01618nas a2200181   4500008004100000022001400041245005500055210005500110260001600165300001600181490000800197520109600205100002101301700001801322700002601340700001901366856005101385       2018                        eng d  a0001-496600aStealthy moths avoid bats with acoustic camouflage0 aStealthy moths avoid bats with acoustic camouflage  cJan-09-2018  a1742 - 17420 v1443 a<p>Intense predation pressure from echolocating bats has led to the evolution of a host of anti-bat defences in nocturnal moths. Some have evolved ears to detect the ultrasonic biosonar of bats, yet there are many moths that are completely deaf. To enhance their survival chances, deaf moths must instead rely on passive defences. Here, we show that furry morphological specializations give moth bodies and wing joints acoustic stealth by reducing their echoes from bat calls. Using acoustic tomography, echo strength was quantified in the spatial and frequency domains of two deaf moth species that are subject to bat predation and two butterfly species that are not. Thoracic fur determines acoustic camouflage of moths but not butterflies. Thoracic fur provides substantial acoustic stealth at all ecologically relevant ultrasonic frequencies, with fur removal increasing a moth&rsquo;s detection risk by as much as 38%. The thorax fur of moths acts as a lightweight porous sound absorber, facilitating acoustic camouflage and offering a significant survival advantage against bats.</p>
1 aNeil, Thomas, R.1 aShen, Zhiyuan1 aDrinkwater, Bruce, W.1 aRobert, Daniel  uhttp://asa.scitation.org/doi/10.1121/1.5067725