Beavers on the rampage

Few animals create such impressive structures or alter their environment so dramatically as the beaver. Few, except for humankind.

"Beavers are like the architects of our waterways," says of Iris Barthel of German conservation group Nabu. "They build dams, burrow, gnaw and fell trees and shrubs. In this way, beavers have shaped our riverscapes for millions of years."

But despite - and sometimes because of - a shared propensity for reshaping the landscape, humans and beavers don’t always make good neighbors.

By the early 20th century, humans had hunted the Eurasian beaver - prized for its meat and warm, dense pelt - almost to extinction. In Germany, a few animals survived in pockets on the Elbe river.

More recently, protection of the species and reintroduction programs have seen beaver numbers bounce back. Today there are around 30,000 in Germany, with strongholds in east Germany, as well as parts of Bavaria, on the Upper Rhine and the southwest of North-Rhine Westphalia.

After a long absence, the hefty rodents - with their unmistakable flat tails and blunt snouts . became, if not a common sight, at least something you might be lucky enough to glimpse on a German riverbank.

Still, beavers are shy, and anyone looking for signs of their presence along the Rhine or Elbe might do better to look out for a beaver's dam, or the stumps of trees felled by gnawing.

Beaver-made flooding

Some riverside residents, however, don't have to go out looking for traces of beaver activity. Just as manmade dams can be disaster for the habitat of other animals, so some Germans have found their own homes flooded by beaver-made reservoirs.

One homeowner who found the foundations of his house in German city of Jülich threatened by rising water levels from a beaver dam told local broadcaster Westdeutscher Rundfunk: "They don’t belong here in the middle of the city. We’re not an open-air zoo."

Nabu says conflict usually occurs when farms or gardens extend right up to the river bank or where the natural floodplain is altered.

"The beavers aren’t aware of property ownership. They see the riverbank as a place they can dig their burrow," says Barthel. "They see tasty food in fields or orchards. So it can happen that a tractor breaks a beaver lodge or a beaver fells a favorite apple tree."

She adds that beavers have been accused of burrowing into dams and dikes, disrupting manmade flood defences, but says there are well-practiced defenses against this kind of damage.

"If beavers are pilloried by politicians, it’s primarily to distract from their own failures in flood prevention," says Barthel.

Warming beaver-human relations

Biologist Jessica Dieckmann told DW that part of her role as newly-appointed commissioner on beavers for the German city of Hamm was to help deal with conflicts arising between homeowners and their beaver neighbors.

She explained that because injuring or killing beavers or damaging their dams and burrows is forbidden in German, “a solution has to be found tactfully.”

"A solution could be that landowners sell a 20-meter-wide (66-foot-wide) riparian strip and make it available for nature protection," says Dieckmann.

Her other tasks as beaver commissioner include finding out whereabouts beavers are in Hamm and how many there are, to know how best to deal with the creatures in the future.

Beavers usually live in burrows in the river bank accessed by an underwater tunnel. The dam ensures the water is deep enough to hide the entrance to their "lodge" beneath the surface.

But while human construction often runs at complete odds with the needs of other living species, beaver dams bring benefits to a whole host of other species.

"They create small ponds, deadwood, marsh areas or open up areas of soil," says Barthel. These provide habitats for dragonflies, amphibians and reptiles, for fish and birds. "Where humans have to spend a lot of money on preserving biodiversity, the beaver helps out for free."

"At the same time, it contributes to the cleanliness of water, re-natures rivers and supports natural flood prevention."