2004/11/19 by Richard A. Holland, Dean A. Waters, Jeremy M. V. Rayner · 2 citations
Agricultural and Biological Sciences · Environmental Science · Biochemistry, Genetics and Molecular Biology · Neuroscience · #Bat Biology and Ecology Studies #Marine animal studies overview #Animal Vocal Communication and Behavior #Human echolocation #Biology #SIGNAL (programming language) #Acoustics #Impulse (physics) #Duration (music) #Sonar #Computer science #Physics #Neuroscience
paper · doi:10.1242/jeb.01288
openalex publication_date 2004/11/19 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
Rousettus aegyptiacus Geoffroy 1810 is a member of the only genus of Megachiropteran bats to use vocal echolocation, but the structure of its brief, click-like signal is poorly described. Although thought to have a simple echolocation system compared to that of Microchiroptera, R. aegyptiacus is capable of good obstacle avoidance using its impulse sonar. The energy content of the signal was at least an order of magnitude smaller than in Microchiropteran bats and dolphins (approximately 4 x 10(-8) J m(-2)). Measurement of the duration, amplitude and peak frequency demonstrate that the signals of this animal are broadly similar in structure and duration to those of dolphins. Gabor functions were used to model signals and to estimate signal parameters, and the quality of the Gabor function fit to the early part of the signal demonstrates that the echolocation signals of R. aegyptiacus match the minimum spectral spread for their duration and amplitude and are thus well matched to its best hearing sensitivity. However, the low energy content of the signals and short duration should make returning echoes difficult to detect. The performance of R. aegyptiacus in obstacle avoidance experiments using echolocation therefore remains something of a conundrum.