Brown Bears Stop Hibernating

Bears in the mountains of northern Spain have stopped hibernating, scientists have revealed in what may be one of the strongest signals yet of how much climate change is affecting the natural world.

Bears are supposed to slumber throughout the winter, slowing their body rhythms to a minimum and drawing on stored resources, because frozen weather makes food too scarce to find. The barely breathing creatures can lose up to 40 per cent of their body weight before warmer springtime weather rouses them back to life.

But many of the 130 bears in Spain’s northern cordillera – which have a slightly different genetic identity from bear populations elsewhere in the world – have remained active throughout recent winters, naturalists from Spain’s Brown Bear Foundation (La Fundación Oso Pardo – FOP) have said.

The change is affecting female bears with young cubs, which now find there are enough nuts, acorns, chestnuts and berries on the bleak mountainsides. “If the winter is mild, the female bears find it is energetically worthwhile to make the effort to stay awake and hunt for food,” said Guillermo Palomero, the FOP’s president and the co-ordinator of a national plan for bear conservation.

The behaviour change suggests that global warming is responsible for this revolution in ursine behaviour, says Juan Carlos García Cordón, a professor of geography at Santander’s Cantabria University, and a climatology specialist. “We cannot prove that non-hibernation is caused by global warming, but everything points in that direction.”

So if you go down to the woods today in Norther Spain, you could be in for a big surprise…