The torrent duck is a member of the duck, goose and swan 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.
Region
Andes Mountains
Typical Environment
Occurs along cold, clear, fast-flowing mountain rivers and streams from Colombia and Venezuela south through Ecuador, Peru, Bolivia, Chile, and Argentina. It favors steep, rocky channels with cascades, rapids, plunge pools, and large boulders. Nests are placed in crevices, among roots, under riverbank overhangs, or in cavities close to the water. The species avoids still or turbid water and rarely uses lakes except when connected by swift inflows.
Altitude Range
0–4500 m
Climate Zone
Highland
Ease of Keeping
Beginner friendly: 1/5
Torrent ducks are extreme river specialists, living on fast, boulder-strewn Andean torrents where few other ducks can forage. They use a stiff tail and strong webbed feet to brace against currents, often diving and clinging to rocks to feed. Pairs hold long, linear territories along stretches of river and often remain together year-round. Hydropower development and river modification can fragment their habitat, though the species is currently not at risk globally.
Temperament
solitary and territorial (usually in pairs)
Flight Pattern
low, direct flight along rivers with short rapid wingbeats; more often swims or dives
Social Behavior
Typically found as territorial pairs defending long stretches of river; pair bonds are strong and may be long-term. Nests in cavities or sheltered sites near water; clutch size is small to moderate, and both parents attend the brood. Ducklings are precocial and quickly take to swift water under parental guidance.
Migratory Pattern
Resident
Song Description
Males give clear, high-pitched whistles that carry over the noise of rushing water. Females respond with softer, rasping calls and contact notes used to keep family groups together.
Plumage
Male is striking with a white head marked by bold black stripes, finely barred gray to black upperparts, and often rich chestnut underparts; female is mostly rufous below with gray-brown upperparts and a contrasting pale face pattern. Both sexes have a long, stiff tail and sleek, waterproof plumage adapted to torrents.
Diet
Feeds largely on aquatic insect larvae such as caddisflies, mayflies, and stoneflies, gleaned from rocks and riverbed substrates. Also takes small crustaceans and other invertebrates when available. Forages by diving, dabbling in fast eddies, and picking from submerged surfaces while bracing with tail and feet.
Preferred Environment
Forages in riffles, rapids, and plunge pools where current is strong and water is well-oxygenated. Frequently uses the lee of boulders to search for prey and rests on midstream rocks between bouts of diving.
