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The beaver: nature's landscaper

Updated Tuesday 3rd May 2011

In an extended interview, the Saving Species team talks to water vole specialist Derek Gow about how the beaver was hunted to near extinction, and why the animal can be helpful for conservation and biodiversity


Copyright The Open University


Interviewer:  Tell me about the history of the beaver in the UK.  It's not had a particularly happy one where humans are concerned has it?

Derek Gow:  No, it's had an incredibly sad one and of course it's an animal which became extinct in late historic times.  We know from North American experience that we slaughtered them in the most appalling way.  It was a gentle animal, a social animal, and we designed the crudest of traps to kill them.  Beavers were once a very common animal in Britain.  We know from medieval records that they were included in the fur trade and that German merchants came to places like Loch Ness in the 1600s to take away furs.  The last record of a beaver being killed in England was in around the 1780s in a place called Bolton Percy just beneath York.

As a species, they were hunted to extinction in this country because they had very valuable glandular secretions which contained a very high concentration of salicylic acid, a primitive aspirin, and it was an agent of pain relief in a time when pain relief wasn't effectively to be found from other commodities.  They were also edible.  They're heavy rodents, about the weight of a roe deer, so you could eat them.  Their fur was very valuable and then various other parts of their body were sought after.  So it was a very common animal, a very widespread animal which we hunted to extinction because it was so valuable.

Interviewer:  Why do beavers make such good conservation tools?

Derek Gow:  Beavers basically engineer landscapes to suit themselves.  They're a fat tubby animal, they look like a little man who's spent a lot of time in the pub drinking Guinness, and what they want to do is float out through waterways to reach either the herbaceous vegetation they're going to eat or the woody vegetation they're going to eat or store in the back end of the year, in the autumn and winter months, and they basically just operate from the water.  And to do this, once the good territories are used up on big river systems so that all the easy to access trees and the easy to access vegetation is already territorially held in river systems by other beaver families, beavers will expand out of rivers up into smaller creeks and stream systems, and there they'll build complexes of dams.  And when they build complexes of dams it has a profound effect on the environment and a profound effect on biodiversity.

Interviewer:  So are there are there any particular habitats that they're very useful for managing?

Derek Gow:  Well I mean if you want to look at it from a biodiversity point of view I'll give you a couple of examples of British species that are probably very closely attuned to beaver presence.  One is the large copper butterfly.  Large copper butterflies were a former native species, they became extinct in historic times in the East of England, and they were absolutely attuned to a system of coppicing at the edge of fens because their caterpillars were dependent on water dock for their survival.

So if there was no natural coppicer of the fen edge habitats then ultimately the water dock would disappear when the willow regrew.  And people at the Rothschild bought reserves and coppiced willow and for a time the butterflies that they reintroduced did well.  As soon as they stopped coppicing the willow and the willow basically outgrew the water dock then the butterflies disappeared, and the butterflies must have been attuned to beaver activity, because it was the only factor that would create that kind of habitat.

Another example might be the bearded tit.  You know, a charming bird of reed beds which needs to nest next to the edge of channels so it can feed its chicks on midge larvae.  Beavers cut channels through reed beds to allow them to go out into the reed bed and feed in either trees or on the reed itself, and when they do that of course they create living opportunities for bearded tits.  So there's two examples of species that are attuned to beaver activity that would positively benefit amongst many others from beavers being reintroduced.

Interviewer:  Now those two species you mentioned there were species which liked very large areas of wetland, generally speaking, so are beavers more suited to landscape scale management or can they also be used in very small areas?

Derek Gow:  Well I think if we were looking at trial reintroductions of beavers, which is how it will all begin, we'll be looking at relatively small catchments and catchments where the animals are not likely to get out.  Beavers as a species like to stick next to the water.  In Denmark 95% of the feeding is within five metres of the water’s edge and an intergalactic journey for a beaver is something like 30/40 metres from the water’s edge.  So if you put them in a catchment which if you can imagine it's like the fingers of a hand water running down from the high land to the sea, which is not linked to another catchment, and these are quite typically river systems that you find in the West of Britain, then evidence from Continental Europe suggests that they will stay there for a very long time and their expansion out of these areas will be very slow, and it's trials in areas like this that we're looking to identify now, so it's sites like this we're looking for when it comes to trialling wild beaver release without fences.  

When you actually look at the wider British landscape there is no doubt and no argument that beavers would do very well on rivers like the Thames, the Severn, the Trent, they offer splendid beaver habitat, and people will tell you that the landscapes changed from when beavers were last here, that it's very different, that the species would have trouble adapting, but we know from ample continental evidence that yes the landscape has changed from when beavers were last here, and it's much much better, so they would go out into these rivers and they would do extremely well because of course we have no commercial use left for the trees, they'd prosper.

Interviewer:  Beavers haven't been at large as wild animals for several centuries in the UK, so isn't there a danger though that they've somehow lost their ecological footprint, that the countryside and the manageable landscape has almost got too small for them because of the way we've controlled it?

Derek Gow:  Not at all, we don't use the trees that we used to use along the edges of water courses, and in fact if you look simply at Google Earth you can basically follow the lines of very many rivers and streams because of the tree cover from above.  So given that we have no commercial use for the trees any more then beavers living in those rivers and streams, providing we're not farming right up to the edge, to within a metre of their edge, would be no kind of issue to most people and most land managers.

When it comes to them losing their ecological role in a Western European Northern Hemisphere type of environment you've got to bear in mind that the first beaver-like fossil animal that's known of is approximately 40 million years old.  This species has survived alongside trees like willow and aspen for 40 million years and we have taken it from this countryside that surrounds us in the British Isles, you know, we've removed it for 200, what grounds do we have to think that the trees which were adapted to this species and then the species which were adapted to the tree cover have lost this relationship we had with the beaver; it's much much more likely they'll remember it and that they've forgotten.

Interviewer:  Well what we have done though we've lost a lot of floodplain woodlands and beavers have a good engineering steer, if you like, on floodplain woodlands but we don't seem to have any at all.  So does that mean that there's nowhere for them to go?  I mean they're going to end up in nature reserves aren’t they, effectively?

Derek Gow:  No, they'd exist right the way through the countryside.  Last year or the year before last we brought a number of German biologists to have a look at the landscape in the West Country, and it was their opinion, I mean and they work and live with beavers in very intensively used landscapes like Lower Bavaria, which is very similar to the East of England, to landscapes like Suffolk and Norfolk where you've intensive arable crop production, and it was their opinion that the landscapes that we look at and we consider to be the poorest habitat for beavers were actually very similar to the very best landscapes they had in Bavaria.

With regard to floodplain woodland, there are two answers to this.  One is okay we may not have as much floodplain as we used to have, we almost certainly don't, but it poses us with huge problems.  I mean if you look at the kind of water resource and the water drawdown we now use, as humans, on this island, it’s a resource which is finite, and we're just beginning to realise that.  I mean two weeks ago there were articles in the paper about major reservoirs running at 70% full and people still continue to use water in a profligate manner.

Now of course that comes down to how we as humans use water, but it also comes down to how we've engineered the landscape over the course, particularly of the last 40/50 years.  We've straightened rivers, we've drained bogs and we've taken out wet soaks, we've taken out meanders, we've drained farm ponds, and what we've done is we basically treated the upper levels of river systems as simple drains taking water off the land fast because we want to use everything, and there's a repercussion from that.

The repercussion is that if you do not have large swamps, wetland soaks in the upper reaches of river systems which release water slowly, then of course when times of drought come you basically don't have sponges and you've no method of storing water in the landscape other than reservoirs.  And the other flipside to that is of course that if you have heavy rains and again you don't have storage mechanisms which slow water down, which set it off to the sides into floodplains again, then you have villages, towns and cities ultimately flooding.

So we have a major problem with the landscape we've created and the beavers as opposed to being a major issue for us could be a very positive resource when it comes to managing water and making sure that we either have it as a resource or we dissipate its effect during times of heavy rainfall.

Interviewer:  We are very good at controlling the way we manage our countryside.  I think we're probably one of the best drained landscapes in the whole of Europe, and so releasing beavers into that and asking them to get on with a job that we normally do would somehow be relinquishing control.  So realistically do you think that's feasible?  You know, can we publicly step back and let rodents get on with it?

Derek Gow:  Well that's a sociological question you’re asking rather than a biological one isn't it?

Interviewer:  Well of course it is but I mean sociology comes into the way we manage the landscape.

Derek Gow:  Well I mean the answer to that is I think the return of the beaver will be driven by economics, and there's a very interesting project that the Environment Agency have developed up in Northumberland called Belford, whereby they built a whole series of impoundments above the village of Belford to basically slow down flood waters which were flooding the village on a regular basis.  They didn’t have enough money to put in regular flood walls and the regular kind of defences that they would have put in and therefore they came to an understanding with other landowners in the wider environment that these mechanisms were going to be very important for dissipating flooding the village, and it's worked extremely well.  And these impoundments are things they call leaky dams.

They built them using tropical hardwood.  It's been a very successful project.  It's cost approximately £600,000 to run for a number of years and these dams basically mimic the effect of beaver dams.  We can either do it unsustainably ourselves, costing ourselves huge amounts of money over a very short period of time before we run out of steam, or we can reintroduce the animal that does the job for us and then start to think about managing the animal.

Interviewer:  Well we talked about sociology just but, you know, people are opposed to beavers and I suspect that they're opposed to them because they actually don't know what they're capable of, or they have the wrong idea about what beavers are capable of, and that's because they don't live in people’s memories any more.  They've been gone for so long.  You know, anglers would argue that they're an obstruction to fish, woodsmen would argue that they may take down some of the most important trees, I know they're natural coppicers.  So how do you answer the concerns of people who are worried about seeing what is actually a largish animal which has a big impact on the landscape back?

Derek Gow:  I would answer very simply, when you actually look at where this animal is in Continental Europe, and it's going to become an extremely widespread and well-distributed species again, what Continental European experience suggests these are landscapes that are very similar to our own landscape is that you can live with beavers.  That doesn't mean to say there isn't minor nuisance, that you're not going to have an odd animal come out of a river and chop down an ornamental cherry tree that you planted in honour of your Auntie Edna who died 15 years ago, but it's largely nuisance value that these animals have when it comes to interaction with people, and the overall benefits they provide vastly outweigh any issues of nuisance that arise when it comes to commercial forestry.

If you look at Scandinavia, foresters do not insure woodlands against beaver damage; they insure them against the damage of the short-tailed vole which basically barks many conifers in the long grasses that surround growing plantations.  This issue with game fish is very grey, but if you look at countries like Norway, which has a major wild salmon fishing industry, they do no research work on beaver interaction with salmonats because they've never considered there to be a problem.

So I think a lot of the limited opposition there is to return of the beaver is based on what you identified earlier in the question, it’s ignorance.  We understood this animal as a species very well throughout our medieval relationship with it.  We understood it intimately because it was worth so much money to us, and we forgot virtually every, we’d forgotten everything we knew about that animal by the time it got to the beginning of the 20th Century, and it's basically removing and blowing away these clouds of ignorance that surround it that is the largest obstacle with regard to its restoration.

Interviewer:  We've talked about the conservation use for the beaver but is that the only reason we should bring it back, don't we have a moral duty as well?

Derek Gow:  Well if you think in this day and age that moral duties and biology count for very much then I think you're probably mistaken.

Interviewer:  I'm young, naïve and impressionable.

Derek Gow:  Okay, if you're young, naïve and impressionable we have a moral duty to bring this animal back.  We ask people in Africa and Asia to tolerate animals which are truly fearsome and yet which are dwindling fast within their nature ranges.  We spent millions of pounds internationally on saving species like pandas and pink pigeons and scimitar horned oryx, and yet when you look in our own back garden how comfortable would we be in five/ten years time if teams of Kenyans arrived at Heathrow Airport and told us what a muck we’d made of water voles or red squirrels or beavers.  Beavers are an easy animal to live with, they don't require massive social change, they certainly don’t require the kind of social change you'd need if you were going to reintroduce a large predator, like the wolf.  If we can't live with the beaver how on earth can we morally expect other people who are much poorer than us to tolerate animals which are truly inconvenient; it's huge hypocrisy.

Interviewer:  So do you think all these conservation experiments with beavers are a rehearsal for the days when beavers roam at large in the countryside?

Derek Gow:  Yes, I do.  I think they're introducing people to the idea that the beaver is a native animal; the beaver could be here once again.  You know, I've been involved with this for many years.  I can tell you in the time of my involvement that if you'd asked me that question five/ten years ago I would not have been optimistic.  Now we're looking at a situation where most of the statutory nature conservations organisations, most of the voluntary nature conservation organisations have a position on this, and that position is one of support.  I think the thing that will drive the return of the beaver is not biodiversity and I don't think it's a moral obligation.  What will drive the return of the beaver is sheer economics.  It’s the economics of water conservation and water management that will see this incredibly effective rodent engineer.

Nutria (Myocastor coypus) beaver Copyrighted image Icon Copyright: Christian Schmalhofer |

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