Diving duck
Encyclopedia
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 the diverse and very large Anatidae
family
that includes ducks, geese
, and swan
s.
The diving ducks are placed in a distinct subfamily, Aythyinae. While morphologically
close to the dabbling ducks, there are nonetheless some pronounced differences such as in the structure of the trachea
. mtDNA cytochrome b
and NADH dehydrogenase
subunit
2 sequence
data indicate that the dabbling and diving ducks are fairly distant from each other, the outward similarities being due to convergent evolution
.
Alternatively, the diving ducks are placed as a tribe
Aythyini in a subfamily Anatidae which would encompass all duck-like birds except the whistling-ducks.
The seaducks commonly found in coastal areas, such as the Long-tailed Duck
(formerly known in the US as Oldsquaw), scoter
s, goldeneye
s, mergansers, bufflehead
and eider
s, are also sometimes colloquially referred to in North America as diving ducks because they also feed by diving; their subfamily (Merginae) is a very distinct one however.
Although the group is cosmopolitan
, most members are native to the northern hemisphere
, and it includes several of the most familiar northern hemisphere ducks.
This group of ducks is so named because its members feed mainly by diving, although in fact the Netta species are reluctant to dive, and feed more like dabbling ducks.
These are gregarious ducks, mainly found on fresh water or on estuaries, though the Greater Scaup
becomes marine during the northern winter. They are strong fliers; their broad, blunt-tipped wings require faster wing-beats than those of many ducks and they take off with some difficulty. Northern species tend to be migratory
; southern species do not migrate though the Hardhead
travels long distances on an irregular basis in response to rainfall. Diving ducks do not walk as well on land as the dabbling ducks; their legs tend to be placed further back on their bodies to help propel them when underwater.
are included in the Aythyini. The Marbled Duck
which makes up the monotypic
genus Marmaronetta, however, seems very distinct and might have diverged prior to the split of dabbling and diving ducks as indicated by morphological and molecular characteristics. The probably extinct Pink-headed Duck
, previously treated separately in Rhodonessa, has been suggested to belong into Netta, but this approach has been questioned. DNA sequence
analyses, which would probably resolve this question, have not been conducted to date for lack of suitable material. It might be an early divergence from the dabbling duck lineage. The molecular analysis also suggests that the White-winged Duck should be placed into a monotypic
genus Asarcornis which is fairly close to Aythya and might belong into this subfamily.
FAMILY ANATIDAE
Duck
Duck is the common name for a large number of species in the Anatidae family of birds, which also includes swans and geese. The ducks are divided among several subfamilies in the Anatidae family; they do not represent a monophyletic group but a form taxon, since swans and geese are not considered...
which feed by diving beneath the surface of the water. They are part of the diverse and very large Anatidae
Anatidae
Anatidae is the biological family of birds that includes ducks, geese and swans. The family has a cosmopolitan distribution, occurring on all the world's continents except Antarctica and on most of the world's islands and island groups...
family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
that includes ducks, geese
Goose
The word goose is the English name for a group of waterfowl, belonging to the family Anatidae. This family also includes swans, most of which are larger than true geese, and ducks, which are smaller....
, and swan
Swan
Swans, genus Cygnus, are birds of the family Anatidae, which also includes geese and ducks. Swans are grouped with the closely related geese in the subfamily Anserinae where they form the tribe Cygnini. Sometimes, they are considered a distinct subfamily, Cygninae...
s.
The diving ducks are placed in a distinct subfamily, Aythyinae. While morphologically
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
close to the dabbling ducks, there are nonetheless some pronounced differences such as in the structure of the trachea
Vertebrate trachea
In tetrapod anatomy the trachea, or windpipe, is a tube that connects the pharynx or larynx to the lungs, allowing the passage of air. It is lined with pseudostratified ciliated columnar epithelium cells with goblet cells that produce mucus...
. mtDNA cytochrome b
Cytochrome b
Cytochrome b/b6 is the main subunit of transmembrane cytochrome bc1 and b6f complexes. In addition, it commonly refers to a region of mtDNA used for population genetics and phylogenetics.- Function :...
and NADH dehydrogenase
NADH dehydrogenase
NADH dehydrogenase is an enzyme located in the inner mitochondrial membrane that catalyzes the transfer of electrons from NADH to coenzyme Q...
subunit
Protein subunit
In structural biology, a protein subunit or subunit protein is a single protein molecule that assembles with other protein molecules to form a protein complex: a multimeric or oligomeric protein. Many naturally occurring proteins and enzymes are multimeric...
2 sequence
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...
data indicate that the dabbling and diving ducks are fairly distant from each other, the outward similarities being due to convergent evolution
Convergent evolution
Convergent evolution describes the acquisition of the same biological trait in unrelated lineages.The wing is a classic example of convergent evolution in action. Although their last common ancestor did not have wings, both birds and bats do, and are capable of powered flight. The wings are...
.
Alternatively, the diving ducks are placed as a tribe
Tribe (biology)
In biology, a tribe is a taxonomic rank between family and genus. It is sometimes subdivided into subtribes.Some examples include the tribes: Canini, Acalypheae, Hominini, Bombini, and Antidesmeae.-See also:* Biological classification* Rank...
Aythyini in a subfamily Anatidae which would encompass all duck-like birds except the whistling-ducks.
The seaducks commonly found in coastal areas, such as the Long-tailed Duck
Long-tailed Duck
The Long-tailed Duck or Oldsquaw is a medium-sized sea duck. 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...
(formerly known in the US as Oldsquaw), scoter
Scoter
The scoters are stocky seaducks in the genus Melanitta. The drakes are mostly black and have swollen bills. Females are brown.They breed in the far north of Europe, Asia and North America, and winter further south in temperate zones of those continents. They form large flocks on suitable coastal...
s, goldeneye
Goldeneye (duck)
Goldeneye are small tree-hole nesting northern hemisphere seaducks belonging to the genus Bucephala. Their plumage is black and white, and they eat fish, crustaceans and other marine life....
s, mergansers, bufflehead
Bufflehead
The Bufflehead is a small American sea duck of the genus Bucephala, the goldeneyes. This species was first described by Linnaeus in his Systema naturae in 1758 as Anas albeola.-Description:...
and eider
Eider
Eiders are large seaducks in the genus Somateria. Steller's Eider, despite its name, is in a different genus.The three extant species all breed in the cooler latitudes of the Northern hemisphere....
s, are also sometimes colloquially referred to in North America as diving ducks because they also feed by diving; their subfamily (Merginae) is a very distinct one however.
Although the group is cosmopolitan
Cosmopolitan distribution
In biogeography, a taxon is said to have a cosmopolitan distribution if its range extends across all or most of the world in appropriate habitats. For instance, the killer whale has a cosmopolitan distribution, extending over most of the world's oceans. Other examples include humans, the lichen...
, most members are native to the northern hemisphere
Northern Hemisphere
The Northern Hemisphere is the half of a planet that is north of its equator—the word hemisphere literally means “half sphere”. It is also that half of the celestial sphere north of the celestial equator...
, and it includes several of the most familiar northern hemisphere ducks.
This group of ducks is so named because its members feed mainly by diving, although in fact the Netta species are reluctant to dive, and feed more like dabbling ducks.
These are gregarious ducks, mainly found on fresh water or on estuaries, though the Greater Scaup
Greater Scaup
The Greater Scaup , just Scaup in Europe, or colloquially known as "Bluebill", for its bright blue bill, is small compared to other diving ducks, however it is larger than the closely related Lesser Scaup...
becomes marine during the northern winter. They are strong fliers; their broad, blunt-tipped wings require faster wing-beats than those of many ducks and they take off with some difficulty. Northern species tend to be migratory
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
; southern species do not migrate though the Hardhead
Hardhead
The Hardhead, Aythya australis, is the only true diving duck found in Australia. Hardheads are common in the south-east of Australia, particularly in the Murray-Darling Basin, but also in the wetter country near the coasts. They are moderately nomadic in normal years, but disperse widely in times...
travels long distances on an irregular basis in response to rainfall. Diving ducks do not walk as well on land as the dabbling ducks; their legs tend to be placed further back on their bodies to help propel them when underwater.
Systematics
Three generaGenus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
are included in the Aythyini. The Marbled Duck
Marbled Duck
The Marbled Duck, or Marbled Teal , is a medium-sized duck. It used to be included among the dabbling ducks, but is now classed as a diving duck....
which makes up the monotypic
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
genus Marmaronetta, however, seems very distinct and might have diverged prior to the split of dabbling and diving ducks as indicated by morphological and molecular characteristics. The probably extinct Pink-headed Duck
Pink-headed Duck
The Pink-headed Duck is a large diving duck 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...
, previously treated separately in Rhodonessa, has been suggested to belong into Netta, but this approach has been questioned. DNA sequence
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...
analyses, which would probably resolve this question, have not been conducted to date for lack of suitable material. It might be an early divergence from the dabbling duck lineage. The molecular analysis also suggests that the White-winged Duck should be placed into a monotypic
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
genus Asarcornis which is fairly close to Aythya and might belong into this subfamily.
- Subfamily Aythyinae: diving ducks
- Genus Marmaronetta
- Marbled DuckMarbled DuckThe Marbled Duck, or Marbled Teal , is a medium-sized duck. It used to be included among the dabbling ducks, but is now classed as a diving duck....
Marmaronetta angustirostris
- Marbled Duck
- Genus NettaNettaNetta is a genus of diving ducks. Unlike other diving ducks, the Netta species are reluctant to dive, and feed more like dabbling ducks.These are gregarious ducks, mainly found on fresh water...
(provisionally including Rhodonessa)- Pink-headed DuckPink-headed DuckThe Pink-headed Duck is a large diving duck 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...
Rhodonessa caryophyllacea ; probably extinct (1945?) - Red-crested PochardRed-crested PochardThe Red-crested Pochard is a large diving duck.Their breeding habitat is lowland marshes and lakes in southern Europe and southern and central Asia. They are somewhat migratory, and northern birds winter further south and into north Africa.The adult male is unmistakable. It has a rounded orange...
Netta rufina - Southern PochardSouthern PochardThe Southern Pochard is a duck.There are two subspecies, the South American Pochard N. e. erythrophthalma and the African Pochard N. e...
Netta erythrophthalma - Rosy-billed Pochard Netta peposaca
- Pink-headed Duck
- Genus AythyaAythyaAythya is a genus of diving ducks. It has twelve described species.Aythya shihuibas was described from the Late Miocene of China. An undescribed prehistoric species is known only from Early Pleistocene fossil remains found at Dursunlu, Turkey; it might however be referrable to a paleosubspecies of...
- CanvasbackCanvasbackThe Canvasback is the largest of the North American diving ducks, that ranges from between long and weighs approximately , with a wingspan of . The canvasback has a distinctive wedge-shaped head and long graceful neck. The adult male has a black bill, a chestnut red head and neck, a black...
Aythya valisineria - Common Pochard Aythya ferina
- RedheadRedhead (duck)The Redhead is a medium-sized diving duck, 37 cm long with an 84 cm wingspan.The adult male has a blue bill, a red head and neck, a black breast, yellow eyes and a grey back. The adult female has a brown head and body and a darker bluish bill with a black tip.The breeding habitat is...
Aythya americana - Ring-necked DuckRing-necked DuckThe Ring-necked Duck is a smaller diving duck from North America.The adult male is similar in color pattern to the Eurasian Tufted Duck, its relative. It has a grey bill with a white band, a shiny purple head, a white breast, yellow eyes and a dark grey back...
Aythya collaris - HardheadHardheadThe Hardhead, Aythya australis, is the only true diving duck found in Australia. Hardheads are common in the south-east of Australia, particularly in the Murray-Darling Basin, but also in the wetter country near the coasts. They are moderately nomadic in normal years, but disperse widely in times...
Aythya australis - Baer's PochardBaer's PochardBaer's Pochard is a diving duck found in eastern Asia. It breeds in southeast Russia and northeast China, migrating in winter to southern China, Vietnam, Japan, and India. The name commemorates the Estonian naturalist Karl Ernst von Baer.At 41–46 cm, it is similar in size and stance to its...
Aythya baeri - Ferruginous DuckFerruginous DuckThe Ferruginous Duck is a medium-sized diving duck from Eurasia. The species is known colloquially by birders as "Fudge Duck"....
Aythya nyroca - Madagascar PochardMadagascar PochardThe Madagascar Pochard is an extremely rare diving duck of the genus Aythya, previously thought extinct. Prior to a rediscovery in 2006, the last confirmed sighting of the species was at Lake Alaotra on the Central Plateau of Madagascar in 1991...
Aythya innotata - feared to be extinct, rediscovered (2006) - Réunion Pochard, Aythya cf. innotata - extinct (c.1690s)
- New Zealand ScaupNew Zealand ScaupThe New Zealand Scaup commonly known as a Black teal, is a diving duck species of the genus Aythya. It is endemic to New Zealand. In Maori commonly known as papango, also matapouri, titiporangi, raipo .-Description:...
Aythya novaeseelandiae - Tufted DuckTufted DuckThe Tufted Duck, Aythya fuligula, is a medium-sized diving duck with a population of close to one million birds.- Description :The adult male is all black except for white flanks and a blue-grey bill. It has an obvious head tuft that gives the species its name.The adult female is brown with paler...
Aythya fuligula - Greater ScaupGreater ScaupThe Greater Scaup , just Scaup in Europe, or colloquially known as "Bluebill", for its bright blue bill, is small compared to other diving ducks, however it is larger than the closely related Lesser Scaup...
Aythya marila - Lesser ScaupLesser ScaupThe Lesser Scaup is a small North American diving duck that migrates south as far as Central America in winter. It is colloquially known as the Little Bluebill or Broadbill because of its distinctive blue bill...
Aythya affinis
- Canvasback
- Genus Marmaronetta