[order] ANSERIFORMES | [family] Anatidae | [latin] Anas georgica | [authority] Gmelin, 1789 | [UK] Yellow-billed Pintail | [FR] Canard a queue pointue | [DE] Spitzschwanz-Ente | [ES] Pato Maicero (Arg,Bo) | [NL] Zuidamerikaanse Pijlstaart | [copyright picture] Jan Harteman
Anas is a genus of dabbling ducks. It includes mallards, wigeons, teals, pintails and shovelers in a number of subgenera. Some authorities prefer to elevate the subgenera to genus rank. Indeed, as the moa-nalos are very close to this clade and may have evolved later than some of these lineages, it is rather the absence of a thorough review than lack of necessity that this genus is rather over-lumped. The phylogeny of this genus is one of the most confounded ones of all living birds. Research is hampered by the fact the radiation of the two major groups of Anas ? the teals and mallard groups ? took place in a very short time and fairly recently, roughly in the mid-late Pleistocene. Furthermore, hybridization may have long played a major role in Anas evolution, with within-subgenus hybrids regularly and between-subgenus hybrids not infrequently being fully fertile. The relationships between species are much obscured by this fact, and mtDNA sequence data is of dubious value in resolving their relationships; on the other hand, nuclear DNA sequences evolve too slowly to resolve the phylogeny of the subgenus Anas for example. Some major clades can be discerned. For example, that the traditional subgenus Anas, the mallard group, forms a monophyletic (in the loose sense, i.e. non-holophyletic) group has never been seriously questioned by modern science and is as good as confirmed (but see below). On the other hand, the phylogeny of the teals is very confusing. For these reasons, the dabbling duck lineages more distantly related to mallard group (which includes the type species of Anas) than the wigeons should arguably be separated in their own genera. These would include the Baikal Teal, the Garganey, the spotted black-capped Punanetta group, and the shovelers and other blue-winged species. Whether the wigeons, which are very distinct in morphology and behavior, but much less so in mtDNA cytochrome b and NADH dehydrogenase subunit 2 sequences, should also be considered a distinct genus Mareca (including the Gadwall and Falcated Duck) is essentially the one remaining point of dispute as regards the question which taxa should remain in this genus and which ones should not.
Anas georgica spinicauda: Head and long neck brown with fine black mottling, paler and plainer throat and foreneck. Body buff-brown with dark brown-black centres to feathers ? appears spotted on breast, paler and less marked on abdomen, upperparts feathers brown-black with buff edges. Wing grey-brown, greater coverts buff-tipped, secondaries glossy black with buff tips – speculum glossy black edged with buff. The female is slightly duller, central abdomen whiter; wing as male except secondaries duller black-brown. Race georgica much darker, more reddish-brown than spinicauda, flanks and abdomen flanks and abdomen darker – red-brown with dark spotting; race niceforoi (extinct) was darker than spinicauda, head and neck more streaked, crown dark brown, tail shorter.
Listen to the sound of Yellow-billed Pintail
Copyright remark: Most sounds derived from xeno-canto
South America : West, South. The Yellow-billed Teal is distributed from southern Colombia to Tierra del Fuego and across to South Georgia in the South Atlantic
Freshwater lakes, marshes, rivers, lagoons, flooded meadows and (particularly Anas georgica georgica) on coasts; up to 4600m in puna zone
Breeding offset with geographical variation, begin October-December in south of range, August to March in Peru, December on South Georgia. Sometimes double-brood in Chile and Falkland Islands. Nest is hidden in vegetation on ground near water, platform of stems, grass and down lining. Solitary or in loose groups, built by female Anas georgica georgica males assist female in tending brood. Clutch size is 4-10 eggs incubated for about 26 days. Young fledge after 45-60 days.
Mixed diet of seeds, roots and vegetative parts of grasses, sedges, algae, other aquatic plants, also stubble and grain. Aquatic invertebrates (crustaceans, insects, molluscs) important for South Georgia population (Anas georgica georgica), which also scavenges on fur seal and penguin corpses; Anas georgica spinicauda more vegetarian.
Video Yellow-billed Pintail
copyright: Christophe Gouraud
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Southern populations of mainland birds migrate as far north (lower latitude) as southern Brazil. Birds of temperate regions generally sedentary; South Georgia population (Anas georgica georgica) mainly sedentary but birds do reach South Shetland Islands