Bronze-winged Duck

Exhibits a robust and highly distinctive morphology, characterized by an unmistakable plumage pattern that sets it apart from other South American ducks. This medium-sized waterfowl reaches an approximate length of 21 inches (54 centimeters) and weighs between 2.2 and 2.6 pounds (1 to 1.2 kilograms). Its deep chocolate-brown head and neck are broken by two bold white patches: a prominent vertical oval patch in front of each eye and a broad crescent running across the throat and lower neck. The body is clad in mottled brown and grey feathers, with finely barred reddish-brown flanks. The closed wing displays a spectacular and highly reflective metallic bronze speculum with a purple sheen, sharply bordered along its posterior edge by a contrasting white band. The bill is slate-gray, and the legs and webbed feet are a vibrant orange-yellow.

Geographical distribution: Is restricted entirely to the southern cone of South America. Its breeding range encompasses the southern Andean cordillera and temperate forests of Chile (from the Maule Region south to Cape Horn) and southwestern Argentina (from Neuquén Province down to Tierra del Fuego). During the winter season, some southern populations undergo short-distance altitudinal or latitudinal migrations, dispersing northward and eastward toward the ecotone of the Patagonian steppe.

Habitat: Primarily frequents pristine, fast-flowing river systems and oligotrophic mountain streams winding through dense, humid temperate forests of Nothofagus. It is regularly observed in deep glacial lakes, forest ponds, and secluded wetlands. Although it generally avoids open marine waters, it occasionally utilizes protected fjords and estuaries. It shows a marked preference for riverbanks shaded by dense canopy and overhanging riparian vegetation, which offer essential cover against aerial predators.

Feeding: Maintains an omnivorous diet highly specialized for exploiting fluvial and benthic food resources. It feeds extensively on aquatic macroinvertebrates, including larvae of midges, caddisflies, stoneflies, mollusks, and small freshwater crustaceans captured by filtering silt or foraging among submerged stones. This animal prey is supplemented with plant material, such as seeds, leaves, and rhizomes of aquatic macrophytes, as well as terrestrial forest fruits and seeds that drop directly into the water.

Behavior: Is a remarkably territorial and solitary species, rarely aggregating in large flocks, instead observed almost exclusively in pairs or small family groups. Vocalizations are highly dimorphic; the female utters a harsh, loud, repetitive bark resembling that of a small dog, which has earned the species its local Spanish name "pato perro", whereas the male produces a soft, wheezy whistle. They are powerful, agile swimmers capable of navigating turbulent currents and are fast, low-altitude flyers over the water surface.

Nesting: Occurs during the austral spring and early summer, typically stretching from September to December. The female builds a well-concealed nest on the ground, hidden amidst thick shoreline grasses, ferns, or dense shrubbery, usually within a few meters of the water´s edge. The nest structure is a shallow scrape lined with dry twigs, grass, and a thick layer of soft down feathers plucked from the female´s breast. A clutch typically consists of 4 to 6 pale cream or buff-colored eggs. Incubation lasts approximately 30 days and is performed solely by the female, although the male remains nearby to assist in territory defense and brood protection.

Conservation status: Is currently evaluated as Near Threatened (NT) by the International Union for Conservation of Nature (IUCN). The global population is relatively small and estimated to be in a gradual decline due to direct anthropogenic pressures. The primary threats include the degradation of riparian ecosystems due to logging, river damming, and overgrazing by livestock along riverbanks. Additionally, the species suffers significant nest predation from introduced invasive carnivores, most notably the American mink (Neovison vison).