A European hedgehog – credit, Fabian Fromwald
The European hedgehog can hear sounds at higher frequencies than is possible for humans, dogs, and cats, a potential breakthrough finding in protecting these animals from becoming roadkill.
There must be only a handful of critters cuter than the hedgehog, yet one-third of all mortality cases among local populations are attributed to car collisions.
It happens so frequently, that despite their rodent-like fecundity, these animals are now considered “Near Threatened,” by the IUCN.
Researchers at the University of Oxford in the UK, where hedgehogs are at risk of localized extinctions from car strikes, have discovered for the first time that hedgehogs can hear ultrasonic sound waves as high as 85,000 hertz. Humans can hear up to 20,000 hertz, dogs more than twice as many, and cats more than thrice as many; but none can match the hedgehog’s 85 kHz, and potentially higher, sensitivity.
The study subjected hedgehogs at a Danish rescue center to short sonic bursts up to 20 seconds long. The animals wore electrodes to measure brain activity between the inner-ear and the brain, and the result was that peak sonic detection was 45 kHz, around as much as a dog whistle.
The study authors paired this data with micro-CT scans of a mortally-injured and euthanized hedgehog to get a detailed picture of the ear cannel of the animal. Their conclusion was that it seemed similarly constructed and functional to that of echolocating bats.
“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,” study co-author Professor David Macdonald, told Euronews.
MORE AUDITORY BIOLOGY: Spiders Use Their Webs as Giant Microphones to Hear What’s Going on Around Them, Says New Research
Dr. Sophie Lund Rasmussen, corresponding author on the study, agreed.
“A fascinating question now is whether they use ultrasound to communicate with each other, or to detect prey—something we have already begun investigating.”
HELPING HEDGEHOGS: Couple Converts Their Home into ‘Hedgehog Haven’ to Rehabilitate Over 500 Spiky Critters
In addition, the team is investigating whether ultrasonic sound emitters, mounted on cars, lawnmowers, and hedge trimmers, could serve as effective hedgehog repellants. Blasting an ultrasonic note which only they can hear, might it dissuade them from attempting their long, slow road crossings that sometimes end in disaster?
The team is looking for volunteer collaborators within the car industry who could spare the funds to finance a prototype repellant device and trial it on their cars.
SHARE This Research To Save The Hedgehog With Your Friends…
