Great Northern Loon
Common loon ( Gavia immer )
The loon ( Gavia immer ) is a species of bird in the genus of the loons (Gavia ). The species breeds in tundra and boreal forest in northern North America, Greenland and Iceland, and winters along the coasts of North America and Europe.
In Central Europe, the loon in the coastal regions is regularly observed in the months of November to March in small numbers as a migrant and winter visitor. Significantly less likely he is to be seen in the interior. He has been observed since the 1970s over and over again on Lake Geneva and Lake Constance.
Description
The loon is on the Yellow -billed Diver is the second largest species of the genus Gavia. It reaches a body length of 73-88 cm and a wingspan of 122-148 cm. The animals weigh 3.6-4.5 kg and are thus about as heavy as a gray goose.
In breeding plumage the species is unmistakable. Ground color of the entire top and head and neck is black. The upper back is tight rows of large white squares, the rear back and the flanks show fine white dot rows. The neck has been located on the sides of a transverse oval field of irregular longitudinal white lines on the throat a narrow line of white dots. Chest, abdomen and under wing-coverts are pure white. Unlike splendor and red-throated divers, however, the loon carries the full adult plumage at the earliest in its fourth calendar year.
The large beak is dark gray to black and straight, it is held almost horizontally while swimming through a corresponding head pose. The legs and feet are gray. The iris is burgundy.
In Plain dress the entire top is dark gray. Head and hind neck are also dark gray, the dark color going forward on the throat and neck quite abruptly in white. At the base of the neck blackish gray half-ring is clearly separated from the rest. To the eye there is a small white area. The beak is bluish -white, at the top and on the ridge dark gray. The forehead is raised sharply. In Plain dress the loon can be confused especially with the yellow -billed Diver. However, the yellow -billed Diver has a paler and slightly raised upwards beak. The distribution of the two species, however, overlaps only slightly.
The juvenile plumage is very similar to the sizing dress, but the birds are gray overall oberseits brighter, the contour feathers of the top and the edges are also edged with light and thereby show a clean wave drawing. The beak is mostly dark only on the ridge.
Vocalizations
Flight calls are similar to those of other loons those of geese. The mating calls are quite variable, most commonly is a widely -sustaining, plaintive " aaoooh ... WÜH wü -a WÜH wü -a WÜH wü -a" to hear.
- Revierruf of the loon
- Warning cry of the loon
Outside the breeding season, the loon is usually not very ruffreudig.
Distribution and habitat
The distribution area of the loon includes the tundra and taiga in northern North America from about 40 ° N to the Arctic, as well as the species occurs in Greenland and in Iceland, Bear Island and Jan Mayen. During the breeding season the species inhabits large and deep lakes.
Nutrition
The food is hunted diving and consists mainly of small fish, next to be frogs, crustaceans, molluscs and looted. When hunting for fish he dives usually three to ten meters deep (maximum and 60-70 m).
Reproduction
The partners come mated to the breeding grounds. The courtship includes in addition to the Call a ceremonial bill dipping and many other elements. The nests are built right on the banks of the waters and are made of plant parts of the environment. Eggs are laid in late April, usually in May and June. The nest usually consists of two, rarely one or three eggs, which are mottled dark brown discolored to dark brown at base. The incubation period lasts 25-29 days. The eggs are incubated by both parents and the chicks then jointly. The young birds are independently after ten to eleven weeks.
Hiking
Common Loons are predominantly medium-to short-distance migrant. The deduction from the nesting area occurs in late summer and ends in October. The breeding birds of Greenland and Iceland winter on the sea around Iceland, the UK and on the European Atlantic coast of northern Norway to the south of Portugal. The populations of North America spend the winter in front of the entire North American Pacific and Atlantic coasts. The return to the breeding areas is carried out in May and June. The species is regularly until March detected in Central Europe in very small numbers predominantly of November, especially on the coasts of North and Baltic Seas; only exceptionally inland on larger lakes.
Inventory and risk
Information on population trends are not available. The world stock was estimated by the IUCN in 2002 to 580,000 individuals and is considered safely.
Trivia
The loon is the national bird of Canada. The Canadian province of Ontario and the U.S. state of Minnesota have chosen him as their icon. He is depicted on the Canadian one-dollar coin. This coin is named after the English name of the loon " loonie ".