The Anatidae are the biological

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

water bird A water bird, alternatively waterbird or aquatic bird, is a bird that lives on or around water. In some definitions, the term ''water bird'' is especially applied to birds in freshwater ecosystems, although others make no distinction from seabi ...

s that includes

duck 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 ...

geese A goose ( : geese) is a bird of any of several waterfowl species in the family Anatidae. This group comprises the genera '' Anser'' (the grey geese and white geese) and ''Branta'' (the black geese). Some other birds, mostly related to the she ...

, and swans. The family has a cosmopolitan distribution, occurring on all the world's continents except Antarctica. These

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

s are adapted for

swimming Swimming is the self-propulsion of a person through water, or other liquid, usually for recreation, sport, exercise, or survival. Locomotion is achieved through coordinated movement of the limbs and the body to achieve hydrodynamic thrust that r ...

, floating on the water surface, and in some cases diving in at least shallow water. The family contains around 174 species in 43 genera. (The magpie goose is no longer considered to be part of the Anatidae and is now placed in its own family, Anseranatidae.) They are generally herbivorous, and are monogamous breeders. A number of species undertake annual migrations. A few species have been domesticated for agriculture, and many others are hunted for food and recreation. Five species have become extinct since 1600, and many more are

threatened Threatened species are any species (including animals, plants and fungi) which are vulnerable to endangerment in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of ''critical depensa ...

with

extinction Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

Description and ecology

The ducks, geese, and swans are small- to large-sized birds with a broad and elongated general body plan. Diving species vary from this in being rounder. Extant species range in size from the

cotton pygmy goose The cotton pygmy goose or cotton teal (''Nettapus coromandelianus'') is a small perching duck which breeds in Asia, Southeast Asia extending south and east to Queensland where they are sometimes called white-quilled pygmy goose. They are among ...

, at as little as 26.5 cm (10.5 in) and 164 g (5.8 oz), to the

trumpeter swan The trumpeter swan (''Cygnus buccinator'') is a species of swan found in North America. The heaviest living bird native to North America, it is also the largest extant species of waterfowl, with a wingspan of 185 to 250 cm (6 ft 2 in to 8 ft 2 ...

, at as much as 183 cm (6 ft) and 17.2 kg (38 lb). The wings are short and pointed, and supported by strong wing muscles that generate rapid beats in

flight Flight or flying is the process by which an object moves through a space without contacting any planetary surface, either within an atmosphere (i.e. air flight or aviation) or through the vacuum of outer space (i.e. spaceflight). This can be a ...

. They typically have long necks, although this varies in degree between species. The legs are short, strong, and set far to the back of the body (more so in the more aquatic species), and have a leathery feel with a scaly texture. Combined with their body shape, this can make some species awkward on land, but they are stronger walkers than other marine and water birds such as

grebe Grebes () are aquatic diving birds in the order Podicipediformes . Grebes are widely distributed freshwater birds, with some species also found in marine habitats during migration and winter. Some flightless species exist as well, most notably ...

s or

petrel Petrels are tube-nosed seabirds in the bird order Procellariiformes. Description The common name does not indicate relationship beyond that point, as "petrels" occur in three of the four families within that group (all except the albatross f ...

s. They typically have

webbed feet The webbed foot is a specialized limb with interdigital membranes (webbings) that aids in aquatic locomotion, present in a variety of tetrapod vertebrates. This adaptation is primarily found in semiaquatic species, and has convergently evolved m ...

, though a few species such as the Nene have secondarily lost their webbing. The bills are made of soft keratin with a thin and sensitive layer of skin on top (which has a leathery feel when touched). For most species, the shape of the bill tends to be more flattened to a greater or lesser extent. These contain serrated

lamellae Lamella (plural lamellae) means a small plate or flake in Latin, and in English may refer to: Biology * Lamella (mycology), a papery rib beneath a mushroom cap * Lamella (botany) * Lamella (surface anatomy), a plate-like structure in an animal * ...

which are particularly well defined in the filter-feeding species. Their feathers are excellent at shedding water due to special oils. Many of the ducks display

sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most an ...

, with the males being more brightly coloured than the females (although the situation is reversed in species such as the

paradise shelduck The paradise shelduck (''Tadorna variegata''), also known as the paradise duck, or in Māori, is a species of shelduck, a group of goose-like ducks, which is endemic to New Zealand. Johann Friedrich Gmelin placed it in the genus ''Anas'' with ...

). The swans, geese, and whistling-ducks lack sexually dimorphic plumage. Anatids are vocal birds, producing a range of quacks, honks, squeaks, and trumpeting sounds, depending on species; the female often has a deeper voice than the male. Anatids are generally

herbivorous A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpar ...

as adults, feeding on various water-plants, although some species also eat fish, molluscs, or aquatic arthropods. One group, the

merganser ''Mergus'' is the genus of the typical mergansers , fish-eating ducks in the subfamily Anatinae. The genus name is a Latin word used by Pliny the Elder and other Roman authors to refer to an unspecified waterbird. The common merganser (''Mer ...

s, are primarily

piscivorous A piscivore () is a carnivorous animal that eats primarily fish. The name ''piscivore'' is derived . Piscivore is equivalent to the Greek-derived word ichthyophage, both of which mean "fish eater". Fish were the diet of early tetrapod evoluti ...

, and have serrated bills to help them catch fish. In a number of species, the young include a high proportion of invertebrates in their diets, but become purely herbivorous as adults.

Breeding

The anatids are generally seasonal and monogamous breeders. The level of monogamy varies within the family; many of the smaller ducks only maintain the bond for a single season and find a new partner the following year, whereas the larger swans, geese and some of the more territorial ducks maintain pair bonds over a number of years, and even for life in some species. However, forced extrapair copulation among anatids is common, occurring in 55 species in 17 genera. Anatidae is a large proportion of the 3% of bird species to possess a

penis A penis (plural ''penises'' or ''penes'' () is the primary sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation. Such organs occur in many animals, both vertebrate and invertebrate, but males d ...

, though they vary significantly in size, shape, and surface elaboration. Most species are adapted for

copulation Sexual intercourse (or coitus or copulation) is a sexual activity typically involving the insertion and thrusting of the penis into the vagina for sexual pleasure or reproduction.Sexual intercourse most commonly means penile–vaginal penetra ...

on the water only. They construct simple nests from whatever material is close at hand, often lining them with a layer of down plucked from the mother's breast. In most species, only the female incubates the eggs. The young are

precocial In biology, altricial species are those in which the young are underdeveloped at the time of birth, but with the aid of their parents mature after birth. Precocial species are those in which the young are relatively mature and mobile from the mome ...

, and are able to feed themselves from birth. One aberrant species, the

black-headed duck The black-headed duck (''Heteronetta atricapilla'') is a South American duck in subfamily Oxyurinae of family Anatidae.HBW and BirdLife International (2021) Handbook of the Birds of the World and BirdLife International digital checklist of th ...

, is an obligate brood parasite, laying its eggs in the nests of

gull Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and skimmers and only distantly related to auks, and even more distantly to waders. Until the 21st century ...

s and

coot Coots are medium-sized water birds that are members of the rail family, Rallidae. They constitute the genus ''Fulica'', the name being the Latin term for "coot". Coots have predominantly black plumage, and—unlike many rails—they are usually ...

s. While this species never raises its own young, a number of other ducks occasionally lay eggs in the nests of conspecifics (members of the same species) in addition to raising their own broods.

Relationship with humans

Duck, eider, and goose feathers and down have long been popular for bedspreads, pillows, sleeping bags, and coats. The members of this family also have long been used for food. Humans have had a long relationship with ducks, geese, and swans; they are important economically and culturally to humans, and several duck species have benefited from an association with people. However, some anatids are damaging agricultural pests, and have acted as vectors for

zoonoses A zoonosis (; plural zoonoses) or zoonotic disease is an infectious disease of humans caused by a pathogen (an infectious agent, such as a bacterium, virus, parasite or prion) that has jumped from a non-human (usually a vertebrate) to a human ...

such as

avian influenza Avian influenza, known informally as avian flu or bird flu, is a variety of influenza caused by viruses adapted to birds.

. Since 1600, five species of ducks have become extinct due to the activities of humans, and subfossil remains have shown that humans caused numerous extinctions in prehistory. Today, many more are considered

. Most of the historic and prehistoric extinctions were insular species, vulnerable due to small populations (often

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to a single island), and

island tameness Island tameness is the tendency of many populations and species of animals living on isolated islands to lose their wariness of potential predators, particularly of large animals. The term is partly synonymous with ecological naïveté, which also ...

. Evolving on islands that lacked predators, these species lost antipredator behaviours, as well as the ability to fly, and were vulnerable to human hunting pressure and

introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived ther ...

. Other extinctions and declines are attributable to overhunting,

habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

and modification, and hybridisation with introduced ducks (for example the introduced

ruddy duck The ruddy duck (''Oxyura jamaicensis'') 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". Taxonomy The r ...

swamping the

white-headed duck The white-headed duck (''Oxyura leucocephala'') is a small diving duck some long. The male has a white head with black crown, a blue bill, and reddish-grey plumage. The female has a dark bill and rather duller colouring. Its breeding habitat is ...

in Europe). Numerous governments and conservation and hunting organisations have made considerable progress in protecting ducks and duck populations through habitat protection and creation, laws and protection, and captive-breeding programmes.

Systematics

The name Anatidae for the

was introduced by the English zoologist

William Elford Leach William Elford Leach FRS (2 February 1791 – 25 August 1836) was an English zoologist and marine biologist. Life and work Elford Leach was born at Hoe Gate, Plymouth, the son of an attorney. At the age of twelve he began a medical appre ...

in a guide to the contents of the

British Museum The British Museum is a public museum dedicated to human history, art and culture located in the Bloomsbury area of London. Its permanent collection of eight million works is among the largest and most comprehensive in existence. It docum ...

published in 1820. While the status of the Anatidae as a family is straightforward, and which species properly belong to it is little debated, the relationships of the different tribes and subfamilies within it are poorly understood. The listing in the box at right should be regarded as simply one of several possible ways of organising the many species within the Anatidae; see discussion in the next section. The systematics of the Anatidae are in a state of flux. Previously divided into six subfamilies, a study of anatomical characters by Livezey suggests the Anatidae are better treated in nine subfamilies. This classification was popular in the late 1980s to 1990s. But

mtDNA Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial DNA ...

sequence In mathematics, a sequence is an enumerated collection of objects in which repetitions are allowed and order matters. Like a set, it contains members (also called ''elements'', or ''terms''). The number of elements (possibly infinite) is calle ...

analyses indicate, for example, the dabbling and diving ducks do not belong in the same subfamily. While shortcomings certainly occur in Livezey's analysis, mtDNA is an unreliable source for phylogenetic information in many waterfowl (especially dabbling ducks) due to their ability to produce fertile hybrids, in rare cases possibly even beyond the level of genus (see for example the "

Barbary duck The Muscovy duck (''Cairina moschata'') is a large duck native to the Americas, from the Rio Grande Valley of Texas and Mexico south to Argentina and Uruguay. Small wild and feral breeding populations have established themselves in the United Sta ...

"). Because the

sample size Sample size determination is the act of choosing the number of observations or replicates to include in a statistical sample. The sample size is an important feature of any empirical study in which the goal is to make inferences about a populatio ...

of many molecular studies available to date is small, mtDNA results must be considered with caution. While a comprehensive review of the Anatidae which unites all evidence into a robust

phylogeny A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spe ...

is still lacking, the reasons for the confusing data are at least clear: As demonstrated by the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

Vegavis iaai ''Vegavis'' is a genus of extinct bird that lived during the Late Cretaceous (Maastrichtian stage) of Antarctica, some 68 to 66 mya. Among modern birds, most studies show that ''Vegavis'' is most closely related to ducks and geese (Anatidae), b ...

'' — an early modern waterbird which belonged to an extinct lineage—the Anatidae are an ancient group among the modern birds. Their earliest direct ancestors, though not documented by fossils yet, likewise can be assumed to have been contemporaries with the non-avian

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

s. The long period of

evolution Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...

and shifts from one kind of waterbird lifestyle to another have obscured many

plesiomorph In phylogenetics, a plesiomorphy ("near form") and symplesiomorphy are synonyms for an ancestral character shared by all members of a clade, which does not distinguish the clade from other clades. Plesiomorphy, symplesiomorphy, apomorphy, a ...

ies, while

apomorph In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have ...

ies apparently are quite often the result of

parallel evolution Parallel evolution is the similar development of a trait in distinct species that are not closely related, but share a similar original trait in response to similar evolutionary pressure.Zhang, J. and Kumar, S. 1997Detection of convergent and paral ...

, for example the "non-diving duck" type displayed by such unrelated genera as '' Dendrocygna'', '' Amazonetta'', and '' Cairina''. For the fossil record, see below. Alternatively, the Anatidae may be considered to consist of three subfamilies (ducks, geese, and swans, essentially) which contain the groups as presented here as

tribe The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide usage of the term in English is in the discipline of anthropology. This definition is contested, in part due to confli ...

s, with the swans separated as subfamily Cygninae, the goose subfamily Anserinae also containing the whistling ducks, and the Anatinae containing all other

clades A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

Genera

For the living and recently extinct members of each genus, see the article List of Anatidae species. * Subfamily: Dendrocygninae (one pantropical genus, of distinctive long-legged goose-like birds) ** '' Dendrocygna'', whistling ducks (8 living species) ** ''

Thalassornis The white-backed duck (''Thalassornis leuconotus'') 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 ...

'', white-backed duck Mute swan flies arp

* Subfamily:

Anserinae The Anserinae are a subfamily in the waterfowl family Anatidae. It includes the swans and true geese. Under alternative systematical concepts (see e.g., Terres & NAS, 1991), it is split into two subfamilies, the Anserinae contain the geese a ...

, swans and geese (3–7 extant genera with 25–30 living species, mainly cool temperate Northern Hemisphere, but also some Southern Hemisphere species, with the swans in one genus wo genera in some treatments and the

in three genera wo genera in some treatments Some other species are sometimes placed herein, but seem somewhat more distinct below.html"_;"title="#Unresolved.html"_;"title="ee_#Unresolved">below">#Unresolved.html"_;"title="ee_#Unresolved">below **_''

below.html"_;"title="#Unresolved.html"_;"title="ee_#Unresolved">below">#Unresolved.html"_;"title="ee_#Unresolved">below **_''Swan">Cygnus'',_true_swans_(6 species,_4 sometimes_separated_in_''Olor'') **_''Anser_(bird).html" "title="Swan.html" ;"title="#Unresolved">below.html" ;"title="#Unresolved.html" ;"title="ee #Unresolved">below">#Unresolved.html" ;"title="ee #Unresolved">below ** ''Swan">Cygnus'', true swans (6 species, 4 sometimes separated in ''Olor'') ** ''Anser (bird)">Anser Anser may refer to: People * Anser (poet), poet of ancient Rome * Anser Farooq, Canadian lawyer Other uses * ANSER, a security and defense analysis group * ''Anser'' (bird), a genus of geese * Anser (putter), a model of golf club made by Pi ...

'', grey geese and white geese (11 species) ** ''Branta'', black geese (6 living species) * Subfamily: Stictonettinae (one genus in Australia, formerly included in the Oxyurinae, but with anatomy suggesting a distinct ancient lineage perhaps closest to the Anserinae, especially the

Cape Barren goose The Cape Barren goose (''Cereopsis novaehollandiae'') is a large goose resident in southern Australia. Etymology The species' common name is derived from Cape Barren Island, where specimens were first sighted by European explorers. It is know ...

) ** '' Stictonetta'',

freckled duck The freckled duck (''Stictonetta naevosa)'' is a waterfowl species endemic to Australia. The freckled duck has also been referred to as the monkey duck or oatmeal duck. These birds are usually present in mainland Australia, but disperse to coas ...

* Subfamily: Plectropterinae (one genus in Africa, formerly included in the "perching ducks", but closer to the Tadorninae) ** '' Plectropterus'',

spur-winged goose The spur-winged goose (''Plectropterus gambensis'') is a large bird in the family Anatidae, related to the geese and the shelducks, but distinct from both of these in a number of anatomical features, and therefore treated in its own subfamily, th ...

* Subfamily:

Tadorninae 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. This group is largely tropical or Southern Hemisphere in distribution, w ...

– shelducks and sheldgeese Common

(This group of larger, often semiterrestrial waterfowl can be seen as intermediate between Anserinae and Anatinae. The 1986 revision has resulted in the inclusion of 10 extant genera with about two-dozen living species ne probably extinctin this subfamily, mostly from the Southern Hemisphere but a few in the Northern Hemisphere; the affiliations of several presumed tadornine genera has later been questioned and the group in the traditional lineup is likely to be paraphyletic.) ** '' Pachyanas'', Chatham Island duck ( prehistoric) ** ''

Tadorna The shelducks, most species of which are found in the genus ''Tadorna'' (except for the Radjah shelduck, which is now found in its own monotypic genus ''Radjah''), are a group of large birds in the Tadorninae subfamily of the Anatidae, the biolog ...

'', shelducks (6 species, 1 probably extinct) – possibly paraphyletic ** ''

Radjah The radjah shelduck (''Radjah radjah''), is a species of shelduck found mostly in New Guinea and Australia, and also on some of the Moluccas. It is known alternatively as the raja shelduck, black-backed shelduck, or in Australia as the Burdekin ...

'', Radjah shelduck ** '' Salvadorina'', Salvadori's teal ** ''

Centrornis The Malagasy sheldgoose (''Centrornis majori'') is an extinct monotypic species of large goose in the shelduck subfamily. It was described from subfossil remains radiocarbon dated to about 17,000 years ago, found in central Madagascar M ...

'', Madagascar sheldgoose ( prehistoric, tentatively placed here) ** ''

Alopochen ''Alopochen'' is a genus of the bird family Anatidae, part of the subfamily Tadorninae along with the shelducks. It contains one extant species, the Egyptian goose (''Alopochen aegyptiaca''), and two or three species which became extinct in the ...

'', Egyptian goose and Mascarene shelducks (1 living species, 2 extinct) ** ''

Neochen ''Neochen'' is a genus of birds in the family (biology), family Anatidae. Extant species The genus contains a single living species: Fossil species * †''Neochen barbadiana'' * †''Neochen debilis'' * †''Neochen pugil'' References

...

'', (2 species) ** ''

Chloephaga ''Chloephaga'' is a genus of sheldgeese in the family Anatidae. Other sheldgeese are found in the genera ''Alopochen'' and '' Neochen''. Taxonomy The genus ''Chloephaga'' was introduced in 1838 by the English naturalist Thomas Campbell Eyton ...

'', sheldgeese (4 species) ** ''

Hymenolaimus The blue duck or whio (''Hymenolaimus malacorhynchos'') is a member of the duck, goose and swan family Anatidae endemic to New Zealand. It is the only member of the genus ''Hymenolaimus''. Its exact taxonomic status is still unresolved, but i ...

'', blue duck ** ''

Merganetta The torrent duck (''Merganetta armata'') is a member of the duck, goose and swan family Anatidae. It is the only member of the genus ''Merganetta''. It is placed in the shelduck subfamily Tadorninae after the "perching duck" assemblage to which i ...

'', torrent duck Male mallard duck 2

* Subfamily: Aythyinae, diving ducks (Some 15 species of

diving duck 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 diving d ...

s, of worldwide distribution, in two to four genera; The 1986 morphological analysis suggested the probably extinct

pink-headed duck The pink-headed duck (''Rhodonessa caryophyllacea'') 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 feared extinct since the 1950s. ...

of India, previously treated separately in ''Rhodonessa'', should be placed in ''Netta'', but this has been questioned. Furthermore, while morphologically close to dabbling ducks, the mtDNA data indicate a treatment as distinct subfamily is indeed correct, with the Tadorninae being actually closer to dabbling ducks than the diving ducks) ** ''

Netta ''Netta'' is a genus of diving ducks. The name is derived from Greek ''Netta'' "duck". Unlike other diving ducks, the ''Netta'' species are reluctant to dive, and feed more like dabbling ducks. These are gregarious ducks, mainly found on fres ...

'', red-crested pochard and allies (4 species, 1 probably extinct) ** ''

Aythya ''Aythya'' is a genus of diving ducks. It has twelve described species. The name ''Aythya'' comes from the Ancient Greek word (), which may have referred to a sea-dwelling duck or an auklet. ''Aythya shihuibas'' was described from the Late Mi ...

'', pochards, scaups, etc. (12 species) * Subfamily:

Anatinae The Anatinae are a subfamily of the family Anatidae (swans, geese and ducks). Its surviving members are the dabbling ducks, which feed mainly at the surface rather than by diving. The other members of the Anatinae are the extinct moa-nalo, a you ...

, dabbling ducks and moa-nalos (The dabbling duck group, of worldwide distribution, were previously restricted to just one or two genera, but had been extended to include eight extant genera and about 55 living species, including several genera formerly known as the "perching ducks"; mtDNA on the other hand confirms that the genus ''Anas'' is over-lumped and casts doubt on the diving duck affiliations of several genera ee below The

moa-nalo The moa-nalo are a group of extinct aberrant, goose-like ducks that lived on the larger Hawaiian Islands, except Hawaii itself, in the Pacific. They were the major herbivores on most of these islands until they became extinct after human settle ...

s, of which four species in three genera are known to date, are a peculiar group of flightless, extinct anatids from the Hawaiian Islands. Gigantic in size and with massive bills, they were believed to be geese, but have been shown to be actually very closely related to mallards. They evolved filling the

ecological niche In ecology, a niche is the match of a species to a specific environmental condition. Three variants of ecological niche are described by It describes how an organism or population responds to the distribution of resources and competitors (for ...

turtles Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked tur ...

ungulates Ungulates ( ) are members of the diverse clade Ungulata which primarily consists of large mammals with hooves. These include odd-toed ungulates such as horses, rhinoceroses, and tapirs; and even-toed ungulates such as cattle, pigs, giraffes, ca ...

, and other

megaherbivore Megaherbivores (Greek μέγας megas "large" and Latin ''herbivora'' "herbivore") are large terrestrial herbivores that can exceed in weight. This polyphyletic group of megafauna includes elephants, rhinos, hippos, and giraffes. The largest ...

s. ** ''

Anas ''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 s ...

'': pintails, mallards, etc. (40–50 living species, 3 extinct) ** '' Chendytes'', diving-geese (extinct c. 450–250 BCE, A basal member of the dabbling duck clade) ** ''

Spatula A spatula is a broad, flat, flexible blade used to mix, spread and lift material including foods, drugs, plaster and paints. In medical applications, "spatula" may also be used synonymously with tongue depressor. The word ''spatula'' derives f ...

'', shovelers ** ''

Mareca ''Mareca'' is a genus or subgenus of ducks in the family Anatidae that includes the wigeons. The species now placed in this genus were formerly placed in the genus ''Anas''. A molecular phylogentic study comparing mitochondrial DNA sequences pub ...

'', wigeons and gadwalls ** '' Lophonetta'', crested duck ** '' Speculanas'', bronze-winged duck ** '' Amazonetta'', Brazilian teal ** '' Sibirionetta'', Baikal teal ** '' Chelychelynechen'', turtle-jawed moa-nalo ( prehistoric) ** ''

Thambetochen Thambetochen is an extinct genus of moa-nalo duck. It contains two species, the Maui Nui moa-nalo (''T. chauliodous'') and the smaller O'ahu moa-nalo (''T. xanion''). The former was found on Maui and Molokai on Hawaii, the latter was fou ...

'', large-billed moa-nalos (2 species, prehistoric) ** '' Ptaiochen'', small-billed moa-nalo ( prehistoric) * Tribe:

Mergini The sea ducks (''Mergini'') are a tribe of the duck subfamily of birds, the Anatinae. The taxonomy of this group is incomplete. Some authorities separate the group as a subfamily, while others remove some genera. Most species within the group sp ...

, eiders, scoters, sawbills and other sea-ducks Bucephala clangula ja 01

(There are 9 extant genera and some 20 living species; most of this group occur in the Northern Hemisphere, but a few ostly extinctmergansers in the Southern Hemisphere) ** '' Shiriyanetta'' ( prehistoric) ** '' Polysticta'', Steller's eider ** ''

Somateria Eiders () are large seaducks in the genus ''Somateria''. The three extant species all breed in the cooler latitudes of the Northern Hemisphere. The down feathers of eider ducks, and some other ducks and geese, are used to fill pillows and quil ...

'', eiders (3 species) ** ''

Histrionicus The harlequin duck (''Histrionicus histrionicus'') is a small sea duck. It takes its name from Harlequin (French ''Arlequin'', Italian ''Arlecchino''), a colourfully dressed character in Commedia dell'arte. The species name comes from the Lati ...

'', harlequin duck (includes ''Ocyplonessa'') ** ''

Camptorhynchus The Labrador duck (''Camptorhynchus labradorius'') was a North American bird; it has the distinction of being the first known endemic North American bird species to become extinct after the Columbian Exchange, with the last known sighting occurr ...

'', Labrador duck ( extinct) ** '' Melanitta'', scoters (6 species) ** ''

Clangula The long-tailed duck (''Clangula hyemalis''), formerly known as oldsquaw, is a medium-sized sea duck that breeds in the tundra and taiga regions of the arctic and winters along the northern coastlines of the Atlantic and Pacific Oceans. It is th ...

'', long-tailed duck (1 species) ** '' Bucephala'', goldeneyes (3 species) ** ''

Mergellus ''Mergellus'' is a genus of duck. The smew ''(Mergellus albellus)'' is the only living species, but an extinct species known as '' Mergellus mochanovi'' has also been described from Late Pleistocene deposits in the Yakutia region of Russia ...

'', smew ** ''

Lophodytes The hooded merganser (''Lophodytes cucullatus'') is a species of merganser. It is the only extant species in the genus ''Lophodytes''. The genus name derives from the Greek language: ''lophos'' meaning 'crest', and ''dutes'' meaning 'diver'. The ...

'', hooded merganser ** '' Mergus'', mergansers (4 living species, 1 extinct). * Tribe: Oxyurini, stiff-tail ducks (a small group of 3–4 genera, 2–3 of them monotypic, with 7–8 living species) ** '' Oxyura'', stiff-tailed ducks (5 living species) ** '' Nomonyx'', masked duck ** '' Heteronetta'', black-headed duck * Unresolved: The largest degree of uncertainty concerns whether a number of genera are closer to the shelducks or to the dabbling ducks. White-winged

Prehistoric species

From subfossil bones found on Kauai ( Hawaiian Islands), two enigmatic waterfowl are known. The living and assignable prehistoric avifauna of the

archipelago An archipelago ( ), sometimes called an island group or island chain, is a chain, cluster, or collection of islands, or sometimes a sea containing a small number of scattered islands. Examples of archipelagos include: the Indonesian Arc ...

contains as Anseriformes ''Branta'' geese and their descendants, and the

s as mentioned above. The following taxa, although certainly new species, cannot be assigned even to subfamily; that Kauai is the oldest of the large Hawaiian Islands, meaning the species may have been evolving in isolation for nearly 10 mya (since the Late

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

), does not help in determining their affinities: * Long-legged "shelduck", Anatidae sp. et gen. indet. * Kaua'i mole duck, ''Talpanas lippa'' Similarly, '' Branta rhuax'' from the Big Island of

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state ...

, and a gigantic goose-like anatid from

Oahu Oahu () ( Hawaiian: ''Oʻahu'' ()), also known as "The Gathering Place", is the third-largest of the Hawaiian Islands. It is home to roughly one million people—over two-thirds of the population of the U.S. state of Hawaii. The island of O� ...

are known only from very incomplete, and in the former case much damaged, bone fragments. The former has been alleged to be a shelduck, but this was generally dismissed because of the damage to the material and

biogeographic Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, ...

considerations. The long-legged Kauai bird, however, hints at the possibility of a former tadornine presence on the archipelago.

Fossil Anatidae

The fossil record of anatids is extensive, but many prehistoric genera cannot be unequivocally assigned to present-day subfamilies for the reasons given above. For prehistoric species of extant genera, see the respective genus accounts. Dendrocheninae – a more advanced relative of the whistling-ducks or an ancestral relative of stifftail ducks paralleling whistling-ducks; if not extinct possibly belong in Oxyurinae (including '' Malacorhynchus'') * '' Mionetta'' (Late Oligocene – Middle Miocene of C Europe) – includes ''"Anas" blanchardi'', ''"A." consobrina'', ''"A." natator'', ''"Aythya" arvernensis'' * '' Manuherikia'' (Bathans Early/Middle Miocene of Otago, New Zealand) * '' Dendrochen'' (Early – Late? Miocene) – includes ''"Anas" integra'', ''"A." oligocaena'' * Dendrocheninae gen. et sp. indet. (Late Miocene of Argentina) Black Swan skeleton

* '' Cygnavus'' (Early Oligocene of Kazakhstan – Early Miocene of Germany) * '' Cygnopterus'' (Middle Oligocene of Belgium – Early Miocene of France) – sometimes included in ''Cygnavus'' * '' Megalodytes'' (Middle Miocene of California, US) * "cf. ''Megalodytes"'' (Haraichi Middle Miocene of Annaka, Japan) * '' Anserobranta'' (Late Miocene of C Europe) – includes ''"Anas" robusta'', validity doubtful * '' Presbychen'' (Temblor Late Miocene of Sharktooth Hill, US) * ''

Afrocygnus ''Afrocygnus'' is an extinct genus of swan, which lived during the Late Miocene, and perhaps up to the Late Pliocene, in what is today North Africa. The only genus of swan known in Africa, aside from fragmentary Pleistocene remains found in East ...

'' (Late Miocene – Early Pliocene of EC Africa) * '' Paracygnus'' (Kimball Late Pliocene of Nebraska, US) * '' Eremochen'' (Pliocene)

* '' Australotadorna'' (Late Oligocene – Early Miocene of Australia) * '' Miotadorna'' (Bathans Early/Middle Miocene of Otago, New Zealand) * Tadorninae gen. et sp. indet. (Calvert Middle Miocene of Maryland, US) * '' Balcanas'' (Early Pliocene of Dorkovo, Bulgaria) – may be synonym of ''Tadorna'' or even common shelduck * '' Anabernicula'' (Late Pliocene ? – Late Pleistocene of SW and W North America) * '' Brantadorna'' (Middle Pleistocene of Vallecito Creek, US) * '' Nannonetta'' (Late Pleistocene of Peru)

* ''

Sinanas ''Sinanas'' is a genus of prehistoric duck that lived during the middle Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Cha ...

'' (Middle Miocene) * '' Wasonaka'' (Middle Pliocene)

Oxyurinae 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 ...

* '' Pinpanetta'' (Late Oligocene – Early Miocene of Australia) * '' Dunstanetta'' (Bathans Early/Middle Miocene of Otago, New Zealand) – tentatively placed here * '' Tirarinetta'' (Pliocene of Australia) ''

Incertae sedis ' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertain ...

'' * ''"Anas" luederitzensis'' (Kalahari Early Miocene of Lüderitzbucht, Namibia) – anatine? * ''

Matanas ''Matanas enrighti'' is an extinct duck from the Miocene of New Zealand. It was described from fossil material (a left humerus) collected from a Saint Bathans Fauna site near Mata Creek, in the lower Bannockburn Formation of the Manuherikia Gr ...

'' (Bathans Early/Middle Miocene of Otago, New Zealand) * Anatidae gen. et sp. indet. MNZ S42797 (Bathans Early/Middle Miocene of Otago, New Zealand) * ''"Oxyura" doksana'' (Early Miocene of Dolnice, Czech Republic) * ''"Aythya" chauvirae'' (Middle Miocene of Sansan, France and Credinţa, Romania) – 2 species * Anatidae gen. et sp. indet. (Middle Miocene of Nördlinger Ries, Germany) – tadornine? * Anatidae gen. et sp. indet. (Sajóvölgyi Middle Miocene of Mátraszõlõs, Hungary) * ''"Anas" meyerii'' (Middle Miocene of Öhningen, Germany) Described from a single badly crushed tarsometatarsus and phalanges. This species was named in 1867 by Milne-Edwards and then recombined in 1964 by Brodkorb to the genus ''

''. This species is currently regarded as Aves ''

incertae sedis ' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertain ...

''. * ''"Anas" velox'' (Middle–Late? Miocene of C Europe) – anatine? May include ''"A." meyerii'' * ''"Anas" albae'' (Late Miocene of Polgárdi, Hungary) – mergine? Formerly in ''Mergus'' * ''"Anas" isarensis'' (Late Miocene of Aumeister, Germany) – anatine? * ''"Anser" scaldii'' (Late Miocene of Antwerp, Belgium) – anserine or tadornine * Anatidae gen. et sp. indet. (Waite Late Miocene of Alcoota, Australia) – anatine, oxyurine? * Anatidae gen. et sp. indet. (Waite Late Miocene of Alcoota, Australia) – tadornine? * ''"Anas" eppelsheimensis'' (Early Pliocene of Eppelsheim, Germany) – anatine? * '' Aldabranas'' (Late Pleistocene of Aldabra, Indian Ocean) – anatine or tadornine * ''"Chenopis" nanus'' (Pleistocene of Australia) – at least 2 taxa, may be living species * '' Garganornis'' (Late Miocene of Gargano, Italy) * '' Mioquerquedula'' (Middle Miocene of Mongolia) Putative or disputed prehistoric anatids are: * '' Romainvillia'' (Late Eocene/Early Oligocene) – anseranatid or anatid (own subfamily) * '' Loxornis'' (Deseado Early Oligocene of Argentina) * '' Paracygnopterus'' (Early Oligocene of Belgium and England) * '' Teleornis'' (Deseado Early Oligocene of Argentina) * '' Guguschia'' (Late Oligocene of Pirəkəşkül, Azerbaijan) – anserine or

Pelagornithidae The Pelagornithidae, commonly called pelagornithids, pseudodontorns, bony-toothed birds, false-toothed birds or pseudotooth birds, are a prehistoric family of large seabirds. Their fossil remains have been found all over the world in rocks dating ...

(same as '' Caspiodontornis''?) * '' Chenornis'' (Early Miocene) – anserine or

Phalacrocoracidae Phalacrocoracidae is a family of approximately 40 species of aquatic birds commonly known as cormorants and shags. Several different classifications of the family have been proposed, but in 2021 the IOC adopted a consensus taxonomy of seven gen ...

* '' Paranyroca'' (Rosebud Early Miocene of Bennett County, US) – anatid (own subfamily) or distinct family? * '' Eoneornis'' (Miocene of Argentina) – anatine? A '' nomen dubium'' * '' Eutelornis'' (Miocene of Argentina) – anatine? The Middle Oligocene '' Limicorallus'' (from Chelkar-Teniz (

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...

) was sometimes considered an anserine. It is now recognized as a primitive cormorant. The middle Eocene '' Eonessa'' was formerly thought to belong to Anatidae, however reexamination of the holotype in 1978 resulted in the genus being placed as Aves

References

External links

Anatidae videos
on the Internet Bird Collection

– Stamps on ducks, swans and geese {{Taxonbar, from=Q7556 Bird families Waterfowl Extant Rupelian first appearances Taxa named by William Elford Leach