Torrent Duck

Description: The male's chin and narrow band at base of bill are black, as are the crown, hindneck, and broad stripe from eye to sides of neck, sometimes throat and median line of foreneck. The sides of the head and neck are otherwise white; the mantle is gray, black, or white. Feathers of upper back, scapulars, and tertials are black, with broad tawny, gray, or white margins, the dorsum appearing boldly striped. The lower back to upper tail coverts dark gray, minutely vermiculated with white posteriorly; the tail is fuscous brown, notably long and stiff. Wings are a sooty gray (coverts) and fuscous brown (primaries), the secondaries iridescent green on outer webs, forming a bright speculum bordered on front and behind with a white band. The undersurface of the body is white to dull ferruginous, the whole striped with black ferruginous. The throat, foreneck and chest are black. The iris is brown, the bill is red, the feet are a dull red, and the webs sooty. The torrent duck utters a shrill, monosyllabic or repeated weet, dropping somewhat in pitch towards the end. It also has a sharp whistle. Females are substantially like the male, but the top of head and hindneck are gray, rather than black. The sides of the head (or cheeks only), and sides of neck are vermiculated with black and white, appearing gray. The throat, foreneck, and undersurface of body are a rich ochraceous brown to chestnut rufous. The speculum is duller, usually obscure. The call is a throatier and carrying less "queech." She also has a sharp whistle.


Breeding: The torrent duck lives in the fast-flowing mountain rivers of the temperate and subtropical vegetation zones along the Andes range. They have long-term pair-bonds. The nest may be hidden in various waterside cavities, but few have been found. Recorded sites include cliff ledges and crevices or rock ledges lined with down. The torrent duck lays 2 dull buff eggs with possibly the longest incubation period in the Anatidae family.

Migrating and Wintering: The torrent duck is endemic to South America and is widespread and fairly common in the Andes from Venezuela and Colombia to Tierra del Fuego (Scott and Carbonell, 1986).

Population: M. a. armata (Northern Andes) 5,000 individuals; M. a. columbiana (Central Andes) 2,500-10,000 individuals; M. a. leucogenis (Southern Andes) 5,000-10,000 individuals (Rose and Scott, 1994).

Food habits: Torrent ducks eat mostly stonefly larvae. To feed they will dive, swim submerged, forage among vegetated rocks, and will also stand at the bottom of small falls and feed in the cascade of water.