Barrow's Goldeneye

Barrow's Goldeneye ( Bucephala islandica ), male

The Barrow's Goldeneye ( Bucephala islandica ) is a monotypic species of the subfamily of ducks ( Anatinae ). It is very similar occurring in Central Europe Goldeneye ( Bucephala clangula ) and the North American buffalo head duck. The three types together form the genus Bucephala and the same also in their way of life very much. However, they differ in their breeding distribution: Barrows colonize the temperate to arctic zone of North America, Greenland and Iceland.

In Central Europe the Barrow's Goldeneye is a very rare Irrgast. It has been observed several times in Germany, Belgium, Poland and the Czech Republic.

Description

Barrows Goldeneye reach a body length of 40-48 cm and a wingspan of 62-77 cm. Overall, the type is very similar to Goldeneye; Females, juveniles and The immature males of the two species are indistinguishable in the field. Fully Colored males have a violet- purple shimmering head ( at Goldeneye green). The head is oval in shape. The beak looks triangular and is short. The white spot between beak and eye, which is characteristic of males in breeding plumage is, compared to Goldeneye males larger, significantly extended upwards and ends above the eye pulled out a point.

Fully Colored females have a brown head and a gray body plumage. In breeding plumage, the beak is black, outside the breeding season, in winter it is orange.

Vocalizations

Barrows are mostly silent. During the mating season the male is heard a soft grunting and ka- kaa or a series of wa wa wa ..- Call. The cries of the female are a cackling ga - ga - gärr or Kaw Kaw.

Distribution and habitat

The area of ​​distribution of the species is very disjoint. The largest deposits are found in the coastal northwestern North America from Oregon to Alaska. A second, small deposits located on the Labrador Peninsula in northeastern Canada. The Barrow's also breeds in southwest Greenland and Iceland. Their habitat is lakes, ponds and rivers in open and bewaldeteten areas. The altitudinal distribution ranges from sea level to 3,000 feet in the Rocky Mountains.

Barrows Goldeneye wintering mainly in sheltered coasts near the breeding grounds, but also on lakes and rivers inland. The species is a very rare Irrgast in Central Europe. Until now there is only a secured proof of an occurrence in central Europe, because in March 1853 adult male was shot at Hiddensee. More often come Barrows as Irrgast but before in the UK and Norway.

Food

The main part of their diet (70-80% ) consists of crustaceans and aquatic insects. Less often they eat fish or fish spawn. The plant food mostly consists of marine algae, aquatic plants and seeds.

Brood

Barrows Goldeneye breed in very loose colonies, as the males are very aggressive during the breeding season. There are monogamous birds, the couple's relationship is, however, only one breeding season.

The Barrow's Goldeneye breeds on lakes and ponds, mostly in forests. They use tree hollows or similar cavities and nest boxes take willingly. In Iceland they use for example, columns in lava fields to create their nests. The nest lining is filled with down. The end of May, but sometimes not until the beginning of June begins laying eggs. The clutch usually consists of 10 to 14 blue-green eggs. The incubation period lasts about 30 days and the end of June, the chicks hatch. They are brooded by the female in the beginning, but find their food independently. The young birds fledge 55 to 65 days. They breed for the first time at the age of two years.

Inventory and risk

The world population was estimated by the IUCN to 180000-210000 individuals 2002. The species is IUCN uncritical ( " least concern "). The European stock, which breeds in Iceland seems stable over time at approximately 1,500 to 1,800 individuals. For short-term stock dips it came to Iceland in 1978 and 1989 due to food shortages.