As well as having one of the most colorful plumages among North American waterfowl, Wood ducks (Aix sponsa) are notable for their unusual nesting habits, which set them apart from other duck species living in the United States.
Our guide below takes an in-depth look at the topic of wood duck nesting habits, so read on to learn more!
Wood ducks do not build traditional waterside nests, instead favoring hollows in tree trunks several feet off the ground. If no suitable tree cavity can be found, they will happily lay their eggs in an artificial nest box.
To learn more about wood duck nest site selection, what time of year they breed, and how many broods per year a wood duck pair raises, please keep reading as our Wood Duck nesting guide aims to answer these questions and more.
Wood Ducks frequently use artificial nest boxes to raise their young
Wood ducks are cavity nesters and seek out hollows in tree trunks or artificial nest boxes that are purpose-built to offer a safe space in which they can safely hatch their eggs.
Once a wood duck has found a successful nesting site, they may use the same spot to raise future broods in subsequent years, even with a different mate.
If your backyard has a mature tree with a suitable hollow that has clear, easy access for birds to fly into, and is close to wetlands then, in theory, it is not impossible to attract nesting wood ducks.
However, ducks are generally quite reclusive during their nesting period so it’s unlikely that they will choose a site that is frequently disturbed by human activity.
Wood Duck ducklings inside of a nest cavity with unhatched eggs
Where there is a lack of natural hollows, wood ducks will not hesitate to turn to an artificial nest box as a readymade space in which to raise their young.
Nest boxes specifically designed for wood ducks often consist of a deep wooden container with a wide, circular entrance hole and a sloping roof on which adult birds can rest or perch before entering the chamber.
Nest boxes with a clear flight path to the entrance hole and positioned over water can be highly successful at attracting nesting wood ducks. They should be placed on metal poles at a height of between 1.2 to 1.8 m (4 and 6 ft).
Wood ducks seek trees with deep hollows, either in upland forests less than a mile from water or in flooded woodlands. Mature trees are favored, particularly those where broken branches have led to the formation of natural cavities.
Trees commonly used by nesting wood ducks include oak, maple, ash, aspen, sycamore, beech, bald cypress, tupelo, and black gum.
Nest sites used by wood ducks can be anywhere between 0.6 and 17.3 m (2 to 56.8 ft) off the ground. Higher sites are preferred, with the average nest cavity at a height of 7.6 m (25 ft).
Where artificial nest boxes are used, mounting heights of between 1.2 and 1.8 m (4 and 6 ft) are typical.
A breeding pair of Wood Ducks preparing the overwater nest box
Wood ducks do not excavate their own nests, and will make use of naturally occurring holes in tree trunks or hollows that have been excavated by woodpeckers.
The female prepares the base of the nest chamber, lining it with feathers plucked from her breast, before laying her eggs on top.
Nest cavities that wood ducks choose to occupy are, on average, around 58 cm (23 in) in depth but can be much larger, up to 4.5 m (14.7ft). Smaller openings of up to around 13 cm (5.1 in) seem to be favored in preference to nest cavities with larger entrances.
Wood Duck nest box above a natural nesting cavity
Wood duck pairs form early, in early fall, with the male defending his mate through the winter, ahead of breeding the following spring. Birds that migrate arrive at their spring breeding grounds together.
In spring, a nest site is chosen, and laying of the first clutch varies depending on geographical location. This can be as early as January in southern parts of their range, but more usually from February to April.
Incubation is undertaken by the female wood duck alone, and lasts on average for 30 days, although hatching has been known as early as 25 days to as late as 37 days. Ducklings are born in a precocial state (fully developed with feathers) and leave the nest within 24 hours.
Wood ducks typically lay their first clutch of eggs in late February to April, although in the warmest parts of their range, laying can occasionally start in late January. If a second brood is attempted, this usually happens around May.
Wood Duck usually start laying their eggs from late February
Rather than building their own nests, wood ducks will search for existing cavities in trees in which to lay their eggs. These may be naturally occurring holes formed by broken branches and decaying trunks.
Alternatively, a hollow excavated by a woodpecker and, since abandoned, may also serve the purpose. Females line the nest cavity with their own feathers and soft grasses and continue to do so while laying takes place.
Wood ducks commonly turn to artificial nest boxes during the breeding season, especially in regions where the landscape does not support many naturally occurring tree cavities.
Both artificial nest boxes and hollows in trees are lined with soft materials such as down and feathers before laying begins.
Females and males set out together to select a nest site, although males take no active role, while the female examines cavities before giving a site her ultimate approval. Lining of the nest in the days leading up to eggs hatching is the sole responsibility of the female.
Male Wood Duck seeking out a nesting cavity
Wood duck eggs are the perfect example of a ‘duck egg’ shape, elliptical and smooth, and around 5cm (2 in) in length. They are mostly a glossy white, but darker tan-colored eggs are frequently laid.
Wood ducks are notorious for raising large broods, with anything from 6 to 16 eggs considered normal.
In addition, the species regularly engages in a practice known as ‘egg dumping’, in which female wood ducks lay extra eggs in nests that are already in use to form vast clutches of up to 40 eggs.
This is thought to be a species survival adaptation, maximizing the chances of successful hatching by laying eggs in different nests.
Male wood ducks do not help to incubate eggs, and once the female has laid her clutch, the male’s involvement begins to decline. During the incubation period, males remain a vigilant presence near the nest site, protecting their mate and unhatched eggs.
As time passes, the male wood duck will disappear off the scene, and head to a molting ground where he assumes an ‘eclipse’ plumage, shedding his bright feathers that are no longer needed at the end of the breeding season.
Females care for young ducklings alone for up to 10 weeks until they gain independence.
A large clutch of Wood Duck eggs inside of a nesting box
Wood duck ducklings are born in a precocial state and are ready to begin foraging and swimming within 24 hours of hatching.
Nest cavities are generally at a significant height off the ground, and chicks must leave the safety of the nest chamber to begin their lives in the outside world, by taking a death-defying plunge to the ground or water below.
Wood ducks are unusual among North American duck breeds as they frequently raise two broods in a season. The first brood is laid between late January and April, while the timing of a second brood, if attempted, is generally May to June.
Wood Duck chick leaving the nest cavity, whilst the others watch
Wood duck nest boxes should be positioned around 1.2 to 1.8 m (4 to 6 ft) above ground level, mounted on a standalone metal or wooden pole.
It’s recommended to space nest boxes at least 300 ft apart and not within sight of any other wood duck nest boxes or natural nest sites. Sites that overlook water should be chosen where possible, with a clear flight path to the entrance hole.
The entrance to a wood duck nest box should face to the south or west, and also be positioned so it faces over water, which helps young birds to find their bearings when they leave the cavity and embark on their initial journey to their first foraging waters.
A predator guard can be fitted to the pole beneath a wood duck nest box, which helps to deter raccoons, snakes and other potential nest raiders.
One of the reasons it’s preferable to mount a nest box on a pole instead of a tree trunk is the ability to limit unwanted access to the nest box and protect any eggs inside.
Nest box maintenance should be carried out annually, and is recommended to take place towards the end of winter, in January, ahead of the new breeding season.
Cleaning a box immediately after young have fledged (e.g. shortly after the day after hatching) is also suggested if it’s likely that the box will be used by a wood duck pair to raise a second brood.
Wood Duck box, with predator guard below
In extreme circumstances, or where their nest has been targeted by a predator, wood ducks may abandon their nest and give up hope of any eggs surviving.
Survival instinct is strong in the species, and many female wood ducks engage in ‘egg dumping’ – laying their own eggs with another clutch already laid by a different female.
Wood ducks rarely nest on the ground, with the lowest heights of nest sites recorded at around 0.6 m (2 ft). Some cavities in bases of trees may occasionally be used; however, these carry a greater risk of predation by land mammals and reptiles.
During the breeding season, female wood ducks remain in their cavity until their eggs have hatched. Males usually sleep on water, and outside of the breeding season, males, females and juvenile Wood Ducks may roost on waterside logs or low branches of wetland vegetation.
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