is typically in May.
A hen will find a suitable nest cavity in a tree or nest box. The hen will dig a shallow depression in the bottom sawdust and will lay one egg per day until she has laid approximately 12 to15 eggs. She will not begin to incubate the eggs until her entire clutch is laid. Once the clutch has been laid, the hen will sit on the nest for 28 to 30 days, leaving only for a short time each morning and evening to feed. While she is gone, the hen covers the eggs with down feathers plucked from her breast. Once the eggs hatch, the hen leaves the nest and softly calls her ducklings out of the nest from the ground or water below.
The incubation period is especially stressful for hens. Predators destroy many nests and hens at this time. Raccoons, bobcats, snakes and woodpeckers are particularly troublesome to ducks nesting in Mississippi. Dump nesting (when more than one hen contributes eggs to a nest) causes many nests to fail. Dump nesting is a natural occurrence, but occurs more often in nest boxes, probably due to their high visibility.
Because of the large numbers of eggs in a dump nest, some eggs do not receive sufficient heat for incubation. Few hens will tolerate intrusion by another hen and will subsequently abandon their nest. However, some dump nests do successfully hatch and can provide extra ducklings to the population.
“One of the greatest success stories in wildlife management has been the restoration of wood duck populations through the use of artificial nest boxes,” said Rob Ballinger, Field Biologist with the Mississippi Fish and Wildlife Foundation. “Fortunately, the woody was rescued by regulations limiting harvest and the discovery in the 1950s by Dr. Frank Bellrose of the Illinois Natural History Survey that wood ducks would nest in artificial cavities.”
“The Mississippi Fish and Wildlife Foundation has provided over 1,000 wood duck boxes on public and private land and the number is steadily increasing,” continued Ballinger. “These boxes produce thousands of ducklings each year. The Foundation has worked with the Central Mississippi Correctional Facility to construct these boxes. Without the lumber contributions of Anderson-Tully Timber Company and Vaiden Timber Company, as well as the contributions by the Mississippi Department of Corrections, these valuable nesting boxes would not have been built.”
According to Ballinger, nest boxes have been constructed in many different forms and the type the Foundation finds easiest to maintain, and most aesthetically pleasing, are vertical wooden boxes.
Wood duck nest boxes, when properly placed and maintained, provide a safe, suitable nest site for wood ducks. However, when boxes are not properly placed or maintained, they are not suitable to raise off a clutch, and can become death traps to the hen! Unless nest boxes are safer from predation than natural cavities, they contribute little or nothing to benefit the birds. In fact, improperly placed and maintained nest boxes will experience less use, more nest failures and greater predation than natural cavities.
“The first consideration when placing a nest box is whether the habitat is suitable to support ducklings once they hatch. Two to four boxes per acre of wetland is plenty,” stated Ballinger.
All species of wildlife need four basic things from their habitat: food, water, shelter and space. Wood ducks need both plant and animal food. Animal food (such as insects and fish larvae) is especially important to hens for egg production and is particularly important to ducklings during their first 6 weeks of life. Other prime foods include duckweed and seeds from aquatic plants.
Overhanging woody vegetation from willows and buttonbush, or dense stands of emergent plants like water lotus and cattails, is particularly important to ducklings for escaping predators. All of these habitat components must be in sufficient amounts to meet the basic life requirements of the ducks.
Here are some important tips and observations that the Mississippi Fish and Wildlife Foundation has gathered over several years of checking and maintaining wood duck boxes:
1) Boxes should be erected two per pole, on a 10 foot 4x4 post, with a minimum 28" diameter conical metal predator guard nailed to the post about 1-2 feet below the boxes (2-3 feet of the post should be driven into the ground).
2) Boxes should be placed in shallow water (3 feet or less) in a site that can be reached easily by wading or by a small boat. Placing boxes in water greatly reduces predation by raccoons. It is important to place the boxes in an area that can be easily accessed to facilitate annual maintenance. Be sure to keep any overhanging limbs and emergent vegetation trimmed back at least 5 feet from the boxes and post to prevent snakes and raccoons from entering the boxes.
3) Nest boxes must be maintained on an annual basis. This is best done during the winter months when water levels are highest (easier to float a boat), vegetation is knocked down (won't clog the outboard or snag the paddle) and the wasps and snakes are hibernating.
4) Boxes need a 4 to 5" layer of fresh wood shavings, sawdust or wood chips placed in them each year prior to the nesting season. WOOD DUCKS WILL NOT NEST IN A BOX WITHOUT NESTING MATERIAL!
5) This is also a good time to make sure that the predator guard is securely fastened to the post. Winter storms have a habit of shaking things loose.
6) Also, check the condition of the lid, the bottom and the door. Sometimes a couple of nails will hold a box together to get another 2-3 years nesting. Replace lids and bottoms that are rotted or split.
The Mississippi Fish and Wildlife Foundation has wood duck nest boxes, predator guards and bluebird/prothonotary warbler boxes available to interested landowners. A donation is requested.
If you are interested in obtaining nest boxes or technical assistance pertaining
to wood duck nest box management, please contact Rob Ballinger, Mississippi
Fish and Wildlife Foundation Field Biologist at (662) 686-3375.