Flying Steamer Duck
Magellanic Flightless Steamer Duck
Falkland Flightless Steamer Duck
The South American steamer ducks have at times been included with the shelducks, but differ enough from them in structure and behavior to be regarded as a separate but closely related tribe. There are three species very similar in appearance; two are essentially flightless. All are found off the coasts of southern South America and the Falkland Islands, where they feed on mollusks and other marine invertebrates. The males differ slightly from females in their plumage and vocalizations, but in both sexes iridescent coloration is totally lacking and only a simple white speculum is present on the wings. Like the shelducks, however, they are highly aggressive during social display activities. The downy young to some extent resemble those of shelducks, but have less spotting and less contrasting coloration.
Available at: http://works.bepress.com/paul_johnsgard/5/