A young female fox, just shy of her first birthday, stunned scientists by covering an unbelievable distance during a short, four-month trek. The animal, also known as a coastal or blue fox, traveled more than 2,700 miles from Spitsbergen, the largest island of the Svalbard Archipelago of Norway, to Ellesmere Island in Nunavut, Canada. The journey is among the longest dispersal events ever recorded for the species.
Researchers from the Norwegian Polar Institute first fitted the fox with a tracking collar in 2017 and released her into nature as part of a larger and ongoing study about the spatial ecology of arctic foxes, according to a report led by researchers Eva Fuglei and Arnaud Tarroux.
For months the fox stayed along the coastline of western Spitsbergen. Toward the end of March 2018, she took off, changing course several times when she met open water.
After finding ice-covered sea for the first time, the fox left Spitsbergen. Having traveled for 21 days and about 939 miles, she arrived in Greenland on April 16, 2018.
Similarly, in 2010 an adult female arctic fox in the Canadian Arctic set off on a journey. She traveled more than 2,800 miles in total but over a longer period of 5.5 months. She used sea ice to link distant regions, as did the Svalbard fox, which eventually arrived on Canada's Ellesmere Island on July 1, 2018.
By crossing extensive stretches of sea and ice glacier during her journey, the fox highlighted "the exceptional movement capacity of this small-sized carnivore species," the report said.
The fox's average traveling speed varied greatly throughout her trip, hitting a mean of about 28 miles per day. Her fastest recorded movement rate was about 96 miles per day while crossing the ice sheet in northwestern Greenland. This indicates that she was using sea ice mostly to help her travel, rather than as a place to forage for food.
"This is, to our knowledge, the fastest movement rate ever recorded for this species," the researchers said. In comparison, the young fox was 1.4 times faster than the maximum rate of the previously recorded adult male arctic fox monitored in Alaska.
Published this morning: "Arctic fox dispersal from Svalbard to Canada: one female’s long run across sea ice" https://t.co/vUvu4NbPEj This is the first satellite tracking of natal dispersal by an Arctic fox between continents. Authors: Eva Fuglei and Arnaud Tarroux pic.twitter.com/gowSov0OBA— Polar Research (@PolarResearch) June 25, 2019
An average arctic fox lives to be 3 to 6 years old in the wild. They carry a thick coat of fur that helps them survive brutal temperatures as low as minus 58 degrees Fahrenheit. The animals hunt marine birds, fish and small rodents such as lemmings.
The researchers suggest the fox may have initially left Norway because of a scarcity of food. During winter, for example, the foxes tend to rely on the leftover scraps from large predators like polar bears.
She found privacy in February. That's when the tracker stopped working and researchers can no longer locate her.