The nominate subspecies of the Yellow-billed Pintail (Anas georgica) is the South Georgia Pintail (Anas georgica georgica), shown here, which lives in South Georgia near the Antarctic (from Antarctic south seas near the Falkland Islands, not the US state of Georgia or the Caucasus).
Yellow-billed Pintails, including the South Georgia Pintail, look similar to Speckled Teals
(and their subspecies Chilean and Sharp-winged Teals) but are larger and have pale blue near the end of the bill and a more-defined black line on the bill; the head is also much lighter and the breast darker and more speckled. Both species come from South America. They are also a little similar to other yellow-billed duck species: the mallard-sized Yellow-billed Duck of south/east Africa and the Spot-billed Ducks of Asia, but all have different patterns of black on the bill and no others have the light grey-blue patch.
This apparent Yellow-billed Pintail has no yellow on its
(her) bill, only the grey-blue. It was together with a
regular Yellow-bill, see above, and the bill pattern isn't
quite the same as the Northern Pintail in eclipse plumage
since the black line doesn't reach the tip and it has no
black at the base. So it is assumed to be an aberrant