Falkland steamer duck

The Falkland steamer duck ("Tachyeres brachypterus") is a steamer duck native to the Falkland Islands in the southern Atlantic Ocean. It is one of only two bird species endemic to the Falkland Islands, the other being Cobb's wren.
Description.
The Falkland steamer duck's wings are very short (hence the scientific name: "brachy" = "short", and "pteron" = "wing"), and it is incapable of flight. The plumage of the Falkland steamer duck is mostly dark grey, but with a white stripe behind the eye. It is very difficult to distinguish from the flying steamer duck in the field since they occupy the same habitat and, although the flying steamer duck can fly, it rarely does.
Historical description.
Charles Darwin devoted two paragraphs to this bird (or the similar flying steamer duck) in The Voyage of the Beagle, having observed them at the Falkland Islands in 1833: