- Carleton University
- University of Washington
Summary
Analysis of the clicks produced by some arctiid moths shows that their acoustic characteristics (power spectra and frequency–time structures) are remarkably similar to those of frequency-modulated echolocation calls produced by many bats as they close with their prey. We suspect that the clicks are initially processed as echoes by the auditory systems of these bats and function by interfering with information processing by the bat.
Methodology
We recorded the ecolocation cries of bats in the field using broadband microphones (Simmons. Fenton. FtrgtI\O!I et al. 1979). and in the lahoratorv we used Brikel and Kjaer f-in. (I in. = 2.54crn) microphones: in holh cltseq thc call were recorded using instrumentatinn ti~pt: recorders operated at Mcrnls. The clicks of arcti~d.; werc recorded wing the nrethodh ontlined in Fullard and Fenton ( 1977). Power spectra of moth clickr and hat calls were measurcd using rnst Fourier transform IFFTI analysi5. while time-frequency stmcrurcs were determined with a digital period meter {Simrnon~, Fenton, Fergu9oo et a!. 1979) and an analog filter to ivoiate individual harmonics.