Artikel-Suche

Schuster, S.

Die Einnischung einer neuen Vogelart am Bodensee: die Weisskopfmöwe Larus cachinnans.

2004

101

115–124

Key words
(von 1994 bis 2006 vergeben)

Larus cachinnans michahellis, Larus c. cachinnans, adaptation, distribution, food resource, population trend, predation, waterbirds, Lake Constance

Anpassung, Nische, Nahrung, Nahrungsangebot, Nahrungssuchverhalten, Prädation, Kleptoparasitismus, Abwehrverhalten, Bestandesentwicklung, Einwanderung, Verbreitung

Schlagwort_Vogelart
(wissenschaftlich)

Tachybaptus ruficollis, Podiceps cristatus, Podiceps nigricollis, Phalacrocorax carbo, Anas strepera, Anas platyrhynchos, Anas clypeata, Netta rufina, Aythya ferina, Aythya fuligula, Mergus merganser, Larus canus, Larus cachinnans, Larus cachinnans michahellis, Larus cachinnans cachinnans

Schlagwort_Vogelart
(deutsch)

Zwergtaucher, Haubentaucher, Schwarzhalstaucher, Kormoran, Schnatterente, Stockente, Löffelente, Kolbenente, Tafelente, Reiherente, Gänsesäger, Sturmmöwe, Weisskopfmöwe

Bodensee, Untersee, Obersee, Ermatinger Becken, Baden-Württemberg, Rheindelta, Vorarlberg

deutsch

Abhandlung

The niche of a new bird at Lake Constance: the Yellow-legged Gull Larus cachinnans. – Since the sixties and the seventies, Yellow-legged Gulls from the Mediterranean have been increasingly observed at lakes in Central Europe. Records from Lake Constance started later (first observation 1961) than at Lake Geneva and Lake Neuchâtel. At the delta of the river Rhine (Vorarlberger Rheindelta, Austria) up to 1000 immature and adult moulting birds have been observed every summer since about 1995, up to 10000 at Lake Geneva. Ring readings indicate that birds at Lake Constance originated from the Adriatic Sea and from Liguria, the ones in Western Switzerland from Sardinia and the Provence. In both areas the main food consists of dead fish (often from fishing boats). The extension of the birds’ feeding area from Lake Constance-Obersee to Untersee resulted in a change of food because dead fishes were less frequent at the Untersee. In this area the Yellow-legged Gulls exploited rubbish dumps, showed kleptoparasitism of waterbirds and predated on juvenile or adult waterbirds. Only 10–20 % of the total population at Lake Constance occurred at the Untersee. The waterbirds changed their behaviour due to predation by gulls in different ways: escaping, hiding, dispersing over large lake areas, forming dense groups, or changing the diurnal rhythm.