Yellow-billed Pintail Anas georgica Scientific name definitions

One of the common ducks of the Southern Cone, the Yellow-billed Pintail is widely distributed from sea level up into the mountains of South America, primarily in the Southern Cone but also north along the Andes. This is a puddle duck which "tips up" to feed just below the surface of freshwater bodies, though it dives occasionally as well. Two subspecies are currently extant, one (A. g. spinicauda) is the common subspecies of mainland South America and the other (A. g. georgica) is endemic to South Georgia; a third (A. g. nicefori) formerly lived in Colombia prior to its extinction.  The Yellow-billed Pintail is largely pale warm brown with a bright yellow bill; structurally it is slim with a long, elegant neck.

41·5–55 cm (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ), male 540–655 g, female 460–495 g (georgica) (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ); 50–65 cm, 663–827 g (spinicauda). Both sexes reminiscent of female A. acuta, but yellow bill with black ridge very characteristic (more yellowish green in female); no eclipse plumage. Only likely to be confused A. flavirostris, which is smaller, much paler and greyer, with obviously darker head, and has brilliant green speculum. Rufous crown flecked black, with buff or grey-brown head-sides, paler neck  , grey or greyish-white throat, predominantly brown upperparts with dark centres to feathers and broad pale fringes, olive-brown tertials with central black stripes, buff-grey wing-coverts with dark shaft-streaks, velvet black speculum with green lustre and buff terminal band , grey-brown primaries and tail, rufous-tinged breast becoming paler on belly  , and brown underwing-coverts and axillaries; bill has slate-blue tip and deep lemon sides, rest black (or pale grey becoming black on tip and yellow slightly duller in females) (2 Wilson, R.E., Goldfeder, S. and McCracken, K.G. (2004). Bill sexual dichromatism of Yellow-billed Pintail (Anas georgica) and Speckled Teal (A. flavirostris). Ornitología Neotropical. 15(4): 543–545. Close ), legs and feet greyish olive-green, and eyes dark brown. Female very similar to male, but in addition to different bill pattern has duller dark brown speculum (becoming velvet black distally), buffier tips to secondaries, less conspicuous black stripes on tertials, and somewhat whiter underparts. Juvenile most like female, but streaked on underparts and breast. Subspecies vary in plumage coloration and size; nominate is distinctly smaller, darker and more compact than subspecies <em>spinicauda</em> ; very rare race niceforoi reportedly larger than spinicauda, with less pointed tail and longer, less upturned bill (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ).

Editor's Note: This article requires further editing work to merge existing content into the appropriate Subspecies sections. Please bear with us while this update takes place.

Thought to be close to A. acuta, with which (and A. eatoni) is sometimes partitioned off in genus Dafila. One genetic study suggested that present species forms a monophyletic group with A. acuta and A. bahamensis (3 Johnson, K.P. and Sorenson, M.D. (1999). Phylogeny and biogeography of dabbling ducks (genus: Anas): a comparison of molecular and morphological evidence. Auk. 116(3): 792–805. Close ). Subspecies niceforoi, described in 1946, had been considered to be extinct by 1956, but was reportedly rediscovered in Jan 2003 (4 Ayerbe-González, S. and Lehmann-Albornoz, P. (2005). Redescubrimiento del Pato Pico de Oro de Nicéforo (Anas georgica niceforoi). Novedades Colombianas. 8(1): 45–52. Close ); however, claim is not convincingly documented, has been questioned (5 Stiles, F.G. (2008). Nota del Editor. Orn. Colombiana. 6: 1–2. Close ) and comes from a region (Cauca) over which disagreement apparently exists as to the subspecies that occurs there. Race spinicauda sometimes considered a full species, but apart from being significantly larger is not particularly distinctive. Two extant subspecies recognized.

Editor's Note: Additional distribution information for this taxon can be found in the 'Subspecies' article above. In the future we will develop a range-wide distribution article.

Found in a variety of habitats throughout range, such as freshwater lakes with abundant fringe vegetation on high ground, lowland rivers and lagoons, flooded meadows and sea shores, where frequents sheltered bays; on South Georgia, race georgica breeds in coastal tussock (Poa flabellata) habitats (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). From sea-level to 4600 m in puna zone.

Partially migratory; southernmost breeders of continental race move N to winter as far as SE Brazil (N to São Paulo) (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close , 6 Macarrão Montanhini, A. and Andrade Figueiredo, L.F. (2007). Primeiro registro da garça-real, Pilherodius pileatus e primeiros registros documentados da marreca-cricri, Anas versicolor e da marreca-parda, Anas georgica para o município de São Paulo. Atualidades Orn.. 138: 18–19. Close ), with undocumented from NE Brazil (Ceará, in Apr 1979, Mar 1980 and May 1983) and extreme N Brazil (Roraima, undated) (7 Teixeira, D.M., Otoch, R., Luigi, G., Raposo, M.A. and de Almeida, A.C.C. (1993). Notes on some birds of northeastern Brazil (5). Bull. Brit. Orn. Club. 113(1): 48–52. Close ); those of more temperate regions chiefly remain within vicinity of nesting area, although some might leave Falkland Is in winter (with comparatively few records from the islands at this season) (8 Woods, R. W., and A. Woods (1997) Atlas of Breeding Birds of the Falkland Islands. Anthony Nelson, Oswestry, UK. Close ) and stragglers (presumably from S populations of spinicauda) have reached King George I, South Georgia (Dec 1979, Dec 1994) (9 Prince, P. A., and J. P. Croxall (1996). The birds of South Georgia. Bulletin of the British Ornithologists’ Club 116(2):81–104. Close ), South Orkney Is, South Shetland Is (Oct 1985, Oct 1989 and 1995/96) (10 Aguirre, C.A. (1995). Distribution and abundance of birds at Potter Peninsula, 25 de Mayo (King George) Island, South Shetland Islands, Antarctica. Marine Orn.. 23(1): 23–31. Close , 11 Hahn, S., H.-U. Peter, P. Quillfeldt, and K. Reinhardt (1998). The birds of the Potter Peninsula, King George Island, South Shetland Islands, Antarctica, 1965–1998. Marine Ornithology 26(1–2):1–6. Close ) and the Antarctic Peninsula (e.g. at Adelaide I in Oct 1979) (12 Milius, N. (2000). The birds of Rothera, Adelaide Island, Antarctic Peninsula. Marine Orn.. 28(1): 63–67. Close , 1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). Nominate subspecies mostly sedentary.

Seeds, roots and vegetative parts of grasses , sedges, algae and other aquatic plants (e.g. Myriophyllum) (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ), stubble, grain, aquatic invertebrates (crustaceans, molluscs, insects). Nominate georgica forages predominantly within intertidal zone or areas close to it, even during austral summer, e.g. in Nov–Dec, spends c. 60% of time on tussock ponds and 17% on seashore and in fjords; at South Georgia, gut analysis suggests that diet includes fairy shrimps (Branchinecta gaini), amphipods, other freshwater invertebrates including dipterans and snails, marine algae and Antarctic starwort (Callitriche antarctica) (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). Feeds by head dipping and upend­ing with aid of long neck; also dabbles on surface , and often dives in shallow water (up to 7 cm deep), at least in race georgica; on land, grazes and digs. On South Georgia, sometimes feeds on Antarctic fur seal (Arctocephalus gazella) carcasses, sometimes in close proximity to other scavengers such as giant petrels (Macronectes spp.) or skuas (Catharacta spp.), which are potential predators of the present species (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). Race georgica regularly feeds at night, at least during austral summer, and forms small loose groups of up to c. 40 birds while so doing (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ).

Generally rather silent. Differences, if any, between nominate georgica and South American mainland race spinicauda  unknown: main vocalization and display call of male georgica is wheezy, hollow-sounding “geeeeegeeeee” followed by shorter, concurrent, double- or triple-noted “twer-dip” (“burp-whistle” call), whereas principal female call is a short quack that is only sometimes repeated, and is generally considered to be similar to the analagous vocalization of A. acuta (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ).

Season variable with locality; laying Sept–Dec in S of range (spinicauda on Faklands) (8 Woods, R. W., and A. Woods (1997) Atlas of Breeding Birds of the Falkland Islands. Anthony Nelson, Oswestry, UK. Close ) or (nominate) Dec–Mar on South Georgia (where copulation observed as early as mid Oct, and broods between late Nov and mid Mar) (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ), Aug–Mar in Peru (spinicauda); presumably double-brooded in places, even triple-brooded in georgica (with 16–22 days between clutches) (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ), and may also lay replacement clutches (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). In single pairs or loose groups, although in captivity, males may attempt to mate with more than one female and with those of other duck species (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ); nest  is shallow platform of stems lined with grass and down  , situated on ground, in thick or sparse vegetation, near water. Clutch 3–12 pale buff or cream-coloured eggs (on average clutch size smaller in nominate, five versus eight in spinicauda in Patagonia) (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ), size in captivity 50·5–67 mm × 36·6–42·8 mm (nominate) or in wild 49–57·3 mm × 35–40 mm (spinicauda), mass in captivity 37–55·5 g (nominate) or 39 g (spinicauda) (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ); incubation c. 26 days (spinicauda) or 24–28 days (georgica) (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ), by female alone, guarded by male (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ); chicks have dark brown down above , yellowish below and on dorsal markings  , with hatch weight of 25·4 g (spinicauda) (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ); young guarded by female alone, but fledging period unknown (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). Mean brood size of spinicauda in Argentina and Chile soon after hatching 5·6 birds (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). Natural predators include Brown Skua (Catharacta antarctica lonnbergi) (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ) and leopard seals (Hydrurga leptonyx) (13 Edwards, E.W.J., Forcada, J. and Crossin, G.T. (2010). First documentation of leopard seal predation of South Georgia pintail duck. Polar Biology. 33(3): 403-405. Close ) on South Georgia. Few data on breeding success, age of first breeding and longevity, but captive individuals of both georgica and spinicauda frequently breed in first year of life, while georgica commonly lives at least 5–8 years and one spinicauda lived 23 years in captivity (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ).

Not globally threatened (Least Concern). Widely distributed and locally abundant. Race spinicauda is one of most abundant ducks in South America, with total population estimated at 100,000–1,000,0000 birds in late 1990s (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ), and also in Falkland Is, where an estimated 600–1000 pairs during breeding bird survey of 1983–1993 (8 Woods, R. W., and A. Woods (1997) Atlas of Breeding Birds of the Falkland Islands. Anthony Nelson, Oswestry, UK. Close ); recorded frequently but less common N of Junín, C Peru. Forms large concentrations in some parts of Argentina, although recent surveys suggest species is declining there (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ): up to 250,000–300,000 in Cañada de Los Tres Arboles y Los Morteros and 11,600 estimated on Meseta de Strobel in Feb 1984. Nominate subspecies typically estimated to number > 2000 individuals (most recently, in 2011, at 6000 breeding pairs) (14 Clarke, A., J. P. Croxall, S. Poncet, A. R. Martin, and R. Burton (2012). Important Bird Areas: South Georgia. British Birds 105(3):118–144. Close ) and has been listed as Near Threatened by Threatened Waterfowl Specialist Group (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ); was common during 19th century, subsequently scarcer than at present after intense hunting by sealers and whalers; appears to tolerate predation by brown rats (Rattus norvegicus) fairly well and breeds well in captivity (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). Race niceforoi of E Andes of Colombia described as recently as 1946 was already considered to be extirpated in Cundinamarca by 1948 and had been lost from principal locality in Boyacá, L Tota, by mid 1950s, but it was reportedly rediscovered in Jan 2003 and a group of more than 40 birds was observed subsequently, albeit outside this subspecies’ known distribution in Cauca (4 Ayerbe-González, S. and Lehmann-Albornoz, P. (2005). Redescubrimiento del Pato Pico de Oro de Nicéforo (Anas georgica niceforoi). Novedades Colombianas. 8(1): 45–52. Close ) (see also Taxonomy); overhunting and wetland drainage considered to be principal causes of decline, but introduction of exotic trout into this taxon’s range may not have been involved (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ).