Shrinking Bears: Unlike their Russian and American counterparts, Eurasian brown bears have undergone a considerable reduction in size during the last millennia and, in the Cantabrian Mountains of northern Spain, (close to the Atlantic coast), bears are among the smallest of the whole species. Why is this?
In western Europe brown bears are now restricted to a handful of remnant groups, two in the Cantabrian mountains, two in the Pyrenees and the other in the Apennines and Alps of Italy. The populations that remain have adapted from what was historically an 85% meat diet to one that is thought to be now less than 15%.
Adaptable: In the Cantabrian mountains bears have virtually stopped hunting altogether and, apart from some insects, carrion and the occasional domesticated animal they are now largely vegetarian. Hunting and habitat destruction long ago drove them out of the more low-lying coastal areas and the few that remain have clung on in the more inaccessible parts of the nearby mountains. It’s a minor miracle that they survived at all.
Fortunately, they are now protected and numbers are rising but, despite their adaptability, Spain’s brown bears are still very vulnerable and can only find a living where there is a plentiful and continuous supply of seasonal nuts, berries, herbs, grasses and fruits. This means that, for them, survival is only possible in the most pristine of native ecosystems containing extensive diverse forest and meadows.
This has not always been the case. The Cantabrian bears are genetically most similar to existing Scandinavian bears and this means that, at one time, they were part of a distinct population that spanned right across coastal, northern Europe from Scandinavia, Ireland and the British Isles to the Pyrenees and northern Spain.
Atlantic Salmon: This possibly makes them as different from the bears of Eastern Europe and Italy as the coastal grizzlies are from their inland cousins in Canada and Alaska. And, as we know, the coastal grizzlies are by far the biggest and fiercest of the entire species. The thing that the Atlantic coastal bears of northern Europe would have had in common with the pacific coastal bears of Russia and the Americas today, was an abundant supply of protein rich salmon.
Fierce and Strong: The Roman Empire could get bears from any number of much nearer places to supply its gladiatorial contests in the Coliseum but, instead, they chose to bring bears all the way from Scotland because of their legendary strength and fierceness. It’s reasonable to assume this was because of their much bigger size due to having a salmon rich diet.
In ancient times, the British Isles and the Atlantic coast of mainland Europe would have been a remote and pristine environment teaming with natural life, much like the north west Pacific coast of the Americas or Kamchatka is today. All along the north coast of Spain, rivers would have choked with Atlantic salmon and, it makes absolute sense that on this high protein diet, Cantabrian bears would have been as strong and fierce as any found in Scotland. A study of red deer neatly makes the point.
Expanding Deer: In the early 20th century red deer were transported from Scotland to New Zealand and released on the rich pastures of that continent. Within 50 years, these Caledonian deer had tripled in size and they now grow to the size of the American elk or wapiti.
And yet, like the Cantabrian bear – in their home territory in Scotland – Caledonian deer are now among the smallest of their kind in Europe. Red deer in the Carpathians grow much bigger but not as big as the Caledonian deer do in New Zealand. This means that DNA in the Scottish deer retain the potential for them to grow to the enormous size that their ancestors did and that they just need the right environmental signals for that potential to be expressed.
Genetic Giants?: The Cantabrian brown bear is, today, one of the smallest bears in Europe but it’s just possible that hiding within its genes lays the potential for it to rival the size and strength of an Alaskan, coastal grizzly.
I like to think so!
Author: Frankie Sikes
Disclaimer: The views and opinions expressed in this article are solely those of the author and do not necessarily reflect the official scienctific position.