Can Ultrasound Save Hedgehogs From Cars?

New research indicates that hedgehogs possess the ability to hear very high-frequency ultrasound, a finding that may pave the way for innovative deterrents against road traffic. Vehicles are a significant factor in the decline of hedgehogs across Europe, contributing to an estimated one in three deaths. Scientists at the University of Oxford, in collaboration with Danish colleagues, conducted studies on rescued hedgehogs. Using electrodes to monitor brainstem responses to sounds, they found hedgehogs reacted to frequencies ranging from 4 to 85kHz, well within the ultrasound spectrum.

Further analysis involved high-resolution scans of a hedgehog's ear. These scans revealed specific anatomical features, including dense middle-ear bones and a fused joint, which enhance the transmission of high-pitched sounds. These adaptations are similar to those found in bats. The researchers suggest this auditory capability could be harnessed to create ultrasound repellers for garden strimmers, lawn mowers, and crucially, vehicles.

These repellers could be designed to operate at frequencies that deter hedgehogs but do not affect domestic animals like dogs. Dr. Sophie Lund Rasmussen, a lead researcher, expressed optimism about collaborating with the automotive industry to develop and fund effective sound repellents. Successful implementation could significantly reduce the threat posed by road traffic to the declining European hedgehog population.