Tails of the Riverbank
Labrador-length rodent engineers are* coming to our rivers. Here's what you need to know about Eurasian Beavers, and where you might see them in a couple of years.
The cute furry animal above is now a native species in the UK, the government quietly decreed last October. The Eurasian Beaver is up to 1.2 metres long, including its famous tail which it slaps on the water as a warning to other beavers when perceived predators are around, like wolves or humans with cameras.
I followed up the recent news of a £96,725 feasibility study to consider beaver reintroductions in and around Sheffield, and learned that no-one wants to officially jump the gun and say where and when it will happen just yet, but given that they’re now already naturalised in the UK, it looks like beavers really are on their way.
“Beavers are out of the box now,” was the summary I heard.
* - are probably coming to our rivers, is closer to the official line.
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Eager for Beavers
There are lots of beaver believers in Sheffield. Council leader Tom Hunt tells me he’s in favour, and local ecologists and rewilders insist that their engineering skills can do a lot of the city’s flood defence and wetland improvement work for free. The occasional misgivings from some parties seem to come from lack of understanding, say the beaver believers. Here are their key points.
1) They Don’t Eat Fish - The first and most common concern is that ‘they’ll eat all our fish’, Roy Mosley from Sheffield and Rotherham Wildlife Trust tells me. (It’s what I thought too, after memories of cartoon beavers in my youth, until a patient ecologist put me right with a quiet laugh a few years ago).
“Some people don’t realise they’re vegetarian,” Roy said, after his conversations with concerned anglers and fishery owners. “Actually, they’re no threat at all to fish.” The dams and environments they create are actually helpful to native fish, I’m told.
2) They Won’t Dam All Our Rivers And Cause Chaos - Rivers are usually far too big for Eurasian Beavers to dam. They build their dams on river tributaries, streams, and brooks. And yes, that will create ponds and wetter ground.
But that’s the point, particularly for the most recent Sheffield feasibility study: research has shown across Europe that beavers building small dams on river tributaries will slow the flow of water considerably, which helps prevent flooding downstream.
That’s not to say that busy beavers won’t ever lead to small areas of upland flooding on farmland near beaver streams. But there are simple ways of dealing with that: catching the beasts and moving them on, for example, or placing a ‘beaver deceiver’ mesh in a dam where the beavers won’t spot it, to regulate water flow more carefully.
3) They Won’t Eat All Our Trees - Beavers eat river plants, leaves, roots and the bark of riverside trees, and gnaw down some trees to build their dams. Most of their favoured trees, like willows, aspens and alders, will grow again if felled, as bushy coppices. The Beaver Trust point out that simple wire guards can protect any larger trees on a nearby beaver’s radar.
Beaver Backstory
It’s been 4-500 years since Eurasian Beavers lived in the UK, which seems like a long time to us. But in evolutionary terms, not so much. As a ‘keystone species’ the dam building and tree felling work of beavers helped now rare species like Water Voles, Willow Tits and Common Otters go about their lives in the past, along with dragonflies, Water Shrews, loads of water insects and river fish like trout and salmon.
Some say that waterside trees that have been here for thousands of years like willow, birch, alder and aspen may coppice and regrow so well because they’ve evolved to cope with beaver attacks. (In general, after beavers have eaten their bark and gnawed down a few branches and saplings, most native trees regrow into bushy coppices that provide homes for birds and insects, and allow light in for understory wild flowers.)
Ecologist Angus Hunter pointed out that dark riversides, as seen by the Rivelin and parts of the Sheaf and Porter, are not that great for biodiversity, with fewer plants and insects, less oxygen and generally less life than you’d get in a river where beavers are at work, opening up the tree canopy by turning trees into small coppices, and making dams and wetland by the incoming brooks.
A beaver makes a dam to provide a pool a metre or so deep, where it can dive away from predators. (Beavers evolved alongside wolves and bears, remember, although foxes, birds of prey and otters might also have a go at their young. )
The dam usually becomes the beaver family home, where the young (known as kits) can grow up in a damp beaver lodge away from the neighbourhood wolf pack.
Eurasian Beavers were once common here. Imagine seeing them and their dams on most of our streams, with light in our river valleys, and wildflowers and dragonflies and the sound of frogs on most of our brooks and riverbanks.
Then in the 1500s beaver fur coats and hats became fashionable, and remained so for a few hundred years. Beaver meat was popular too for some, and castoreum from glands near their tail was used in perfume. So they were hunted to extinction in the UK for hats, coats and perfume. Until now.
Beavers Beckon
There’s already been one beaver feasibility study, looking at land south west of Sheffield. The problem with a depleted ecosystem is that changes may be needed before reintroductions can happen. So in some places, we might have to plant young trees like aspen or birch so beavers have the raw materials for their work.
The Burbage Valley, for example, may not have enough native trees along the watercourse just yet, although Burbage beavers would certainly help the small Water Vole population there, by building them more dams to hide from stray dogs.
It looks like the city council and the Sheffield and Rotherham Wildlife Trust, who are leading on the new feasibility study (funded by the Yorkshire Regional Flood & Coastal Committee) will consider a couple of dozen sites, to be whittled down to a short list of about five or six after considering the existing habitat, how dams may affect landowners, and how beavers there will help flood alleviation and biodiversity.
Roy Mosley explains that having a handful of sites ready to go means that once a small family of beavers on a stream running off Blackamoor, say, give birth to a few kits, some of the growing family can be moved on somewhere else, along with a few more from out of town. (The succesful beaver rewilding projects across Europe have a well-honed beaver logistics programme now, so shipping beavers round to where they’re needed is fairly simple.)
Equally, if beavers don’t work out in one place, for whatever reason, having a few other streams ready for them nearby means we can help them up sticks and move there instead.
And while the feasibility study is going on, the beaver believers can get some planting done so sites are ready when the beavers finally arrive.
Rowan Longhurst, Sheffield Council’s service manager for countryside, is very keen.
“It’d be brilliant to bring back a species that was once very common in our natural environment,” she said. “I’d be really excited if (this work) led to plans for other species too. But let’s wait and see.”
She added that the upcoming study around Sheffield will help inform other local authorities. The government has already consulted on all this, and their National Beaver Strategy report is overdue, it seems, although Roy Mosley is in no doubt that our national government believes beavers are now here to stay, and their strategy is about how to deal with that fact.
He expects their directives will simply be, do we fence them off in the first instance, or not. It’ll probably be a bit of both, he says. And fencing may not mean beaver cages. Since beavers don’t stray far from a watercourse, a fence for Burbage beavers, say, might just be where the stream meets the roads.
The Sheffield work is focused on flood prevention and slowing water off the hills, but will look at benefits to wildlife too. And given that beavers are free flood prevention and nature recovery labour, there will be figures to show how much money they’ll save us in the long run. No one really has that evidence yet, said Rowan, “up to now”, she added, with an eye to what we might start to find out over the next 12-18 months.
Beaver Brooks
So the plan now is to work out where to put our beaver families: streams and brooks with beaver-friendly landowners nearby, where resident beavers would slow the flow of water, and where there are (or could be soon) enough small trees and river plants to keep them happy.
Angus Hunter thinks we should perhaps prioritise places where they’ll help rare species like Water Voles. And I’ve heard people talk about how beaver tree work will allow woodland plants to regrow and stop the erosion caused by the lack of ground cover plants under dark trees in places like Graves Park and the Limb Valley.
Some of the places where the experts hint they might take a look are as follows. But there’ll be more, as I hear the long list they’ll consider might cover at least 20 sites.
Agden Dike and area
Blackamoor
Blackburn Brook Valley
Burbage Valley
Charlton Brook
Graves Park
Leash Fen
Limb Valley
Moss Valley
Shire Brook
Strines Dike and area
Ulley Brook (Rotherham)
Whiston Brook (Rotherham)
And then in a year or so, there’ll be a shortlist, then maybe in two years time, there’ll be Eurasian Beavers, back in the brooks of the Outdoor City, after 500 years.
I should say that none of the sites above is official, except Blackamoor, so if you live nearby, don’t panic. They’re just checking the lie of the land at this stage.
But a few ecologists I spoke to told me, well, beavers make dams and cause wetlands here and there. That’s a good thing. Maybe we need to get used to that, because having our beavers back is worth it, to us and all the others trees and plants and animals who’ve missed them all this time.
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Another comment from a reader by email about the ancient ties between species that lived here together for many thousands of years before we came along -
"A comment I hear people make is 'The Beaver taught the Salmon to jump'. People have got to get it through their heads that the interrelationships between these species goes back before humans ever came on the scene. It is truly ancient and transcends multiple species groups and families.
"Another reason reintroduction is so critical for our dying ecology. It is estimated that beaver have a positive influence on 75% of aquatic and terrestrial ecology."
Thanks David, a really interesting article that answers a lot of the questions people might have about Beaver reintroduction.