The Cantabrian Brown Bear

(Ursus arctos, Linnaeus 1758)

Listed on Spain's National Catalogue of Endangered Species as being In Danger of Extinction and in the European Mammal Assessment as Critically Endangered, the Cantabrian brown bear’s existence in Spain is not widely known on an international level.

The genetic makeup of the Cantabrian brown bear is rather complicated. Here is its history, so far, in a nutshell! Having previously believed to have developed a separate genetic identity to other European brown bears due to isolation during the Last Glacial Maximum (about 20,000 years ago), the Cantabrian brown bear has been found to be more closely related to other European brown bears than was thought. In the early part of the 20th century, the Spanish naturalist Ángel Cabrera considered the Cantabrian brown bear to be a distinct sub-species of European brown bear, Ursus arctos arctos, (itself a classification under debate) and named it Ursus arctos pyrenaicus (Fischer, 1829), characterised by the yellow colouring of the points of its hair and by its black paws. A recent study, however, led by mainly Spanish scientists hoping to prove the Iberian bears to be a distinct subspecies, instead discovered that they weren't cut off by the ice pack and that there was free-flow of bears travelling around Europe via the ice-free corridors. One route led as far as Southern Scandanavia, via the west coast of France, while another led to the Balkan peninsulas following the Mediterranean coastline, leaving the remnant bears of these populations the most closely related to the Cantabrian brown bears. Human activity has further isolated them over a relatively short space of time, a period not long enough for them  to be sufficiently genetically different to be given sub-species status. The Cantabrian brown bear is now recognised by most Ursidae specialists as belonging to one of the eight bear species, the Brown bear, Ursus arctos ( L. 1758).



Left - front paw   Centre - hind paw   Right - Cantabrian brown bear tracks

Photos © Fundación Oso Pardo

Historically, the Cantabrian brown bear was seen by man to be competition for food. Having once roamed most of the mountains of the Iberian peninsular, the Cantabrian brown bear’s population was reduced in the first half of the twentieth century to two isolated pockets in the mountains of the Cordillera Cantábrica and to a tiny enclave in the Pyrenees. (This latter population, no longer seen as viable with only two indigenous male bears remaining, is being supplemented by introductions of bears from Slovenia.) Systematic persecution through hunting led to a drastic decline in numbers, a total ban not coming into force until 1973. The maximum fine for killing a bear in Spain is now €300,000. 

Latest, most optimistic figures for the Cantabrian mountains give a total of around 140 bears split between a population straddling the borders of Asturias, León and Galicia to the west (100-110) and another population around the borders of Cantabria, León and Asturias to the east (25-30), being separated by some 30-40km.


Weighing in at an average of 130kg for females and 180kg for males and measuring between 1.6m – 2m in length and between 0.90m -1m in height, the Cantabrian brown bear, or Oso pardo cantábrico, is one of the smallest of the brown bear family. Their weight varies hugely depending on the time of year. Emerging from their winter hibernative state they can be very underweight and need to feed to restore their body fat whereas during the autumn they should be at their heaviest in readiness for the winter, although recent winters in the Cordillera Cantábrica have been so mild that the bears have not found the need to hibernate completely.



After mating in the spring females give birth in their dens, during December/January, to cubs weighing only about 350g each. This is tiny compared to the size of the mother and doesn’t correlate with the length of the nine-month gestation period. Interestingly, it has been discovered that there is a natural delay in the development of the fertilised eggs early on at the blastocyst stage, the eggs not becoming implanted in the uterus until five months after mating. This is attributed to the fact that the female doesn’t eat during the latter stages of pregnancy as her metabolic rate slows down for winter. To compensate for this her milk is extremely rich in nutrients and the young don’t need to suckle as much as other mammals.  Litters are usually two, occasionally three, and will stay with their mother for eighteen months to two years before complete independence.

Infant mortality is high with only one of the young likely to reach maturity. On emerging from the den in spring the cubs have many dangers to face including disease and the male bear’s predilection for infanticide in the hope that this will prematurely bring the mother into season again, this naturally not happening for about three years after giving birth. The main cause of death among bears is now, however, man-induced. Furtive trapping using snares and poisoned bait left for other species such as wild boar still causes deaths among the bears. Between 1980 and 1994, 54 Cantabrian brown bears died at the hands of furtive hunters. Of these, 19 were caught in traps, 2 were poisoned and the rest were shot. The Cantabrian brown bear is not aggressive to humans and would flee rather than confront man.


Photo © Fapas

The Cantabrian brown bear is an opportunistic omnivore. Eating mainly roots, fruits, berries and nuts, its mostly vegetarian diet is supplemented by insects, eggs, honey, fungi and carrion. Since the outbreak of Bovine spongiform encephalopathy (BSE or mad cow disease), the EU brought in laws enforcing the removal of carcasses (apart from equine species) from the countryside. This had led to a drastic shortage of carrion for the more well-known carrion eaters such as Griffon vultures and Red kites. A less well-known fact is that bears also rely on carrion, especially in the spring when they need to boost their body weight lost through the winter and in the autumn when they need to store as much fat as possible in order to survive the coming winter and its scarce food supply. An estimated 8–10 cubs died this spring (2007) due to, it is believed, the lack of carrion on the ground. Apiarists are also suffering as beehives are being destroyed by the bears in their search for other food supplies. Although the laws have been revised conditionally for the re-opening of feeding stations (comederos or muladeros in Spanish) for carrion-eating birds, provision has yet to be made for the bears. The matter is currently under discussion at the EU.     

Conservation efforts presently centre on joining the two isolated populations with the purpose of strengthening their genes in order to create a viable population of bears. Groups such as the Fundación Oso Pardo (FOP) and the Fundación para la Protección de Animales Salvajes (FAPAS) are working towards creating a communication corridor of protected land for the two bear-inhabited zones. Fapas, in particular, are doing some very interesting work including photographic monitoring, planting of fruit trees, encouraging the goodwill of hunters to collaborate with the locating of snares, and the installation of beehives. A “Plan para la Recuperación del Oso Pardo Cantábrico” (Plan for the Recovery of the Cantabrian brown bear) has been drawn up by the Spanish Ministry of the Environment to unite all efforts towards the conservation of this most emblematic of Spanish species.

Paca and Tola, two female Cantabrian brown bears rescued after their mother was killed by a hunter. They now live in an enclosure of almost 5 ha near Proaza, Asturias.

A major threat to the bear’s survival, however, is currently being posed in the form of a project to build a macro ski resort in the area of the San Glorio pass in the middle of the main corridor of access for the two bear populations in the Cantabrian mountains. Much of this area is covered by the EU’s Natura 2000 and Habitat’s Directive protection laws. A national law, the Ley de Ordenación del Territorio has already been modified due to pressure from  lawyers working for the promoters of the resort, Tres Provincias S.A., to enable this kind of project to go ahead if seen to be of financial benefit to the local community. A Green Party MEP based in Valencia, David Hammerstein, has taken the matter to the EU and groups such as the Plataforma en Defensa de San Glorio (PDSG) are working towards halting the project. Ridiculously, the promoters have asked the EU for €45,000,000 (40% of the estimate) in funds to finance the project, the very same institution that made the laws to protect the rich, natural habitat of the area in the first place.

Although the High Court of Castille recently vetoed the project, on the grounds of climate change, it looks likely to be appealed against so....








Fauna Europaea (European Biodiversity Taxonomic Authority)

Spanish Ministry for the Environment -

Catálogo Nacional de Especies Amenazadas

European Commission's European Mammal Assessment

SCI Foundation - European Brown Bear Compendium

Fundación Oso Pardo

Fondo para la Protección de los Animales Salvajes (FAPAS)

Pays de l'Ours - Reintroduction Programme for Bears in the Pyrenees


For more information, see also Wikipedia, Cantabrian brown bear


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