Grazing by sheep Ovis aries reduces island populations of water voles Arvicola amphibius

Fauna norvegica

Karl Frafjord¹ 

[1] Tromsø MuseumUniversitetet i Tromsø

关键词: competition;    ecosystem;    grazing;    islands;    sheep;    Mammalia;   

DOI  :  

学科分类：动物科学

来源: NTNU/NTNU,University Museum

【 摘 要 】

The population of water volesArvicola amphibiuswas surveyed on 21 islands in the Solvær archipelago, northern Norway, in August 2012; 11 islands with semi-wild domestic sheepOvis ariesand 10 islands without sheep. Signs from water voles are very easy to detect and were used as a measure of the population (on a scale 0-10), and the numbers of sheep were counted. The ranking of signs on islands with and without sheep was compared, and a significant difference was found. Islands with sheep had, with one exception, only very small and fragmented populations of water voles, the one exception being a fairly largeCarexswamp that was not grazed by the sheep and where a moderate-sized population of voles was found. Islands without sheep had much larger populations of water voles, giving a ranking about four times higher. One reason for the devastating effect of sheep on water voles is probably the fact that the sheep are living year-round on these islands with no supplemental food.

【 授权许可】

Unknown