Ring-billed duck

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Ring-billed duck
Ring-billed duck ♂ (Aythya collaris)

Ring-billed duck ♂ ( Aythya collaris )

Systematics
Order : Goose birds (Anseriformes)
Family : Duck birds (Anatidae)
Subfamily : Anatinae
Tribe : Diving ducks (aythyini)
Genre : Aythya
Type : Ring-billed duck
Scientific name
Aythya collaris
( Donovan , 1809)

The ring-billed duck ( Aythya collaris ), also known as the ring-necked duck , is a small North American diving duck from the duck family . Even though it clearly belongs to the genus of diving ducks, the ring-billed duck has some behaviors that are reminiscent of gudgeons . For a diving duck, it lies relatively high on the water, can rise immediately from the water without running, often pounds and sometimes only searches for food with its head submerged. She keeps her young hidden in the bank vegetation and, unlike most diving ducks, does not lead them straight into the open water. These behaviors are probably due to the fact that, unlike most diving ducks, they prefer shallow marsh waters as their habitat.

In Central Europe, the ring-billed duck is a very rare stray visitor, although the number of observations has increased since the 1970s. There have been at least seven winter certificates for Switzerland since the 1966s. It was observed a total of 22 times in Germany between 1977 and 1997. In Great Britain and Ireland she has been a frequent visitor since 1955. There are also observations that can be traced back to prisoner refugees.

features

Ring-billed ducks are 37 to 46 cm long, weigh 600 to 1200 g and have a wingspan of about 72 cm. They are similar to tufted ducks , but have a "bulged" looking back of the head.

The male has a dark head that shines purple. The chest, tail and wing covers are black, the belly white. The beak is gray with a white band and a white line around the base of the beak, the eyes are yellow.

Ring-billed duck (female)

The female is gray-brown. The beak has a light border.

It can be confused with the scallop and the violet duck . The ring-billed duck, however, has a black instead of gray back, which is the main distinguishing feature between these two species.

distribution

The ring-billed duck breeds from Alaska to Nova Scotia . Their breeding areas include Washington, the two Dakota states, Minnesota and Maine. Her habitat are lakes, where she builds her nest in the reeds. As a migratory bird, it migrates further south to Central America to Panama and the Caribbean in winter . The main wintering area is the Gulf of Mexico from Florida to the Yucatan.

Ring-billed ducks keep coming back to Europe as random visitors. The first scientific description was made in 1809 using a ring-billed duck, which was shot in Great Britain and was sold in Leadenhall Market in London. Since the ring-billed duck has expanded its breeding area due to the population increase in North America, wanderings have become more common in Europe. In the UK, some ring-billed ducks can be found most winters. In 1980 alone, 35 individuals were counted. But wanderers can also be found in Iceland, Portugal, Austria and the Azores.

Way of life

The ring-billed ducks' diet is mainly vegetable. They ingest large amounts of seeds, spawning herbs and other marsh and bank plants. Up to 20 percent of the diet is animal food. It eats insect larvae, mollusks, worms and crustaceans, which it often ingests unintentionally with its vegetable food. The chicks and young birds also feed predominantly on plants, which is unusual because this food is significantly lower in energy than animal food.

The nests are built close to the water and are often located in the flood zone. The eggs are olive in color. The first clutch usually consists of nine eggs. The second clutch is slightly smaller and usually has seven eggs. The female breeds alone. The breeding season is 25 to 29 days, the young are fledged after 49 to 56 days. The females prefer to return to the region in which they were raised. For females older than a year, the return rate was 53 percent.

Duration

male

The ring-billed duck population is increasing in the United States. In the 1950s, the population was estimated at 334,000 individuals. In the 1990s, the population comprised an average of 923,100 individuals. The population increase was accompanied by an expansion of the breeding area. Wetland International estimated the world population for 2002 at 1.2 million individuals. The species is very adaptable and opens up new habitats very quickly.

supporting documents

literature

Web links

Commons : Ring-billed Duck  - Album with pictures, videos and audio files

Individual evidence

  1. ↑ a b Gooders and Boyer, p. 89
  2. ↑ 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 , p. 114
  3. ^ Kear, p. 667
  4. ↑ a b Kear, p. 669
  5. ↑ a b Kear, p. 670