Small Rodent Winter Habitats in an Alpine Area, Finse, Norway

• Main Author: Landa, Miriam
• Format: Master Thesis
• Language: English
• Published: 2020
• Subjects: Arctic; Norway; Climate change
• Online Access: http://hdl.handle.net/10852/79618; http://urn.nb.no/URN:NBN:no-82804

Small rodents in alpine areas are known to appear in multiannual cycles, usually with a population peak every 3 – 5 years. Since the mid 1980’s, a dampening in these population peaks have been observed in Northern Europe. Trying to understand the cause behind the changes in population dynamics, a lot of different hypotheses have been put forward. One hypothesis suggests that climate change is the main cause. As small rodents live under the snowpack during winter, stable winter conditions are necessary for their survival. Changes in winter climate may therefore affect small rodent survival. The aim is therefore to investigate whether vegetation type and snow depth affects small rodents winter distribution in an alpine area like Finse, Hardangervidda, in Norway. By gathering data on snow depth, vegetation cover and winter activity of small rodents within a 1x1 km area, probability of rodent activity could be estimated. Five out of six habitats were found to be suitable winter habitats for rodents; snowbed, arctic-alpine heaths and leeside, boulder fields, open fen, and wet snowbed and snowbed spring. Snow depth was shown to affect small rodent winter habitat preference in snowbed habitats suggesting an optimum around two meters of snow. Similar peak patterns could be argued found for both arctic-alpine heath and leeside and boulder fields however, the uncertainties in the estimates were too large to conclude without further research.