Torrent Duck
Encyclopedia
The Torrent Duck is a member of the duck
, goose
and swan
family
Anatidae
. It is the only member of the genus
Merganetta. Today 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. Its closest relative may be the Blue Duck
of New Zealand
.
This 43 centimetre long species
is a resident breeder in the Andes
of South America
, nesting in small waterside caves and other sheltered spots. Like the Blue Duck, it holds territories on fast flowing mountain rivers, usually above 1500 metres (4,921.3 ft). 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, and the female's is throatier whistle.
The subspecies
taxonomy is quite confusing. Males of the southern nominate subspecies, the Chilean Torrent Duck, have a 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 steaked 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 not less than 4 subspecies (leucogenis, turneri, garleppi and berlepschi), but these are more likely simply color variations, as they are not limited to distinct areas.
This is a declining species now due to competition for its invertebrate
food from introduced trout
, pollution, forest destruction, and damming of mountain rivers for hydroelectric schemes. The Chile
an population seems to be relatively stable.
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...
, goose
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...
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...
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...
. It is the only member of the genus
Genus
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...
Merganetta. Today it is placed in the shelduck subfamily Tadorninae
Tadorninae
The Tadorninae is the shelduck-sheldgoose subfamily of the Anatidae, the biological family that includes the ducks and most duck-like waterfowl such as the geese and swans....
after the "perching duck
Perching duck
The perching ducks were previously treated as a small group of ducks in the duck, goose and swan family Anatidae, grouped together on the basis of their readiness to perch high in trees...
" assemblage where it was formerly assigned to was dissolved because it turned out to be paraphyletic. Its closest relative may be the Blue Duck
Blue Duck
The Blue Duck is a member of the duck, goose and swan family Anatidae endemic to New Zealand. It is the only member of the genus Hymenolaimus, placed in the shelduck subfamily Tadorninae after previously being considered part of the paraphyletic "perching duck" assemblage...
of New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
.
This 43 centimetre long species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
is a resident breeder in the Andes
Andes
The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...
of South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
, nesting in small waterside caves and other sheltered spots. Like the Blue Duck, it holds territories on fast flowing mountain rivers, usually above 1500 metres (4,921.3 ft). 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
Speculum feathers
The speculum is a patch, often distinctly coloured, on the inner remiges of some birds.Examples of the colour of the speculum in a number of ducks are:* Common Teal and Green-winged Teal: Iridescent green edged with buff....
.
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, and the female's is throatier whistle.
The subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
taxonomy is quite confusing. Males of the southern nominate subspecies, the Chilean Torrent Duck, have a 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 steaked 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 not less than 4 subspecies (leucogenis, turneri, garleppi and berlepschi), but these are more likely simply color variations, as they are not limited to distinct areas.
This is a declining species now due to competition for its invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
food from introduced trout
Trout
Trout is the name for a number of species of freshwater and saltwater fish belonging to the Salmoninae subfamily of the family Salmonidae. Salmon belong to the same family as trout. Most salmon species spend almost all their lives in salt water...
, pollution, forest destruction, and damming of mountain rivers for hydroelectric schemes. The Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
an population seems to be relatively stable.