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 Anatidae are the biological family of water birds that includes ducks, geese, and swans. The family has a cosmopolitan distribution, occurring on all the world's continents except Antarctica. These birds are adapted for swimming, floating on the water surface, and, in some cases, diving in at least shallow water. The family contains around 174 species in 43 genera.
Anseriformes is an order of birds also known as waterfowl that comprises about 180 living species of birds in three families: Anhimidae, Anseranatidae, and Anatidae, the largest family, which includes over 170 species of waterfowl, among them the ducks, geese, and swans. Most modern species in the order are highly adapted for an aquatic existence at the water surface. With the exception of screamers, males have penises, a trait that has been lost in the Neoaves. Due to their aquatic nature, most species are web-footed.
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 diving ducks, commonly called pochards or scaups, are a category of duck which feed by diving beneath the surface of the water. They are part of Anatidae, the diverse and very large family that includes ducks, geese, and swans.
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 40–56 cm (16–22 in) long with an 74–84 cm (29–33 in) wingspan; the weight ranges from 1,030–1,080 g (36–38 oz), with males weighing an average of 1,080 g (38 oz) and females an average of 1,030 g (36 oz). 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. This waterfowl is easily distinguished from most other ducks by the male's copper colored head and pale blue bill during the breeding season; from its close relative canvasback it is distinguished by the more rounded head, shorter bill, and yellow, not red, eye. The Eurasian common pochard is even more similar, but very rarely overlaps in range; it also differs in having a red eye, and a more acute, less rounded head shape.
The white-backed duck is a waterbird of the family Anatidae. It is distinct from all other ducks, but most closely related to the whistling ducks in the subfamily Dendrocygninae, though also showing some similarities to the stiff-tailed ducks in the subfamily Oxyurinae. It is the only member of the genus Thalassornis.
The lesser whistling duck, also known as Indian whistling duck or lesser whistling teal, is a species of whistling duck that breeds in the Indian subcontinent and Southeast Asia. They are nocturnal feeders that during the day may be found in flocks around lakes and wet paddy fields. They can perch on trees and sometimes build their nest in the hollow of a tree. This brown and long-necked duck has broad wings that are visible in flight and produces a loud two-note wheezy call. It has a chestnut rump, differentiating it from its larger relative, the fulvous whistling duck, which has a creamy white rump.
The white-faced whistling duck is a whistling duck that breeds in sub-Saharan Africa and much of South America.
The comb duck or American comb duck, is an unusual duck, found in tropical wetlands in continental South America south to the Paraguay River region in eastern Paraguay, southeastern Brazil and extreme northeastern Argentina, and as a vagrant on Trinidad.
Aix is a bird genus that contains two species of ducks: the wood duck, and the mandarin duck. Aix is an Ancient Greek word used by Aristotle to refer to an unknown diving bird.
The crested shelduck, or Korean crested shelduck, is a species of bird in the family Anatidae. It is critically endangered. The male crested shelduck has a greenish-black crown, breast, primaries, and tail, while the rest of its face, chin, and throat are brownish black. The male's belly, undertail coverts, and flanks are a dark grey with black striations. The upper wing coverts are white, while its speculum is an iridescent green. The female has a white eye ring, black crest, white face, chin, throat, neck, and uppers wing coverts and a dark brown body with white striations. Additionally, both sexes have a distinctive green tuft of feathers protruding from the head.
The West Indian whistling duck is a whistling duck that breeds in the Caribbean. Alternative names are black-billed whistling duck and Cuban whistling duck.
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 falcated duck or falcated teal is a gadwall-sized dabbling duck from the east Palearctic.
The pink-headed duck is a large diving duck that was once found in parts of the Gangetic plains of India, parts of Maharashtra, Bangladesh and in the riverine swamps of Myanmar but has been feared extinct since the 1950s. Numerous searches have failed to provide any proof of continued existence. It has been suggested that it may exist in the inaccessible swamp regions of northern Myanmar and some sight reports from that region have led to its status being declared as "Critically Endangered" rather than extinct. The genus placement has been disputed and while some have suggested that it is close to the red-crested pochard, others have placed it in a separate genus of its own. It is unique in the pink colouration of the head combined with a dark body. A prominent wing patch and the long slender neck are features shared with the common Indian spot-billed duck. The eggs have also been held as particularly peculiar in being nearly spherical.
The black-bellied whistling duck, formerly called the black-bellied tree duck, is a whistling duck that before 2000 bred mainly in the southernmost United States, Mexico, and tropical Central to south-central South America. It can be found year-round in much of the United States. It has been recorded in every eastern state and adjacent Canadian province. Since it is one of only two whistling duck species native to North America, it is occasionally just known as the "whistling duck" or "Mexican squealer" in the southern USA.
The spotted whistling duck is a member of the duck family Anatidae. It is also referred to as the "spotted tree duck". This duck can be found in Indonesia, New Guinea, Australia and the Philippines. Spotted ducks are also held in captive populations.
The wandering whistling duck is a species of whistling duck. They inhabit tropical and subtropical Australia, the Philippines, Borneo, Indonesia, Papua New Guinea, and the Pacific Islands.
