Beavers! Taking a bite out of habitat restoration

By Beth Paddon

Camera footage of a beaver in a shallow brook — Beaver feeding on hazel felled hazel trees – captured on a camera trap at Poole farm, Plymouth.

There's a large species of rodent out there right now, it weighs more than your dog and might be half as cute. But this unusual critter has the unique ability to build structures up to 2 metres high and half a mile long. Why? Because they are ecosystem engineers. They can see the weak points in their environment and dedicate their lives to fixing them. Beavers build their dams to flood areas to feel safe from predators but this in turn creates a wetland, allowing the return of rare plants and habitats some of which may have been thought to be lost in that region. This attracts insects along with birds and bats to feed on them. Walking into an area where beavers have been given free rein will take your breath away and if you stop and listen the hum of life is all around you, louder than some of you may have ever heard before.

I have dedicated the last few years of my life to studying Castor fibre (Eurasian Beavers), we all know what beavers are and have a vague idea of what it is they do but I had never seen their power before. Whilst at university during the pandemic I watched a seminar by Shropshire Wildlife Trust, I was shocked by the things beavers could do and wanted to know more. To do so I gained access to several beaver reintroduction sites as there are times in life where reading about things in a book or seeing a picture really doesn’t do justice. I saw dams taller than I was (yes, I may not be very tall but my point stands), and these dams were solid enough to walk along. One pond had been completely dug out and made from scratch on dry land only a foot high, but the pond was more than 15 metres wide.

I wrote my dissertation on the effects beavers can have on an area within just ten years of reintroduction. The water was cleaner as the beaver sequestered carbon and nitrogen through the collection of sediment and matter in the ponds they create. The water was slower which nurtured plants and juvenile fish. These areas had more things living in them than I had seen in most places I had visited in England. Studying aerial photos and previous surveys of the areas showed that the beavers had even altered the way that place looked creating a rich habitat mosaic which could be seen from the sky.

Large pond amongst trees in a woodland — Beavers constructed a large pond out of the ground by making a 1-foot high solid perimeter for the pond to form – taken at Wood Valley Farm, Cornwall (Beth Paddon)

Each beaver or family group had their own feeding preference and had different favourite foods for each season. Some of their food choices were unusual and unexpected like one beaver loved holly. Some studies such as the River Otter beaver trial even found the beavers to be eating invasive species like Himalayan balsam. Beavers never feed on conifers (such as pine), or sick trees like ash and rarely attempt to feed on older trees.

Small stump that has been gnawed down — The distinctive pencil-shaped stump left by beavers after felling a tree – taken at the Gweek Seal Sanctuary’s beaver project (Beth Paddon)

I took a trip to Sweden to study wild beavers at an undisclosed location, and let me tell you, you couldn’t swing a cat up there without seeing signs of beavers as they were everywhere! In all the places they were living there were more species per square metre than elsewhere. Despite conifers being the dominant group of trees in Sweden the beavers still never feed on them preferring birch. In locations which the beavers abandoned long ago, they left clearings for smaller plants and dams which slowed the rushing rivers. At one point I had to cross one of those rushing rivers with more than 20kg strapped to my back. Now I'm not the most sure-footed person without a third of my body weight on my back like some sort of lop-sided tortoise. I was scared to cross the river but a beaver dam long abandoned but still intact provided the perfect path.

Humans benefiting from the things beavers built is not new. Humans used to build their villages next to beavers. It makes perfect sense to have a well-maintained bridge built by beaver activity and fish congregating around the dams making it ideal for fishing. The history of the natural world and our history have been intertwined with beavers so deeply that their absence has been felt dramatically across the country. Like a game of Jenga, the removal of the beaver (or the base bricks) can cause the tower to shake and crumble. However, upon reinserting the beaver, an ecosystem will stabilise.

A large pile of sticks and logs at the edge of a pond — This unassuming pile of sticks 1.5 meters high is a beaver lodge (nest) its entrance is underwater (Beth Paddon)

If hearing all of this doesn’t make your little nature-loving heart flutter with hope then I'm not sure what will, but there is still a glass ceiling for the beaver to break before they return to a river near you. Certain organisations stand in the way of this step towards happily ever after, spreading and maintaining rumours that the beavers damage fish populations or bringing disease. Both of these are untrue all beavers brought to the country and thoroughly tested before release. beavers and fish have lived side by side for thousands of years and fish aren’t extinct in the areas where beavers once lived. This means they have adapted and continue to prosper despite this relationship and according to the River Otter Beaver trial report the population of fish actually increased by 37%. so for those of you deceived by a popular children’s book, beavers do not eat fish! if there's a lack of fish in your area perhaps we should look to a less furry culprit.

But in summary, beavers are awesome. I hope that someday in the not-too-distant future to be able to walk down to my local river and be met with the hum of insects, the soothing sounds of flowing water and well-fed birds singing in the trees. Perhaps reading this article has inspired your love for beavers and if it has maybe some of you will be down by the water's edge standing in awe at things nature has made for us, and maybe I will see you there.

If you’re a student or young person and wish to get involved with beavers then check out the websites of your local Wildlife Trusts or the Beaver Trust to see if they have opportunities available for you. Seeing what these animals can do I believe is something everyone should witness. If you would like to see the skill of the beaver in person take a trip to the Gweek Seal Sanctuary reintroduction program or the River Otter where beavers live wild near Otterton Village. Remember to always be respectful when visiting these places and that beavers are crepuscular (they are only awake from dusk to dawn) but keep your eyes peeled for track and field signs! I also recommended reading The River Otter Trail for a scientific summary of their abilities or Derek Gow's book ‘Bringing Back the Beaver’ for an eccentric account of the rocky road taken to reintroduce Britain’s beavers.