The results of the recent beaver re-introduction in Knapdale, Argyll, have just been released.  I remember being interviewed by John Craven at the site for Countryfile in 2009 at the outset of the trial, and I have followed it with despair since then. While the report contained little of interest other than arguing that it attracted tourists and discouraged anglers, the biggest shock is that this very meaningless and ecologically foolish enterprise had the backing of Scotland’s leading zoology institution, the Royal Zoological Society of Scotland, and a leading environmental guardian, Scottish Wildlife Trust, as well as 2 million pounds of funding that could have been much better spent saving the Scottish wildlife that is still clinging on to our shores and hills. Shocking because of the very basic biology that was ignored.  While we can more easily forgive the amateur do-gooders around the Tay and in Devon who have illegally and irresponsibly released many beavers that now form a feral population of 150 individuals, ecologically educated members of these two institutes should really know better. Resitting Population Biology 101 is advised.  There are three reasons why re-introducing beavers, and any other single organism to an existing ecosystem is insane, and a single reason why the ecologists in SWT and RZSS, as well as the Taysiders and Devonians, got it so badly wrong.

 1. Philosophical reasons or The Garden of Eden Fantasy

What I also refer to as “Golden Age environmentalism”, the compulsive yet foundationless desire to recreate some habitat from the past, by “re-wilding” is rampant among conservationists. This is a very strange concept, given that you cannot go back in time. What is Eden, and when was it? 15000 years ago, for example, most of Britain was covered in ice. So should we kill everything but the snow algae and spread the country with liquid nitrogen to re-wild it back to this stage? It’s a bit like plastic surgery – it may make you look 20 years younger, but beneath it, you’re still the same age, and getting older by the day! Unfortunately, some of our leading environmental organizations practice this cosmetic approach to conservation. Scottish Natural Heritage, for example, appears to be playing a game of King Canute at Tentsmuir National Nature Reserve, where they cut down birch and willow in an attempt to “freeze” the dune system.

We live in a changing world: communities have evolved away from what they were 400 years ago, when the beaver was last in Scotland, and from 800 years ago, when the beaver was in England. The industrial and agricultural revolutions, human population expansion, urbanization and climate change have made this a very different place. More essentially, its natural predators no longer exist here.

2. Biology

The European beaver is actually made up of 8 sub-species. The decision to move one of these, the Norwegian sub-species, to Scotland is extremely dubious. At the end of the last ice age, the most likely sub-species was the French one (Castor fiber gallicus), because the land bridge was to France, not to Norway. Norway was covered in ice just like Britain, and so the Mediterranean refuges were much more likely to form the source of our beavers. DNA analysis of beaver pelts from British beavers could be carried out to check this, but, surprisingly, this hasn’t been done.

A study in the journal Molecular Ecology by Walter Durka and his colleagues (leading experts) stressed that geographically nearest forms should be used, and that there was a huge danger related to re-wilding in terms of the future evolution of the beaver. In evolutionary terms, species start off as sub-species, and to intervene in this process by moving groups around the continent, we are potentially impacting on the future direction of beaver evolution.

3. Ecology

The context of an organism is everything. Every species needs food and a predator for a natural balance to be achieved. Without the predator, the population will, always, spiral out of control without culling. In Germany, beaver culling must now occur every year following beaver re-introductions in the 1960s. But what is the point of bringing the beaver here just to be culled? There is a moral issue here. Beavers are advanced mammals, and so if our actions deliberately lead to us needing to cull, then this is not a positive approach. Culling is also not a simple process. By killing particular beavers, we will not necessarily replicate the natural force of predation (for example those that disperse most). This can lead to a genetically altered population, and thus to all sorts of evolutionary problems.

Beavers that wandered too far from Knapdale were tracked and, literally, driven back in taxis to the site, in order to convince neighbouring land owners that there would be no threat to their property. This is also extremely worrying. For example, after 2 years, juvenile beavers migrate from their natal site. They can travel up to 150 km. The reasons for this are to reduce population load at a particular habitat, and, even more importantly, to prevent inbreeding. If we do not allow these migrations to happen, inbreeding depression will occur, and this can lead to terrible deformities. Do we really want this? To avoid this, we would need to allow these migrations. If we do this, then there can be no control on the spread of these creatures, and they are likely to encounter roads, probably acting as a significant hazard to drivers at night.

As we have seen, re-wilding is not a sensible idea. Neither is the use of the beaver for tourism. First, they are basically nocturnal, and in a British summer, this will mean 10pm. Shortly after seeing them, it gets dark. So safety concerns will come into play.  Tourists have to try to get back off the water or river bank in dark conditions. Secondly, the moral issue of disturbing a shy and reclusive animal must be considered. The beavers do not want to be seen, and ecological tourism will be very detrimental to them (as it is for most wildlife), stressing them, and suppressing their immune system, due to an increase in cortisol levels. This will increase their susceptibility to a range of diseases, potentially leading them to become disease vectors. This has been widely researched, for example with mountain gorilla tourism of the 1980s.

One beaver family destroys 300 young trees in a single winter. Tree regeneration is difficult enough with rabbits and deer already putting unacceptable pressure upon young saplings. However the beaver removes bark, which contains the main transport system for sugar, thus killing the tree. Grey squirrels also do this, and so in combination, this is an unacceptable problem.

To use the beaver as a means of terraforming (changing a habitat into one that works for us) is an extremely risky strategy. Living trees are far better water controls than dead trees in a beaver dam. The Harlequin ladybird was introduced to act as a predator on aphids, and now its population has run out of control in the UK and threatens many of our native ladybirds. The cane toad, introduced to Australia to kill insect pests of sugar cane, didn’t eat the pests, but instead ate many endangered insects, and has greatly damaged the other species. Biological control and biological engineering are never likely to work because the ecology is usually too complex to model and predict. It is like a car mechanic attempting brain surgery. In fact it is like a brain surgeon attempting brain surgery – the outcome is not secure.

So why did these ecologists get it so wrong?  It is because reductionist thinking pervades modern science.  Little boxes made out of ticky tacky (to quote Malvina Reynolds) that can be inserted wherever we want to insert them, building what we want.  Nature doesn’t work like that.  Ecosystems emerge, they are not built.  If you don’t have the wolf, then you have a beaver population in exponential rise, with little to curb it other than self-induced habitat destruction.  How foolish can you be not to see that nature is a system, not a Lego set? Quite clearly, you have to be as foolish as the two organizations running this shambolic waste of resources. But hey, it brings in tourists.



Fiona Napier
12/14/2014 6:58am

Agree 100%! To waste all that money and effort to artificially shoehorn a species into a niche that no longer exists is nonsensical - and to then try to contain it, even more so! I've seen the physical damage beaver can do to even the largest trees around Tayside. Our landscape can no longer accommodate a natural population of beaver - spend that money enabling one of our many threatened species to recover to a viable population.

Fiona Napier
12/29/2014 12:01pm


I'm always trying not to be as foolish as the two organizations running that shambolic waste of resources...

06/08/2016 10:48pm

It is really because reductionist thinking pervades modern science!


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