Wood Duck Basics
familiar call of the wood duck is a sure sign that spring has arrived, but
where will the wood duck find a home this year?
Wood ducks can be found in southern
Canada and the northwestern and eastern parts of the United States near wooded
swamps, ponds, and rivers. They are cavity dwellers and are not capable of
creating cavities of their own. Therefore, they are totally reliant on cavities
made by other birds, Mother Nature or man. Because they are large birds, wood
ducks often have difficulties finding natural cavities large enough for the
mother and the brood. A great source of housing for these ducks is man-made wood
At the start of spring, female wood ducks have found their
mates and have begun to look for a nesting site. Wood ducks may have up to two
broods each year from April through June. The female begins the search and will
settle in the most suitable site. She will be looking for a nest box mounted 5 –
20 feet high in a pole or a tree no farther than 200 feet to the water. It is
best to mount the box as near to the water as possible. To make her and her
brood more comfortable add approximately 3” of woodchips in the bottom of the
box. After laying her clutch of about 14 eggs, she will pull some of her own
down feathers to soften the bed for her little ones.
The eggs will incubate for 30 days.
One day after they hatch, the mother will call to them from outside the box. The
fledglings will obediently follow their mother’s voice. They will climb up the
inside wall of the box to exit through the hole. It is imperative to provide a
“ladder” by horizontally scoring the inside surface of the box from the bottom
of the house to the hole or by stapling a 5”-6” wide wire-cloth in the same
location. After making the climb, they will fall to the ground unharmed and
follow their mother to water. The trip from the box to the water is the perfect
time for raccoons, hawks or snakes to pounce. It is best to keep the distance
from the box to the water as short as possible. Mounting the box above water is
Wood ducks nest in woodland areas along lakes, rivers, and
vegetated wetland areas. During the winter months, wood ducks inhabit bottomland
hardwood wetlands, beaver ponds and flowages, river oxbows, meanders and
backwaters, and other inland freshwater forested wetland areas. Habitat areas
chosen by wood ducks are commonly used by other waterfowl species such as black
ducks, hooded mergansers, and ring-necked ducks. High-quality wood duck habitat
is intricately linked to preservation and management of old growth timber along
river corridors and availability of nesting sites. Although wood duck
populations have recovered, the largest threat to their future is the continued
loss of habitat. By protecting and restoring floodplain timber, river oxbows and
meanders, and other freshwater wetland and riparian habitats, landowners can
assist in the continued success of wood ducks and other migratory waterfowl
species that rely on similar habitats.
Food for young birds and adults differs dramatically. The
early diet of ducklings consists largely of insects, aquatic invertebrates,
small fish, and other high-protein animal material. After six weeks of age, the
young switch to plant foods until their diet consists of approximately 90
percent vegetative material, primarily aquatic plants such as algae, watermeal,
watershield, sago pondweed, and duckweed. Adult wood ducks feed on a variety of
nuts and fruits, aquatic plants and seeds, and aquatic insects and other
invertebrates. Insects and aquatic invertebrates are particularly important food
items of adult hens during egg laying in spring. Acorns and other forest mast
are important fall and winter foods. While acorns are the primary winter foods,
the seeds of bald cypress, hickory, sweet gum, buttonbush, arrow-arum, bur-reed,
and wild rice are also common winter foods. Wood ducks feed primarily in shallow
water areas, but will also forage on the forest floor for seeds, acorns, and
Important wood duck food plants. The following species are known to be important food items
in the diet of wood ducks.
oak (acorns), hickory (nuts),
elm, bald cypress, beech (nuts), sweet gum, ash, button bush, maple, blackgum,
rice cutgrass, row-arum, wild rice, sedge, smartweeds, nightshade, cowlily,
beggarticks, duckweed, grape, panic grasses, bulrush, pondweed, watershield,
waterlily, bur-reed, barnyard grass and St.John's-wort.
These species may be used to enhance vegetation which already exists in and around woodland areas and aquatic habitats. Adding these species to those currently existing will enhance food availability for wood ducks.
Cover - Nesting
|Wood ducks nest in natural tree cavities and in some cases, those
excavated and abandoned by woodpeckers. Nesting boxes are also readily
accepted for nesting. Nesting pairs typically select cavities in deciduous
woodland areas in close proximity to rivers, wetlands, and other suitable
aquatic habitats used for brood rearing. Cavities located 30 feet or more
above the ground are preferred, but the height can vary from near ground
level to 65 feet. Suitable natural cavity dimensions typically have an
entrance hole diameter of at least 4 inches, an inside diameter of
approximately 6 to 8 inches, and a depth of at least 24 inches. Optimal
nesting habitat contains up to five suitable cavities per acre in close
proximity to brood-rearing habitat; however, since most natural cavities
are not suitable for use by nesting wood ducks, these conditions
frequently require that 50 or 60 natural cavities per acre exist. This
illustrates the utility of providing suitable artificial nesting boxes to
augment the availability of natural cavities.
Cover - Brood Rearing
Wood duck broods require shallow water for foraging on invertebrates and
aquatic plants that contain some protective cover from predators. A ratio of 50
to 75 percent cover to 25 to 50 percent open water is preferred as brood-rearing
(and breeding) habitat. Cover may be provided by trees or shrubs overhanging the
water, flooded woody vegetation and debris, and herbaceous emergent vegetation.
Ideal shrub cover is provided by mature shrubs that provide a dense canopy about
two feet above the water surface. Button bush is an important shrub species in a
large portion of the wood duck's range due to its brushy growth form, providing
brood cover, and its prolific seed production, used heavily by foraging adults.
Reliance on permanent, deeper water bodies for brood habitat should be avoided
to minimize duckling mortality from aquatic predators such as snapping turtles
and large fish.
Adult molting cover requirements are generally met by suitable brood-rearing
habitat. Permanent water, cover, and food are the key elements of molting
Cover - Winter
|In areas where wood ducks winter, areas similar to brood rearing
habitat provide adequate winter cover. Bottomland hardwood wetlands and
quiet river backwaters and streams with an abundance of partially
submerged downed timber, shrubs, and woody debris are favored.
Winter-persistent herbaceous emergent vegetation that has a shrubby-like
life form (e.g., cattail, soft rush, bulrush, bur-reed, etc.) may also
provide adequate winter cover. Security provided by overhead woody cover
is the key element of good wood duck roosting habitat.
Water requirements for wood ducks are assumed to be met where suitable
brood-rearing and wintering habitat exist.
Interspersion of Habitat Components
In order for successful wood duck reproduction and survival to occur, all the
habitat components must be available in relative proximity to one another. Since
wood ducks are highly mobile during winter, the most critical aspect of habitat
interspersion, or the mix of different habitat types, is the proximity of
suitable brood-rearing habitat to nesting habitat in the spring. The
highest-quality nesting habitat is of little use if the nearest brood-rearing
habitat is more than a mile distant. Likewise, the best brood-rearing habitat
will not support wood duck broods if there is no nesting habitat in the
vicinity. In southern areas where wood ducks are year-round residents, the best
habitats consist of a complex of forested wetland habitats that include live
forest, green-tree reservoirs, rivers, oxbows, riparian corridors, beaver ponds,
shrub-scrub and robust emergent herbaceous wetlands.
Minimum Habitat Area
Since wood ducks are able to nest at some distance from brood-rearing
habitat, no reasonable estimate of minimum nesting habitat size exists. In
addition, no good estimates for minimum wintering habitat area are available due
to the high mobility of wintering birds. However, at least 10 acres of wetland
or other aquatic habitat in a contiguous unit, or in isolated parcels separated
by no more than 100 feet of upland, is needed in close proximity to nesting
habitat to support brood rearing. Lands outside the immediate planning area
should be considered when making the determination of minimum habitat area for
wood duck reproduction.
Nest Box Installation
Wood ducks are highly secretive in selecting nest sites to minimize impacts
of nest predators and competition from other wood ducks. Therefore, it is
important to locate individual nest boxes in relatively secluded areas within
timber stands where natural cavities would occur naturally. Nest boxes can be
placed either on land or over the water. If located over the water, they should
be placed at least 4 feet above the high water level and the entrance hole
should face the open water rather than the shoreline. Because of ease of access
by predators, installation of nest boxes directly on trees should be avoided.
Nest boxes placed on land should be located from 30 to 150 feet away from the
shoreline. Boxes placed directly on the shoreline appear to be more likely
frequented by nest predators. Since the hen must lead her ducklings to water
soon after they hatch, the area between the nest box and the water's edge should
be free of any major obstacles such as roads or fencing. Nest boxes placed on
poles over water are generally more easy to monitor than those placed in trees.
Regardless of whether the box is placed over the water or land, the entrance
should be clear of obstructions to provide easy access for the ducks.
In order to maximize nest box use while minimizing nest
dumping, it is generally recommended that nest boxes should be placed at
least 600 feet apart and should not be visible to one another. When placing nest
boxes in isolated locations, consider ease of access for monitoring purposes.