Why did beavers go extinct in Britain, and when did it actually happen?
Beavers were hunted to extinction in Britain by the early 20th century. Humans pursued them relentlessly for three distinct resources: their waterproof fur, their meat, and their anal secretions — a substance called castoreum — which was prized in medieval perfumes for its vanilla-like scent and consumed by Romans for its supposed medicinal properties. By the time the last British beavers disappeared, only approximately 1,200 individuals remained across all of Europe and northern Asia.
The demand for castoreum illustrates just how comprehensively beavers were exploited. Far from being hunted simply for food or pelts, they were targeted for nearly every part of their body, making population recovery essentially impossible before legal protection existed. The scale of that collapse — from widespread presence across Britain to complete local extinction — took centuries of sustained hunting pressure to achieve.
What is castoreum?
Castoreum is a substance secreted by the anal glands of beavers. In the medieval period, it was harvested for use in perfumes due to its vanilla-like scent. Romans also consumed it believing it had medicinal properties. This demand made beavers targets not just for their pelts and meat, but for their internal secretions — contributing directly to their extinction across Britain.
It was only in 1992 that the European Union passed legislation requiring member states to investigate species driven extinct by human activity and explore reintroduction programs — the legal trigger that eventually brought beavers back. The first step came in 2009, when two Norwegian beavers named Millie and Bjornar were relocated to Napdale Forest in western Scotland, marking Britain's first beaver reintroduction in roughly 400 years. NPR's Lauren Frayer reported the full story for Up First, traveling across Britain to document how these animals — once erased by human greed — are now being actively recruited to solve the flooding crises caused by climate change.
"The beavers can do it, probably a fraction of the cost, probably better than we can, certainly more sustainably for the environment."
— Lauren Frayer, NPR CorrespondentAbout Lauren Frayer
Lauren Frayer is an NPR correspondent who conducted the on-the-ground reporting for this investigation into Britain's beaver reintroduction program. For this story, she traveled to four distinct beaver locations across Britain — a level of fieldwork that gives her account unusual breadth and firsthand authority.
Her reporting took her to Napdale Forest in western Scotland, where Britain's first reintroduced beavers arrived in 2009, and to the Ealing Beaver Project in West London, where beavers have effectively replaced an expensive flood engineering solution near a London Underground station. She hiked with forest rangers beginning at 4 a.m. to observe beaver behavior in the wild.
For this episode, Frayer interviewed a wide range of specialists — scientists, veterinarians, conservationists, and farmers — including representatives from the National Farmers Union Scotland, whose members have complex and sometimes conflicting views on beaver reintroduction. That range of sources positions her reporting not as advocacy but as a rigorous examination of the ecological, economic, and political stakes involved.
Her work on this story makes her one of the few journalists to have documented in depth both the historical extinction of British beavers and the active scientific and policy effort to reverse it.
See also
Beavers are semi-aquatic rodents — the second largest rodent in the world after capybaras — equipped with webbed back feet and flat tails used to build dams and wetlands that naturally slow and store water, making them key allies in Britain's climate adaptation strategy.
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