Reintroduction of Beavers to Britain – Is It a Good Idea?
After an absence of hundreds of years, wild beavers are once more swimming free in the rivers and lochs of the British Isles. But is the reintroduction of beavers to Britain a good idea, or will the addition of a keystone species such as the beaver into areas where they have not been part of the local ecosystem for centuries lead to habitat destruction and problems for fishermen and landowners?
Like many other countries, many of Britain’s native species are struggling to maintain their numbers, and there are also problems with invasive species threatening habitats and food supplies, so the decision to reintroduce a species that has already once been driven to extinction is a fraught one, and one that has its supporters and its detractors.
What Are Beavers?
There are two species of beaver living in the world today, the North American beaver (Castor Canadensis) and the Eurasian beaver (Castor fiber), and it is the Eurasian species that was once native to Britain and has been selected to be reintroduced.
There is some fossil evidence that beavers were present in Scotland as long as 8,000 years ago, but they were finally hunted to extinction for their fur and for a secretion from their scent gland called castoreum which was once thought to have medicinal properties.
They are large rodents and lead a semi-aquatic life in freshwater lakes, ponds and slow flowing streams. The males and females are of a similar size, with the female even being sometimes slightly larger and they are well adapted for spending much of their time in water as they have big, flat tails that are very muscular, webbed hind feet that help push them through the water, and a thick, waterproof coat.
They are very territorial rodents, who build lodges with underwater entrances on the edge of freshwater lochs or streams where they live in family groups. Beavers live on average for between ten and fifteen years.
They reach sexual maturity at around two years of age, and once they find a mate they stay with them for life. They only breed once a year and produce a litter of between two or three kits. They do not hibernate, so they are active all year round and do most of their foraging for food, tree felling and building around dawn and dusk.
One of the more common myths about beavers is that they eat fish but they are in fact herbivores and they much prefer to feed on grass, shrubs, aquatic plants and they also like to gnaw a bit of bark.
They build low dams, usually not more than a metre tall, across small streams and ditches, and use the pond that is formed for storing a food supply underwater so that they can always access it, even if the pond water freezes over in the cold winter months.
The Knapdale Trial
It was in 2008 that an application was approved by the Scottish Government for a trial to reintroduce the beaver into a designated area of the Knapdale Forest in the Scottish Highlands.
The trial was given a set time frame, where the released beavers would be tracked in the wild and as much data as possible would be collated. The data is used to see whether the beavers can actually now survive in Scotland, how they are integrating back into the landscape and what kind of impact they are having on the environment.
The data is also necessary to assess if the presence of the reintroduced rodents is negatively affecting human activities such as angling, agriculture, forestry or tourism in any way. The animals that were released were Norwegian beavers, as they are the same species as those that became extinct in Britain, and they were all quarantined prior to their release and given stringent testing for diseases and parasites.
The beavers involved in the trial are recaptured annually so that they can be tested again, and water is regularly collected from the areas they live in, to ensure that water quality is being maintained and that no parasites have been introduced.
What Are The Objections To The Knapdale Trial?
You may think that reintroducing a species that has become extinct back into its natural habitat is a good thing, but there were several objections to the Knapdale Trial being started.
One of the big questions, as always, is money. It is very expensive to reintroduce a species, and at a time when the UK economy is not doing so well there are people who think that the money could be better spent elsewhere.
There are also worries that if the trial is too successful and beaver numbers start getting out of control then there will be calls to have them culled or for some of the animals to be sterilised which would be both very expensive and very unpopular with certain animal rights and environmental groups.
However, it has already been proved that the trial is helping to bring tourists into the area, eager to see beavers in the wild, who are spending their money locally and bringing income into the region.
There are also concerns about the beaver’s building activities. There are some anglers who think that the dams they are building will block the path of migrating fish, making it more difficult for them to spawn and thus reducing fish stocks.
The myth that these animals eat fish has also led fishermen to worry about the negative impact they could have on fish stocks. The reality is that a beaver’s dam will do little to hinder migrating fish, as they only build across narrow streams or ditches and in any case these dams are not watertight.
The introduction of the beaver is actually a good thing for fishermen, as the rodent’s activities include dumping debris such as logs and twigs into the lochs and rivers, which supplies young fish with food and somewhere safe to shelter.
Another concern is that the dams will cause flooding, but in fact they are very beneficial for creating and maintaining wetlands. The dams can also help to improve water quality in the ponds created, because any silt, rubbish or agricultural run-off gets trapped behind them.
Beavers are capable, however, of altering the local landscape because as well as the dams and ponds they create, if the beavers need to access new feeding grounds or transport timber and food back to their lodges, they will also create canals to navigate down.
This is very beneficial for the environment as the ponds and wetlands created by the beaver’s activities are a haven for a profuse variety of other wildlife such as otters, fish, birds, insects, amphibians and water voles.
Another question frequently asked is whether or not the beavers will cause significant damage to the trees.
But it must be remembered that they are a native species and they evolved alongside our native woodland. The trees they fell for their building activities are the native broad-leafed trees and they will also gnaw bark on some shrubs during the winter.
However, their activities usually do not range very far from the water’s edge, so their impact on woodland is not that large. In addition, forestry trees are generally safe as they do not like gnawing on conifers as the sticky resin clogs up their teeth, so they avoid building their lodges on stretches of water circled by pines and evergreens.
Even the trees they do fell tend to be coppiced, causing the tree to send out new shoots and regrow, and creating a greater diversity of age in the trees growing in that stretch of forest. This activity also extends and strengthens the tree’s root system, which helps to stabilise the riverbanks and stops them crumbling.
However, whether the Knapdale trial succeeds or fails may be moot, as a population of beavers has already made a home for themselves along the River Tay.
These animals were not reintroduced on purpose, but are thought to be descended from some Bavarian beavers that escaped from captivity around a decade ago. They seem to have have bred successfully and estimates are that there are now over a hundred individuals living in the region, so can certainly be regarded as native Scottish beavers.
A couple of years ago there was also a mysterious young male beaver caught in a slurry pit near Gunnislake in Cornwall. Initially it was thought that it was an animal called Igor who had previously escaped from captivity and never been recaptured, but the newly captured beaver was a much younger, smaller beaver than Igor leading to speculation that it was the offspring of an unknown pair of wild, breeding beavers.
So it will be interesting to see if the Knapdale Trial is deemed a success or a failure, and whether or not they let the beavers stay.
However, they already have unaccounted for escaped animals who may have already set up home in a different part of the area, so it might not be quite so easy to eradicate them as they may have hoped.
There is also the breeding population on the River Tay, who appear to be thriving and causing little damage or limitation to human activity.
Personally, I think that it is wonderful that a previously extinct native species like the beaver are once more swimming in our lochs and streams and building their dams and lodges, and by doing so are helping to create and protect a rich, vibrant wetland full of biodiversity and bursting with life.