Dam and blast

The Swiss hotline to calm villagers’ fears about their new beaver neighbours

- Phoebe Weston

“I hate beavers,” a woman tells the beaver hotline. Forty years ago she planted an oak tree in a small town south of Zurich - now at the frontier of beaver expansion - and it has just been felled: gnawed by the large, semi-aquatic rodents as they enter their seasonal home-improvement mode.

The caller is one of 10 new people getting in touch each week at this time of year. Beavers, nature's great engineers, can unleash mayhem during winter as they renovate their lodges and build up their dams. For people, this can mean flooding, sinkholes appearing in roads and trees being felled. A single incident can clock up 70,000 Swiss francs (£66,000) in damages.

To cope, the beaver-rich canton of Zurich came up with the hotline. The local beaver advisory centre is staffed by ecologists who give advice, assess damages and evaluate potential compensation (the oak tree-bereft woman is advised to wrap wire around the base of the other trees to stop the rodents' chewing).

Part of the job is calming down people furious at their beaver neighbours. “Some farmers are so angry you can hardly understand them, but they calm down when you go and see them,” says first responder Caroline Nienhuis, a biologist from Fornat, the consultancy that runs the hotline.

Switzerland is experiencing a beaver boom. When top predators first recolonise a former habitat - such as when wolves, bears and eagles return to areas across Europe - the immediate reaction is often one of awe. As the animals spread, however, it can often lead to conflict. Population growth of a new species is usually slow at first, then it moves exponentially.