Dwarf slayer
| Dwarf slayer | ||||||||||||
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Dwarf warrior ( Mergellus albellus ), |
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Mergellus | ||||||||||||
| Selby , 1840 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Mergellus albellus | ||||||||||||
| ( Linnaeus , 1758) |
The dwarf slayer ( Mergellus albellus ) is a small species of sawmill from the family of duck birds (Anatidae) native to Northern Europe and North Asia . The Smew is closely related to the Common Goldeneye ( Bucephala clangula , which is also evident from the fact) related that both species hybridize with each other. In Central Europe, the dwarf slayer is a regular winter visitor from October to April and is often associated with golden ducks. The most important winter resting places are on the coast. It is much less common inland.
features
With a body length of 37 to 45 centimeters, the dwarf hawker is shorter and shorter-billed than the other hawks. The wingspan is 44 to 70 centimeters. The weight varies between 550 and 750 grams.
Males and females of the dwarf hawk have distinctly different plumage. The male's plumage is white with fine black lines. The male still has a black spot on the face and the bonnet can be raised. The black spot between the beak and the eye is striking. The back is sometimes black. When resting, the drake resembles the female. However, the back is black and it is significantly larger and fuller than the females. Males can also be identified by their larger beak.
The female dwarf hunter, on the other hand, is more plainly colored and has significantly smaller hood feathers. Her back is dark gray, the flanks are a little lighter. The head and sides of the neck are red-brown.
Fledglings show a brownish-white spot on their wings and cinnamon-brown instead of black-brown reins (between the eye and the base of the beak). The chin and throat are white. The feathers of the trunk are brownish-gray and lined with a lighter color than that of adult birds. The color of the chicks is almost indistinguishable from the golden golden ducks. However, they are of smaller size and already have the typical sawbill.
voice
Dwarfs are mostly silent and rarely heard. The mating call of the male is a wooden, is accelerating Knirren that on tek tek tek arorr ... recalls. The bird throws its head far back. Females call a predominantly monosyllabic Raeg or gräg , but also ga ga .. .
distribution and habitat
The distribution area of the dwarf saws extends south of the Arctic Circle in the boreal coniferous forest from Finland to Kamchatka. There are isolated and probably no longer regular breeding occurrences in the steppe zone of European Russia; earlier the dwarf slayer was also found in Romania. The world population is around 130,000 to 200,000 individuals. Around 5,300 to 8,400 breeding pairs were breeding in Europe around the turn of the millennium. The largest population, namely 4,000 to 6,000 breeding pairs, is found in European Russia. About 1,000 to 2,000 breeding pairs live in Finland. There are very small stocks in northern Norway and northern Sweden as well as Belarus .
Dwarf hawks need trees as cave breeders , but the number of breeding trees in the breeding area is limited. Most of the time, dwarf slayers hang out at fish-rich lakes and slow-flowing rivers. Their habitat are the boreal coniferous forest belts with large stands of pine and larch. They prefer to breed on lakes and lowlands enclosed by high forest. The nests are usually created on small islands with groups of trees.
As migratory birds, they leave their breeding grounds in autumn to overwinter on the protected coastal waters of the southern Baltic Sea and the Black and Caspian Seas, on the Mecklenburg Baltic Sea coast, in the Netherlands in the IJsselmeer area and in North Rhine-Westphalia on the Lower Rhine.
nutrition
In the winter months, the food consists almost exclusively of 8–12 cm long fish. In summer, dwarf hawks feed not only on fish but also on aquatic insects and their larvae and eat frogs, crabs, worms and parts of plants as complementary food; in this they differ from their great relatives, middle sawsers and goosanders .
Reproduction
The pair formation of the dwarf slayers takes place in the winter quarters (February, March). In April and May the pairs arrive in their breeding areas, the eggs are laid mostly in May, in some areas until mid-June. They breed preferentially in tree hollows, several meters high and often at some distance from the water, but also in artificial nest hollows. 6 to 11 cream-colored eggs are incubated for 28 to 30 days. The chicks jump out of their nest holes 24 to 36 hours after hatching. Youngsters are grown up at around ten weeks and sexually mature at two.
Stock and stock forecast
The IUCN estimates the total population according to data from 2002 at 130,000 to 210,000 animals and classifies the dwarf hawk as not endangered . The northern European population is estimated at a maximum of 15,000 individuals. A research team that, on behalf of the British environmental authority and the RSPB, examined the future development of the distribution of European breeding birds on the basis of climate models, however, assumes that there will be a large-scale reduction in area of the dwarf predator by the end of the 21st century as a result of global warming. According to this forecast, the distribution area will decrease significantly and shift to the north. Large parts of the current distribution area are then no longer suitable for this species. According to this forecast, only regions in the northern part of European Russia and the south of Novaya Zemlya offer suitable breeding areas.
Individual references, literature and web links
literature
- Hans-Günther Bauer, Einhard Bezzel and Wolfgang Fiedler (eds.): The compendium of birds in Central Europe: Everything about biology, endangerment and protection. Volume 1: Nonpasseriformes - non-sparrow birds. Aula-Verlag Wiebelsheim, Wiesbaden 2005, ISBN 3-89104-647-2 .
- T. Bartlett: Ducks And Geese - A Guide To Management. The Crowood Press, 2002, ISBN 1-85223-650-7
- Hartmut Kolbe: The world's ducks. Ulmer Verlag 1999, ISBN 3-8001-7442-1
- Richard Sale: A Complete Guide to Arctic Wildlife , published by Christopher Helm, London 2006, ISBN 0-7136-7039-8
Web links
- Picture of some saws 1
- Picture of some saws 2
- Picture of some saws 3
- Mergellus albellus in the endangered Red List species the IUCN 2006. Posted by: BirdLife International, 2008. Accessed on December 19 of 2008.
http://www.luontoportti.com/suomi/sv/linnut/salskrake
Individual evidence
- ↑ Sale, p. 133
- ↑ Kolbe, p. 312
- ↑ Hans-Heiner Bergmann; Hans-Wolfgang Helb; Sabine Baumann; The voices of the birds of Europe - 474 bird portraits with 914 calls and chants on 2,200 sonograms , Aula-Verlag, Wiesbaden 2008, ISBN 978-3-89104-710-1 ; P. 73. This source was used for the onomatopoeic description of the voices.
- ↑ Bauer et al., P. 139
- ↑ Kolbe, p. 313
- ↑ Kolbe, p. 313
- ^ Brian Huntley, Rhys E. Green, Yvonne C. Collingham, Stephen G. Willis: A Climatic Atlas of European Breeding Birds , Durham University, The RSPB and Lynx Editions, Barcelona 2007, ISBN 978-84-96553-14-9 , P. 96