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 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 Tadorninae is the shelduck-sheldgoose subfamily of the Anatidae, the biological family that includes the ducks and most duck-like waterfowl such as the geese and swans.
The gadwall is a common and widespread dabbling duck in the family Anatidae.
The term perching ducks is used colloquially to mean any species of ducks distinguished by their readiness to perch high in trees.
The Eurasian teal, common teal, or Eurasian green-winged teal is a common and widespread duck that breeds in temperate Eurosiberia and migrates south in winter. The Eurasian teal is often called simply the teal due to being the only one of these small dabbling ducks in much of its range. The bird gives its name to the blue-green colour teal.
The American teal or green-winged teal is a common and widespread duck that breeds in the northern areas of North America except on the Aleutian Islands. It was considered conspecific with the Eurasian teal for some time, but has since been split into its own species. The American Ornithological Society continues to debate this determination; however, nearly all other authorities consider it distinct based on behavioral, morphological, and molecular evidence. The scientific name is from Latin Anas, "duck" and carolinensis, "of Carolina".
The knob-billed duck, or African comb duck, is a type of duck found along the tropical/sub-tropical wetlands and waterways of Sub-Saharan Africa and the island of Madagascar, as well as most of South Asia and mainland Indochina.
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.
Anas is a genus of dabbling ducks. It includes the pintails, most teals, and the mallard and its close relatives. It formerly included additional species but following the publication of a molecular phylogenetic study in 2009 the genus was split into four separate genera. The genus now contains 31 living species. The name Anas is the Latin for "duck".
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 Australian wood duck, maned duck or maned goose is a dabbling duck found throughout much of Australia. It is the only living species in the genus Chenonetta. Traditionally placed in the subfamily Anatinae, it might belong to the subfamily Tadorninae (shelducks); the ringed teal may be its closest living relative.
The pygmy geese are a group of very small "perching ducks" in the genus Nettapus which breed in the Old World tropics. They are the smallest of all wildfowl. As the "perching ducks" are a paraphyletic group, they need to be placed elsewhere. The initially assumed relationship with the dabbling duck subfamily Anatinae has been questioned, and it appears they form a lineage in an ancient Gondwanan radiation of waterfowl, within which they are of unclear affinities. An undescribed fossil species from the late Hemphillian of Jalisco, central Mexico, has also been identified from the distal end of a tarsometatarsus. It is only record of the genus in the New World.
The moa-nalo are a group of extinct aberrant, goose-like ducks that lived on the larger Hawaiian Islands, except Hawaiʻi itself, in the Pacific. They were the major herbivores on most of these islands until they became extinct after human settlement.
The Brazilian teal or Brazilian duck is the only duck in the genus Amazonetta. It is widely distributed in eastern South America.
The ringed teal is a small duck of South American forests. It is the only species of the genus Callonetta. Usually placed with the dabbling ducks (Anatinae), this species may actually be closer to shelducks and belong in the subfamily Tadorninae; its closest relative is possibly the maned duck.
The steamer ducks are a genus (Tachyeres) of ducks in the family Anatidae. All of the four species occur at the southern cone of South America in Chile and Argentina, and all except the flying steamer duck are flightless; even this one species capable of flight rarely takes to the air. They can be aggressive and are capable of chasing off predators like petrels. Bloody battles of steamer ducks with each other over territory disputes are observed in nature. They even kill waterbirds that are several times their size.
Bradley Curtis Livezey was an American ornithologist with scores of publications. His main research included the evolution of flightless birds, the systematics of birds, and the ecology and behaviour of steamer ducks.
