Wood Duck

Wood Ducks nest in tree cavities — natural hollows formed where branches have broken off and the heartwood has rotted — in large trees typically over 30 cm in diameter. Cavity openings as small as 10 cm are preferred, as they exclude larger predators. Nest heights range from less than a metre to 18 metres above the ground, and sites can be up to 1.2 miles (2 km) from water. The female makes the final cavity selection after the pair searches together during early morning flights. She lines the nest with down feathers plucked from her own breast.

Breeding begins in February–March in the south and mid-March to mid-April in northern areas. Clutch size is typically 9–14 eggs (range 6–16), glossy creamy-white to tan in colour and elliptical in shape (approximately 5 × 3.8 cm). Incubation is by the female alone for 28–37 days. Intraspecific brood parasitism is exceptionally common: females regularly lay eggs in neighbouring nests, sometimes producing clutches of 20–30 or more eggs that are too large to incubate successfully. The proliferation of conspicuous artificial nest boxes is thought to have amplified this behaviour by making cavities easier to locate.

Ducklings hatch alert and fully downy. On the morning after hatching — before they have eaten or drunk anything — the female calls from below and the ducklings climb to the cavity entrance using their sharp claws and leap to the ground or water. They survive falls of up to 15 metres unharmed, cushioned by their light weight and the elasticity of their downy bodies. The female leads them to water but does not physically assist them. Young are tended by the female for 5–6 weeks and can fly at approximately 8–9 weeks (56–70 days).

The Wood Duck is the only North American duck that regularly produces two broods per year. Second broods are most common in the southern parts of the range, where the breeding season is long enough to allow a female to raise a second clutch after successfully fledging the first. Nest boxes — predator-proofed with metal baffles on the supporting pole — have been a critical tool in supporting breeding populations where natural cavities are scarce.

The typical wild lifespan of a Wood Duck is 3–4 years, though this average is heavily skewed by high first-year mortality. Many ducklings do not survive their first autumn, falling prey to predators, starvation, or the hazards of migration. Adults that survive their first year have a considerably better outlook, and birds that reach breeding age often live for 5–8 years in the wild.

The maximum recorded lifespan is 22 years and 6 months — a male banded in Oregon and recovered in California, logged in the Cornell Lab / Patuxent Wildlife Research Center banding records. This is exceptional; most Wood Ducks live a fraction of this. The gap between typical and maximum lifespan reflects the high predation pressure on young birds and the cumulative risks of annual migration, hunting, and nest predation.

Key mortality factors include predation (raccoons, mink, foxes, and large raptors take both adults and ducklings), regulated hunting (approximately 976,325 birds harvested annually in the US), and nest failure due to brood parasitism and predation of eggs. Females face additional mortality risks during incubation, when they are confined to the nest cavity and vulnerable to predators that locate the site. Compared to longer-lived waterfowl such as the Whooper Swan, which can reach 26 years, Wood Ducks are relatively short-lived — but their capacity to raise two broods per year compensates for this with a higher reproductive rate.

The Wood Duck's conservation story is one of the most dramatic recoveries in North American wildlife history. By the late 19th century, the species had been brought to the brink of extinction by two simultaneous pressures: the wholesale destruction of bottomland hardwood forests through logging and wetland drainage, and intensive market hunting for meat and feathers — the latter driven by demand from the European ladies' hat trade. By around 1900, Wood Ducks had disappeared from large parts of their former range.

Recovery began with the Migratory Bird Treaty Act of 1918, which banned Wood Duck hunting nationwide — a prohibition that remained in force until 1941. The Duck Stamp Act (1934), the Pittman-Robertson Act (1937), and the North American Wetlands Conservation Act (1989) provided further legislative and financial support for habitat protection. A pivotal practical contribution came from Dr. Frank C. Bellrose at Chautauqua National Wildlife Refuge in Illinois, who pioneered the use of predator-resistant nest boxes in the 1930s. The nest box programme has since expanded to hundreds of thousands of boxes across North America, compensating for the shortage of natural cavities caused by the removal of large dead trees from managed forests.

Today the Wood Duck is listed as Least Concern by the IUCN, with an estimated population of approximately 4.6 million mature individuals (Partners in Flight 2019; Waterbird Population Estimates 2020). The USFWS estimates as many as 3 million breeding pairs across North America. Populations grew by 9–16% per year in the Mississippi Flyway and 7–9% per year in the Atlantic Flyway between 1959 and 1986. The Mississippi Flyway population continues to increase at approximately 1.5% per year. Wood Ducks are now the most harvested duck in the Atlantic Flyway and second only to Mallards in the Mississippi Flyway, with approximately 976,325 birds harvested annually in the US (2019–2022 average).

Ongoing threats include the continued degradation and loss of forested wetlands, a shortage of natural nesting cavities due to the removal of large dead trees from managed woodlands, and regulated hunting. Predator-proofing of nest boxes remains important, as raccoons, squirrels, and other predators readily exploit unprotected boxes.

The Wood Duck's near-extinction and subsequent recovery is one of the defining conservation narratives of 20th-century North America. By the 1890s, the combination of industrial-scale logging — which stripped the bottomland hardwood forests that Wood Ducks depend on — and unregulated market hunting had reduced the species to a remnant of its former numbers. Hunters shot Wood Ducks for their meat and their feathers, the latter destined for the European millinery trade. Contemporary accounts described the species as effectively gone from large parts of its range.

The first turning point came with the Migratory Bird Treaty Act of 1918, which placed Wood Ducks under federal protection and banned hunting entirely — a ban that remained in force for 23 years, until 1941. The Duck Stamp Act of 1934 created a dedicated funding stream for wetland acquisition and protection, and the Pittman-Robertson Act of 1937 directed excise taxes on hunting equipment into wildlife restoration. The North American Wetlands Conservation Act of 1989 extended this framework to international wetland protection.

The practical breakthrough came from Dr. Frank C. Bellrose, a wildlife biologist at Chautauqua National Wildlife Refuge in Illinois, who began installing artificial nest boxes in the 1930s to compensate for the loss of natural cavities. His work demonstrated that Wood Ducks would readily adopt boxes and that predator-resistant designs — mounted on poles with metal baffles — could dramatically increase nesting success. The programme spread across the continent, and today hundreds of thousands of nest boxes support Wood Duck populations in areas where large hollow trees are scarce.

The results have been extraordinary. Population surveys in the Mississippi Flyway recorded growth rates of 9–16% per year between 1959 and 1986. The species is now the most harvested duck in the Atlantic Flyway — a status that would have been unimaginable a century ago. The Wood Duck's recovery is frequently cited as evidence that targeted conservation intervention, backed by legislation and sustained over decades, can reverse even severe population declines.

Courtship begins in autumn and intensifies through winter, with most pairs forming on the wintering grounds by January. The male's displays are among the most elaborate of any North American duck. The wing-and-tail-flash — in which he rapidly raises his wings and spreads his tail to expose the full iridescent glory of his plumage — is the centrepiece of his repertoire. He also performs ritualized drinking (dipping and raising the bill repeatedly), exaggerated preening of his wing feathers, head-tilting to show off the crest pattern, and swimming past the female with wings and tail elevated in a slow, deliberate display posture.

Mutual preening between paired birds is common and serves to reinforce the pair bond. The male accompanies his visual displays with his thin, rising whistle — "ter-weeeee?" — which is audible mainly at close range and quite different from the female's louder calls. Females signal receptivity through a specific inciting posture, stretching the neck forward and tilting the head.

Once paired, the male follows the female closely and guards her against rival males. Pair bonds are maintained through the breeding season but dissolve after the female begins incubation, at which point the male departs to moult. Because the male follows the female to her breeding area rather than the reverse, his genetic contribution is spread across the female's natal population — a subtle but significant consequence of this unusual migration arrangement. Females that successfully raise a brood typically return to the same nesting area the following year, while males may pair with a different female and travel to an entirely different location.