Trumpeter Swan
| C. buccinator | ||||||||||||
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Trumpeter Swan ( Cygnus buccinator ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Cygnus buccinator | ||||||||||||
| Richardson , 1832 |
The trumpeter swan ( Cygnus buccinator ) is a monotypic bird species in the genus of swans and the family of the Anatidae (Anatidae). It owes its name to its trumpet-like calls. The species was critically endangered in the 1930s. In 1935 it was assumed that only 69 individuals remained. This does not include the Trumpeter Swans living in remote regions in Canada and Alaska. Since then, extensive protective measures have resulted in the population recovering. In 2000 the number of individuals was estimated at more than 23,000.
The trumpeter swan , native to North America, takes on the position there that the whooper swan has in northern Eurasia . Both show similar behavior and breeding biology.
Appearance
With a length of 150 to 180 cm, the Trumpeter Swan is the largest, if not the heaviest swan. Its wing span is about 2.10 meters. With a body weight of up to 12.5 kg, it lags slightly behind the mute swan ( Cygnus olor ). With its white plumage and black legs, it resembles other swan species in the northern hemisphere. Trumpeter swans sometimes have a slightly rusty brown colored plumage on their head and neck. This is due to the fact that they often look for their food in iron-rich waters. The black beak is straight. Some individuals have a fine red border at the top of the lower mandible. The face up to the eyes is also black. Feet and legs are also black in color. Leucism occasionally occurs among the trumpeter swans . Leucist trumpeter swans are characterized, among other things, by their yellowish legs and feet. The swinging moult lasts 30 to 40 days and falls from June to September. During this time, the swans are unable to fly for about 30 days. Breeding pairs show an asynchronous moulting process.
Young animals are initially greyish and only gradually turn white.
distribution
The trumpeter swan was originally widespread in North America . It occurred from Alaska to Ontario and south to the Rocky Mountains and north of the state of Missouri . Its occurrence was reduced to several sub-areas through hunting.
A western population group breeds in Alaska, Yukon, and British Columbia and winters along the coast between Alaska and northern Oregon .
A second inland population group breeds east of the Rocky Mountains in western Canada from the Northwest Territories to Saskatchewan and in the area of Yellowstone National Park . The birds in this group overwinter in Idaho and Wyoming .
More recently, Trumpeter Swans have been reintroduced to several locations in the northwestern United States . Thanks to the dense plumage and well-developed sebum glands , the birds of these populations stay in the area in winter . Settlements in the east of the USA, however, were controversial, as the historical distribution area of the trumpeter swan is unclear. However, the (new) settlement was also successful in the east.
The Trumpeter Swan prefers large, shallow ponds and wide, slow rivers. Since the birds need a long run-up before they can get into the air, they must have at least 100 meters of water available.
The IUCN puts the total population of the Trumpeter Swan at around 18,000 animals. The species is considered harmless.
Way of life
At the end of April or beginning of May, Trumpeter Swans seek their breeding grounds. Couples immediately start building a new nest or improving an existing one. Cubs from the previous year band together and settle in a body of water in which no pair can breed.
Females lay one egg per day - a total of three to nine eggs - in a nest made of plant material on an island, on an abandoned beaver or muskrat burrow or on a floating platform. They keep the eggs warm for 32 days. In the southern distribution area the young hatch around mid-June, in the north in early July. They sometimes use the same nesting place for several years. The young can swim shortly after hatching; However, they can only fly after three to four months.
Trumpeter swans mainly feed on aquatic plants. Occasionally they dip their heads underwater for food. In winter they also eat grass and grain in the fields. Young animals are fed insects and shellfish . After a few months, they switch to plant-based foods.
Adult Trumpeter Swans tend to molt in summer . They also temporarily lose their flight feathers: females shortly after hatching and males about a month later, when the females can fly again.
Naturally living Trumpeter Swans migrate to the Pacific coast and the northwestern USA towards winter. They fly in a V-shaped swarm.
Systematics
No subspecies are distinguished for the trumpeter swan. There is evidence in the literature that the populations breeding in Alaska have larger feet than those breeding in Idaho and Montana. The differences found may be due to different measurement methods. Studies of three populations, which have their breeding areas in Alaska, Canada and Montana, show only minor genetic differences. In the case of the population in Montana, it is conceivable that this is due to the sharp decline in the population at the beginning of the 20th century. However, it is not yet clear why the other two populations, whose number of individuals (presumably) had not collapsed so much, also show such great genetic similarities.
The close relationship between the individual species in the swan genus is shown, among other things, in the fact that the individual species cross with each other in captivity. Offspring have emerged from pairings between Trumpeter Swan and Mute Swan , Miniature Swan , Whistle Swan and Whooper Swan .
Individual references, literature and web links
Individual evidence
- ^ Kear, p. 235
- ↑ Kolbe, p. 97
- ↑ Kear, p. 234
- ↑ Kear, p. 234
- ↑ Alderfer, p. 12
- ↑ Alderfer, p. 12
- ↑ Kear, p. 234
- ↑ Kear, p. 234
- ↑ Kear, p. 234
literature
- Jonathan Alderfer (Ed.): Complete Birds of North America , National Geographic, Washington DC 2006, ISBN 0-7922-4175-4
- Winston E. Banko : The Trumpeter Swan: Its History, Habits and Population in the United States North American Fauna Series No. 63, United States Fish and Wildlife Service, Washington DC, 1960
- T. Bartlett: Ducks And Geese - A Guide To Management. The Crowood Press, 2002, ISBN 1-85223-650-7
- Janet Kear (Ed.): Ducks, Geese and Swans. Oxford University Press, 2005, ISBN 0-19-854645-9 .
- Hartmut Kolbe: The world's ducks. Ulmer Verlag 1999, ISBN 3-8001-7442-1
Web links
- Trumpeter Swan Society (Engl.)
- Hinterland Who's Who: Trumpeter Swan
- Cygnus buccinator in the Red List of Threatened Species of the IUCN 2008. Posted by: BirdLife International, 2008. Accessed January 31 of 2009.
- Videos, photos and sound recordings for Cygnus buccinator in the Internet Bird Collection