Male torrent ducks (drakes) have a striking black and white head and neck pattern and a red bill as evidenced by this photograph. Both of these are males and they are competing for a female (hen) just to camera right. In flight they show dark wings with a green speculum. You can see this speculum in another photograph, “Male Torrent Ducks Displaying“. Females of all subspecies are somewhat smaller than the drakes; they have orange underparts and throat, with the head and upper parts grey and a yellower bill. See my other photograph, “Male Torrent Ducks Posturing for a Fight“. Juveniles are pale grey above and whitish below.
Torrent Ducks inhabit the Andes mountains of western South American from the southern tip of Argentina all the way north to Venezuela. See the inserted range map. Unlike most waterfowl that prefer calm pools or sluggish water, this is a duck of fast-flowing rivers and streams above 4900 feet. Although able to swim up-current with no apparent exertion, Torrent Ducks are reluctant to fly more than very short distances. They nest in small waterside caves and other sheltered spots. Seldom associating with other water fowl, Torrent Ducks are almost always seen as singles or pairs. They feed mainly on aquatic invertebrates, mainly insect larvae, mollusks and crustaceans and probably some fish and terrestrial worms. I photographed these Torrent Ducks in the Rio Quijos River in Ecuador not far from Guango Lodge.
Torrent Ducks are not quite as large as Mallards, ranging 17–18 in long. They are about the size of North America’s Wood Duck.
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 food from introduced trout, pollution, forest destruction, and damming of mountain rivers for hydroelectric schemes. The Chilean 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 subspecies taxonomy can be confusing. Males of the southern nominate subspecies 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.
Torrent ducks, like other perching ducks (e.g. North America’s Wood Duck, Black-bellied Whistling Duck, Fulvous Whistling Duck) have a spur or boney extension at the wing bend; analogous to our elbow. This assists them climbing over slippery rocks in their fast-current environments. Male and female Torrent Ducks display sexual dimorphism. The sexes have significantly different plumages as this photo clearly shows.