Editing Torrent duck (section)

{{Short description|Species of Andean bird}}
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{{Speciesbox
| name = Torrent duck
| image = Merganetta armata (Pato de torrente) (24726521941).jpg
| image_caption = Female (left) and male Colombian torrent duck, Cañón del Río Anaime, Colombia
| status = LC
| status_system = IUCN3.1
| status_ref = <ref name="iucn status 12 November 2021">{{cite iucn |author=BirdLife International |date=2016 |title=''Merganetta armata'' |volume=2016 |page=e.T22680118A92844656 |doi=10.2305/IUCN.UK.2016-3.RLTS.T22680118A92844656.en |access-date=12 November 2021}}</ref>
| genus = Merganetta
| parent_authority = Gould, 1842
| species = armata
| authority = [[John Gould|Gould]], 1842
| subdivision_ranks = Subspecies
| subdivision =
''M. a. colombiana'' <small>([[Marc Athanese Parfait Oeillet Des Murs|Des Murs]], 1845)</small><br /><small>Colombian torrent duck</small><br/>
''M. a. leucogenis'' <small>([[Johann Jakob von Tschudi|Tschudi]], 1843)</small><br /><small>Peruvian torrent duck</small><br/>
''M. a. armata'' <small>(Gould, 1842)</small><br /><small>Chilean torrent duck</small><br/>
''M. a. berlepschi'' <small>([[Ernst Hartert|Hartert]], 1909) (disputed)</small><br/>
''M. a. garleppi'' <small>([[Hans von Berlepsch|Berlepsch]], 1894) (disputed)</small><br/>
''M. a. turneri'' <small>([[Philip Sclater|Sclater]] & [[Osbert Salvin|Salvin]], 1869) (disputed)</small><br/>
| range_map = Merganetta armata map.svg
}}

The '''torrent duck''' ('''''Merganetta armata''''') is a member of the [[duck]], [[goose]] and [[swan]] [[family (biology)|family]] [[Anatidae]]. It is the only member of the [[genus]] '''''Merganetta'''''. It is placed in the shelduck [[subfamily]] [[Tadorninae]] after the "[[perching duck]]" assemblage to which it was formerly assigned was dissolved because it turned out to be [[paraphyletic]].<ref name=Livezey>{{cite journal|author=Livezey, Bradley C. |year=1986|title= A phylogenetic analysis of recent anseriform genera using morphological characters|journal=[[Auk (journal)|Auk]]|volume=103|issue=4|pages= 737–754|doi=10.1093/auk/103.4.737|url=http://sora.unm.edu/sites/default/files/journals/auk/v103n04/p0737-p0754.pdf}}</ref>

This {{convert|43|-|46|cm|adj=on}} 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 {{convert|1500|m}}. 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 green [[speculum feathers|speculum]]. Females of all subspecies are 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]] food from introduced [[trout]], pollution, forest destruction, and damming of mountain rivers for hydroelectric schemes. The [[Chile]]an population seems 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]].