I hate beavers, a woman tells the beaver hotline. Forty years ago she planted an oak tree in a small town in southern 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.
Compared with England, where the beaver population is estimated at 500, that's quite a feat. But there's a significant downside to the booming Dutch beaver population. Beavers are increasingly digging burrows and tunnels under roads, railways and even more worrying in dykes. For a country where a quarter of the land sits below sea level, this is not a minor problem especially as beavers are not exactly holding back when digging.