Gadwall

The Gadwall (Mareca strepera) is a widespread, medium-sized dabbling duck with an understated but elegant beauty. Often overshadowed by flashier waterfowl like the Mallard, a closer look at a breeding male reveals an intricate tapestry of herringbone-patterned gray, brown, and black. They are highly successful ducks, occurring across much of North America, Eurasia, and parts of Africa, and are often spotted in quiet, vegetated wetland environments.

Identifying Gadwalls relies on observing subtle but distinct field marks.

Males (Breeding):

• Overall gray-brown body with an incredibly detailed, scale-like pattern on the breast.
• Distinct jet-black rump and undertail coverts, contrasting sharply with a pale gray flank.
• Plain sandy-brown head and a dark, charcoal-gray bill.
• A small but bright white square on the wing (speculum), which is often visible as a small white patch even when swimming.

Females and Non-breeding (Eclipse) Males:

• Mottled brown overall, closely resembling a female Mallard.
• Key distinctions from Mallards include a steeper, more squared forehead, a thinner dark bill bordered neatly with orange, and yellow-orange legs.
• Females also possess the white speculum patch in the wing, which distinguishes them from female Mallards (which have a blue-and-white speculum).

Gadwalls prefer still or slow-moving freshwater environments with abundant emergent vegetation.

• Breeding Range: They nest primarily in the shortgrass prairies, parklands, and northern grasslands of North America and Eurasia. They heavily utilize seasonal and semi-permanent wetlands, prairie potholes, and marshy lake edges.
• Winter Range & Migration: During migration and winter, they move south to ice-free lakes, reservoirs, large rivers, agricultural pools, freshwater marshes, brackish estuaries, and coastal lagoons. In North America, their winter range spans from the central United States down to Central America.

Gadwalls exhibit classic dabbling duck behaviors, feeding primarily on aquatic vegetation by dipping their heads or tipping forward with tails up in the air.

• Feeding Ecology: Uniquely among dabbling ducks, Gadwalls are highly herbivorous, feeding on submersed aquatic plants (like pondweed, coontail, and milfoil). They are known to associate with diving ducks and American Coots, frequently stealing vegetation brought to the surface by these deep-diving species.
• Vocalization: Males emit a distinctive nasal, low-pitched 'meb' or 'gack' sound, as well as a short, high whistle during courtship displays. Females produce a raspy, descending series of quacks, similar to but higher-pitched and less resounding than a Mallard's quack.
• Nesting: Females select nesting sites in dense upland grass, often hundreds of yards away from water, concealing the nest excellently to protect it from predators. They lay 7 to 12 creamy-white eggs in a cup lined with down.