Where do reindeers go? Hardangervidda National Park faces the challenges of climate and human pressures

Tessa Bahiga Bargmann and Ole Reidar Vetaas, University of Bergen

Hardangervidda National Park is Norway’s biggest national park and is home to the largest and the southernmost intact wild reindeer population in Europe. Wild reindeer have migrated across the Hardangervidda plateau for thousands of years in search for food. However, in recent years, a changing climate and human interference have caused disruptions in their movements. The winter on Hardangervidda is long and harsh, and although reindeer are well adapted to this type of climate, they are also dependent on finding suitable nutritious summer pastures to last them through the cold. Locals have reported that the animals were often seen in the north and northwest of the national park, but today, they seem to prefer the south as their calving and summer grazing grounds. No one really knows for sure why, but when you visit the different areas of the park, the terrain becomes an obvious clue. The north is very popular among tourists – there are expanses of flat terrain that is easy to hike with family members of all ages. The south, on the other hand, has more rugged terrain and far fewer tourist cabins where you can spend the night. It is easy to conclude that the reindeer are hiding from the hustle and bustle of summer activities.

Hardangervidda is also directly in the middle of the main route between Bergen and Oslo, Norway’s two largest cities. The Norwegian Institute of Nature Research has shown that this road, which runs to the north of the national park, is a barrier for reindeer migration and that paths and cabins are also avoided by reindeer. Human activity is a hindrance to wild reindeer movement, but a changing climate is also likely to be taking its toll. Climate warming is predicted to lead to a change in the timing of spring and to warmer temperatures all year around. In the spring, this can be a particularly daunting problem, as the timing of calving is highly synchronized with the beginning of the season and females are dependent on enough food to be able to feed their young.

In winter, reindeer have been known to dig through up to 150 cm of snow to get to their staple winter diet: lichens. When winter temperatures fluctuate, this causes a melting and re-freezing of snow, making the surface impenetrable for reindeer. This can make an already difficult situation worse and threaten the animals’ survival.

The ECOPOTENTIAL project uses reindeer movement data, climate data, tourist data and remote sensing data on vegetation and snow to investigate how reindeer migration patterns have changed and can change in the light of climate change and human interference. We need this information to be able to inform the management of tourism, but also to tell us what challenges we will face as climate change progresses.