London, Beavertown
Here’s a lovely dose of promising news for you.
Baby beavers have been born as part of a new reintroduction program in West London, with conservationists saying it is proof that humans and beavers can live side by side in urban environments.
The beavers were reintroduced in West London last year and this new development is being hailed as “a huge advancement in urban rewilding”.
I thought this was a good opportunity to dust off an article that I originally published in October 2023, when the family was first reintroduced.
Beavers used to be widespread across the UK, an iconic native mammal that was unfortunately both very furry and very tasty. Our cousins back in the Elizabethan era made short work of them, hunting and trapping them for their fur and meat, and they quickly vanished from the British landscape.
Fast forward to today, and wildlife and conservation organisations are championing the beaver, clamouring for their return in the face of declining biodiversity and intensifying climate hazards.
Because it turns out that beavers are incredible ecosystem engineers.
When left to their own devices, beavers will get busy. Their front teeth never stop growing, so they never stop gnawing - specifically on tree bark. They use the fallen trees to build dams across rivers and streams, slowing the flow of water.
Beyond simply rearranging the landscape, beaver activity actually makes it healthier. Firstly, the slowing of water creates a deeper pond and a wetland habitat. This attracts other species such as dragonflies, fish, birds, and aquatic mammals like water voles and otters, increasing biodiversity. It filters the water, reducing pollution further downstream. The wetlands acts as a carbon sink, absorbing greenhouse gases from the atmosphere and helping to mitigate the effects of climate change, and it absorbs excess water, dramatically reducing flash flooding.
This reduction in flooding is one of many reasons why scientists are keen to reintroduce the beaver into urban environments.
Due to the way that humans have drastically changed the landscape over the last few decades, removing trees and soil, flash flooding is now commonplace. When towns and cities are nothing but tarmac and concrete, water has nowhere to go. If an unusual amount of rain blasts an urban environment, the drainage systems are quickly overcome, and flooding destroys lives and livelihoods.
As warm air holds more water, climate change is intensifying this rainfall.
The River Otter Beaver Trial in Devon suggests that the beavers reduced flooding by up to 60%1, even after very wet weather.
Beaver-powered landscapes also retain water in times of drought. As overall groundwater levels drop, wetlands hold water and become a refuge for wildlife - and soil - in the local area.
In areas prone to wildfires, beavers are indispensible. This interview with California-based ecohydrologist Emily Fairfax is worth reading, if only for this wonderful 45-second video explanation of how beavers prevent the spread of wildfires.
But beavers are more than just firebreakers. I love this story in Scientific American about the discovery of a complex of beaver dams after a catastrophic wildfire in Oregon that acted not only as a wildlife sanctuary, but as a filter.
This was more than a refuge from fire, which hundreds of beaver dams are known to have afforded to other riparian areas. Whereas fish seemed to have disappeared upstream of the Dixon Creek dam site, the downstream water was crystal clear—and trout were thriving as though the fire had never happened. The dams and ponds appeared to have altered the hydrology of the landscape around them…The beavers had effectively built something like a water treatment plant that staved off fire-related contamination.
As we have spent the last hundred years degrading our landscapes, building over natural features, straightening rivers and polluting water, it’s no wonder the environmental movement has adopted the beaver as a symbol of rewilding - reverting the landscape back to its natural state.
The beaver reintroductions in London have been the result of some incredible work from London Wildlife Trust, Beaver Trust, Ealing Wildlife Group, Citizen Zoo, Ealing Council, Friends of Horsenden Hill and Groundwork London. The ambition is lofty: Dr Sean McCormack, chair of Ealing Wildlife Group and a key driver of this project, explains:
Paradise Fields is already a highly suitable habitat for beaver reintroduction, and we hope it will become a flagship London rewilding project. We’re enclosing most of the 10-hectare site and uniquely the project will allow visitors to enter an immersive experience in a rewilding beaver landscape, after a month of closure to allow the beavers to settle in.2
Fast forward to today and the team is understanably buzzing, not only because the family have settled in well enough to breed but because the effects of ecosystem engineering are already being seen.
Improved water quality, reduced flooding, more insects and other wildlife on site, habitat improvements. And now at least two cute baby beavers to boot.3
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But beaver reintroduction is not without its critics.
Beavers were reintroduced - possibly illegally - into Scotland a few years before any official reintroduction programs were explored in England. Numbers have been building gradually and they have established themselves nicely across Scotland.
Not everybody is happy about this. Farmers and landowners claim that beaver floods and tree destruction damage their property. In 2018, 87 beavers were culled under license in Scotland4 - nearly 20% of the population at the time. Few people dispute that land is flooded and trees are felled, causing minor localised economic losses. But even the Scottish government accepts the overall benefits of increased biodiversity, flood and climate mitigation and wildlife tourism5. As a result they made the beaver a protected species in 2019.
I can envision a world where humans once again live happily alongside beavers. A beaver-powered landscape is a flood and drought-resistant landscape of fertile soil, biodiversity-rich wetlands, and happier people.
It won’t be an easy road. A family of beavers in London is an exciting start, but no more than two weeks after they were released last year the UK government said that “reintroducing species is not a priority.6” Instead (they said) they will focus on restoring biodiversity through habitat restoration and reducing pollution which are both admirable efforts, but it would be a sorely missed opportunity to ignore the rocket-propelled environmental booster that is the humble beaver. This year, a new UK government, and what’s shaping up to be a successful program, now provide a powerful opportunity to re-examine this.
There are plenty of other exciting rewilding projects going on, too. Blean Woods just outside Canterbury in Kent is now home to bison, another set of incredible ecosystem engineers. If governments don’t want to support them then it’s up to us to make sure the rewilding movement doesn’t lose steam.
It all comes down to embracing change. Humans haven’t lived closely alongside beavers for 400 years, and never in dense urban environments. We’re afraid of doing things differently, but the success of this project is an exciting step on the path to a society that is more accepting, understanding and tolerant of the natural world.
It’s the only path we should take.
Additional sources:
I can also strongly recommend reading Bringing Back The Beaver by Derek Gow.
https://onlinelibrary.wiley.com/doi/10.1002/hyp.14017
https://beavertrust.org/ealing-beaver-project-the-journey-to-bring-beavers-back-to-central-london/
https://www.bbc.co.uk/news/articles/crmw2yg8xjvo
https://scottishwildlifetrust.org.uk/news/trust-responds-to-alarming-beaver-cull-numbers/
https://www.gov.scot/news/protecting-scotlands-beaver-population/
https://www.bbc.co.uk/news/science-environment-67230751
They really are incredible creatures! Last year I visited the Cornwall Beaver Project where they had been introduced with an aim to stop flooding downstream of the farmland. The engineers had quickly got to work and it’s incredible to see the little wetland they created, as well as the species that have made their home there as a result. I hadn’t realised how much they have an impact on polluted rivers too - incredible!
There were two Beaver reintroduction programmes the official SNH / Scottish Royal Zoological Society Argyll and the unofficial / illegal releases in the Tay basin. The latter is the area of conflict because it was much less isolated and controlled. I worked for Scottish Wild Life Trust 2004-5 when civil servants halted the Argyle Trial for spurious reasons provided to Labour Ministers. But ultimately conservation interests won over Scottish Ministers when the SNP government took office after 2007.