The Gadwall’s strange name has been in use since around 1666, although its etymology is unknown. The plural form is either “gadwall” or “gadwalls.”
Although not brightly colored or flashy, the gadwall’s plumage has a subtle elegance; the bird is gray and brown with a white belly. The female is similar in appearance to a mallard hen; because of this similarity, gadwalls are often misidentified.
Courtship displays are quite involved. First the male begins posturing with his head and tail and then the female joins in at which point they may display separately or together.
Gadwalls pair up four to five months before the breeding season and remain monogamous until the start of incubation, when the males leave to gather in all-male group.
In general, gadwalls breed later in the season than other ducks. The female selects the nest site and makes a nest of grasses and down. She lays eight to ten eggs and incubates them for just under four weeks. It doesn't take long for the newly hatched gadwalls to leave the nest, swim and find their own food.
Males have a short call and a whistle; females a quack.
Gadwalls feed on vegetation and can be seen far from shore, dabbling their heads into the water, tail up in the air, or diving for their food. They have a predilection for ponds and marshes.
When young they also eat invertebrates and sometimes fish. In winter they often forage in brackish water.
With the cooler weather, gadwalls migrate to the southern US as well as Guatemala. These birds have the widest range of any duck. Very often they can be seen alongside the American widgeon and the American coot.
The bird is of medium size, about 14 ½ inches long. It has many predators, including humans, coyotes, raccoons, foxes, badgers and hawks. Its most vulnerable times are when molting or nesting.