Title: Acoustic perception of an anti-bat sensory illusion

Program: Biology MS

Committee Chair: Leonora Bittleston

Committee Co-Chair: Jesse Barber

Committee: Leonora Bittleston, Jesse Barber, Jen Cruz

Abstract: Bats and insects have long been entangled in an intimate evolutionary relationship, a link that has yielded a diverse range of anti-predator traits. Bats use echolocation to hunt prey in darkness, while insects have evolved deceptive techniques to exploit bats’ sensory systems and evade predation. The long hindwing tails of saturniid moths create a sensory illusion, causing bats to target their attack away from the moth’s body to unrewarding hindwings. However, the mechanism underlying this deception remains unclear. To determine how the spatial characteristics of bat calls change in response to this illusion, we reconstructed the sonar beam of big brown bats (Eptesicus fuscus) hunting luna moths (Actias luna) with and without hindwing tails. We found that bats attacking tailed moths emit less focused calls and shift their sonar aim closer to the moth’s posterior compared to attacks on non-tailed animals. These findings suggest that bats primarily target the echoic center of their prey, and that luna moth tails create an enlarged echo that offsets the perceived echoic center away from vital body parts, and towards the hindwings. Understanding how moth tails deceive bats not only elucidates the function of this anti-predator strategy but also reveals the limitations of an active sensing system honed by millions of years of battling insect counter-defenses.