Pointed tail duck

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Pointed tail duck
Pointed-tailed duck, Puerto Natales, Patagonia, Chile

Pointed-tailed duck, Puerto Natales , Patagonia, Chile

Systematics
Order : Goose birds (Anseriformes)
Family : Duck birds (Anatidae)
Subfamily : Anatinae
Tribe : Swimming ducks (anatini)
Genre : Actual ducks ( Anas )
Type : Pointed tail duck
Scientific name
Anas georgica
Gmelin , 1789
Subspecies Anas georgica spinicauda

The pointed tail duck ( Anas georgica ) is a South American species from the genus of real swimming ducks . It is assigned three subspecies, one of which is now considered extinct.

Appearance

The males of the nominate form weigh an average of 630 grams, while the females weigh 535 grams. The Chile pointed tail is a little heavier. Males and females of this subspecies weigh between 700 and 800 grams.

Pointed-tailed ducks have no noticeable plumage. In the males, however, the head and neck are rather light red-brown plumage. The middle control spring is significantly longer, which is also what led to the German name. The most striking feature of the drakes is their beak, which is yellow on the sides and has a broad, dark gray ridge stripe. In the female, on the other hand, the beak sides are yellowish green; the central control feathers are pointed like in the male, but not so noticeably elongated. The head and neck are rather gray-brown feathered. Young birds not yet sexually mature do not show any noticeable difference to the adult birds.

It can be confused with the Chile teal , among other things . This also has a yellow beak, but is much smaller and more compact. It is also less spotted on the flanks and many individuals of this species have a whitish underside of the body. The kerguelen duck differs from the pointed-tailed duck by its bluish beak.

Habitat, distribution and way of life

Pointed-tailed ducks are found over most of South America. They are also found in the Falkland Islands and are therefore part of the subantarctic avifauna. The habitat of the pointed-tailed ducks includes lakes and wetlands in the agricultural and pampas regions of South America. They can also be found on the lagoons of the coastal areas and on smaller reservoirs. Outside the breeding season, this species of duck occasionally gathers in large flocks. It can then also be found in association with other water birds. The food is mainly consumed thoroughly and is mainly vegetable.

The breeding season of the pointed-tailed ducks falls from October to December. The nests are built in the reed zone along the water or in adjacent meadows. A clutch usually consists of four to five cream-colored eggs. The incubation period is 25 to 26 days. The drake is also involved in guiding the chicks. Young pointed-tailed ducks are sexually mature at around one year of age.

Duration

The northern pointed- tailed duck ( Anas georgica niceforoi ) was endemic to Colombia and has been considered extinct since 1956. The populations of the nominate form , which is also called the South Georgia pointed-tailed duck ( Anas georgica georgica ) to distinguish it from the other two subspecies , have declined sharply. It was heavily hunted by whalers, especially towards the end of the 19th century and the beginning of the 20th century. The effect of the brown rat , which has meanwhile been introduced to this island, on the population of pointed-tailed ducks has not yet been conclusively investigated. The number of the South Georgia pointed-tailed duck is now estimated at only 2,000 individuals. The subspecies is actually limited to South Georgia in its range. However, wanderers of this subspecies occasionally reach the South Shetland Islands .

The Chilean pointed-tailed duck ( Anas georgica spinicauda ), on the other hand, is a species that is widespread in South America. In some regions it is even the only representative of the duck birds . The Argentine population alone is estimated at 300,000. It also occurs in small numbers on the Falkland Islands, where it can still be hunted. In their inventory of breeding birds in the Falkland Islands, however, ornithologists Robin and Anne Wkood pointed out that the population in the Falkland Islands is too low and that the species should be given a higher protection status.

Individual evidence and further information

literature

  • PJ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds , Volume 1, Ratites to Ducks, Oxford University Press, Oxford 1990, ISBN 0195530683
  • Hartmut Kolbe; Die Entenvögel der Welt , Ulmer Verlag 1999, ISBN 3-8001-7442-1
  • Hadoram Shirihai: A Complete Guide to Antarctic Wildlife - The Birds and Marine Mammals of the Antarctic Continent and Southern Ocean , Alula Press, Degerby 2002, ISBN 951-98947-0-5
  • Robin and Anne Woods: Atlas of Breeding Birds of the Falkland Islands , Anthony Nelson, Shorpshire 1997, ISBN 0904614-60-3

Individual evidence

  1. ^ Wood, p. 92
  2. ↑ Kolbe, p. 249
  3. ^ Higgins, p. 1303
  4. ↑ Higgins, p. 1304
  5. ^ Shirihai, p. 246
  6. ↑ Kolbe, p. 250
  7. ^ Wood, p. 93

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