Barn owl ears don't age, scientists discover
Understanding how barn owls regenerate the sensory cells in their ears could inform the treatment of hearing loss in humans.
The German researchers say that understanding how these birds are able to regenerate sensory cells in their ears may lead to new treatments for hearing loss in humans.
“The barn owl is a predatory bird with remarkably sensitive hearing that also outperforms other vertebrates in spatial hearing… it relies on its sense of hearing for hunting prey,” the paper, published in the Proceedings of the Royal Society B today, reads. However, whether or not this strong hearing stood the test of time was unknown.
To explore the strength of this hearing in old age the researchers trained seven barn owls — three of which hatched in 1993, two in 1997 and another two hatchlings from 2015 — to sit and wait for a sound, which alternated in frequency, that signalled the bird to fly from one perch to another where they would be rewarded with food.
The scientists found no significant differences between the hearing of older barn owls and that of the younger specimens. “The lack of hearing loss in our old barn owls is remarkable, given that the average life expectancy of barn owls is rather low,” said the authors of the paper.
"It's a nice demonstration that in birds, hearing is preserved much better than in mammals and humans with age and one could make the hypothesis that this is correlated with the bird's ability to repair the damage in their ears," co-author of the paper, Georg Klump told the International Business Times UK.
"Humans cannot do this. If you go to a rock concert you may lose some hearing sensitivity, or if you work in noisy environments, a disc jockey in a club is a typical example. They will lose hearing sensitivity due to overstimulation and that's related to the inability of humans to repair damage in their ears,” he said.
The researchers say that the ability to regenerated sensory cells in human ears may have been possible at different stages of human evolution.
"In the vestibular system – which is for balance – we can actually do it, so it's interesting why this ability has been switched off, we don't know why," Klump explained.
"People are looking at the differences between birds and mammals and if they find out which 'switch' has been turned off in the development of the cells in the mammals, it might be possible to turn it on."