The torrent duck (''Merganetta armata'') is a member of 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 ...

goose 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 ...

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 ...

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 ...

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 ...

. It is the only member of the

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 ...

''Merganetta''. It is placed in the shelduck

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 ...

Tadorninae after the "

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 ...

" assemblage to which it was formerly assigned was dissolved because it turned out to be

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 ...

. This long

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

is a resident breeder in the

Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sou ...

, nesting in small waterside caves and other sheltered spots. Like the

blue duck 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, b ...

, it holds territories on fast flowing mountain rivers, usually above . It is a powerful swimmer and diver even in white water, but is reluctant to fly more than short distances. It is not particularly wary when located. Male torrent ducks have a striking black and white head and neck pattern and a red bill. In flight they show dark wings with a green speculum. Females of all subspecies are somewhat smaller than the drakes; they have orange underparts and throat, with the head and upperparts grey and a yellower bill. Juveniles are pale grey above and whitish below. The male's call is a shrill whistle, while the female's is a throatier whistle. This is a declining species due to competition for its

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chorda ...

food from introduced

trout Trout are species of freshwater fish belonging to the genera '' Oncorhynchus'', '' Salmo'' and '' Salvelinus'', all of the subfamily Salmoninae of the family Salmonidae. The word ''trout'' is also used as part of the name of some non-salm ...

, pollution, forest destruction, and damming of mountain rivers for hydroelectric schemes. The

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the eas ...

an population seems to be relatively stable, while the more northern ones are more seriously affected. However, the overall population is still large enough to warrant classification as a Species of Least Concern in the

IUCN Redlist The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biologi ...

Subspecies

The

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. Not all specie ...

taxonomy can be confusing. Males of the southern

nominate subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. Not all speci ...

''M. a. armata'', the Chilean torrent duck, have grey back and blackish underparts, with a chestnut belly. Males of the slightly smaller northern subspecies, the Colombian torrent duck, ''M. a. colombiana'', are paler underneath, with streaked grey-brown underparts. Males of a third subspecies, the Peruvian torrent duck, ''M. a. leucogenis'', are intermediate but very variable in plumage; some have entirely black underparts (''turneri'' morph). Only males of the Chilean torrent duck have a black 'teardrop' mark beneath the eye. The Peruvian torrent duck is sometimes split into 4 subspecies (''leucogenis'', ''turneri'', ''garleppi'' and ''berlepschi''), but these are more likely simply color variations, as they are not limited to distinct areas. File:Merganetta armata - Rio Urumamba, Peru -juvenile and female-8.jpg, Juvenile (left) and female Peruvian torrent duck on the

Urubamba River The Urubamba River or Vilcamayo River (possibly from Quechua ''Willkamayu'', for "sacred river") is a river in Peru. Upstream it is called Vilcanota River (possibly from Aymara ''Willkanuta'', for "house of the sun"). Within the La Convención ...

, Peru File:Merganetta armata - Rio Urumamba, Peru -male-8.jpg, Male Peruvian torrent duck on the rocky banks of the Urubamba River, Peru File:MerganettaTurneriSmit.jpg, Male (top) and female Peruvian torrent duck, ''turneri'' morph File:TorrentDuckM.jpg, Male Chilean torrent duck near Fitz Roy, Argentina File:TorrentDuckF.jpg, Female Chilean torrent duck near Fitz Roy, Argentina

References

* {{Taxonbar, from=Q914045 torrent duck torrent duck Birds of the Andes torrent duck