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Hans Märki, Gaston Adamek

Die Verbreitung des Zitronenzeisigs Carduelis citrinella – ungelöste Rätsel und mögliche Erklärungen.

2022

119

366–375

Key words
(von 1994 bis 2006 vergeben)

Verbreitungsgebiet, Abundanz, Dichte, Lebensraumansprüche, genetische Unterschiede, Gebirge, Nahrungsangebot, Kiefer, Fichte,

Schlagwort_Vogelart
(wissenschaftlich)

Carduelis citrinella

Schlagwort_Vogelart
(deutsch)

Zitronenzeisig

Schweiz, Alpen, Mitteleuropa, Spanien, Iberische Halbinsel

englisch

Abhandlung

The distributional range of the Citril Finch Carduelis citrinella – unsolved riddles and possible explanations. – This report is an overview pointing to still unresolved issues in the evolution of the distributional range of the Citril Finch Carduelis citrinella. The current distribution, abundance, and genetic differences between Spanish and central European populations indicate that the glacial refuge of the Citril Finch was on the Iberian Peninsula. In contrast to other subalpine species, the Citril Finch did not colonise a zone of about 200 km length of suitable habitats directly adjacent to its distributional range in the northern part of the eastern Alps. Both density and occurrence decrease towards the east, and from north to south in the central and eastern Alps. Following a brief discussion of the advantages and limitations of genetic methods and distribution modelling on the Citril Finch and its postglacial dispersal, we explain the importance of vegetation. Only mast years of pine and spruce lead to strong population increases throughout the range. Currently, pine forests in Spain that regularly bear fruit are ideal habitats for the Citril Finch. In contrast, spruce forests in the Alps seem suboptimal due to their long intervals between years with full mast seeding. Reproduction and survival rates are probably better in pine habitats than in spruce habitats. The decreasing density from north to south and the distribution in the central and eastern Alps correlates with limestone and dolomite zones. The herb layer on limestone and dolomite is more species-rich than on crystalline bedrock and probably provides seeds continuously and in sufficient quantity, with dandelions serving as the most important food for nestlings. Finally, open questions about the size of the wintering area as well as physiological limitations on migration are discussed. The interaction of historical and current ecological factors, including the small wintering area and the low genetic variability of the central European population, are likely to lead to low population pressure and may explain the irregular and decreasing distribution of the Citril Finch in the easternmost part of the Alps.