Steamship ducks

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Steamship ducks
Magellan steamship ducks in Cologne Zoo

Magellan steamship ducks in Cologne Zoo

Systematics
Sub-stem : Vertebrates (vertebrata)
Class : Birds (aves)
Order : Goose birds (Anseriformes)
Family : Duck birds (Anatidae)
Subfamily : Half geese (Tadorninae)
Genre : Steamship ducks
Scientific name
Tachyeres
Owen , 1875
Falkland steamship duck

The steamship ducks ( Tachyeres ) are a genus of half geese (Tadorninae) in southern South America ( Patagonia , Tierra del Fuego ) and on the Falkland Islands . Of the four types of bulky birds, only the long-winged steamship duck ( T. patachonicus ) is capable of flying, the wings of the others are reduced.

These ducks owe their name to the peculiarity of using their wings to help them move faster on the water, for example when attacking or fleeing. To do this, they alternately use their small, narrow wings, much like a kayaker uses a double paddle . The rapid, shoveling movement lets a lot of water splash up and is reminiscent of a paddle steamer .

Appearance

Steamship ducks are large, bulky-looking, short-legged ducks. The females of the long-winged steamship duck are the lightest with an average weight of 2441 grams. The heaviest are the males of the Magellan steamship duck with an average weight of 6039 grams. In all four species, the female is lighter than the male. This difference in weight is most pronounced in the Magellan steamship duck, in which the male weighs on average 1.9 kilograms more than the female. In the smallest species of steamship duck, the long-winged steamship duck, this difference in weight is on average about 600 grams.

The four species are similar in their body plumage. The differentiation of species is possible based on the color of the beak and the head.

Besides its size, the Magellan steamship duck differs from the other species by its orange beak. In the male, this occasionally has a dark base. In the female it is always a solid orange. Both adult sexes have gray heads. The male is characterized by a white headstock. In the female, some individuals have white eye stripes. Their wings reach up to their rump. The male of the Falkland Steamship Duck also has an orange beak. This lightens flesh-colored towards the tip. The adult male has a white head color. In not yet fully grown males, the face is brown or gray with a white streak of eyes. The female, on the other hand, has a gray head cap. The face is reddish brown and has a white eye stripe. Their beak is olive gray, the base and the ridge of the beak are yellow. The Falkland steamship duck is also a large species of duck. Males weigh an average of 4,334 grams. The females, on the other hand, weigh an average of 3,383 grams. The wings of both sexes reach to the middle of the rump.

The eponymous white head color, which extends to the neck, is only shown by the male of the white-headed steamship duck . The headstock is also light gray. The female, on the other hand, has a reddish-brown head color that gradually turns white starting with the eye. In the male, the beak is predominantly orange. Only the nail at the tip of the beak is black. In the female, however, the beak is gray. The long-winged steamship duck, also known as the Patagonian steamship duck, is significantly smaller than the other species. In the male, the beak has an orange base. The sides of the beak are olive gray from the nostrils. The face of adult males is almost white. Similar to the Falkland steamship duck, the not yet fully grown males have a gray or brown face with a white eye stripe. In the female, the headstock is gray. The face is auburn. The white eye stripe curves downwards. Their beak is predominantly olive gray. The base and the beak roof, on the other hand, are pale yellow. The wings reach to the base of the tail.

Reproduction

The clutch of all four species usually consists of four to seven eggs, which are clay-colored. The incubation period is around 30 days for all species. Young birds are sexually mature in their third year of life.

species

A distinction is made between these types:

supporting documents

Individual evidence

  1. Bernhard Grzimek (Ed.): " Grzimeks Tierleben ". Volume 7 - Birds I, p. 292. Weltbild Verlag , 2000. Unchanged reprint of the dtv edition from 1979/80.
  2. Kolbe, p. 165

literature

Web links

Commons : Steamship Ducks ( Tachyeres )  - Collection of images, videos and audio files