Why One Arctic Fox Took the Longest Migration in the Species’ History

The effects of climate change can be tracked in a single animal’s record-breaking journey

Published in

OneZero

5 min readJun 25, 2019

Twenty-seven hundred miles — 2,743, to be exact — is how far one arctic fox traveled over sea ice and glaciers last year during a 76-day polar marathon. The fox’s journey began on the island of Spitsbergen, off the coast of Norway in the Svalbard archipelago, and ended on Ellesmere Island in Canada’s remote Nunavut Territory, a full continent away.

The migration was among the longest ever recorded for an arctic fox. The farthest northern point reached by the juvenile female was on the sea ice off Greenland at more than 87 degrees north, not far from the North Pole.

Researchers from the Norwegian Polar Institute and the Norwegian Institute for Nature Research studied the fox’s movements via satellite tracking; they captured her in Spitsbergen and placed a small transmitter on the fox which then transmitted daily location every three hours. The young fox, who lived on the coast and weighed a little over 4 pounds when weighed by researchers, started the trip in her blue fur pelage on March 26, 2018, and averaged about 28.5 miles a day. While on Greenland’s ice sheet, she more than tripled her time, averaging about 96 miles a day, the fastest movement rate ever recorded for the species.

Arctic foxes are an impressive species. In the barren tundra, they’re known as secret gardeners because during long winters they spend so much time in their dens — where they bring back kills that decompose, creating what’s essentially fertilizer, turning their mound-like homes into splashes of color in an otherwise drab landscape. Their long-distance roaming has been known since the days of early polar explorers like Fridtjof Nansen, who observed fresh fox tracks far offshore on the sea ice during his 1885 North Pole expedition aboard the Fram. “Why do they leave the coasts?” Nansen wrote in his journals, as confused by the animal’s behavior as modern biologists. And why do they travel so far from land on the ice, he wondered. “That is what puzzles me most. Can they have gone astray?”