The steamer ducks are a genus (Tachyeres) of ducks in the family Anatidae. Three of the four species occur in the southern part of the Southern Cone of South America in Chile and Argentina, and the fourth on the Falkland Islands 500 km to the east; all except the flying steamer duck are flightless, and even this one species capable of flight only rarely takes to the air. They can be aggressive and are capable of chasing off predators like petrels. Bloody battles of steamer ducks with each other over territory disputes are observed in nature. They even kill waterbirds that are several times their size.

Taxonomy

The genus Tachyeres was introduced in 1875 by the English zoologist Richard Owen to accommodate the Falkland steamer duck. The genus name Tachyeres, "having fast oars" or "fast rower", comes from Ancient Greek ταχυ- "fast" + ἐρέσσω "I row (as with oars)". The common name "steamer ducks" arose because, when swimming fast, they flap their wings into the water as well as using their feet, creating an effect like a paddle steamer.

They were usually placed in the shelduck subfamily Tadorninae. However, mtDNA sequence analyses of the cytochrome b, NADH dehydrogenase subunit 2, and other genes indicate that Tachyeres instead belongs in a distinct clade of aberrant South American dabbling ducks, which also includes the Brazilian teal Amazonetta brasiliensis, the crested duck Lophonetta specularioides, and the bronze-winged duck Speculanas specularis.

A 2026 study argued that traditional morphometric traits such as wing loading and body mass are insufficient for species delimitation in the genus, supporting the use of bioacoustic data alongside molecular evidence.

Phylogeny

Genetic evidence suggests the species form two sister groups:

References

  • Fuegian steamer duck using wing-assisted swimming video clip at macaulaylibrary.org