Spain's Environment Minister, Cristina Narbona, said 15 brown bears would be released over coming years into the mountains that straddle the frontier with France. The first five, including four females, are being introduced now, as the bears emerge from their winter hibernation.
The repopulation plan has been jointly agreed with France and Andorra, a breakthrough in cross-border co-operation designed to preserve ursus arctos pyrenaicus, known in Spain as the oso pardo or brown bear.
This unprecedented common action to protect in its natural habitat the animal that once roamed the mountains and forests of Spain responds to a crisis unleashed 18 months ago when the last fertile female brown bear in the Pyrenees was killed by French hunters.
Animal rights activists in Europe raised an outcry when the 15-year-old female bear, known as "Canela", was shot in November 2004 as she tried to defend her cub against hunters' dogs.
The oso pardo has been a protected species in Spain since 1973.
Fewer than 20 bears, split into two colonies, are thought to still prowl the Pyrenean peaks. "The only way to ensure the survival of this endangered species in the Pyrenees is to introduce some supplementary examples," the environment ministry said.
Some 160 brown bears - of slightly different genetic makeup - remain in Spain's northern Cantabrian mountain region. But there are too few to consider removing any to boost the threatened Pyrenean population.
Numbers have declined in the Pyrenees because loggers and forest fires have encroached upon the bears' woodland habitat. Farmers have chopped down trees and parcelled up forest areas. Human encirclement over the years has provoked the bears to react aggressively on occasions, which in turn has prompted illegal hunters to kill them with traps, poison or shotguns.
Ms Narbona is to meet environment officials from the three regions affected - Aragon, Catalonia and Navarra - in the coming days. She promises them €1m (£690,000) to finance measures to guarantee the bears' habitat, support the repopulation initiative and to ensure peaceful coexistence between human and bear.
Many farmers living in the Pyrenean foothills need persuading that they won't be assailed by ursine diseases and predatory attacks. Emili Medán, the mayor of Les, in Aragon near the French border, has condemned the proposal as "a dangerous experiment that threatens local livestock farmers". Mr Medán, and others, have called for a meeting to draw up demands for compensation from the French and Spanish governments for possible future risks.
On the French side, too, locals have complained that more bears could threaten farming and tourism. As a result, the proposed introduction of 15 bears will take place gradually, at the rate of five a year, and only around villages that have approved the scheme.
France's Ecology Minister, Neli Ollin, said that in the 150 years of study of Pyrenean bears, not one had ever attacked a person. Ms Ollin said her ministry had compiled a manual on how to behave when confronted by a bear.
Ms Narbona said the experience of Spain's Cantabrian region, mainly in Asturias, "showed that it is perfectly possible to live peacefully with bears".Reuse content