Red fox displacing blue counterparts in Norway’s alpine areas

The red fox, one of the most widespread carnivores in the world, is spreading in Norway’s alpine areas at the cost of the Arctic or blue fox, aided by anthropological changes, a study has said.

Lars Rød-Eriksen, a researcher in terrestrial ecology at NINA, the Norwegian Institute for Nature Research, found that more cabins were being built in the alpine region for tourism purposes. These cabins and the roads built to reach them were playing a major role in causing the spread of the red and the decline of the blue fox, according to his study.

Rød-Eriksen found that both, red and blue foxes were attracted to the roads built by humans. The red foxes used them to make their way from lower altitude areas to the mountainous ones.

These roads were also littered with garbage and refuse left by tourists as well as roadkills due to accidents of animals with cars. Consequently, these roads meant food for the foxes as well as other scavengers like crows.

The density of red foxes increased closer to roads while that of blue ones decreased. It was not because blue foxes were not attracted to trash but rather because the red fox, being bigger than the blue, tended to dominate it in these areas.

There were examples of red foxes killing the blue ones and hence the blue fox tended to avoid the roads altogether. The competition for food especially intensified during the winter months, according to Rød-Eriksen.

While the red fox has existed in alpine regions, it is essentially an invasive species. The blue fox is already endangered and the spread of the red fox could not just impact it but also ground dwelling birds like the ptarmigan, the researcher said.

To record the movements of red and blue foxes during the winter, Rød-Eriksen used tracking, supplemented by a game camera with bait at different distances from the road. These methods yielded good and reliable findings.

During the summer, he placed artificial bird nests containing a real quail egg and a fake egg made from modelling clay along transects.

He called for a legislation against littering to counter the spread of the red fox in Norway’s alpine areas.