Researchers at the University of Oxford have made a significant discovery that could transform how conservationists protect hedgehogs from road traffic: the animals are capable of hearing very high frequency ultrasound waves. The finding opens the possibility of deploying roadside acoustic devices that emit ultrasound signals to steer hedgehogs away from dangerous roads. Scientists believe this technology could meaningfully reduce the number of hedgehog fatalities caused by vehicles each year.
Traffic currently accounts for one in three hedgehog deaths, making road collisions one of the most significant threats to a species already in serious decline across the United Kingdom. Conservation efforts to date have largely focused on physical infrastructure solutions, such as tunnels built beneath roads to create so-called hedgehog highways. While these tunnels have proven effective, scientists at Oxford argue that an acoustic approach could offer a scalable and less costly alternative.
Working alongside wildlife researchers, the Oxford team conducted tests to establish the upper range of hedgehog hearing. Their findings confirmed that hedgehogs can detect sounds at frequencies far beyond what was previously understood, placing them within range of ultrasonic devices already used in various pest deterrent technologies. The researchers suggest that emitters placed along road verges could produce directional ultrasound signals designed to alert hedgehogs to danger and prompt them to change their route before reaching the road surface.
The study adds a new dimension to the growing body of research exploring how acoustic signals can be used to influence animal behavior in human-dominated environments. Scientists have previously investigated similar approaches with other species, including deer and birds, with varying degrees of success. The hedgehog research, however, is notable because it identifies a specific biological capability that can now be directly targeted with existing technology.
Conservationists have welcomed the findings but cautioned that further field trials are needed before any large-scale deployment can be recommended. Key questions remain about how hedgehogs respond to ultrasound in real-world conditions, including whether the animals would habituate to the signals over time and whether the devices could be made weatherproof and cost-effective enough for widespread roadside installation. Researchers indicated that follow-up studies are being planned to test the acoustic deterrent in controlled outdoor environments.
The hedgehog population in Britain has declined sharply over recent decades, with estimates suggesting numbers have fallen by more than a third since the turn of the millennium. Road deaths, alongside habitat loss and the use of garden pesticides, have been identified as primary drivers of the decline. If ultrasound deterrent technology proves effective in field conditions, experts say it could represent one of the most practical and deployable tools yet developed for protecting the species at scale.
