The Tadorninae is the shelduck-sheldgoose

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus Genus ( plural genera ) is a taxonomic rank used in the biological classifica ...

of the

Anatidae The Anatidae are the biological family of water birds that includes ducks, geese, and swans. The family has a cosmopolitan distribution, occurring on all the world's continents except Antarctica. These birds are adapted for swimming, flo ...

, 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 ...

that includes the

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 ...

s and most duck-like waterfowl such as the

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

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

s. This group is largely tropical or Southern Hemisphere in distribution, with only two species, the

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

and the

ruddy shelduck The ruddy shelduck (''Tadorna ferruginea''), known in India as the Brahminy duck, is a member of the family Anatidae. It is a distinctive waterfowl, in length with a wingspan of . It has orange-brown body plumage with a paler head, while the ...

breeding in northern temperate regions, though the

crested shelduck The crested shelduck (''Tadorna cristata''), or Korean crested shelduck, is a species of bird in the family Anatidae. It is critically endangered and may be extinct. The male crested shelduck has a greenish-black crown, breast, primaries, and ta ...

(presumed extinct) was also a northern species. Most of these species have a distinctive plumage, but there is no pattern as to whether the sexes are alike, even within a single

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

Systematics

Following the review of Livezey (1986), several species formerly classified as aberrant

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 yo ...

s or as "

perching duck The term perching ducks is used colloquially to mean any species of ducks distinguished by their readiness to perch high in trees Until the late 20th century, perching ducks meant ''Cairinini'', a tribe of ducks in the duck, goose and swan family ...

s" were placed in the Tadorninae.

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 called ...

analyses cast doubt on the allocation of several genera; many supposed dabbling ducks and one peculiar goose may more correctly belong here, while some genera believed to be close to shelducks appear to have different relationships altogether. The available data indicates that the Tadorninae are indeed, as their appearance suggests, somewhat intermediate between geese and dabbling ducks, but the molecular data suggests they are not the only lineage to evolve towards a more duck-like morphology, with the diving ducks and

seaduck 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 ...

s being more distant.

Family Anatidae

Subfamily Tadorninae

*Unequivocally placed in this group: **''

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 biologi ...

'': shelducks (Europe, Africa, Australasia; 6 species) – possibly

paraphyletic In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and most of its descendants, excluding a few monophyletic subgroups. The group is said to be paraphyletic ''with respect to'' the excluded subgroups. In ...

**'' Radjah'': Radjah shelduck (Australia, New Guinea) **'' Centrornis'': Madagascar sheldgoose (Madagascar,

prehistoric Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The us ...

) **''

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 ...

'': Egyptian goose, and extinct African and Mascarene shelducks (Africa and Madagascar region; 1 living species, 2–3

extinct 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 ...

) **'' Neochen'': Orinoco goose and Andean goose (South America) **''

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 (South America; 4 species) **'' Hymenolaimus'': blue duck (New Zealand)—formerly in "perching ducks" **'' Merganetta'': torrent duck (Andes mountains, South America) – formerly in "perching ducks" *Provisionally placed in this group: **'' Malacorhynchus'': pink-eared ducks (Australia; 1 living species, 1

) – may be closer to Oxyurinae **'' Cyanochen'': blue-winged goose (Ethiopia) – may belong to a distinct subfamily **'' Tachyeres'': steamer ducks (South America; 4 species) – may belong to Anatinae **'' Plectropterus'': spur-winged goose (sub-Saharan Africa) – may be in monotypic subfamily *May belong to Tadorninae, currently placed elsewhere: **''

Aix Aix or AIX may refer to: Computing * AIX, a line of IBM computer operating systems *An Alternate Index, for a Virtual Storage Access Method Key Sequenced Data Set * Athens Internet Exchange, a European Internet exchange point Places Belgiu ...

'': Mandarin duck and wood duck (East Asia and North America, respectively) **''

Cairina moschata 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 ...

'': Muscovy duck (tropical America; genus

Cairina 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 ...

may be paraphyletic) **''

Cereopsis 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 known ...

'': Cape Barren goose (Australia) **'' Callonetta'': ringed teal (South America) **''

Chenonetta ''Chenonetta'' is a genus of dabbling duck. One species is extinct, while the other is extant. Species The genus includes the following two species: * Australian wood duck (''Chenonetta jubata'') *Finsch's duck Finsch's duck (''Chenonetta f ...

'': maned duck (Australia and formerly New Zealand; 1 living species, 1

) **'' Salvadorina'': Salvadori's teal (New Guinea)—formerly in Anatidae and "perching ducks"

References

{{Taxonbar, from=Q21153 Bird subfamilies Ducks Taxa named by Ludwig Reichenbach