Food characteristics and territory habitat selection in Lapland longspurs Calcarius lapponicus in the early part of the breeding season at Hardangervidda, southern Norway
Master thesis
Permanent lenke
https://hdl.handle.net/1956/15787Utgivelsesdato
2017-05-04Metadata
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Sammendrag
Climate change currently affects the whole globe. Especially tundra and alpine areas are expected to change in the coming decades, affecting the species which today inhabits these areas. The Lapland longspur Calcarius lapponicus is a common passerine bird breeding in such habitats. It has shown a considerable population decline all over Fennoscandia during the last decades. The reason for this decline is suggested to be caused by habitat changes at the breeding ground. Since little is known about the Lapland longspur’s diet in the declining populations, I analyzed the stomach content of 39 individuals sampled in early June at Hardangervidda, southern Norway. Seeds dominated the diet, and from this I predicted that the birds would establish their territories in areas rich in seed producing plants as found in the stomach analysis. I also predicted that the longspur did not establish territories in areas dominated by lichens, but that they were found in areas influenced by shrubs. I compared the vegetation within 17 Lapland longspur territories at Hardangervidda in the early part of the breeding season and compared it with vegetation samples in areas with no territories. Contrary to expected, I found that the Lapland longspurs did not establish their territory in a specific plant community. Furthermore, I found no support for the hypothesis that the longspurs avoided lichen dominated areas, but the birds did favor the presence of shrubs like Salix sp. and/or Betula nana. My results might suggest that the territories do not serve as an exclusive food reservoir in terms of seeds for the Lapland longspurs.