Collaborative Research: Acoustic Deflection in Bat-Moth Interactions: Revealing the Mechanism and Evolution of a Sensory Illusion

点击翻译按钮获取中文摘要

Predators are under pressure to perform lethal strikes on prey. Prey, in turn, are under pressure to deflect predators away from vital body parts. To do so, some animals have evolved traits to take advantage of their assailants' sensory systems and vulnerabilities therein, creating sensory illusions - that is, discrepancies between what the predator perceives and reality. Understanding how prey manipulate sensory processing by their predators will reveal important driving principles and limitations of sensory systems. This team of researchers has shown that moth tails divert echolocating bat attack to these expendable appendages by creating an acoustic illusion. Using arrays of high-speed cameras and ultrasonic microphones, this research will quantify battles between bats and long-tailed moths and reveal the underlying mechanism of this illusion. To provide naturally replicated tests of their hypotheses, the team will study multiple origins of long tails in moths on different continents and incorporate this knowledge into a comprehensive phylogeny. In doing so, they will parse the roles of both constraint and selection on the emergence of convergent traits to reveal general principles that govern diversification. The team will engage in activities to broaden the impact of their work. For example, they will live videoconference from the field into undergraduate classrooms to use the natural charisma of bat-moth interactions to excite students and increase STEM retention. In addition, the team will produce a museum exhibit that will include hundreds of moth specimens, a rendition of the resulting phylogeny and multiple computer monitors displaying high-speed videos of bat-moth interactions. Tactics adapted to circumvent the sensing strategies of predators are likely underappreciated defenses in diverse taxa. This project will determine the mechanism underlying deflection of bat attack by moth tails. The team will use 3D high-speed videography of bat-moth interactions to parse mechanistic hypotheses by quantifying precisely where bats strike their prey. In addition, they will quantify the physical information available to bats in returning echoes from moths using a 3D ensonification array and then pit those moths against bats in predator-prey battles to examine auditory object formation by the predator. The fundamentals of how bats organize and separate the auditory scene bear strongly on bat and insect ecology and evolution. By quantifying behavior across silk moth diversity, the team aims to test the evolutionary route of echoic profile convergence. They will quantify echoes reflected off hundreds of silk moth species across the world's tropics and build a robust phylogeny to unfold the pattern of convergent evolution and tease apart the roles of both historical bias and selection on the independent origins of this anti-bat defense. Understanding how moth tails alter echoic information to "fool" bats will reveal the limitations of an active sensing system that has been honed by millions of years of battling insect counter-defenses and may lead to an understanding of the fundamental limitations of extracting information from an echo stream. Further, this project has broad implications for the evolution of the diverse nocturnal insects, one of the dominant animal lineages on Earth.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.