01898nas a2200133   4500008004100000245006000041210005900101520143500160100003101595700002601626700002601652700001901678856006701697       2006                        eng d00aKeeping up with Bats: Dynamic Auditory Tuning in a Moth0 aKeeping up with Bats Dynamic Auditory Tuning in a Moth3 a<p>Many night-flying insects evolved ultrasound sensi- tive ears in response to acoustic predation by echolo- cating bats [1&ndash;10]. Noctuid moths are most sensitive to frequencies at 20&ndash;40 kHz [6], the lower range of bat ultrasound [5, 11&ndash;13]. This may disadvantage the moth because noctuid-hunting bats in particular echo- locate at higher frequencies shortly before prey cap- ture [7, 11&ndash;13] and thus improve their echolocation and reduce their acoustic conspicuousness [6&ndash;10, 12&ndash;16]. Yet, moth hearing is not simple; the ear&rsquo;s non- linear dynamic response shifts its mechanical sensi- tivity up to high frequencies. Dependent on incident sound intensity, the moth&rsquo;s ear mechanically tunes up and anticipates the high frequencies used by hunt- ing bats. Surprisingly, this tuning is hysteretic, keep- ing the ear tuned up for the bat&rsquo;s possible return. A mathematical model is constructed for predicting a lin- ear relationship between the ear&rsquo;s mechanical stiff- ness and sound intensity. This nonlinear mechanical response is a parametric amplitude dependence [17, 18] that may constitute a feature common to other sen- sory systems. Adding another twist to the coevolu- tionary arms race between moths and bats, these re- sults reveal unexpected sophistication in one of the simplest ears known and a novel perspective for inter- preting bat echolocation calls.</p>
1 aWindmill, James, Frederick1 aJackson, Joseph, Curt1 aTuck, Elizabeth, Jane1 aRobert, Daniel  uhttps://linkinghub.elsevier.com/retrieve/pii/S0960982206023219