The Anatidae are the biological

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

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 (biology), family Anatidae. Ducks are generally smaller and shorter-necked than swans and goose, geese, which are members of the same family. Divided among several subfam ...

geese A goose (: geese) is a bird of any of several waterfowl species in the family Anatidae. This group comprises the genera '' Anser'' (grey geese and white geese) and ''Branta'' (black geese). Some members of the Tadorninae subfamily (e.g., Egyp ...

, and

swan Swans are birds of the genus ''Cygnus'' within the family Anatidae. The swans' closest relatives include the goose, geese and ducks. Swans are grouped with the closely related geese in the subfamily Anserinae where they form the tribe (biology) ...

s. The family has a

cosmopolitan distribution In biogeography, a cosmopolitan distribution is the range of a taxon that extends across most or all of the surface of the Earth, in appropriate habitats; most cosmopolitan species are known to be highly adaptable to a range of climatic and en ...

, occurring on all the world's continents except Antarctica. These

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

s are adapted for

swimming Swimming is the self-propulsion of a person through water, such as saltwater or freshwater environments, usually for recreation, sport, exercise, or survival. Swimmers achieve locomotion by coordinating limb and body movements to achieve hydrody ...

, floating on the water surface, and, in some cases, diving in at least shallow water. The family contains around 174 species in 43

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

(the

magpie goose The magpie goose (''Anseranas semipalmata'') is the sole living representative species of the family Anseranatidae. This common waterbird is found in northern Australia and southern New Guinea. As the species is prone to wandering, especially ...

is no longer considered to be part of the Anatidae and is now placed in its own family,

Anseranatidae Anseranatidae, the magpie-geese, is a biological family of waterbirds. The only living species, the magpie goose, is a resident breeder in northern Australia and in southern New Guinea. Systematics and evolution This family is placed in the orde ...

). They are generally herbivorous and are

monogamous Monogamy ( ) is a relationship of two individuals in which they form a mutual and exclusive intimate partnership. Having only one partner at any one time, whether for life or serial monogamy, contrasts with various forms of non-monogamy (e.g. ...

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 with

extinction Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce 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 t ...

, 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 304.8 cm (6 ft 2 in ...

, at as much as 183 cm (6 ft) and 17.2 kg (38 lb). The largest anatid ever known is the extinct flightless '' Garganornis ballmanni'' at 22 kg (49 lb). The wings are short and pointed, and supported by strong wing muscles that generate rapid beats in

flight Flight or flying is the motion (physics), motion of an Physical object, object through an atmosphere, or through the vacuum of Outer space, space, without contacting any planetary surface. This can be achieved by generating aerodynamic lift ass ...

. 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 (biology), order Podicipediformes (). Grebes are widely distributed freshwater birds, with some species also found in sea, marine habitats during Bird migration, migration and winter. Most grebes f ...

s or

petrel Petrels are tube-nosed seabirds in the phylogenetic order Procellariiformes. Description Petrels are a monophyletic group of marine seabirds, sharing a characteristic of a nostril arrangement that results in the name "tubenoses". Petrels enco ...

s. They typically have webbed feet, 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 (: 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 * Lame ...

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 sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

, 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'' w ...

). 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 evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat n ...

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

piscivorous A piscivore () is a carnivorous animal that primarily eats fish. Fish were the diet of early tetrapod evolution (via water-bound amphibians during the Devonian period); insectivory came next; then in time, the more terrestrially adapted rept ...

, 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

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 (; : penises or penes) is a sex organ through which male and hermaphrodite animals expel semen during copulation (zoology), copulation, and through which male placental mammals and marsupials also Urination, urinate. The term ''pen ...

, though they vary significantly in size, shape, and surface elaboration. Most species are adapted for copulation 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 Precocial species in birds and mammals are those in which the young are relatively mature and mobile from the moment of birth or hatching. They are normally nidifugous, meaning that they leave the nest shortly after birth or hatching. Altricial ...

, and are able to feed themselves from birth. One aberrant species, the black-headed duck, is an obligate

brood parasite Brood may refer to: Nature * Brood, a collective term for offspring * Brooding, the incubation of bird eggs by their parents * Bee brood, the young of a beehive * Individual broods of North American periodical cicadas: ** Brood X, the largest ...

, laying its eggs in the nests of

gull Gulls, or colloquially seagulls, are seabirds of the subfamily Larinae. They are most closely related to terns and skimmers, distantly related to auks, and even more distantly related to waders. Until the 21st century, most gulls were placed ...

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 usual ...

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

agricultural Agriculture encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created f ...

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 virus, bacterium, parasite, fungi, or prion) that can jump from a non-human vertebrate to a human. When h ...

such as

avian influenza Avian influenza, also known as avian flu or bird flu, is a disease caused by the influenza A virus, which primarily affects birds but can sometimes affect mammals including humans. Wild aquatic birds are the primary host of the influenza A viru ...

. Since 1600, five species of ducks have become

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

due to the activities of humans, and subfossil remains have shown that humans caused numerous extinctions in prehistory. Today, many more are considered threatened. 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 only 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 foun ...

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 als ...

. 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 or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...

and modification, and hybridisation with introduced ducks (for example the introduced ruddy duck swamping the white-headed duck 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

History of classification

The name Anatidae for the

was introduced by the English zoologist

William Elford Leach William Elford Leach (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 apprenticesh ...

in a guide to the contents of the

British Museum The British Museum is a Museum, public museum dedicated to human history, art and culture located in the Bloomsbury area of London. Its permanent collection of eight million works is the largest in the world. It documents the story of human cu ...

published in 1819. 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 and mDNA) is the DNA located in the mitochondria organelles in a eukaryotic cell that converts chemical energy from food into adenosine triphosphate (ATP). Mitochondrial DNA is a small portion of the DNA contained in ...

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 cal ...

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"). Because the

sample size Sample size determination or estimation 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 abo ...

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 or phylogeny is a graphical representation which shows the evolutionary history between a set of species or Taxon, taxa during a specific time.Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, M ...

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 more recent 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 ''cre ...

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 preserve ...

'' Vegavis iaai''—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 Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

s. The long period of

evolution Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...

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 Phenotypic trait, character shared by all members of a clade, which does not distinguish the clade from other clades. Plesiomorphy, symplesiomorph ...

ies, while apparent

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 ha ...

ies are quite often the result of parallel evolution, for example the "non-diving duck" type displayed by such unrelated genera as ''

Dendrocygna The whistling ducks or tree ducks are a subfamily, Dendrocygninae, of the duck, goose and swan family of birds, Anatidae. In other Taxonomy (biology), taxonomic schemes, they are considered a separate family (biology), family, Dendrocygnidae. S ...

'', '' 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 use of the term in English is in the discipline of anthropology. The definition is contested, in part due to conflict ...

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

clades In biology, a clade (), also known as a monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach to taxonomy ...

Genera

For the living and recently extinct members of each genus, see the article

List of Anatidae species The avian family Anatidae, commonly called waterfowl, comprise the ducks, geese, and swans. The International Ornithological Committee (IOC) recognizes these 174 Anatidae species distributed among 53 genera, 32 of which have only one species. Eig ...

. * Subfamily: Dendrocygninae (one pantropical genus, of distinctive long-legged goose-like birds) ** ''

'', 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 similaritie ...

'', white-backed duck Mute swan flies arp

* Subfamily:

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

, 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

s 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 Below may refer to: *Earth *Ground (disambiguation) *Soil *Floor * Bottom (disambiguation) *Less than *Temperatures below freezing *Hell or underworld People with the surname * Ernst von Below (1863–1955), German World War I general * Fred Belo ...

]) ** ''Swan, Cygnus'', true swans (6 species, 4 sometimes separated in ''Olor'') ** ''Anser (bird), Anser'', 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''), sometimes also known as the pig goose, is a species of goose endemic to southern Australia. It is a distinctive large, grey bird that is mostly terrestrial and is not closely related to oth ...

) ** '' Stictonetta'', freckled duck * Subfamily: Plectropterinae (one genus in Africa, formerly included in the "perching ducks", but closer to the Tadorninae) ** '' Plectropterus'', spur-winged goose * Subfamily:

Tadorninae The Tadornini is a biological tribe that includes the shelducks and sheldgeese, which is placed in subfamily Anatinae of family Anatinae, which includes the ducks and most duck-like waterfowl such as the geese and swans. It has been treated a ...

– 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 extinct NE, Ne or ne may refer to: Arts and entertainment * Neutral Evil, an alignment in the American role-playing game ''Dungeons & Dragons'' * New Edition, an American vocal group * Nicomachean Ethics, a collection of ten books by Greek philosopher Ar ...

in 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 Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

.) ** ''

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

) – possibly paraphyletic ** '' Radjah'', Radjah shelduck ** '' Salvadorina'', Salvadori's teal ** '' Centrornis'', Madagascar sheldgoose (

prehistoric Prehistory, also called pre-literary history, is the period of human history between the first known use of stone tools by hominins million years ago and the beginning of recorded history with the invention of writing systems. The use o ...

, tentatively placed here) ** '' Alopochen'', Egyptian goose and Mascarene shelducks (1 living species, 2

) ** '' Neochen'', (2 species) ** '' Chloephaga'', sheldgeese (4 species) ** '' Hymenolaimus'', 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 ...

'', 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 ...

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 Indo-Gangetic Plain, Gangetic plains of India, Nepal, parts of Maharashtra, Bangladesh and in the riverine swamps of Myanmar but has b ...

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

) ** ''

Aythya ''Aythya'' is a genus of diving ducks, with twelve species currently accepted. The genus was described in 1822 by the German zoologist Friedrich Boie, with the type species being greater scaup. The name ''Aythya'' comes from the Ancient Greek ...

'', 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 ...

, dabbling ducks and moa-nalos (The

dabbling duck 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 y ...

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 (island), Hawaii itself, in the Pacific. They were the major herbivores on most of these islands until they became extinct a ...

s, of which four species in three genera are known to date, are a peculiar group of flightless, extinct anatids from the

Hawaiian Islands The Hawaiian Islands () are an archipelago of eight major volcanic islands, several atolls, and numerous smaller islets in the Pacific Ocean, North Pacific Ocean, extending some from the Hawaii (island), island of Hawaii in the south to nort ...

. Gigantic in size and with massive bills, they were believed to be geese, but have been shown to be actually very closely related to

mallard The mallard () or wild duck (''Anas platyrhynchos'') is a dabbling duck that breeds throughout the temperate and subtropical Americas, Eurasia, and North Africa. It has been introduced to New Zealand, Australia, Peru, Brazil, Uruguay, Arge ...

s. 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 Resource (biology), resources an ...

of turtles,

ungulates Ungulates ( ) are members of the diverse clade Euungulata ("true ungulates"), which primarily consists of large mammals with hooves. Once part of the clade "Ungulata" along with the clade Paenungulata, "Ungulata" has since been determined to b ...

, and other

megaherbivore Megaherbivores (Greek :wiktionary:μέγας, μέγας megas "large" and Latin ''herbivora'' "herbivore") are large herbivores that can exceed in weight. The earliest herbivores to reach such sizes like the Pareiasauria, pareiasaurs appeare ...

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

) ** '' 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 ...

'', 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 (

) ** ''

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 found ...

'', large-billed moa-nalos (2 species,

) ** '' Ptaiochen'', small-billed moa-nalo (

) * 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 spend ...

, 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'' (

) ** ''

Polysticta Steller's eider (''Polysticta stelleri'') is a migrating Arctic diving duck that breeds along the coastlines of eastern Russia and Alaska. It is the rarest, smallest, and fastest flying of the eider species. Due to the extensive contraction of i ...

'', Steller's eider ** ''

Somateria The 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 q ...

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

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

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

) ** '' Melanitta'', scoters (6 species) ** ''

Clangula The long-tailed duck (''Clangula hyemalis'') or coween, 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 the only member of ...

'', long-tailed duck (1 species) ** '' Bucephala'', goldeneyes (3 species) ** '' Mergellus'', smew ** '' Lophodytes'', hooded merganser ** ''

Mergus ''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 Ancient Rome, Roman authors to refer to an unspecified waterbird. The common mer ...

'', mergansers (4 living species, 1

). * Tribe:

Oxyurini 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 ...

, 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 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 ...

bones found on

Kauai Kauai (), anglicized as Kauai ( or ), is one of the main Hawaiian Islands. It has an area of 562.3 square miles (1,456.4 km2), making it the fourth-largest of the islands and the 21st-largest island in the United States. Kauai lies 73 m ...

(

), 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. An archipelago may be in an ocean, a sea, or a smaller body of water. Example archipelagos include the Aegean Islands (the o ...

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 ''Branta rhuax'', the giant Hawaii goose, is an extinct goose endemic to the island of Hawaii. It was initially described as the monotypic genus ''Geochen'', but then reassigned to '' Branta'' by Storrs L. Olson in 2013 after reexamination of t ...

'' from the Big Island of

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

, and a gigantic goose-like anatid from

Oahu Oahu (, , sometimes written Oahu) is the third-largest and most populated island of the Hawaiian Islands and of the U.S. state of Hawaii. The state capital, Honolulu, is on Oahu's southeast coast. The island of Oahu and the uninhabited Northwe ...

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 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 ''

'') * '' Mionetta'' (Late Oligocene – Middle Miocene of Central Europe and Kazakhstan) – 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 Miocene of Germany) * '' Cygnopterus'' (Middle Oligocene of Belgium – Early Miocene of France) – sometimes included in ''Cygnavus'' * ''

Megalodytes ''Megalodytes'' is an extinct genus of waterfowl. The only known species, ''M. morejohni'', is known from fragmentary wingbones found in Middle Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and e ...

'' (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'' (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 The common shelduck (''Tadorna tadorna'') is a waterfowl species of the shelduck genus, ''shelduck, Tadorna''. It is widespread and common in the Euro-Siberian region of the Palearctic realm, Palearctic, mainly breeding in temperate and wintering ...

* ''

Anabernicula ''Anabernicula'' is an extinct genus of waterfowl related to shelducks that existed from the Pliocene to the Pleistocene in North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Weste ...

'' (Late Pliocene ? – Late Pleistocene of SW and W North America) * '' Brantadorna'' (Middle Pleistocene of Vallecito Creek, US) * '' Nannonetta'' (Late Pleistocene of Peru) * '' Zqueheanas'' (Miocene of Argentina)

* '' Sinanas'' (Middle Miocene of Shandong Province, China) * '' Wasonaka'' (Middle Pliocene of Mexico) Oxyurinae * '' Dunstanetta'' (Bathans Early/Middle Miocene of Otago, New Zealand) – tentatively placed here * '' Lavadytis'' (Miocene of Nevada, USA) * '' Pinpanetta'' (Late Oligocene – Early Miocene of Australia) * '' Tirarinetta'' (Pliocene of Australia) ''

Incertae sedis or is a term used for a taxonomy (biology), 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, uncertainty ...

'' * '' Aldabranas'' (Late Pleistocene of Aldabra, Indian Ocean) – anatine or tadornine* ''"Anas" albae'' (Late Miocene of Polgárdi, Hungary) – mergine? Formerly in ''Mergus'' * ''"Anas" eppelsheimensis'' (Early Pliocene of Eppelsheim, Germany) – anatine? * ''"Anas" isarensis'' (Late Miocene of Aumeister, Germany) – anatine? * ''"Anas" luederitzensis'' (Kalahari Early Miocene of Lüderitzbucht, Namibia) – anatine? * ''"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 is a term used for a taxonomy (biology), 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, uncertainty ...

''. * '' Ankonetta larriestrai'' (Miocene of Argentina) * ''"Anser" scaldii'' (Late Miocene of Antwerp, Belgium) – anserine or tadornine* Anatidae gen. et sp. indet. (Waite Late Miocene of Alcoota, Australia) – anatine, oxyurine? * ''"Anas" velox'' (Middle–Late? Miocene of C Europe) – anatine? May include ''"A." meyerii'' * Anatidae gen. et sp. indet. (Waite Late Miocene of Alcoota, Australia) – tadornine? * Anatidae gen. et sp. indet. MNZ S42797 (Bathans Early/Middle Miocene of Otago, New Zealand) * Anatidae gen. et sp. indet. (Middle Miocene of Nördlinger Ries, Germany) – tadornine? * Anatidae gen. et sp. indet. (Sajóvölgyi Middle Miocene of Mátraszõlõs, Hungary) * ''"Aythya" chauvirae'' (Middle Miocene of Sansan, France and Credinţa, Romania) – 2 species * '' Caerulonettion'' (Early Miocene of France and the Czech Republic, Middle Miocene of Germany) * '' Cayaoa'' (Early Miocene of Argentina) * ''"Chenopis" nanus'' (Pleistocene of Australia) – at least 2 taxa, may be living species * ''

Garganornis ''Garganornis'' (meaning "Gargano bird") is an extinct genus of enormous flightless anatidae, anatid waterfowl from the Late Miocene of Gargano, Italy. The genus contains one species, ''G. ballmanni'', named by Meijer in 2014. Its island gig ...

'' (Late Miocene of Gargano, Italy) * '' Gracanicanetta'' (Middle Miocene of Bosnia and Herzegovina) * '' Lavanttalornis'' (Middle Miocene of Austria) * '' Matanas'' (Bathans Early/Middle Miocene of Otago, New Zealand) * '' Mioquerquedula'' (Middle Miocene of Mongolia) * ''"Oxyura" doksana'' (Early Miocene of Dolnice, Czech Republic) * '' Protomelanitta'' (Middle Miocene of Mongolia and Nevada, USA) * '' Uyrekura'' (Early Oligocene of Kazakhstan) 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 (biology), family of large seabirds. Their fossil remains have been found all over the wor ...

(same as '' Caspiodontornis''?) * '' Chenornis'' (Early Miocene) – anserine or Phalacrocoracidae * '' Paranyroca'' (Rosebud Early Miocene of Bennett County, US) – anatid (own subfamily) or distinct family? * '' Eoneornis'' (Miocene of Argentina) – anatine? A ''

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium,'' it may be impossible to determine whether a ...

'' * '' Eutelornis'' (Miocene of Argentina) – anatine? The Middle Oligocene '' Limicorallus'' (from Chelkar-Teniz (

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a landlocked country primarily in Central Asia, with a European Kazakhstan, small portion in Eastern Europe. It borders Russia to the Kazakhstan–Russia border, north and west, China to th ...

) was sometimes considered an anserine. It is now recognized as a primitive

cormorant 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 International Ornithologists' Union (IOU) ado ...

. The middle Eocene ''

Eonessa ''Eonessa'' is an enigmatic genus of Aves, bird possibly belonging to Aves, bird order Gruiformes and which consists of the single species ''Eonessa anaticula''. It was first described by Alexander Wetmore in the ''Journal of Paleontology'' in ...

'' 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 {{Authority control Bird families Waterfowl Extant Rupelian first appearances Taxa named by William Elford Leach

Description and ecology

Breeding

Relationship with humans

Systematics

History of classification

Genera

Prehistoric species

Fossil Anatidae

See also

References

Further reading

External links