Comments on animal sonar symposium

The precision and refinement of echolocation as practiced by bats and cetaceans is proving to be more and more surprising and significant as successive improvements are achieved in the procedures and apparatus used to analyze these biological sonar systems. The multiple and overlapping specializations of animal echolocation are one of their most striking features. Different species of bats employ specialized types of orientation sounds to locate and discriminate among small targets obscured by noise and clutter. Furthermore each bat adapts its sonar technique continuously as it shifts rapidly from one form of echolocation behavior to another. Further discoveries of equal significance will result from improvements that can readily be anticipated in instrumentation for measuring ultrasonic sounds of low intensity in air. Critical observations of orientation behavior under natural conditions will continue to be especially important, because many species do not reveal their full capabilities for complex echolocation under laboratory conditions.