Hot topics in animal bioacoustics

Abstract

Recent discoveries in the field of animal bioacoustics include everything from active auditory mechanics in insects to the behavior of large marine mammals in response to manmade sounds. Using laser Doppler vibrometry, Göpfert and Robert found that active auditory mechanics in male mosquitoes provides tuning that allows them to detect flying females. Their exciting discovery revealed new similarities between insect and vertebrate hearing. Many researchers have reported the behavior of fishes and marine mammals in response to underwater manmade sounds that is most likely controlled by other factors than the sound itself. Wardle and his colleagues found that repeated firing of seismic air guns had little effect on the day-to-day behavior of reef fishes off the coast of Scotland unless the explosions were visible. Madsen and Mo/hl also reported no change in behavior or click rate of sperm whales when detonators were discharged off the coast of Norway. Thus marine animals may not swim away from anthropogenic sounds even though they could be harmful. Gerstein determined masked thresholds and critical ratios for manatees that may prevent them from detecting boat noise in their natural habitat. His findings will lead to new solutions enabling manatees to detect boats and avoid collisions.