Description: It is a medium to large-sized duck with a sturdy build and elegant appearance, typical of South American wetlands. The species shows a pronounced sexual dimorphism, especially during the breeding season. The male displays a glossy black head and neck, bright red eyes, and a predominantly pale gray body covered with fine vermiculations, contrasting with the darker breast and rear portions. The female is generally brownish, with chestnut and gray tones that provide excellent camouflage among marsh vegetation. Both sexes possess a relatively broad bill and strong legs adapted for swimming. In flight, it exhibits powerful wingbeats and a distinctive contrasting wing pattern that can be recognized from a considerable distance.
Geographic distribution: It is widely distributed throughout central and southern South America. Its range includes areas of Argentina, Uruguay, Paraguay, southern Brazil, and parts of Bolivia. In some regions it performs seasonal movements associated with fluctuations in water levels and food availability. Large concentrations may occur in certain wetlands during favorable periods, while at other times individuals disperse across a wide network of lakes, marshes, reservoirs, and floodplain habitats.
Habitat: It inhabits a broad range of freshwater wetlands, including shallow lakes, marshes, swamps, reservoirs, oxbow lakes, and calm river sections. It favors environments with abundant emergent and floating aquatic vegetation, which provide shelter, feeding opportunities, and nesting sites. The species may also occur in more open water bodies when food resources are abundant. It is particularly associated with extensive wetland systems located in lowland regions.
Diet: Its diet is primarily herbivorous, consisting of seeds, shoots, leaves, and various aquatic plant parts. It also supplements its feeding with small aquatic invertebrates, mollusks, insects, and other organisms encountered while foraging. Individuals commonly feed while swimming or by making partial dives to reach submerged vegetation. Food availability strongly influences local movements and habitat use.
Behavior: This species is generally gregarious, occurring alone, in pairs, or in flocks that may number hundreds of individuals. Outside the breeding season, it often gathers in large mixed groups with other duck species. It is usually cautious and vigilant, quickly responding to potential threats. Daily activities include alternating periods of feeding, resting, and plumage maintenance. During courtship, males perform conspicuous displays involving body postures and vocalizations aimed at attracting females.
Breeding: Reproductive activity is closely linked to wetland conditions and water availability. The nest is built within dense vegetation near water using stems, dry leaves, and other plant materials. The female lays several pale-colored eggs and performs most of the incubation duties. Ducklings hatch covered with down and leave the nest shortly after emergence, following their mother to sheltered feeding areas. Breeding success often depends on water levels, vegetation cover, and predator pressure.
Conservation status: The species is classified as Least Concern (LC) because of its broad distribution and generally large population throughout much of its range. Nevertheless, some local populations may be affected by wetland loss and degradation, pollution, hydrological alterations, and other human-related pressures. The protection and sustainable management of wetland ecosystems are essential for the long-term conservation of this species.
Author of this compilation: EcoRegistros – 16/06/2026