A History of the Study of Echolocation

Abstract

The discovery of echolocation by Griffin and Galambos in 1938 was the first step in what has become arguably the greatest triumph of neuroethology. This chapter reviews early developments in the field through about 1980: Griffin’s discovery that bats not only use echoes to detect obstacles but also to track flying insects on the wing; research proving that bats use pulse-echo delay to determine target distance; a variety of ingenious early experiments used to measure the accuracy of bats’ echolocation skills; and the first electrophysiological forays into elucidating key neural adaptations that helped to account for these abilities. Furthermore, early observations showed that bats of different species use different types of signals and different principles of echo analysis to operate in different ecological niches. The field has grown exponentially since the 1980s, with bursts of productivity tied to technological advances and to new young investigators and new labs joining the search for answers to how bats (and now toothed whales) echolocate. The ensuing chapters in this volume bring the field up to date, but we realize that this is still only a middle stage in what seems to be an endlessly fascinating subject.