50 bears recolonizing after near extinction. Genetic analysis shows this population is the sole source for Pyrenean reintroduction, making their survival critical for the species across Spain.
Juan lacruz, CC BY-SA 4.0, via Wikimedia Commons
A Population's Last Stand
In the rugged Cantabrian Mountains of northern Spain, the brown bear, Ursus arctos arctos, faced extinction. Once widespread across the Iberian Peninsula, hunting and habitat loss had, by the early 1990s, reduced the entire Spanish population to as few as 50-60 individuals. This remnant group was itself fractured into two isolated pockets: a small eastern population and a slightly larger western one centered in and around what is now Somiedo Natural Park. The two groups were separated by a 30-40 km gap filled with human infrastructure, preventing genetic exchange.
The Somiedo region became the species' final stronghold. The population here was critically endangered, threatened by poaching, habitat fragmentation from coal mining, and the conversion of forests to pasture. A ban on bear hunting in 1973 was a first step, but the population continued to decline for years. The establishment of Somiedo Natural Park in 1988 provided a sanctuary, covering 283 square kilometers of dense forests and high mountain passes ideal for the bears' needs. This protection allowed the western subpopulation to stabilize and begin a slow, natural recovery without the introduction of foreign bears.
Recent genetic censuses reveal a remarkable comeback. The total Cantabrian population now exceeds 370 individuals. The western subpopulation, with Somiedo at its core, numbers around 250 bears and is important for the species' future in Spain.
A Genetic Lifeline
The recovery of the Somiedo bear population is important beyond its own survival. Genetic studies show that the last native bears of the Pyrenees, before they vanished, were genetically part of the same lineage as the Cantabrian bears. This makes the Somiedo population the last reservoir of the original Iberian bear's genetic code. The reintroduction programs in the Pyrenees, which began in 1996, have used bears sourced from Slovenia to establish a new population, as the native one was functionally extinct. This new Pyrenean group, now numbering over 80 animals, suffers from extremely low genetic diversity because most individuals descend from a single male, Pyros.
This situation shows the immense value of the Somiedo bears. Their population retains a greater natural genetic diversity compared to the reintroduced Pyrenean bears. Conservation efforts are now focused on maintaining and strengthening the connection between the western (Somiedo) and eastern Cantabrian subpopulations to create a single, more resilient population. As this population grows, it represents the only potential source of native Iberian bears for future genetic reinforcement, should the inbreeding in the Pyrenees prove unsustainable. The survival of the Somiedo bears is therefore directly linked to the long-term viability of the entire species across the mountains of Spain.
💡Fun Facts
The Cantabrian brown bear is primarily vegetarian. More than 85% of its diet consists of plants like grasses, berries, acorns, and chestnuts.
These bears are among the smaller subspecies of *Ursus arctos*. Males average 115-200 kg (254-440 lbs), while females are significantly smaller, typically weighing 85 kg (187 lbs).
They don't truly hibernate. Instead, they enter a state of winter lethargy or "torpor," and their body temperature drops only slightly. They can be awakened during this period.
A bear's footprint is plantigrade, meaning it walks on the entire sole of its foot, similar to a human. A rear paw print can be up to 16 cm in length.
The park is always open, but bear watching is a specialized activity. The best times are dawn and dusk in spring (April-June) and late summer (August-October). Viewing is only from a safe distance at designated viewpoints.
Admission
Entry to the Somiedo Natural Park is free. Guided bear-watching tours are available from local companies for a fee. The Park Interpretation Centre is in Pola de Somiedo.
Accessibility
The terrain is mountainous and rugged. Bear viewing points are accessible but require patience and binoculars or a spotting scope for a good view.
