Arctic Fox
19.07.2019 Animal tracking applications

From Svalbard to Canada, the long travel of an arctic fox tracked by Argos

Arctic foxes are living in all the regions around the Arctic ocean. Argos satellite telemetry tracking demonstrates that some of those foxes are changing continent using the sea ice as bridge, travelling thousands of kilometers in a few months in the process, from Svalbard to Canada.

‘Recordfox’ of distance

Since 2012, the Norwegian Polar Institute have fitted arctic foxes (Vulpes lagopus) with lightweight Argos PTTs on the Svalbard archipelago. Some of those arctic foxes are of the “coastal” type with blue (dark) fur, feeding on marine resources in addition to carcasses of reindeer and seal (wrt to the ”lemming” type feeding on lemmings in Canada and Siberia).

Among the more than 50 tracked arctic foxes, a young “blue” female made a record trip – more than 3500 km in less than 80 days, crossing the ice for an intercontinental trip to Canada. The scientific team tracking the foxes even wondered if the transmitter went on a boat or other modern mean of transportation, as in Around the World in Eighty Days, but evidences are that she went all the way on her paws.

Argos gives information all the way

Argos satellite telemetry not only enabled to pinpoint the departure at Spitsbergen (Svalbard Archipelago, Norway) on 26 March 2018 and arrival at Ellesmere Island (Nunavut, Canada) 76 days later on 1 July 2018, but also to measure the whole distance and the different velocities during that trip. She went at a mean speed of 46.3 km/day, with peaks at 155 km/day, the fastest ever recorded for this species.

Analysis of the different parts of the track shows that the fox went faster over the Greenland ice sheet, where she probably found little food. She also went faster over sea ice with an average speed of 65.4 km/day (faster than over land where she went at about 31.4 km/day) suggesting that she was travelling more than foraging, but on two occasions slowed down to less than 10 km/day. These stopovers can have a number of reasons, among which feeding: in those areas leads are forming in the sea ice, which can act as biodiversity hotspots. Those leads could also be barriers with open waters several hundred meters wide she had to wait freezing or closing before crossing.

The travel of the young female Arctic fox between 1 March 2018 and ending when she settled on Ellesmere Island, after 4415 km. Color codes her speed, with the two two-day stopovers showed. She went as far north as 84.7°N (Credits A. Tarroux, Norwegian Institute for Nature Research)
The travel of the young female Arctic fox between 1 March 2018 and ending when she settled on Ellesmere Island, after 4415 km. Color codes her speed, with the two two-day stopovers showed. She went as far north as 84.7°N (Credits A. Tarroux, Norwegian Institute for Nature Research)

 

Intercontinental travels by sea ice

If only one over more than fifty foxes made that trip, there are evidences of gene exchanges between the populations, including ones separated by sea or ocean but bridged by ice in winter. Thus today there are very few really isolated populations of arctic foxes. Those long travels are more frequent in the lemming-eating population, since the food is more seasonal. But even the coastal population and its relatively more stable food occasionally goes long-distance, maybe triggered by food shortages lasting for several weeks in winter. However, as sea-ice is shrinking in the Arctic such long-distance intercontinental treks may no longer be feasible in the future.

 

Daily movements based on Argos satellite data of the young Arctic fox female from 1 March to 1 July 2018 overlaid on sea ice concentration (Credits A. Tarroux, Norwegian Institute for Nature Research)

 

Photo: The young arctic fox female with an Argos collar (Credits Elise Strømseng, Norwegian Polar Institute)

 

References & links

See also