Who were Millie and Bjornar, and what role did they play in Britain's beaver reintroduction?
Millie and Bjornar were two Norwegian beavers relocated by wildlife officials in 2009 to Napdale Forest, a temperate rainforest in western Scotland, as part of Britain's official beaver reintroduction program. They became the founding pair of the modern British beaver population — described by scientists as the "Adam and Eve" of the species in Britain — and went on to produce more than a dozen offspring, known as kits.
Their story, however, took an unexpected turn. Scientists later discovered that Millie and Bjornar were not just a founding pair — they were also father and daughter. The revelation prompted authorities to import additional beavers from Norway, Germany, and Poland in order to diversify the gene pool and ensure the long-term viability of the reintroduced population. Their complicated family history aside, Millie and Bjornar remain the biological cornerstone of every beaver now living wild in Britain. To hear Lauren Frayer's full on-the-ground reporting on this story, listen to the episode on Listenly.
Their arrival in 2009 was the direct result of a legal trigger set in motion years earlier: a 1992 EU law that required member states — including Britain at the time — to investigate species that had gone extinct due to human activity and to explore reintroduction. Beavers had been absent from Britain since the early 20th century, and by the time Millie and Bjornar were selected for relocation, only around 1,200 beavers remained across Europe and northern Asia combined. Their placement in Napdale Forest was carefully chosen, and within years their engineering instincts — damming, channeling, and reshaping waterways — began transforming the landscape in ways that would later attract serious attention from climate scientists and flood management authorities.
"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 Correspondent, reporting for Up FirstAbout Lauren Frayer
Lauren Frayer is an NPR correspondent whose reporting on Britain's beaver reintroduction program stands out for its exceptional depth and firsthand access. For this investigation, she traveled to four separate beaver sites across Britain, venturing as far as Napdale Forest in western Scotland — one of the program's founding locations — and the Ealing Beaver Project in West London, where beavers have been deployed as a practical solution to urban flooding near a London Underground station. Frayer hiked with forest rangers starting at 4 a.m. to observe beavers in their natural setting, gaining the kind of direct, ground-level perspective that gives her reporting particular credibility. Beyond the wildlife itself, she conducted interviews with scientists, veterinarians, farmers, and conservationists, building a comprehensive picture of how a centuries-old extinction is being reversed — and what it means for Britain's approach to climate adaptation. Her work sits at the intersection of environmental journalism and public policy, making complex ecological and legal dynamics accessible to a broad audience.
See also
In 1992, when Britain was still part of the European Union, the EU passed a law requiring member states to investigate which species had gone extinct as a result of human activity and to explore their reintroduction.
Beavers were hunted to extinction in Britain by the early 20th century. Humans wanted their waterproof fur, their meat, and their anal secretions — a substance valued for use in perfumes and medicines.
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 help mitigate flooding driven by climate change.