Acoustic Aposematism, Mimicry, and Sonar Jamming: Efficacy in the Field

The interactions between insect-eating bats and their prey are a classic example of an evolutionary arms race. Bats began the race with the evolution of sophisticated biosonar to track insects in complete darkness. Night-flying insects, including moths, countered with the evolution of sonar detection devices (ears) and erratic evasive maneuvers. Impressive aerobatic 'dog fights' ensue. Tiger moths (Lepidoptera: Arctiidae) added a new twist to the fray - they answer bats with ultrasonic clicks produced by specialized structures called tymbals. Laboratory experiments by this research group over the past decade have demonstrated an impressive array of functions for the clicks. Some moth species use them to warn bats that they are poisonous. Other palatable tiger moths mimic the sounds of noxious species. And, perhaps most impressively, some species make a cacophony of ultrasound to jam bat sonar.

The project delves into this exquisite predator-prey system using state-of-the-art technologies in the first comprehensive study of bat-tiger moth warfare under natural conditions. First, using thermal infrared videography and voice recognition software, the investigators will test the effectiveness of acoustic warning, acoustic mimicry, and sonar jamming against natural foraging bats that differ in echolocation strategies and foraging capabilities. The work will also reveal details of aerial battles that have thus far remained hidden. Second, the investigators will use species-specific molecular probes to quantify the DNA of specific moth species naturally occurring in bat guano. The results will be used to determine the utility of each of the tiger moth acoustic defenses in evading predation. The bat-moth story has shaped the field of animal behavior and is one of the most sophisticated predator-prey interactions known. An understanding of these processes will not only explain the fascinating details of bat-tiger moth evolution, it will also illustrate how fundamental behavioral interactions have shaped the acoustic world.

The most exciting educational aspect of this project is a partnership with SciWorks in Forsyth County, North Carolina. SciWorks is a science center and environmental park visited by over 30,000 K-12 students per year. The research group will assist in the development of interactive exhibits for SciWorks based on our bat-moth research.