Moth tails divert bat attack: evolution of acoustic deflection.

Moth tails divert bat attack: evolution of acoustic deflection.

Barber Jesse R; Leavell Brian C; Keener Adam L; Breinholt Jesse W; Chadwell Brad A; McClure Christopher J W; Hill Geena M; Kawahara Akito Y

Proceedings of the National Academy of Sciences of the United States of America

2015

2015-03

Adaptations to divert the attacks of visually guided predators have evolved repeatedly in animals. Using high-speed infrared videography, we show that luna moths (Actias luna) generate an acoustic diversion with spinning hindwing tails to deflect echolocating bat attacks away from their body and toward these nonessential appendages. We pit luna moths against big brown bats (Eptesicus fuscus) and demonstrate a survival advantage of approximately 47% for moths with tails versus those that had their tails removed. The benefit of hindwing tails is equivalent to the advantage conferred to moths by bat-detecting ears. Moth tails lured bat attacks to these wing regions during 55% of interactions between bats and intact luna moths. We analyzed flight kinematics of moths with and without hindwing tails and suggest that tails have a minimal role in flight performance. Using a robust phylogeny, we find that long spatulate tails have independently evolved four times in saturniid moths, further supporting the selective advantage of this anti-bat strategy. Diversionary tactics are perhaps more common than appreciated in predator-prey interactions. Our finding suggests that focusing on the sensory ecologies of key predators will reveal such countermeasures in prey.

*Biological Evolution; *Chiroptera; Animal Structures/anatomy & histology/*physiology; Animals; antipredator defense; bat-moth interactions; Food Chain; Lepidoptera; Moths/*physiology; Saturniidae

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