Sanderling
Sanderling (Calidris alba)
The Sanderling (Calidris alba ) is a small shorebird distinguished from the kind of beach runners. In the Wadden Sea of the Netherlands and Germany, he appears especially in the winter months in some large schools on the North Sea coast, far less inland. It can also be observed throughout the year, at least in small numbers. On the Baltic Sea, however, wintered only a small part of the Sanderlings. During the migration period there can be observed at most a few hundred birds.
- 5.1 Literature
- 5.2 External links
- 5.3 Notes and references
Description
Adult birds
The Sanderling reaches a body length of 20 to 22 inches. The wingspan is 40 to 45 centimeters. The weight varies between 45 to 65 grams.
He stands out for its relatively bright plumage in winter. The top is light gray to gray, the underside white. Striking is the dark of wing, the primaries are also dark. Beak and legs are black, the three-toed feet are because they lack the hind toe. In flight, the Sanderling appears silver-gray and shows a distinct white wing stripe.
In breeding plumage the Sanderling is the dwarf beach runners not dissimilar. The top is brown brindle and is increasingly towards russet especially in the American subspecies against summer. In contrast to the winter dress the color of the top goes over the entire head and up to the front chest.
In winter, the Sanderling often found on flat sandy beaches. Along the drift lines it runs in a typical run step behind the flowing waves and takes the aufgestrudelten crustaceans and worms. Sanderlings have the ability to sent waves to get around, so they do not have to blow the whistle.
Young birds
The Dunenjungen are on the underparts white and tinted light beige on the throat. The body top is ocher with larger black spots and fine white polka dots. On the front the Dunenjungen have a black middle stripe. The top sides have narrow black reins, eyes and Barstreifen. In the ear-coverts, there are some dark marks. The iris is brown. The beak is gray with a black tip. The legs and toes are black to bluish black or greenish gray. The dress of the young birds shows similarity to the winter dress, but is spotted on the upper side dark, with a clear scale pattern.
Voice
The Sanderling often gets a short plitt, tjick or tiwick, which he usually ranked ejects when flying up.
Distribution and habitat
The Sanderling is a breeding bird in the Arctic tundra and arctic islands such as Spitzbergen. The circumpolar species has two subspecies, the Eurasian (Calidris alba a ) and the American ( C. a rubida ). The species overwinters not only in the temperate latitudes, but also attracts long distances - depending on the population to South Africa, South America or Australia.
Reproduction
During the short breeding period of the nesting site is found mainly on dry elevations in the tundra. The nest cavity is lined with a few sparse stalks and lichens. The nest usually consists of 3-4 olive, brown speckled eggs. Both parents birds are involved in the incubation of the scrim. Some of the females lay two clutches, one of which is incubated by him and the other by the male. The incubation period is 24 to 27 days. At 17 days the young birds fledge and with 23 to 24 days are self-employed.
In the breeding area, the Sanderling feeds primarily on insects and plant parts, which he finds to the sumpfigeren points of its habitat.
The highest occupied with ring again finds the age of Sander Lingen is 18 years and six months for a ringed in the British Isles individual and 16 years and six months for a ringed on Helgoland animal.
Stock
The European breeding population was at the beginning of the 21st century 25000-50000 breeding pairs. This bred mainly in Greenland and a few copies on Spitsbergen. About Central Europe, the East Atlantic railway line leads that way you will be used by birds whose breeding grounds are located in the north eastern Canada and the northeastern Greenland and Spitzbergen to the West of Taimyr. Approximately 123,000 Sanderlings use this train route.