About Merganetta armata Gould, 1842
The torrent duck (Merganetta armata) is a species in the Anatidae family, which includes ducks, geese, and swans. It is the only living member of the genus Merganetta. Previously grouped with the paraphyletic "perching duck" assemblage, it is now classified in the shelduck subfamily Tadorninae after that former grouping was dissolved. This species is 43 to 46 centimeters (17 to 18 inches) long, and is a resident breeder in the Andes of South America, nesting in small waterside caves and other sheltered sites. Similar to the blue duck, it defends territories along fast-flowing mountain rivers, most often located above 1,500 meters (4,900 feet). It is a powerful swimmer and diver, even in white water, but will only fly short distances when necessary. It does not act particularly wary when people encounter it. Male torrent ducks have a distinctive black and white pattern on the head and neck, plus a red bill. When in flight, males display dark wings with a green speculum. Females of all subspecies are smaller than males; they have orange underparts and throat, with grey head and upperparts, and a yellower bill. Juvenile torrent ducks are pale grey on their upper bodies and whitish on their under bodies. Males produce a shrill whistle call, while females produce a deeper, throatier whistle. This species is currently declining. Threats to the torrent duck include competition for its invertebrate food from introduced trout, water pollution, deforestation, and the damming of mountain rivers for hydroelectric projects. The Chilean population of the species remains relatively stable, while populations further north are impacted more severely. Even so, the total global population is still large enough that the species is classified as Least Concern on the IUCN Red List.
