What are beavers and why are they considered important for climate adaptation in Britain?
Beavers are semi-aquatic rodents — the second largest rodent in the world after capybaras — with webbed back feet and flat tails that they use to build dams. In Britain, their ability to dam rivers and retain water has made them effective natural flood-control engineers, capable of transforming small rivers into vast wetlands and acting as a buffer against the increasingly erratic weather caused by climate change.
After being hunted to extinction in Britain in the early 20th century — at a point when only approximately 1,200 beavers remained across all of Europe and northern Asia — they were reintroduced starting in 2009, when the first two Norwegian beavers, Millie and Bjornar, were relocated to Napdale Forest in western Scotland. That reintroduction was triggered in part by a 1992 EU law requiring member states to investigate human-caused extinctions and explore bringing species back.
The results have been striking. In Ealing, West London, a 20-acre park formerly used as a golf course was transformed into a water-retaining wetland within weeks of beavers arriving at the Ealing Beaver Project. The site had previously suffered persistent flooding at a nearby London Underground station — a problem that costly engineering solutions had failed to fix cheaply. Beavers solved it at a fraction of the estimated hundreds of thousands to over one million pounds that conventional flood mitigation would have required.
"The beavers can do it, probably a fraction of the cost, probably better than we can, certainly more sustainably for the environment."
— Lauren Frayer, Correspondent / Reporter, NPRKey figures from the episode
About Lauren Frayer
Lauren Frayer is a correspondent and reporter at NPR whose work for this episode took her across Britain to investigate the reintroduction of beavers as a climate adaptation strategy. Rather than relying on desk research, Frayer reported from the field across four distinct beaver locations — an approach that places her account squarely in the tradition of on-the-ground environmental journalism.
For this story, she traveled to Napdale Forest in western Scotland, the site of Britain's first modern beaver reintroduction in 2009, as well as to the Ealing Beaver Project in West London, where beavers are actively mitigating urban flooding. She hiked with forest rangers beginning at 4 a.m. to observe beaver activity at dawn — the animals' most active period — and gained firsthand access to dam sites that local conservationists described as among the most impressive they had seen.
Her reporting for this episode drew on interviews with scientists, veterinarians, farmers, and conservationists, giving her account breadth across the ecological, economic, and policy dimensions of beaver reintroduction. That range of sources — including representatives from the National Farmers Union Scotland, who hold concerns about beaver expansion — positions Frayer as a credible and balanced voice on a topic that sits at the intersection of wildlife science, flood engineering, and climate policy.