The Wet Web

THE start of October saw a new gang of canal builders officially recognised in England. Yes, beavers are back on the list of native species, centuries after they died out and are protected.

They are, of course, better known for building dams, but their sometimes extensive constructions create ponds and, to navigate between ponds, they excavate canals, swimming being their preferred and most predatorfree way to move around.

They proved their worth in this year’s hot summer. “Beavers have created green oases in our parched river valleys because of their ability to store water through dam building and wetland creation,” said Harry Barton, Devon Wildlife Trust’s CEO. At the other extreme, their dams can hold back excess water and mitigate flooding in winter.

But… what if these canal builders take a fancy to the ones already there? Until now, beavers could only be released into enclosures. The new legislation ( see www. gov. uk/ guidance/ beavers-how-to-manage-themand-when-you-need-a-licence) makes it illegal to fence them in and they will naturally spread as new generations go looking for new places to live. This question was asked by the Grand Western Canal’s Joint Advisory Committee last March. England’s only colony of wild beavers has been allowed to spread naturally from their original home on the River Otter and signs of their activity have appeared on the River Exe, north of Tiverton. Concern was raised that, if they find the canal, their burrows – made by digging into banks under water and then excavating upwards – could cause leaks or breaches.

The result was that the Canal Ranger Team spent a morning with Devon Wildlife Trust (DWT) on Otterhead Lakes, learning to spot signs of beaver activity.

Steve Hussey, of the DWT ( www. devonwildlifetrust. org/ beavers), said over the last couple of years the trust has been contacted by a number of landowners who have sighted beavers on their land. Most are happy, but some report localised flooding. “We’ve gone in and helped the landowner to address that, maybe removing something that the beavers have built,” said Steve.

How many beavers will be released around the country in future – and exactly how much support will be available to landowners around the country, though – is currently unclear.

“We don’t know what beaver management will be until the Government announces its future plans,” he added.

Wherever they spread in future, we must be prepared for some jostling for co-existence. Reintroduced in Sweden in the 1920s and now numbering around 130,000, beavers finally arrived in Stockholm in the 1990s. While attitudes to them are widely positive, their enthusiasm for gnawing trees creates problems in parks; in 2015, power was cut to 15,000 homes thanks to a beaver felling a tree that took down power cables.

Farmers in Scotland have warned of problems encountered along the River Tay, where beavers have damaged drainage channels on agricultural land, flood banks and established woodland. They may also block road culverts and flood productive farmland. Experience on the Continent, however, has shown that there are management techniques that can reduce their impact.

As it is noise and flow of water that triggers beavers to build dams, one may conjecture that, on a canal, they are most likely to cause trouble below lock gates, where constant activity would surely put them off. Also, dams that are less than two weeks old may be legally removed and would be spotted quickly.

The Beaver Trust (beavertrust. org) would like to see the Government create a support system for use by farmers, landowners and communities as new beaver populations become established, as well as an ambitious timeline for reintroducing them to English river catchments.

For the environment, there seems no downside. Apart from aiding water management, beavers are also nature’s coppicers. Settling near trees, they open up the canopy, encouraging grasses, wildflowers and saplings, which feed deer. Studies also show that their dams filter the water, storing silt and significantly reducing nitrogen and phosphate levels in water downstream. The result has proved to be an increase in trout, birds and aquatic invertebrates, among other wildlife. Whatever happens, beavers are here to stay and may one day be a common sighting along our waterways. If you can’t wait, check out the Cornwall Wildlife Trust’s beaver cam (www.cornwallwildlifetrust. org.uk/live-beaver-cam) at dawn or dusk for a chance to see them about their beaverish business.

PHOTO: MIKE SYMES A female beaver with kits. Once common in Britain, beavers were hunted for their pelts (their fur is an exceptionally good insulator) and for castoreum, used by beavers for scent marking and waterproofing their coat and by humans in perfume and as a painkiller.

PHOTO: KENT WILDLIFE TRUST Beavers are very fond of willow.

PHOTO: STEVE GARDNER An adult beaver at Knapdale, Scottish Wildlife Trust. The European beaver is not the same as the American beaver (which has been known to build a dam half a mile long) and tend not to have such an impact on the landscape. In fact, they don’t always build dams.