Barely a week goes by in Germany without a news story about a human encounter with wild boars -- joggers getting chased up trees, boars smashing their way into living rooms and tearing up the furniture, even whole hordes of the shaggy beasts rampaging through village streets. Last year, two police officers were so scared of a marauding boar that they leapt onto a low balcony and opened fire on it with their service revolvers. They missed.
It's not the boars' fault. The species of pig may look fearsome with their big heads, short legs and tusks that can grow to 20 centimeters (eight inches). But they are naturally shy animals and only become aggressive when they feel trapped or threatened. Confrontations with humans have become commonplace because the wild boar population is exploding across Europe as a result of human activity -- global warming and radical changes in agricultural land use.
It's the same story in France, where 500,000 boars were shot last year. In Poland, it was 200,000, and their numbers have also been increasing in Austria, Switzerland, the Netherlands and the whole of eastern Europe, Torsten Reinwald, a biologist and expert on wild boars at the DJV, told SPIEGEL ONLINE. And boars are also thriving in Asia and the Americas.
"Wild boars are the clear winners of climate change and of the change in nature caused by humans," said Reinwald. "But it's wrong to say there's a plague of them. We have 4 million hares in Germany, and they're still on the endangered species list."
Gorging on Maize and Acorns
Warmer winters in recent years have reduced the death rate of older boars and of young ones born late in the year, and the rise in carbon dioxide levels has intensified the sunlight and led trees to produce more acorns and chestnuts -- a high-energy delicacy for boars, whose reproduction naturally increases with the amount of available food.
"A sow can produce a litter of up to eight piglets per year," Reinwald said. "And because their reproduction depends on weight rather than age, we're seeing boars of just nine months -- mere teenagers -- producing young."
Boars also have a penchant for maize and rapeseed, now being grown in vast quantities for biofuel. In Germany, the switch from traditional small fields with varied crops to gigantic swaths of agricultural land devoted just to one crop has provided wild boars with veritable hypermarkets in which they can gorge themselves after the winter, Reinwald said.
In the eastern state of Brandenburg, there are maize fields eight square kilometers (almost 2,000 acres) in size. "You can't spot wild boars in there," Reinwald said. "They have shelter, water and food."
A total of 27 percent of Germany's surface area is devoted to cultivating just three crops -- wheat, rapeseed and maize. Add to that all the woodland, which covers more than a fifth of the country, and you have a vast area in which boars can frolic and flourish.