NOWADAYS they spend most of their time on Arctic ice floes – but 18,000 years ago polar bears may have lived in the Scottish Highlands.
Why the world's largest carnivore was there, what it fed on and how different it was from its modern descendants are questions a study is intended to answer.
Scientists hope to unlock secrets in the DNA of what are believed to be the only polar bear remains found in Britain.
The skull, of which only half survives, was found at Inchnadamph in Sutherland in 1927 by archaeologists looking for evidence of Stone Age human habitation. It was first thought to be that of a cave bear and then a brown bear.
It has been in the National Museum of Scotland in Edinburgh since the 1950s.
Carbon dating established the skull dated back some 18,000 years to when Scotland was in the peak of the last Ice Age. Further tests revealed it was more likely to be a polar bear skull.
Experts at Trinity College, Dublin, have approached the National Museums about running tests on its DNA.
Dr Ceiridwen Edwards, of Trinity's Smurfit Institute of Genetics, said it may be found that the ancient animal preyed on reindeer, rather than seals like its modern counterpart.
She said the results could also shed light on what it was doing in Assynt 18,000 years ago and reinforce scientists' understanding that it is Britain's only confirmed polar bear find.
The research will involve drilling a small hole and taking a part of the skull – less than a gram – then extracting DNA from the powdered residue. A technique known as stable isotope analysis will be used to study the animal's diet.
Dr Edwards said: "I want to see how it fits in with modern polar bears as well as data on brown bears. I also want to examine whether it ate a marine diet like modern-day polar bears or a terrestrial diet.
"If it ate reindeer and did not survive on a marine diet, that would be interesting as it would tell us things about the area at the time. If it ate reindeer and was near a marine resource why did it not eat a marine resource?
"It could be that in the past they had a more varied diet and it's only because they have been more marginalised into the Arctic region that they have started to become more marine based."
Dr Andrew Kitchener, curator of birds and mammals at the National Museums, said it is hoped the work will add to the attraction of the exhibit.
"It's always good where you have a specimen around for a long time and you find out new things about it," he said. "It doesn't just sit there looking pretty for the public, but as new techniques come along we can find out more about it.
"In the past, the amount of bone you would have needed for a specimen was far too damaging. We don't want to damage the skull any more than we have to.
"We have to balance the need to find out more about it with the fact that you are destroying the specimen.
"The amount needed for study has reduced year after year as the methodology and techniques become more sophisticated."