Swans

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Swans
Trumpeter Swan (Cygnus buccinator)

Trumpeter Swan ( Cygnus buccinator )

Systematics
Class : Birds (aves)
Order : Goose birds (Anseriformes)
Family : Duck birds (Anatidae)
Subfamily : Geese (anserinae)
Tribe : Cygnini
Genre : Swans
Scientific name of the  tribe
Cygnini
Vigors , 1825
Scientific name of the  genus
Cygnus
Bechstein , 1803

The swans ( Cygnus ) are a genus of the duck birds (Anatidae). Within this family they are assigned to the geese (Anserinae). Swans are the largest of all duck birds. Because of the pure white plumage of the European species and their impressive size, they have entered numerous myths and fairy tales.

features

The plumage of the swans is either pure white or shows a mixture of black and white, whereby white variants can have black wing tips. The mourning swans are the only species of swans that appear completely black (in flight they are also recognizable partly white). The sexes of all species show only minor differences in external appearance .

Swans differ from geese in the narrower sense of the word in that they have an even longer neck, which allows them to gudge in deeper water, and their body size, which makes them the largest waterfowl alongside some pelicans . Their wingspan can be up to 240 cm, their weight can reach 14.3 kg. The legs are relatively short and set far back on the body, so that swans look rather clumsy on land. Swans are also more aquatic than other geese , so they leave the water much less often.

distribution and habitat

The genus Cygnus comprises six or seven species, depending on the taxonomic view (the status of the dwarf swan Cygnus bewickii , which many ornithologists consider a subspecies of the whistling swan), four of which have a high northern distribution area: They breed and migrate in the arctic tundra in winter in the temperate zone . The mute swan is now common in temperate zones around the world, but its origins were in the Palearctic . Two species come from the southern hemisphere: the black-necked swan from Australia and the black-necked swan from South America. Another species, the New Zealand swan , was extinct in the 16th or 17th centuries.

The Koskorobaschwan , also known as the swan but belonging to a different genus , also lives in South America.

The swans live in swamps, shallow lakes and slow flowing rivers. The bottom must always be accessible, so that too deep waters are unsuitable for swans.

Way of life

Mute swan
Pair of swans at the pounding
Mute swan on the nest
Mute swan defending its brood
Mute swan with brood (Moselle)

Swans feed mainly on aquatic plants that are brought from the bottom of the water. When they go ashore, swans also eat plants growing on the shore. In addition, aquatic insects, molluscs , small fish and amphibians are taken in to a much smaller extent .

The couples bind for life. In a group of mute swans, it was found that 97% of the successfully breeding animals brooded with the same partner in the following year. It is therefore extremely rare for couples to separate. In the dwarf swan , for example , which has a lifespan of up to 27 years, a pair bond of at least 19 years was found. Accordingly, it is difficult for older swans who have lost their partner to find a new partner.

Most swans are loners, so mute swans usually bitterly defend their territory. If another swan breaches the territory, a fatal fight can ensue. However, when the population becomes very large and sufficient food is available, even mute swans can become more tolerable and breed in small colonies. Breeding in colonies is common in the black-necked swan and a common phenomenon in the black-necked swan.

The swan's nest is made of aquatic plants, grass and twigs and is often of considerable size. Since a couple uses the same nest over and over again, it can grow in size from year to year. The nest of a trumpeter swan is usually 40 cm high at the beginning and can grow to 90 cm. Both parent birds build the nest for the swans. The male swan swims or stands with his back to the nest on which the female is sitting and hands it the nesting material with a backward movement of her head and neck. The nest is later padded thinly with down by the female. The female then only breeds; the male only participates in the black swan. Four to six (rarely one to eleven) eggs are laid and incubated for around 40 days. The boys are accompanied by both partners. Occasionally they are carried on the back. Swans that have fledged usually remain in association with their parent birds until the next reproductive period.

Systematics

The genus Cygnus is monophyletic with high probability , both according to morphological examinations as well as according to phylogenomic examinations (examinations of the relationships based on the comparison of homologous DNA sequences) . The position of the Coscorobaschwan is problematic and has not been clarified with absolute certainty . This is consistently listed in a monotypical genus Coscoroba, which is separate from the other swans . However, their relationship to the genus Cygnus is unclear . Ornithologists working morphologically consider both genera to be sister groups . They then combine both in a tribe Cygnini or, with other genera, in a broad tribe Anserini . In the genetic analyzes, however, unexpectedly, the Coscorobaschwan turned out to be more closely related to the Australian hen goose ( Cereopsis novaehollandiae ). Chromosome examinations also indicate this placement. Systematic reference works such as Handbook of the Birds of the World Alive (online edition, 2017), following this interpretation, interpret the Cygnini tribe as monotypical, exclusively with the genus Cygnus . They combine the genera Coscoroba and Cereopsis in a tribe Cereopseini (alternatively also written Cereopsini ). This view is followed here. Other authors place, with the same phylogeny, the three genera Cygnus , Coscoroba and Coreopsis together in a broader tribe Cygnini .

The deviant Coscorobaschwan of South America
Head portrait of a mute swan (Cygnus olor) from the right.

No longer belonging to the "real" swans:

  • Tribus Cereopseini

According to the genetic data, the following relationships would result (as a cladogram )



Whistling geese (Dendrocygninae) (the genus Thlassornis has not been tested)


   

Anatinae


 Geese (anserinae)   

Real geese ( Anserini )


   

Swans ( cygnus )


   

Coscoroba Swan ( Coscoroba coscoroba )


   

Chickens goose ( Cereopsis novaehollandiae )







According to morphological characteristics, a deviating phylogeny would result (only recent groups considered):



Whistling Geese (Dendrocygninae)


   

Anatinae + demi -geese (Tadorninae) + monkey duck ( Stictonetta )


   

Chickens goose ( Cereopsis novaehollandiae )


   

Real geese ( Anserini )


   

Coscorobaschwan, Coscoroba coscoroba


   

Swans ( cygnus )







The pygmy swan is often considered a subspecies of the whistling swan. The Nordic species trumpeter, whistle, dwarf and whooper swan form a family group. Occasionally a sister species relationship between the black-necked swan and the black-necked swan is assumed, which are then summarized in a subgenus Chenopsis . The mute swan is mostly considered a sister species to the Nordic swans.

Swans and man

The word swan is very old. Already in Old High German and Middle High German these birds were called swan , which is also identical to the English word for swan. The name is probably derived from the Indo-European word suen , which stands for rustling and sounding and is a reference to the striking flight noises these birds make.

Swans have often sparked the human imagination: not only the myth of Leda or the swan song testify to this , but also fairy tales such as The Ugly Duckling . In this tale of the swan symbolizes among other things, maturing and perfect he is in art and literature but also as an allegory used for purity, to name would be in this context about the swan knight Lohengrin at Richard Wagner , whose boat drawn by a swan. In the Prose Edda it is mentioned that two swans swim in the sacred primeval fountain . Irish mythology uses swans very often in its symbolism.

In medieval Europe, keeping swans in open waters was a sovereign right. As a political symbol of imperial immediacy , z. B. the city council of Hamburg 1664 the harassment of the Alster swans (mute swans on the Alster ) under penalty. The city's feed payments to the animals can be documented from 1591. Today the animals are looked after by a swan overseer (vernacular: swan father ). Since 1957, the Eppendorfer mill pond has been kept ice-free for the approx. 120 animals .

The swan as food

Due to the protection of the swan, which has existed for centuries, there is little current experience with its consumption. From the Carmina Burana of the 11th to 13th centuries, not least because of the setting of the same name by Carl Orff , a song about a swan roasted on a spit is known ( Cignus ustus cantat : “Olim lacus colueram”). In England swans stood next to peacocks and herons on royal menus. It is reported that the English King Henry III. 1251 needed 125 swans for his Christmas banquet. For example, recipes for “Baked Swan” have been handed down from centuries past. The increasing disappearance of swans from court meals coincided with the appearance of the turkey in Europe after the discovery of America.

It is reported that swans are tough and taste muddy and fishy. On the other hand, the composer Sir Peter Maxwell Davies thought that swan terrine prepared with the leg and breast meat of hung animals was "delicate". He said the meat was dark with a strong taste reminiscent of pheasant and also something of venison . In connection with the consumption of swan meat, it is advisable to hang the meat for four days, as bacteria make the meat more tender and taste better during this time.

Some Jews and Christians interpret a passage in Leviticus ( Lev 11:17  LUT84 ) in the sense that they have to forego the consumption of swans.

literature

Web links

Commons : Swans  - Collection of images, videos and audio files

Individual evidence

  1. ↑ Collin Harrison and Peter Castell: Field Guide Bird Nests, Eggs and Nestlings , HarperCollins Publisher, revised edition from 2002, ISBN 0007130392 , p. 62
  2. ↑ a b Bradley C. Livezey (1996): A Phylogenetic Analysis of Geese and Swans (Anseriformes: Anserinae), Including Selected Fossil Species. Systematic Biology 45 (4): 415-450. doi: 10.1093 / sysbio / 45.4.415 (open access).
  3. ^ Paul A. Johnsgard (2010): The World's Waterfowl in the 21st Century: A 2010 Supplement to Ducks, Geese, and Swans of the World. Ducks, Geese, and Swans of the World by Paul A. Johnsgard. 20. online
  4. ^ A b Carole Donne-Goussé, Vincent Laudet, Catherine Hänni (2002): A molecular phylogeny of anseriformes based on mitochondrial DNA analysis. Molecular Phylogenetics and Evolution 23: 339-356. doi: 10.1016 / S1055-7903 (02) 00019-2
  5. ↑ Joanna Warzecha, Agnieszka Fornal, Maria Oczkowicz, Monika Bugno-Poniewierska (2017): A molecular characteristic of the Anatidae mitochondrial control region - a review. Annals of Animal Science, online ahead of print, doi: 10.1515 / aoas-2017-0016 (open access).
  6. ↑ Benilson S. Rodrigues, Maria De Fatima, L. de Assis, Patricia CM O'Brien, Malcolm A. Ferguson-Smith Edivaldo, HC de Oliveira (2014): Chromosomal studies on Coscoroba coscoroba (Aves: Anseriformes) reinforce the Coscoroba– Cereopsis clade. Biological Journal of the Linnean Society 111 (2): 274-279. doi: 10.1111 / bij.12202 (open access)
  7. ↑ Handbook of the Birds of the World Alive: Taxonomic structure and notes: Family Anatidae (Ducks, Geese, Swans)  ( page no longer available , search in web archives ) accessed on December 12, 2017@1@ 2Template: Dead Link / www.hbw.com
  8. ↑ Viktor Wember: The names of the birds in Europe - meaning of the German and scientific names , Aula-Verlag, Wiebelsheim 2007, ISBN 978-3-89104-709-5 , p. 78
  9. ^ Howell Raines: Henley Journal; A Scene of Old England: The Mute Swan Census , New York Times, July 25, 1987 (accessed March 31, 2012)
  10. ^ Baked Swan - Old Elizabethan Receipe , Baked Swan, based on a recipe by Hannah Woolley , published 1672 (accessed April 23, 2011)
  11. ↑ Adam Roberts: Eating Swan , The Amateur Gourmet, March 28, 2005 (accessed April 23, 2011)
  12. ↑ Meaders: Swan terrine , Dead Men Left, March 23, 2005 (recipe for swan terrine) (accessed: April 23, 2011)
  13. ↑ Louise Gray: Sir Peter's taste for swan has him fall foul of law , The Scotsman , March 19, 2005 (accessed: March 31, 2012)
  14. ↑ 7 Things You Need To Know About ... Swans , Herald Scotland, March 20, 2005 (accessed: April 23, 2011)