by Kat Peterson
As birders, we search out extraordinary birds, whether that be a quick glimpse at a rare and elusive bird or to visually dissect beautiful plumage. The latter is just what is in store for us who are lucky enough to view a striking male Wood Duck (Aix sponsa). This small dabbling duck displays rainbow feathers that are contrasted with white lining the striking colors in drakes. Females and juveniles, are drab brown with a unique and petite body shape, a white eye ring, and spotted flanks. Young ducks’ diets consist of invertebrates and insects while adults eat mostly seeds of both aquatic and terrestrial plants. Unlike other ducks, their feet have claws that are able to grip and perch on branches. Each mating season the ducks will pair with a new mate and remain monogamous with that mate that year.
Wood Ducks, similar to many other waterfowl species, were brought to the brink of extinction in the early twentieth century by overhunting and habitat loss. The first major driver in their recovery was the 1918 Migratory Bird Treaty Act which implemented regulations on hunting. Another contributing factor of Wood Duck conservation was the passage of the 1934 “Duck Stamp Act”. This act assisted regulation of hunting seasons, and required hunters to pay an annual fee that went toward waterfowl management and habitat restoration. Although they are no longer a species of concern, woodies are still vulnerable to wetland habitat loss and deforestation, which negatively Impacts their nesting sites.
Wood ducks are cavity nesters who use preformed cavities that are already excavated. They will also readily take to nest boxes, therefore many conservation efforts have adopted building nest boxes. These little dabblers are the only duck species in North America to lay two broods of eggs per year (although this is more common in their southern range). Wood ducks are precocial, meaning they are hatched in an advanced physiological state where they can already eat and walk. This allows them to reach sexual maturity in their first year of life. In Spring, dozens of nestlings will safely jump out from their nest cavities that reach heights up to 65 feet above ground or water. These day-old ducklings climb to the cavity’s opening when prompted by their mother’s call.
A very interesting behavior that has recently caught the attention of ornithologists is the Wood Duck’s intraspecific brood parasitism. In this case, one hen will lay eggs in another Wood Duck’s nest and rely on them to incubate and raise their eggs to conserve the parasitic duck’s own energy. In a single normal clutch, a hen will lay 11-15 eggs, but nests with brood parasites have been recorded as having as many as 40 eggs! Sometimes a hen will lay a single egg in multiple nests all over the place. This is one reproductive strategy of the ducks, but hens have 4 different pathways they can choose to lay their clutch: They may not breed in a given year, only lay eggs parasitically, be traditional nesters, or do both! Researchers are still not certain how or why each hen chooses her reproductive strategy.
Some woodies are known to be permanent residents to Flathead Valley. A majority of them will migrate from Montana to California and Mexico resulting in their peak abundance being April through early May, and September to early November. These small ducks live in a variety of habitats in Northwest Montana including creeks, rivers, marshes, ponds, small lakes or wherever there is standing water among trees. They are found in pairs or small groups, but never in large flocks. Viewing Wood Ducks can be as easy as taking a stroll through Woodland Park in Kalispell, or spying them at Spring Creek, Ashley Creek, McWenneger Slough and West Valley Ponds.