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Build a Wood Duck Box

The gorgeous wood duck is the only member of the "puddle" or surface-feeding ducks to nest in trees. Wood ducks prefer natural hollows in tree trunks or large branches close to or over water. They will nest a considerable distance away if suitable sites near water are lacking. The hole may be close to the ground or as high as 50 or 60 feet above it.

The female deposits 14 to 16 dull white eggs on wood chips found in the cavity. After egg laying has begun, she supplements the nest material with down pulled from her breast. Incubation requires 28 to 31 days. The male accompanies the female to the nesting site each day and waits nearby for her while she lays each egg. Soon after incubation begins, however, he loses interest and abandons her.

About 24 hours after the eggs hatch, the female leaves the nest hole and, from the ground or the water beneath the nest, begins to call softly to the ducklings. Within a few minutes, the young climb up to the hole and, with practically no hesitation, no matter how high the hole, jump out. Within a few minutes all are out and the female is leading them to water or, if the nest hole is over water, swimming with her brood to brushy or herbaceous cover.

Wood ducks nest throughout the United States and into southern Canada wherever nesting conditions are favorable. They are most numerous in the eastern half of the United States and along the West Coast. They winter throughout much of their breeding ground in the West and in the East from the southernmost parts southward to central Mexico and the West Indies. Northward migration may begin in mid-February.

As bottomlands are cleared and mature trees are cut, available holes for wood ducks become scarce. Biologists have known for years, however, that wood ducks will nest in artificial structures. Since the 1930s, the U.S. Fish & Wildlife Service and various state game departments have initiated nest-box programs that have demonstrated that wood duck numbers can be increased through the erection of properly constructed boxes.

Wooden boxes should be made of rough lumber, if possible; cypress, redwood, or cedar is good. Boxes should not be painted, but some woods may need to be treated with a preservative. Boxes should be approximately 12 inches square and 22 inches high. An oval hole of 3-1/2 x 4 inches will admit a wood duck and, at the same time, exclude some of the more troublesome predators.

If rough, unplaned lumber is used in construction, the young will be able to climb up to the exit hole to leave the nest. If finished lumber is used, a two- or three-inch-wide strip of hardware cloth should be attached to the inside front wall below the hole to provide a purchase for the fledglings when they leave the box. Be sure to cover or eliminate sharp wire edges on the hardware cloth. One side of the box should be hinged to allow easy access for cleaning and for nesting-material placement.

Completed boxes should be attached to a pole instead of a tree. Ideally, the pole should be made of metal or treated wood. "It is far easier for predators to get into a box attached to a tree than it is for them to get into a box on a pole," explains Robert Helm, a Louisiana Department of Wildlife & Fisheries waterfowl study leader. A metal predator shield should be placed around the pole to prevent snakes and raccoons from getting to the nest and feeding upon eggs. "Some places have so many snakes and raccoons that you end up raising predators and not ducks if you do not use predator guards," Helm says.

Placement of nesting boxes is dictated by the size of the body of water. The best rule is to ensure that no box is within sight of another. Dump-nesting, with more than one hen laying eggs in the same box, may result if boxes are placed too close to each other. "Birds become confused, and you end up with dozens of eggs in one box,'' says Helm, "Then ducklings don't hatch, and you have greatly reduced production." Boxes placed over water should be four to six feet above the high water mark; those over land should be 10 or more feet above ground level.

Boxes should be placed near wooded ponds, in areas with good brood habitat so hens will not have to march chicks long distances in search of wetlands. Beaver ponds, wooded sloughs, and swamps with dense, woody growth and numerous fallen logs and branches provide ideal habitat.

Boxes should be erected by late winter or early spring. Wood ducks begin searching for nest sites as early as February, but the peak of the nesting period is mid-March to mid-May. Boxes may be erected later in the year, however, so that they will be ready for next season.

You should fill the bottom of the box with three to six inches of wood shavings for nesting material. "When a hen leaves the nest, she covers the eggs with this material," says Helm. "Wood shavings remain fluffy, while small, granular material like sawdust tends to compact too much."

Once you have your box up, you should visit the site during the year to make sure it has survived the elements. Always make sure that the roof and door panel are intact, as these are vital to keeping the nesting material dry. Old nesting material should be replaced each year in midwinter. Boxes should be repaired at this time, also. Wood ducks prefer a dark cavity for nesting, and any cracks that admit light should be filled or covered. Predator baffles should also be checked and replaced if necessary.

Download the instructions for building the Wood Duck Box.