Sound-absorbing fur helps moths avoid bat predation
The fur on the thorax of some moths absorbs the sound waves emitted by
bats and their sonar systems, making them harder to detect, according to
new research by scientists at Bristol University in England.
Some moths boast ears capable of recognizing bats' ultrasonic signals,
helping them avoid predation. But many moth species are deaf. Without
the ability to hear swooping bats, deaf moths must rely on other defense
strategies.
Several Bristol researchers, including Thomas Neil, who studies
bioacoustics, were interested in learning more about these alternative
defense mechanisms.
"Bats and moths have been involved in an acoustic arms race for 65
million years, we were interested in how deaf moths might try to
increase their survival chances against bats," Neil told UPI. "Any
defense they had would have to be passive, and so dampening the echoes
returning to a hunting bat seemed like a plausible strategy."
Neil and his colleagues measured the acoustic qualities of fur found on
the thoraxes and wing joints of moths and butterflies. Their analysis
showed moth fur was thicker and denser than butterfly fur. In the lab,
tests showed moth fur was better at absorbing ultrasonic waves.
The less a bat's acoustic signals echo off an object, the harder it is for a bat to recognize the object.
"The study is a sort of a proof of concept, we've shown that the fur on
the thorax can absorb ultrasound, but the extent to which it is present
amongst the many moth species is currently unknown," Neil said.
Though the new research featured two deaf moth species, Antherina suraka
and Callosamia promethea, it's possible some species can both hear
approaching bats and hide themselves using sound-absorbing fur.
"There's no reason for the stealth coating and the ability to hear to be
mutually exclusive, it would still be of a benefit for a moth with ears
to also be camouflaged acoustically," Neil said.
Neil and his colleagues are preparing to present their research this
week at the 176th Meeting of the Acoustical Society of America.
The fur's acoustic qualities could prove beneficial for non-moths, too.
"Lessons learned from how the thorax fur of moths absorbs ultrasound
could inspire a new design of noise insulation material," Neil said.
"The size of the material would have to be scaled up so that the sounds
it was absorbing were more relevant for human hearing, but its
performance could better those of current sound insulating materials."
https://www.geezgo.com/sps/45625
Join Geezgo for free. Use Geezgo's end-to-end encrypted Chat with your Closenets (friends, relatives, colleague etc) in personalized ways.>>
No comments