Duck is the common name for numerous species of waterfowl in the family Anatidae. Ducks are generally smaller and shorter-necked than swans and geese, which are members of the same family. Divided among several subfamilies, they are a form taxon; they do not represent a monophyletic group, since swans and geese are not considered ducks. Ducks are mostly aquatic birds, and may be found in both fresh water and sea water.
The Oxyurini are a tribe of the duck subfamily of birds, the Anatinae. It has been subject of considerable debate about its validity and circumscription. Some taxonomic authorities place the group in its own subfamily, the Oxyurinae. Most of its members have long, stiff tail feathers which are erected when the bird is at rest, and relatively large, swollen bills. Though their relationships are still enigmatic, they appear to be closer to swans and true geese than to the typical ducks. The highest diversity is found in the warmer parts of the Americas, but at least one species occurs in a major part of the world.
The redhead is a medium-sized diving duck. The scientific name is derived from Greek aithuia, an unidentified seabird mentioned by authors including Hesychius and Aristotle, and Latin americana, of America. The redhead is 37 cm (15 in) long with an 84 cm (33 in) wingspan. Redhead weight ranges from 2.0 to 2.5 lbs, with males weighing an average of 2.4 lbs and females weighing an average of 2.1 lbs. It belongs to the genus Aythya, together with 11 other described species. The redhead and the common pochard form a sister group which together is sister to the canvasback.
The ring-necked duck is a diving duck from North America commonly found in freshwater ponds and lakes. The scientific name is derived from Greek aithuia, an unidentified seabird mentioned by authors including Hesychius and Aristotle, and Latin collaris, "of the neck" from collum, "neck".
The musk duck is a highly aquatic, stiff-tailed duck native to southern Australia. It is the only living member of the genus Biziura. An extinct relative, the New Zealand musk duck or de Lautour's duck, once occurred on New Zealand, but is only known from prehistoric subfossil bones. It was about 8% longer than the living species, with a particularly large head.
The ruddy duck is a duck from North America and one of the stiff-tailed ducks. The genus name is derived from Ancient Greek oxus, "sharp", and oura, "tail", and jamaicensis is "from Jamaica".
The fulvous whistling duck or fulvous tree duck is a species of whistling duck that breeds across the world's tropical regions in much of Mexico and South America, the West Indies, the southern United States, sub-Saharan Africa and the Indian subcontinent. It has plumage that is mainly reddish brown, long legs and a long grey bill, and shows a distinctive white band across its black tail in flight. Like other members of its ancient lineage, it has a whistling call which is given in flight or on the ground. Its preferred habitat consists of wetlands with plentiful vegetation, including shallow lakes and paddy fields. The nest, built from plant material and unlined, is placed among dense vegetation or in a tree hole. The typical clutch is around ten whitish eggs. The breeding adults, which pair for life, take turns to incubate, and the eggs hatch in 24–29 days. The downy grey ducklings leave the nest within a day or so of hatching, but the parents continue to protect them until they fledge around nine weeks later.
The Orinoco goose is a Near Threatened species of waterfowl in the tribe Tadornini of subfamily Anserinae. It is found in every mainland South American country except Chile, French Guiana, Suriname, and Uruguay.
The Madagascar pochard or Madagascan pochard is an extremely rare diving duck of the genus Aythya. Thought to be extinct in the late 1990s, specimens of the species were rediscovered at Lake Matsaborimena near Bemanevika in Madagascar in 2006. By 2017, a captive breeding program had produced a population of around 90 individuals. The birds were reintroduced to the wild in December 2018.
The masked duck is a tiny stiff-tailed duck ranging through the tropical Americas.
The blue-billed duck is a small Australian stiff-tailed duck, with both the male and female growing to a length of 40 cm (16 in). The male has a slate-blue bill which changes to bright-blue during the breeding season, hence the duck's common name. The male has deep chestnut plumage during breeding season, reverting to a dark grey. The female retains black plumage with brown tips all year round. The duck is endemic to Australia's temperate regions, inhabiting natural inland wetlands and also artificial wetlands, such as sewage ponds, in large numbers. It can be difficult to observe due to its cryptic nature during its breeding season through autumn and winter. The male duck exhibits a complex mating ritual. The blue-billed duck is omnivorous, with a preference for small aquatic invertebrates. BirdLife International has classified this species as Least concern. Major threats include drainage of deep permanent wetlands, or their degradation as a result of introduced fish, peripheral cattle grazing, salinization, and lowering of ground water.
The Maccoa duck is a stiff-tailed diving duck found across Eastern and Southern Africa.
The pearly-breasted cuckoo is a species of bird in the tribe Phaenicophaeini, subfamily Cuculinae of the cuckoo family Cuculidae. It is found in Argentina, Bolivia, Brazil, Ecuador, French Guiana, Guyana, Paraguay, Suriname, Venezuela, and possibly Colombia and Panama.
The giant wood rail is a species of bird in the subfamily Rallinae of the rail, crake, and coot family Rallidae. It is found in Argentina, Bolivia, Brazil, Paraguay, and Uruguay.
The red-gartered coot is a species of bird in subfamily Rallinae of family Rallidae, the rails, gallinules, and coots. It is found in Argentina, Brazil, Chile, Paraguay, and Uruguay.
The giant coot is a species of bird in subfamily Rallinae of family Rallidae, the rails, gallinules, and coots. It is found in Argentina, Bolivia, Chile, and Peru.
The white-winged coot is a species of bird in subfamily Rallinae of family Rallidae, the rails, gallinules, and coots. It is found in Argentina, Bolivia, Brazil, Chile, Paraguay, Uruguay, and the Falkland Islands.
The red-fronted coot is a species of bird in subfamily Rallinae of family Rallidae, the rails, gallinules, and coots. It is found in Argentina, Bolivia, Brazil, Chile, Peru, and Uruguay.
The rufous-sided crake is a species of bird in subfamily Rallinae of family Rallidae, the rails, gallinules, and coots. It is found in every mainland South American country except Chile.
The Andean duck is a bird species native to the Andean Mountains of South America, one of the stiff-tailed ducks. It was considered a subspecies of the ruddy duck. In fact, some taxonomic authorities still consider it conspecific, including the American Ornithological Society.
