The Guardian reports that an arctic fox has been documented walking 2,000 miles across the sea ice from Spitsbergen in the Svalbard Archipelago to Canada’s Ellesmere Island.
The vixen, a blue phase arctic fox, was collared with a tracking device on Spitsbergen. The Norwegian Polar Institute then followed her travels for the next 76 days. She wandered across the sea ice to Greenland, probably scavenging polar bear kills and catching sea birds. She then wandered across northern Greenland, eventually the sea ice again to settled on Ellesmere.
She traveled an average of 46.3 km per day, which is a little less than 29 miles day. On one day, she traveled 155 km or 96 miles across the ice sheet in Greenland.
Arctic foxes are significantly smaller than red foxes, which kill them where their ranges overlap. The two species have hybridized in captivity, but the offspring are sterile. Arctic foxes are most closely related to the kit and swift foxes of North America, and they probably could produce fertile hybrids with them if they were ever given the opportunity.
Arctic foxes are not extremely dependent upon sea ice for survival, but the sea ice is useful for augmenting their diets in the winter, when they can follow polar bears.
Because it is unlikely that this fox’s journey is but a fluke, sea ice has been essential in retaining gene flow in the species across northern Eurasia and North America. More research must be performed on the genetics of this species, but it would surprise me if there wasn’t at least some gene flow across the arctic.
Arctic foxes are about the size of a toy dog, averaging 6-7 pounds in weight, but they are so well-adapted to long-distance travel that they can make such amazing journeys.