Gadwall (Anas strepera)
Description: 18-21″ (46-53 cm) ADULT MALE Has a buffy gray head and neck, with clear separation from the darker gray, finely patterned breast and flanks. Center of belly is white and vent is black, the latter a useful identification feature even at a distance. Note the dark bill and yellow legs. In eclipse plumage, male resembles an adult female. ADULT FEMALE Has mottled brown plumage with a grayish head. Note the yellow bill. White speculum can sometimes be glimpsed in feeding birds. JUVENILE Resembles an adult female.
Voice: Male Gadwall make short, deep, reedy calls referred to as “burps,” given in steady succession or 2–5 at a time while flying. They also make high whistles. Females quack rather like Mallards, but with a slightly higher pitch and more nasal quality.
Habitat: Gadwalls are almost invariably associated with freshwater habitats, favoring shallow water where they can dabble (and if necessary upend) for water plants. Breeds extensively across central North America, particularly in prairie pools, and winters mainly south and west of breeding range, south to Central America. Numbers have increased in recent years, due largely to conservation measures aimed at improving breeding habitat.
Nesting: The female scrapes out a hollow, then settles into the nest and reaches out to grab twigs and leaves with her bill. She sets these against herself to form the base of a nest cup, then plucks her own down feathers to make an insulating lining. The finished nest is about a foot across with a cup 3 inches deep. It takes 5–7 days to go from looking for a nest site to having a finished nest ready for egg laying. Gadwall pairs form during fall migration. Once they return to their breeding grounds, they select their nest site while flying low over dry, grassy areas. The female makes a closer inspection on foot while the male stands guard near her. They typically choose dense brush or grasses at least a foot tall, usually within 200 yards of open water, and nest on islands when possible for greater safety from predators. In heavily cultivated areas, untilled land for nest sites can be a scarce resource.
- Gadwall sometimes steal food from American Coots and from other ducks.
- Gadwall have increased in numbers since the 1980s, partly because of conservation of wetlands and adjacent uplands in their breeding habitat through the Conservation Reserve Program and the North American Waterfowl Management Plan. Their habit of nesting on islands within marshes gives them some protection from predators.
- Female Gadwall produce an egg a day while they are laying their 7–12-egg clutches. To meet their demand for protein during this stressful time, female Gadwall eat more invertebrates than males during this period—in addition to using reserves of nutrients they’ve stored in their bodies during the winter.
- The oldest known Gadwall was 19 years 6 months old. It was banded in Saskatchewan in 1962 and shot during hunting season in Louisiana in 1981.
Resource material provided by:
The Cornell Lab of Ornithology/ http://www.allaboutbirds.com