The Arctic Fox is the only indigenous mammal In Iceland.  Scientists say that  about 10,000 years ago the Arctic Fox came over to Iceland on the frozen sea.  When the Vikings arrived over a 1000 years ago, the only mammal living there was the Arctic Fox.  Dogs, cats, the Icelandic Horse, sheep, two species of rat, and antelope can be found in Iceland, but humans brought them all there.

 How does this fox survive the harsh conditions of an Icelandic winter?  To begin with, it has deep, thick fur, but that is only the beginning to its evolutionary adaptations.  The Arctic Fox has a counter current heat exchange in the circulation of its paws.  This system of arteries and veins, lying close to each other, utilizes blood flowing in opposite directions, with heat being exchanged easily between arterial and venous blood.  The Arctic Fox has a good amount of body fat, low surface area to volume ratio, and body shape adaptations (rounded body, short muzzle, short legs and thick ears) that allow less heat to escape.   Its heavily furred paws grip the ice while walking. In addition, the Arctic Fox has a keen sense of hearing and smell that allows it to find food under the snow. The arctic fox in Iceland lives on birds — in particular, fulmar, ptarmigan, eider and goose, and in summer, it particularly likes eggs and young birds.The Arctic Fox also eats mice, beached seals and sometimes lambs, along with berries and mushrooms. The Arctic fox can be seen pouncing with a high arc into the air and then punching through the snow to catch prey. Watch a fox jumping in the air for food at: http://www.youtube.com/watch?v=D2SoGHFM18I (This is not an Arctic Fox in Iceland.  It is a fox in North Dakota, but the Arctic Fox does the same thing to get food.) Watch other videos of the Arctic Fox at: http://www.arkive.org/arctic-fox/vulpes-lagopus/videos.html Unfortunately, I did not see any foxes on my trip.  They are shy animals that appear only at dawn or dusk. To learn more about the Arctic Fox in Iceland visit http://www.melrakki.is/arctic_fox/

Range of the Arctic Fox

Countercurrent heat exchange in the leg of an arctic Fox. Courtesy of the University of Miami

Science Is My Specialty recently travelled to Iceland.   This is one of a series of blogs about the trip. in·dig·e·nous (adjective): belonging to a place, natural mam·mal (noun) class of warm-blooded vertebrate animals with hair or fur.