New research on ancient bear fossils found in a Highland cave suggests that polar bears may have once lived in Scotland.
Scientists studying bones from the Inchnadamph “Bone Caves” in Sutherland have uncovered surprising evidence that some bears had diets almost entirely made up of seafood, unlike modern brown bears.
The study, conducted by the University of Aberdeen and National Museums Scotland, used advanced chemical analysis to examine the bones and teeth of these ancient bears.
The team, which included University of Edinburgh Master’s student Holland Taekema, analyzed stable isotopes—chemical markers used to study the diets of ancient humans and animals.
Their findings, published in Annales Zoologici Fennici, show that three bear samples from 30,000 to 50,000 years ago lived mainly on marine fish and other seafood.
This unusual diet is vastly different from the meat- and plant-based diets of modern brown bears or those in Britain before their extinction roughly 1,000 years ago.
The researchers believe these findings could point to the presence of polar bears in Scotland during the Last Ice Age.
Professor Kate Britton, from the University of Aberdeen, explained, “These bears didn’t eat like today’s brown bears or even ancient ones from the same region.
Instead of meat or plants, they relied almost entirely on seafood.
It’s such an unusual diet that we need to reconsider whether these were brown bears with unique habits or possibly another species, like polar bears.”
Polar bears are known today for living in Arctic regions, but during the Last Ice Age, the sea ice stretched much further south.
This could have allowed polar bears, which are excellent swimmers, to move into areas like Scotland.
This isn’t the first time scientists have questioned whether polar bears lived in ancient Scotland. In the 1990s, a bear skull with polar bear-like features was found, but later dating techniques raised doubts about its age.
However, this new study provides fresh evidence to reopen the debate.
Dr. Andrew Kitchener, Principal Curator of Vertebrates at National Museums Scotland, explained, “Polar bears and brown bears can interbreed, so it’s possible that during the Ice Age, they met and shared habitats in Scotland. This raises fascinating questions about the ancestry of bears on the islands.”
To confirm the species of these bears, researchers are conducting DNA analysis with experts in Sweden.
They are also planning a closer physical study of the bones using advanced methods. This work will continue in 2025 as part of the PALaEoScot project.
If confirmed, this discovery could reshape what we know about Scotland’s Ice Age wildlife and the history of polar and brown bears in Europe.
