The South Georgia pintail (Anas georgica georgica), also misleadingly known as the South Georgian teal, is the nominate subspecies of the yellow-billed pintail (Anas georgica), a duck in the dabbling duck subfamily Anatinae. It is endemic to the large (3,756 km2) subantarctic island of South Georgia and its accompanying archipelago, and is a vagrant to the South Sandwich Islands. It was among the birds noted by James Cook in January 1775, on the occasion of the first recorded landing on South Georgia, and was formerly considered a full species.
Taxonomy The duck has long been recognised as a distinct taxon, with its affinities previously considered to be with the teals. Robert Cushman Murphy was the first to demonstrate that it is a pintail, its closest relatives the yellow-billed pintails of South America (now split as the Chilean pintail A. g. spinicauda and the extinct Niceforo's pintail A. g. niceforoi), though he retained it as a full species for its isolated distribution and its 16 (rather than 14) rectrices, or tail feathers. However, the number of rectrices in the ducks is variable, with many mainland pintails also having 16 rectrices and a few South Georgia pintails even having 18, and the three ducks are now usually lumped as the yellow-billed pintail.
Description
The duck is a distinctive small, mottled, predominantly brown pintail. It is smaller and stockier than the remaining mainland subspecies (A. g. spinicauda), with more uniform and darker plumage. It has a reddish crown, light brown cheeks and throat, dark grey underwings and a pointed tail. The back, breast and flanks are scalloped with buff; the underparts are buffy white, mottled with brown. The bill is yellow with a blue and black line on the culmen and tip, and the feet are greenish-grey. The downy chick is dark brown with yellowish buff markings. Unlike other pintails, the males are similar in appearance to the females, though larger. The ducks are 45 to 65 cm in length, the males weighing 610 to 660 g, the females 460 to 610 g. Minor differences are that the male has uniformly brownish-grey upperwing coverts and a glossy greenish-black speculum, while the female has mottled upperwing coverts and a dull brown speculum.
Identification The only species it is likely to be confused with is the yellow-billed teal, a relatively recent self-introduction first recorded breeding on South Georgia in 1971. The speckled teal also has a yellow bill but differs in being smaller and more compact, with less spotting on the flanks, and having a buff bar in front of the speculum, a central white stripe on the underwing, and a shorter and less pointed tail.
Distribution and habitat
The pintail is widely distributed along the north coast, and the western third of the south coast, of South Georgia, as well as on its offshore islands. It is largely absent from most of the south coast of the main island because of unfavourable topography. Favoured habitat includes freshwater pools and streams fringed by tussock grassland, seal wallows and poorly drained land next to wetlands and melting snow, as well as coastal habitats.
Behaviour Outside the breeding season, and when food is locally abundant, the ducks may congregate in small flocks, sometimes of up to about a hundred. Murphy noted:On December 20th, 1912, I photographed a pair of teals feeding in a trickle of water which ran through tall tussock grass from the melting edge of a glacier. The birds were well hidden by the screen of grass, and I almost stumbled over them before seeing them. They appeared quite unconcerned, however, and continued prodding about in the mud. When I had come within two steps of them, they raised their heads and waddled farther off among the hummocks, from where they peered out through drooping grass. All but the bright eyes and yellow bills blended completely with the surroundings. Matthews has well said that their pattern fits in so thoroughly with the environment that it is sometimes only the movement of the conspicuous yellow bill that calls one’s attention to their presence. Many observers have noted the birds’ preference to lose themselves in the grass when they are approached, rather than to seek safety in the air, and it is likely that before the arrival of men and guns at South Georgia they used their wings only for relatively short and infrequent flights.
Feeding The ducks are omnivorous; they feed on vegetation, including marine and freshwater algae, dabbling and diving in the sea when the water is calm. They also consume a range of invertebrates, including freshwater fairy shrimp (Brachinecta gaini), marine amphipods, Diptera, small clams, nematodes and snails, foraging in the intertidal zone and sometimes scavenging at seal carcasses.
David Parmelee describes the latter behaviour from Bird Island as follows:
"One might surmise that the delicate little pintails wait their turn to pick at the bones and small scraps left by the larger predators. Wrong assumption! As soon as there is a small opening in the seal carcass the ducks dive headlong into the hole, which conceals from view their bills and at times even their heads. "The head is methodically withdrawn time and again for surveillance, but it is not unusual to see both giant petrels and pintails simultaneously picking at the same carcass. The ducks are so clever in maneuvering that not many are caught unaware. Unlike the giant petrels that acquire grisly scarlet heads while gorging on the bloody flesh, the fastidious pintails remain remarkably clean by dipping frequently into streams or pools of water."
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