Full Breakdown
New Research Offers Hope for Protecting European Hedgehogs from Road Deaths
3/29/2026, 11:39:20 AM
Discovery of Ultrasonic Hearing in Hedgehogs
Recent research from the University of Oxford has revealed that European hedgehogs (Erinaceus europaeus) can detect high-frequency ultrasound, a finding that could lead to innovative solutions for reducing road fatalities among this declining species. The International Union for Conservation of Nature classified the European hedgehog as “near threatened” in 2024, with road accidents accounting for a significant portion of their mortality—estimates suggest that up to one in three hedgehogs in certain populations die from vehicle collisions.
Research Methodology and Findings
To investigate the auditory capabilities of hedgehogs, researchers collaborated with colleagues in Denmark, measuring the auditory brainstem responses of 20 rehabilitated hedgehogs. This involved placing electrodes on the animals to track electrical signals in response to sound pulses. The results indicated that hedgehogs can hear sounds ranging from 4 to 85 kHz, with peak sensitivity around 40 kHz, confirming their ability to detect ultrasound, which begins above 20 kHz.
Additionally, high-resolution micro-CT scans of a deceased hedgehog revealed unique anatomical features of the ear, including tiny, dense middle ear bones and a partly fused connection between the eardrum and the first bone in the chain. These adaptations enhance the transmission of high-frequency sounds, similar to traits found in echolocating bats.
Potential Applications for Conservation
The implications of these findings are significant. Researchers propose that ultrasonic repellents could be developed to deter hedgehogs from roads and other hazards, such as robotic lawnmowers and garden strimmers. Assistant Professor Sophie Lund Rasmussen emphasized the importance of collaborating with the automotive industry to design effective sound repellents. She stated, “If our future research shows that it proves possible to design an effective device to keep hedgehogs away from cars, this could have a significant impact in reducing the threat of road traffic to the declining European hedgehog.”
Criticism and Future Research Directions
While the research presents a promising avenue for conservation, critical questions remain regarding the hedgehogs' behavioral responses to ultrasound and whether these responses could effectively mitigate collision risks. Further investigations are needed to explore whether hedgehogs utilize ultrasound for communication or prey detection, as suggested by co-author Professor David Macdonald.
Conclusion
The discovery of ultrasonic hearing in European hedgehogs opens new possibilities for their protection against road traffic. As researchers continue to explore this avenue, the potential development of ultrasonic repellents could play a crucial role in conserving this beloved species, which faces increasing threats from human activity.
Verbatim Quotes
- “Having discovered that hedgehogs can hear in ultrasound, the next stage will be to find collaborators within the car industry to fund and design sound repellents for cars. If our future research shows that it proves possible to design an effective device to keep hedgehogs away from cars, this could have a significant impact in reducing the threat of road traffic to the declining European hedgehog.” — Assistant Professor Sophie Lund Rasmussen, University of Oxford
- “ Co-author Professor David Macdonald (Wildlife Conservation Research Unit/Department of Biology, University of Oxford) said, “It is especially exciting when research motivated by conservation leads to a fundamental new discovery about a species biology, which, full circle, in turn offers a new avenue for conservation.” — Professor David Macdonald, University of Oxford
