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Anatinae

(Subfamily)

Overview

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The Anatinae is a 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-nalos, a young but highly apomorphic lineage derived from the dabbling ducks.

There has been much debate about the dabbling ducks' systematical status and what ducks belong to the Anatinae. As understood here, the subfamily contains only the dabbling ducks and their close relatives, the extinct moa-nalos. Alternatively1], the Anatinae are considered to include most "ducks" and the dabbling ducks form a tribe Anatini within these. The classification as presented here more appropriately reflects the remaining uncertainty about the interrelationships of the major lineages of Anatidae (waterfowl)[2].

Systematics

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The dabbling duck group, of worldwide distribution, was delimited in a 1986 study[3] to include 8 genera and some 50-60 living species. However, Salvadori's Teal is almost certainly closely related to the Pink-eared Duck[citation needed], and other genera are likewise of unresolved affiliation[4][2]. The peculiar Marbled Duck, formerly tentatively assigned to the dabbling ducks, is actually a diving duck or even a distinct subfamily[2].

This group of ducks is so named because its members feed mainly on vegetable matter by upending on the water surface, or grazing, and only rarely dive. These are mostly gregarious ducks of freshwater or estuaries. These birds are strong fliers and northern species are highly migratory. Compared to other types of duck, their legs are placed more towards the centre of their bodies. They walk well on land, and some species feed terrestrially.

Puddle ducks generally feed on the surface of the water or feed on very shallow bottoms. They are not equipped to dive down several feet like their diving counterparts. The most predominant difference between puddle ducks and divers are the size of the feet. Puddle ducks feet are generally smaller because they do not need the extra propulsion to dive for their forage.

Another distinguishing characteristic of puddle ducks when compared to diving ducks is the way in which they take flight when spooked or are on the move. Puddle ducks spring straight up from the water and diving ducks need to gain momentum to take off, so they must run across the water a short distance to gain flight.

History of Classification

Traditionally, most ducks were assigned to either the shelducks, the perching ducks, and the dabbling and diving ducks; the latter two were presumed to make up the Anatinae. However, the perching ducks turned out to be a paraphyletic assemblage of various tropical waterfowl that simply had happened to evolve the ability to perch well in their forested habitat. Several of these, such as the Brazilian Duck, were subsequently assigned to the Anatinae.

As for the diving ducks, mtDNA cytochrome b and NADH dehydrogenase subunit 2 sequence data[2] indicates that they are fairly distant from the dabbling ducks, the morphological similarities[3] being due to convergent evolution.

In addition, the genus Anas as traditionally defined is not monophyletic; several South American species belong to a distinct clade which would include the Tachyeres steamer-ducks[2], and other species such as the Baikal Teal should also be considered distinct. See the genus article for more on this subject.

Genera

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The Baikal Teal
Spotbill, Anas poecilorhyncha in Hyderabad, India.

The following genera are (with one exception) unequivocal dabbling ducks:

The 3 known genera and 4 known species of moa-nalos are went extinct around 1000 AD. They formerly occurred on the Hawaiian Islands and were derived from dabbling ducks, possibly even a close ancestor of the mallard:

The Comb Duck: a misplaced dabbling duck?

Subfossil remains of a small, flightless dabbling duck have been recovered on Rota in the Mariana Islands[5]. These cannot be assigned to a known genus, but probably are closest to Anas. A most bizarre ducklike fowl has been found on the Hawaiian island of Kaua?i[6]. Due to its unique apomorphies (it seems to have had small eyes high and far back on its head) the placement of this anatid is likewise unresolved; only dabbling ducks and true geese are with certainty known to have colonized the Hawaiian chain.

Frequently placed into the Anatinae are these genera, whose relationships must be considered uncertain at present:

On the other hand, the following genera, usually considered to belong into the Tadorninae, may actually be dabbling ducks:

Photos

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Taxonomy

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The Subfamily Anatinae is a member of the Family Anatidae. Here is the complete "parentage" of Anatinae:

The Subfamily Anatinae is further organized into finer groupings including:

Genera

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Aix

[more]

Alopochen

The Egyptian Goose (Alopochen aegyptiacus) is a member of the , goose and swan family Anatidae. It is in the shelduck subfamily Tadorninae, and is the only extant member of the genus Alopochen. mtDNA cytochrome b sequence data suggest that the relationships of Alopochen to Tadorna need further investigation (Sraml et al. 1996). [more]

Amazonetta

The Brazilian Duck or Brazilian Teal (Amazonetta brasiliensis) is the only in the genus Amazonetta. It was formerly considered a "perching duck", but more recent analyses indicate that it belongs to a clade of South American dabbling ducks which also includes the Crested Duck, the Bronze-winged Duck, and possibly the steamer ducks (Johnson & Sorenson, 1999). [more]

Anas

Anas is a of dabbling ducks. It includes mallards, wigeons, teals, pintails and shovelers in a number of subgenera. Some authorities prefer to elevate the subgenera to genus rank. Indeed, as the moa-nalos are very close to this clade and may have evolved later than some of these lineages, it is rather the absence of a thorough review than lack of necessity that this genus is rather over-lumped. [more]

Anser

The word anser comes from Latin, meaning goose, and can refer to: [more]

Aythya

Aythya is a of diving ducks. [more]

Branta

The black geese of the Branta are waterfowl belonging to the true geese and swans subfamily Anserinae. They occur in the northern coastal regions of the Palearctic and all over North America, migrating to more southernly coasts in winter, and as resident birds in the Hawaiian Islands. A self-sustaining population derived from introduced birds of one species is also found in New Zealand; these are the only true geese ever to occur in the Southern Hemisphere in a wild (or rather feral in this case) state. [more]

Bucephala

[more]

Cairina

Cairina is a of ducks in the bird family Anatidae. [more]

Callonetta

The Ringed Teal (Callonetta leucophrys) is a small of South American forests. It is the only species of the genus Callonetta. Usually placed with the dabbling ducks (Anatinae), this species may actually be closer to shelducks and belong in the subfamily Tadorninae; its closest relative is possibly the Maned Duck. [more]

Camptorhynchus

The Labrador Duck, Camptorhynchus labradorius, was a striking black and white -like sea duck that was never known to be common, and is believed to be the first bird to become extinct in North America after 1500. The last Labrador Duck is believed to have been seen at Elmira, New York on ; the last preserved specimen was shot in 1875 on Long Island. It was thought to breed in Labrador, although no nests were ever described, and it wintered from Nova Scotia to as far south as Chesapeake Bay. [more]

Casarca

[more]

Cereopsis

The Cape Barren Goose, Cereopsis novaehollandiae is a large resident in southern Australia. [more]

Chenonetta

The Australian Wood Duck or Maned Duck, Chenonetta jubata, is a found throughout much of Australia. It is the only living species in the genus Chenonetta. Traditionally placed in the Anatinae (dabbling duck) subfamily, it might actually belong to the Tadorninae (shelduck) subfamily (Sraml et al. 1996); possibly, the Ringed Teal is its closest living relative (Johnson & Sorenson 1999). [more]

Chloephaga

Chloephaga is the sheldgeese in the bird family Anatidae. [more]

Clangula

The Long-tailed Duck (Clangula hyemalis) is a medium-sized . It is the only living member of its genus, Clangula; this was formerly used for the goldeneyes, with the Long-tailed Duck being placed in Harelda. An undescribed congener is known from the Middle Miocene Sajóvölgyi Formation (Late Badenian, 13-12 mya) of Mátraszőlős, Hungary (Gál et al. 1998-99). [more]

Cyanochen

The Blue-winged Goose (Cyanochen cyanoptera) is a large , which is endemic to Ethiopia. It is the only member of the genus Cyanochen. Placement of this species in the waterfowl phylogeny is unresolved; while it is morphologically closest to shelducks[citation needed] and resembles sheldgeese in habitus, mtDNA sequence analyses of the cytochrome b and NADH dehydrogenase subunit 2 genes indicates that it might belong to a very distinct and ancient "duck" clade, perhaps together with Hartlaub's Duck. Interestingly, the wing color pattern - the best morphological indicator of evolutionary relationships in waterfowl - is nearly identical in these two species, and very different from any other anatid. [more]

Histrionicus

The Harlequin Duck, Histrionicus histrionicus, is a small . In North America it is also known as Lords and ladies. Other names include painted duck, totem pole duck, rock duck, glacier duck, mountain duck, white-eyed diver, squeaker and blue streak. [more]

Hymenolaimus

The Blue Duck (Hymenolaimus malacorhynchos) is a member of the , goose and swan family Anatidae. It is the only member of the genus Hymenolaimus, placed in the shelduck subfamily Tadorninae[citation needed] after previously being considered part of the paraphyletic "perching duck" assemblage. The Maori name is whio, which is an onomatopoetic rendition of the males' call. the blue duck is born with a green beak for just 8 hours after birth ; where it then develops to its final color. [more]

Lophodytes

The Hooded Merganser (Lophodytes cucullatus) is a small and is the only member of the genus Lophodytes. [more]

Lophonetta

The Crested Duck (Lophonetta specularioides) is a of duck native to South America, the only member of the monotypic genus Lophonetta. It is sometimes included in Anas, but it belongs to a South American clade that diverged early in dabbling duck evolution (Johnson & Sorenson, 1999). There are two subspecies: L. specularioides alticola (Andean Crested Duck) and L. specularioides specularioides (Southern Crested Duck). The Southern Crested Duck is also called the Patagonia Crested Duck and its range is the Falklands, Chile, and Argentina. [more]

Malacorhynchus

The Pink-eared Duck (Malacorhynchus membranaceus) is a species of found in Australia. It has a large spatulate bill like the Australasian Shoveler, but is smaller at 38-40 cm length. Its brown back and crown, black and white barred sides and black eye patches on its otherwise white face make this bird unmistakable. Juveniles are slightly duller, but otherwise all plumages are similar. Its vernacular name refers to a pink spot in the corner formed by the black head pattern; it is only noticeable at close distance however, making the seldom-used Australian name of Zebra Duck more appropriate. [more]

Marmaronetta

The Marbled Duck, or Marbled Teal (Marmaronetta angustirostris), is a medium-sized . It used to be included among the dabbling ducks, but is now classed as a diving duck. [more]

Melanitta

The scoters are stocky in the genus Melanitta. The drakes are mostly black and have swollen bills. Females are brown. [more]

Merganetta

The Torrent Duck (Merganetta armata) is a member of the , goose and swan family Anatidae. It is the only member of the genus Merganetta. Nowadays, it is placed in the shelduck subfamily Tadorninae after the "perching duck" assemblage where it was formerly assigned to was dissolved because it turned out to be paraphyletic[citation needed]. Its closest relative may be the Blue Duck of New Zealand[citation needed]. [more]

Mergellus

The Smew (Mergellus albellus) is a small which is somewhat intermediate between the typical mergansers (Mergus) and the goldeneyes (Bucephala). It is the only member of the genus Mergellus; sometimes included in Mergus, this genus is well distinct (though closely related) and might actually be a bit closer to the goldeneyes. The Smew has interbred with the Common Goldeneye (B. clangula). [more]

Mergus

Mergus is the of the typical mergansers, fish-eating ducks in the seaduck subfamily (Merginae). The Hooded Merganser, often termed Mergus cucullatus, is not of this genus but closely related. The other "aberrant" merganser, the Smew (Mergellus albellus), is phylogenetically closer to goldeneyes (Bucephala). [more]

Neochen

The Orinoco Goose (Neochen jubata ) is a member of the , goose and swan family Anatidae. It is in the shelduck subfamily Tadorninae, and is the only living member of the genus Neochen. Two fossil relatives have been described from Late Pleistocene sites: Neochen pugil and Neochen debilis of Brazil and Argentina, respectively. [more]

Netta

Netta is a genus of . Unlike other diving ducks, the Netta species are reluctant to dive, and feed more like dabbling ducks. [more]

Nettapus

The pygmy geese are a group of very small "" in the genus Nettapus which breed in the Old World tropics. They are the smallest of all wildfowl. As the "perching ducks" are a paraphyletic group (Livezey 1986), they need to be placed elsewhere. The initially assumed relationship with the dabbling duck subfamily Anatinae[citation needed] has been questioned, and it appears they form a lineage in an ancient Gondwanan radiation of waterfowl, within which they are of unclear affinities (Sraml et al. 1996). [more]

Plectropterus

The Spur-winged Goose, (Plectropterus gambensis), is a large 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, the Plectropterinae. It occurs in wetlands throughout sub-Saharan Africa. [more]

Polysticta

The Steller's Eider (Polysticta stelleri) is a medium-large , which breeds along the Arctic coasts of eastern Siberia and Alaska. The lined nest is built on tundra close to the sea, and 6-10 eggs are laid. [more]

Pseudotadorna

[more]

Pteronetta

The Hartlaub's Duck (Pteronetta hartlaubii) is a dark chestnut-colored of African forests. Formerly included in the paraphyletic "perching duck" assemblage, it was later moved to the dabbling duck assemblage. However, it is fairly distinct from the "typical" dabbling ducks, and is placed in the monotypic genus Pteronetta to reflect this. [more]

Rhodonessa

The Pink-headed Duck (Rhodonessa caryophyllacea) is (or was) a large that was once found in parts of the Gangetic plains of India, Bangladesh and in the riverine swamps of Myanmar but feared extinct since the 1950s. Numerous searches have failed to provide any proof of continued existence. It has been suggested that it may exist in the inaccessible swamp regions of northern Myanmar and some sight reports from that region have led to its status being declared as "critically endangered" rather than extinct. The genus placement has been disputed and while some have suggested that it is closer to the pochards, others have placed it in a separate genus of its own. [more]

Salvadorina

The Salvadori's Teal or Salvadori's Duck (Salvadorina waigiuensis) is a of bird native to New Guinea. It is placed in the monotypic genus Salvadorina. [more]

Sarkidiornis

The Comb Duck (Sarkidiornis melanotos), formerly known as the Knob-billed Duck, is an unusual, pan-tropical , found in tropical wetlands in sub-Saharan Africa, Madagascar and south Asia from Pakistan to Laos and extreme southern China. It also occurs in continental South America south to the Paraguay River region in eastern Paraguay, southeastern Brazil and the extreme northeast of Argentina, and as a vagrant on Trinidad. [more]

Somateria

Eiders are large in the genus Somateria. Steller's Eider, despite its name, is in a different genus. [more]

Tachyeres

Tachyeres (Steamer Ducks) is a of ducks in the bird family Anatidae. All of the four species occur in South America, and all except T. patachonicus are flightless; even this one species capable of flight rarely takes to the air. [more]

Tadorna

The Shelducks, genus Tadorna, are a group of large birds in the subfamily of the Anatidae, the biological family that includes the ducks and most duck-like waterfowl such as the geese and swans. [more]

At least 11 species and subspecies belong to the Genus Tadorna.

More info about the Genus Tadorna may be found here.

References

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Footnotes

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  1. ^ Terres, J. & NAS (1991)
  2. ^ a b c d e Johnson, K. & Sorenson, M. (1999)
  3. ^ a b Livezey, B. (1986)
  4. ^ Sraml, M. et al. (1996)
  5. ^ Steadman, D. (1999)
  6. ^ Burney, D. et al. (2001)

Sources

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Last Revised: January 24, 2010
2010/01/24 03:51:32