The Beaver: Building Britain’s ecosystems, one dam at a time

Amy writes about Britain's natural engineers, the beavers and how they are keystone species due to being essential in our wildlife.

Eurasian beavers (Castor fiber) are Britain’s largest rodent and believe it or not, they aren’t just a fluffy face; they’ve adapted perfectly to be architects of the natural world. Most well known for their ability to build dams, they’ve got the world’s best natural tools, their teeth. With a unique chisel shape, this allows them to fell trees in record time. As well as carefully chewing off the bark to eat, a staple of a beaver diet.

Eurasian beaver. Image Credits: Martina Lion on Wikimedia Commons.

However, it’s not all about wood. Beavers spend a lot of time underwater. To deal with this, they’ve adapted to have clear eyelids to protect their eyes, alongside valves in their nostrils and ears, to keep water out. Speaking of nostrils and water, did you know that beavers can smell water? If all this wasn’t enough, they’ve got huge lungs to allow them to hold their breath for up to 15 minutes.

Obviously, being such an incredible species, us humans couldn’t just leave them alone. We hunted them to extinction almost 400 years ago to make use of their meat, fur and an excretion called castoreum, which comes from a gland right on the beavers bottom. With a lovely vanilla scent, castoreum has been used in perfume, food or even once upon a time to flavour cigarettes. Due to the dramatic drop in numbers, one of the first controlled releases of the Eurasian beaver took place in Scotland, aptly named the Scottish beaver trial, in 2009. Which, after proven success, kick started reintroductions all over the UK.

With such a tragic history, beavers are now coming back from the brink. And they’re creating waves of change across the British countryside. Known as a keystone species; they’re an essential part of the environment. As ecosystem engineers, beavers create, change, and destroy habitats – for the good of the environment. The beaver is the most common example of an ecosystem engineer so it’s no wonder we want them back in British waterways.

A Eurasian beaver dam. Image Credits: Joel Berglund on Wikimedia Commons.

We’ve brought beavers back up and down the country, so what are they actually doing? Their overarching use is to restore the UK's wetlands; which we've lost 90% of in the last century. WWT is attempting to create 100,000 hectares of wetland, an area three times the size of my home, the Isle of Wight (which is bigger than you’d think). Beavers can really help this process with the use of their expertly crafted dams. With initially only a small pool of water, the beavers dam can slow down the flow of water and create a huge wetland area.

This leads to a string of positive effects. Trees are gnawed down to leave an exposed stump for new growth; the deadwood that’s left behind then creates a lovely new home for various insects. With less trees, this leaves gaps in the tree canopy to allow more light through. You wouldn’t think this would make much difference, but it quite literally creates a whole new world. More light on the forest floor means that those little ground dwelling plants have a much higher chance of growing big and strong. And that wetland that the beavers also created, gets warmer and warmer with the sun beaming on it. This becomes a haven for aquatic invertebrates and breeding amphibians, and I’m sure we can all agree, the more frogs the merrier.

New growth as a result of the Eurasian beaver. Image Credits: Lamiot on Wikimedia Commons.

All this positive change and I haven’t even mentioned the benefits of the newly restored wetlands yet. They’re an incredible tool during droughts, the soil stays damp even with the lack of rain, which allows plants to continue to grow. They also provide refuge for various species if wildfires ignite nearby. Aside from all the incredible wildlife we get to experience, there are benefits for humans too, beavers reduce the risk of flooding, often released near towns and cities where flooding is prevalent. With our increasingly unpredictable weather patterns, wetlands could quite literally be lifesavers from natural (or not so natural) disasters.

Of course, there are still conflicts between beavers and humans, some things will never change. This is normally from landowners who manage their land in a certain way that isn’t usually suitable for beavers, such as drainage on their land, which can be blocked by beavers. It is also believed beavers spread diseases such as tapeworm. But it’s all about knowledge and understanding. If we can educate these naysayers on the actual benefits of beavers, especially to their own livelihoods, then hopefully we’ll increase the success and support of reintroductions so that they can breathe some new life into the UK’s wetlands. 

About the Author: Amy Hall is an aspiring conservation communicator currently studying MSc Wildlife Biology and Conservation. Having grown up on the Isle of Wight, now living in Cornwall, she’s in touch with nature and uses it as a source of inspiration. This passion is being channeled into drawing, creating and writing to hopefully inspire others. Follow @amyinthewild_ to find out more!