Crested Duck

This is a medium-sized waterfowl taxon with an elegant profile, measuring between 19.6 and 23.6 inches (50 to 60 centimeters) in length and weighing approximately 1.9 to 2.4 pounds (900 to 1100 grams). Its plumage features a predominantly mottled gray-brown and ochre pattern, with distinct scaly markings on the breast. The most defining anatomical characteristic is a shaggy, dark brown occipital crest that drapes down the back of the neck, which is more pronounced in males during courtship displays but present in both sexes. The face is noticeably paler, creating a stark contrast with a dark patch or mask surrounding the eyes, which feature a striking bright red or orange iris. The bill is a uniform lead-gray. In flight, it reveals a brilliant bronze, purple, or greenish speculum bordered by a prominent white trailing edge. Sexual dimorphism is minimal regarding plumage coloration, although males tend to be slightly larger and exhibit more developed crests than females.

Geographical distribution: This species is endemic to South America, where its range extends along the Andes mountain range and down through the Patagonian plains. It is divided into two distinct subspecies: Lophonetta specularioides alticola, which inhabits high-altitude wetlands from central Peru and western Bolivia to northern Chile and northwestern Argentina; and Lophonetta specularioides specularioides, found throughout central and southern Chile, southern Argentina, Tierra del Fuego, and the Falkland Islands.

Habitat: It occupies an extraordinarily diverse range of aquatic ecosystems depending on the specific altitude and latitude of its population. The northern Andean subspecies is specialized in high-altitude environments, favoring saline lakes, brackish lagoons, marshes, and peat bogs (bofedales) in the Puna ecosystem at elevations ranging from 9,800 to 15,700 feet (3000 to 4800 meters) above sea level. Conversely, the southern subspecies is common along marine coastlines, subantarctic fjords, sheltered bays, estuaries, kelp forests, and freshwater lakes within forested or steppe landscapes at sea level.

Feeding: It exhibits a highly versatile omnivorous diet adapted to seasonal food availability. It feeds extensively on aquatic invertebrates, such as amphipods, mollusks, chironomid larvae, and water beetles. In marine coastal areas, it is frequently seen foraging among kelp beds (such as Macrocystis), consuming algae and the diverse micro-organisms associated with these marine ecosystems. It also supplements its diet with seeds and soft parts of floating or submerged vascular plants.

Behavior: It is well known for its highly territorial and aggressive temperament, particularly during the breeding season. It vigorously defends its nesting territory against conspecifics and other waterfowl species through physical chases and harsh, rasping vocalizations. It is usually observed in pairs or small family units, and the formation of large flocks is rare, occurring only at rich feeding grounds or during the post-breeding molt. Foraging methods include filter-feeding in shallow mud, surface-dabbling, and upending to reach benthic organisms.

Nesting: The breeding season varies by latitude, taking place between September and January in the southern regions, while being much more flexible in the high Andes. The nest is a shallow scrape on the ground, carefully concealed within dense vegetation such as tall bunchgrass, rushes, thorny shrubs, or close to the water´s edge. The cup is lined with dry grass and filled with a thick layer of pectoral down plucked by the female. A typical clutch consists of 5 to 8 cream-colored eggs. Incubation is performed solely by the female for about 30 days, while the male remains nearby to protect the territory and help guard the precocial ducklings once they hatch.

Conservation status: It is currently classified as Least Concern (LC) on the IUCN Red List of Threatened Species. Although some local populations face challenges from habitat degradation in high-altitude wetlands, mining pollution, and the introduction of invasive predatory species, its global population remains stable and does not show evidence of significant long-term declines.