If you want a forest to grow, you cannot have three beaver dams on the drainage ditch running through it: the forest becomes a swamp, the trees don't grow, and the beaver is the problem.
At least, that's how the animal has been seen for a long time. Today, however, the beaver is increasingly recognised as an ecosystem engineer who builds wetlands, boosts biodiversity, and helps with climate adaptation. Not many animals get such a career change.
Why they build
Why go through all the trouble to block an entire river with a wall of mud, branches, entire trees, and stones? Beavers do not build dams out of passion for landscaping; they're simply trying to not get eaten.
The beaver is slow on land and brilliant in water, so its lodge has an underwater entrance. But if the water levels drop too low, predators can reach it. That's why the beaver does what any cautious homeowner with an engineering degree would do: it raises the water level.
Everything else – the flooded forest or field, the furious farmer – comes as a side effect from that one act of self-preservation.
The comeback
For most of European history, we've seen beavers as a resource. They were valued for what humans could take from them: fur, meat, and gland castoreum for perfumes and medicines (yep – their anal secretion). By the early 20th century, hunting had pushed the Eurasian beaver close to extinction. Only around 1,200 animals remained across the continent.
But we managed to bring them back: today, Europe is home to over 1.5 million beavers. They are now strictly protected under EU law, except in Estonia, Latvia, Lithuania, Finland, and Sweden, where populations are considered stable. It is one of the continent's most remarkable wildlife recovery stories.
Latvia is one of the most beaver-dense countries in Europe, and it was one of the first to bring them back. Its last native beaver had been killed in 1873; in 1927, the first beavers arrived from Norway. Now Latvia may have between 80,000 and 100,000 beavers.
The hero we didn't know we needed
As Europe grapples with droughts, floods, and biodiversity loss, scientists increasingly see the beaver as a natural ally in adapting to climate crisis.
By slowing water down, beavers create wetlands that reduce floods, filter agricultural pollution, and provide habitat for countless species, Anita Zariņa, geographer and leading researcher at the University of Latvia who studies human-water relations, told us. Their ponds can also offer resting and feeding places for young migrating fish, rather than necessarily blocking their journey upstream. “The beaver simply boosts ecological complexity,” Zariņa said.
In 2021, when wildfires burnt down parts of the western US and miles of landscape turned to ash, researchers noticed that patches of green survived around beaver ponds. The wetlands had acted as small refuges in a burning landscape.
In France, engineers are modelling artificial beaver dams to prevent flooding; their ecological work in waters is also the reason they were reintroduced in the UK. Last year in Czechia, eight beavers built a dam overnight, saving a lot of money for the authorities that had spent years planning a project just like that.
Learning to coexist with the ”pest”
Still, we're not quite ready to fully trust the beaver. In Latvia, they're still mostly seen as a nuisance rather than an ally.
It's not even about flooded fields or fallen trees. Zariņa explained that the beaver challenges a deeply rooted idea that nature is something people should manage, improve and keep under control. It clashes too much with our productivist vision of the landscape.
“The animals that transform landscapes people have cultivated, organised, and made controllable, are the animals people tend not to like,” she said.
“The beaver emerged as what I would call a threshold animal,” she added. “A species that society clearly does not quite know what to do with.”
In Latvia, where drainage ditches still shape much of the landscape, beaver dams are routinely dismantled to keep water flowing and protect forests and farmlands. Municipalities, foresters, and even conservation groups remove them, while around 25,000 to 30,000 beavers are hunted every year as a part of wildlife management.
None of this means every beaver dam should stay, Zariņa noted. Roads and fields do flood, and infrastructure gets damaged, in part because it now occupies so much of the landscape.
Increasingly, though, the question is where we should allow them to work, she said. “It is about coexistence. About whether we can make room for other forms of life, and other ideas of what nature is supposed to do.”