I have gone back in time to a landscape not seen in this part of the world for the best part of 500 years. All around me are signs of intensive engineering – not by humans, but by beavers.
Mark Elliott at the Devon Wildlife Trust is showing me round 2.8 hectares of wetland on the edge of Dartmoor, UK. In 2011 the trust released a pair of Eurasian beavers here. “They’re really busy at the moment,” he says.
Before the release, the area was a scrubby woodland with a small stream running through it. “It wasn’t much good for anything else,” says landowner John Morgan. But the beavers quickly got busy, building a lodge, deepening the pond around it and damming the headwaters of the stream.
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Elliot and his colleagues collated , including the huge improvement they’ve had on flood management.
On the surrounding countryside, rain (of which there is a lot) runs quickly off the land, surging into rivers and causing flash floods. But on beaver territory the water is now held up in the ponds and flows out at a much more leisurely pace. “It takes days or weeks,” says Richard Brazier at the University of Exeter, one of the project’s lead scientists. Even during a downpour the outward flow of water barely rises above baseline.
Hardly anybody lives around here so flooding isn’t an issue. But elsewhere it is a serious and growing menace. The UK has earmarked £2.5 billion a year to upgrade its flood defences. Judging from the research done here, beavers could be part of the solution.
The team have kept the location of the project secret to avoid people interfering. Some people are just keen to see the beavers for themselves, but others may wish to sabotage the trial because they oppose the reintroduction of a “nuisance” species.
Beavers are known as ecosystem engineers. I can see that every inch of the site has signs of ceaseless beavering: felled trees, gnawed stumps, chewed logs and sticks stripped of bark. The stream has been turned into a series of 13 large pools held back by dams made of sticks, mud and grass. The oldest dam resembles a Neolithic earthwork, several metres across and grassed over. It holds a serious amount of water with over a million litres behind dams on the site.
Radiating out from the pools are long, deep canals that the beavers use to move around their territory. Their activity has opened up the dense thicket and biodiversity is thriving. Compared with the monotony of the surrounding farmland, it is stunningly beautiful. “The British landscape would have looked very different when it had beavers in it,” says Elliott.
This isn’t a reintroduction or rewilding project – there are plenty of those elsewhere – but a scientific experiment into how beavers alter the landscape, for both good and ill.
Beavers used to be common across Great Britain but were hunted to extinction for their fur, meat and scent glands. The last written record of a wild beaver in England dates from 1526. It has taken half a millennium to fully realise what we lost.
There is no doubt that beavers can be a nuisance, for example blocking storm drains and gnawing down the wrong trees. But these can be easily managed, says Elliott. For example, they can be fenced in, as the trust has done here.
Half way down the stream is beaver HQ, the lodge. Unfortunately, this is not a good time of year to see beavers in action. Though winter is when they are busiest, beavers are nocturnal and secretive meaning that it is currently dark before they get moving.
We squelch past the lodge knowing they are asleep inside. Their musty scent hangs in the air. Close, but no beaver.
As we drive back from beaverland, Brazier points out flood defences that have recently been built to protect Exeter city centre. More will be needed as climate change kicks in and rainfall increases. Brazier laments that the government has set aside ÂŁ15 million for natural flood management but zero for beaver reintroductions.
That may change soon. Despite being a native species, in England and Wales beavers are classed as “not normally resident” and require a license to be released. But under pressure from Brazier and others, the government is reviewing these rules. Environment secretary Michael Gove is said to be receptive. He needs to get busy.
