Moths have evolved stealth acoustic cloaking to evade bat sonar

[Clive_T]

Originally published at: https://boingboing.net/2020/12/25/moths-have-evolved-stealth-acoustic-cloaking-to-evade-bat-sonar.html

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[prooftheory]

The bats around here have evolved to just swoop around street lamps, rather than having to do much detecting.

[Mercenary_Garage]

I’ve long suspected that the frequency at which moths beat their wings is the reason moths trapped in a room will cause panic in some people, yet I’ve never seen anyone freaked out by a butterfly. My thesis is they flap at about 20 Hz which is at the lower end of human hearing.

I’ve have no idea if this is true, but it’s my theory.

[AnthonyC]

@Clive_T

Again, this contrasts with butterfly scales, which tend to be rather uniform in shape and size.

That may be true, but butterfly wings are also often metamaterials, optical ones for structural coloration.

[Archisonic]

Pet peeve here:
Features do not evolve ‘to’ do something, which implies intentionality. Headline should read:

Moths have evolved stealth acoustic cloaking THAT evade bat sonar

Which better explains why these moths perpetuated and the others got eaten.

[bogus_strawman]

Interesting they used a butterfly’s wings as a comparison and that the bat sonar reflection is increased by these wings. Butterflies are active in daytime, so would not usually be subject to bat predation. Probably not happening, but as a number of insects mimic other poisonous/dangerous insects (hover flies that mimic wasps), I wonder if defensive aural mimicry occurs - an insect that, to a bat, sounds like an inedible species?

[anon87143080]

Given that it isn’t mimicking a sound, but rather is reducing its sonar cross section, the effect may be that it makes the bat think that the moth is too small to bother with.