Zur sekundären Expansion des Kormorans Phalacrocorax carbo am Baikalsee, Südost-sibirien, samt Aspekten zu Nahrungsökologie und Parasitologie.

Elaev EN, Ananin AA, Weigl S (2024) On the secondary expansion of the Great Cormorant Phalacrocorax carbo at Lake Baikal, southeastern Sibiria, including aspects of feeding biology and parasitology. Ornithologischer Beobachter 121: 166-176. The Cormorant Phalacrocorax carbo sinensis was a common breeding bird at Lake Baikal in south-eastern Siberia until the middle of the 20th century. For reasons that are not entirely clear, it disappeared from the region, only to return at the beginning of the 21st century. A connection is suspected with human persecution, overexploitation of fish stocks and the cyclical drying up of waters in the breeding areas of Transbaikalia and Mongolia. Today, the population has stabilized at a high level with up to 40 000 birds. In order to contribute to research on the ecology of the Cormorant during its recolonisation of the Baikal region, we carried out dietary analyses and studies of endoparasites and ectoparasites. Material for the cormorant dietary analyses consisted of 28 stomachs of dead birds, visual observations of feeding cormorants using optical equipment, and regurgitated stomach contents from chicks. The cormorants' main diet consisted of locally economically unimportant fish such as Chinese Sleeper Perccottus glenii, Perch Perca fluviatilis and Roach Rutilus rutilus. Parasitological studies have revealed eight species of helminths with varying degrees of infestation. As hosts of ticks, helminths and other ecto- and endoparasites, Cormorants are, just like other waterfowl, potential sources for the occurrence and spread of ornithosis and helminthiasis that may be transmitted from their breeding grounds. [ABSTRACT FROM AUTHOR]