Beavers are back - and their numbers are growing fast, not just in the countryside. International environmentalist organisation WWF estimates there are now up to 21,000 of the once-threatened rodents in the country.
“The population development is positive, especially as [beavers] had almost died out,” said Roland Gramling from WWF.
The flat-tailed animals, which can grow up to 130 centimetres in length and weigh up to 30 kilograms, had been under threat from urban development and pollution, but now appear to be making themselves at home in urban areas.
Gnawed trees on the banks of the Nidda River in the northern suburbs of Frankfurt are testimony to a growing community of urban beavers, said German conservationists.
“A few weeks ago we held the city's first beaver watch [in Frankfurt],” said biologist Mark Harthun of conservationist group Nabu. The mammals, which are native to Germany, have also been spotted in Spandau on the outskirts of Berlin.
The beaver boom is a welcome development, said Harthun, as their presence encourages the growth of other species along Germany's riverbanks. “Beavers pave the way for the rehabilitation of our rivers,” he said.
Experts are generally not concerned that the critters will cause chaos with their penchant for dam-building. Beavers are unlikely to build dams on the Nidda or Main rivers, said Harthun, as the water is already deep enough to cover the entrances to their stick lodges.
However, authorities said the animals were still liable to fell trees, which must be removed if they float downstream and get stuck on bridges. “It means extra work, but no real trouble,” said Volker Rothenburger, head of the local nature conservation authority in Frankfurt.