The wood duck, Aix sponsa, is probably the most attractive waterfowl in North America. The only other species in this genus is an Asian species the Mandarin duck, Aix galericulata found in Japan and China. The male wood duck has an iridescent glossy green and purple head with a prominent crest at the rear, white throat, chestnut chest speckled with white, solid white stripes on the sides, a red and white bill and a red eye. Although these colorful markings are not present all year they do help attract females during the breeding season. By late summer male wood ducks molt and grow gray feathers with blue markings on the wings this is “eclipse plumage”.
The female has her own unique subtle look with a bright white teardrop patch completely surrounding her eye. Wood ducks have the largest eye of any duck. She also has a crest and a speckled chest.
Wood ducks are unique. Not only do they nest in tree cavities, but they are also perching ducks with highly developed toes and claws that allow them to grasp and perch on tree branches. Their young use their clawed feet to climb out of a nest that can be between 2 to 15 feet deep. They are about half the size of a mallard duck, 19 – 21 inches long, with a wingspan of 26 – 29 inches. They are uniquely equipped to fly through the woods with a broad wing, the broadest wing of any duck, for maneuvering, and a tail that is long and wide. They are strong fliers and can reach speeds up to 30 miles per hour. Their legs are near the center of their body aiding them in dabbling and tipping for food in a shallow pond or walking on the forest floor in search of seeds and acorns in the fall and winter.
Wood ducks can be observed bobbing their heads back and forth while flying or swimming, like a pigeon. They live in wooded swamps, marshes, beaver ponds and small lakes. As cavity nesters they take readily to nest boxes and are considered to be the most successful in adapting to artificial nest boxes. Hooded mergansers are also cavity nesters. They cannot make their own cavities and rely often on the cavities made by pileated woodpeckers. They prefer deciduous trees that hang over water or are close to a water source, though they will use cavities up to one mile from water.
Wood ducks are considered monogamous for a breeding season. The males, drakes, follow the females, hens, during the spring migration. The hen will often return to the natural cavity or nest box that she used the previous season and a juvenile hen will return to where she was hatched. This instinct is called philopatry. It is estimated that only about two-thirds of wood ducks will migrate to and from northern breeding grounds.
The clutch size is 6-16 eggs and they often have two broods per year. The incubation period is 28-37 days. A day after hatching the chicks climb out of the nest and do not return. The females tend to the young on the water for 5-6 weeks and they are capable of flying in 8-9 weeks. They eat aquatic plants, seeds, fruit, insects and other invertebrates. Plant material makes up 80% or more of their diet.
Common in wood ducks is what is called egg dumping. Females will lay eggs in the nest of other wood ducks and leave them to be raised by another female. She then might lay more eggs in her own nest cavity later in the season. There is a high mortality rate in wood ducks and there lifespan is 3-4 years.
Wood ducks were on the verge of extinction in the 19th century, but their recovery can be attributed to successful wildlife management including the implementation of the Migratory Bird Treaty Act 1918, the construction of nest boxes and the protection of high quality wetland habitat.
You can help and become part of this success story by building and monitoring wood duck nest boxes and encouraging the preservation and protection of wetland habitat.
Resources
Wildlife Fact Sheet – Wood Duck
https://portal.ct.gov/DEEP/Wildlife/Fact-Sheets/Wood-Duck
Cornell’s All About Birds – Wood Duck