The first meeting on biosonar that I had the opportunity to attend was held in 1978 on the Island of Jersey in the English Channel. That meeting, organized by Professor R.G. Busne1 and Dr. Jim Fish, was my introduction to an exciting and varied group of hard-working and dedicated scientists studying animal echolocation. They are, by nature, a very diverse group. They tend to publish in different journals and rarely interact despite the fact that they all work on echolocation. When they do interact as a group, as they did in Frascati Italy in 1966, in Jersey i~ 1978, and during the meeting reported in this volume, the meetings are intense, interesting, and exciting. This volume is a composition of a series of contributed papers written to foster an interdisciplinary understanding of the echolocation systems of animals. The echolocation pulse production studies in bats and dolphins have recently been concentrated on the ontogeny of infant pulses, other studies, with three-dimensional computer graphics and x-ray computed tomography, have concentrated on finally resolving the old controversy concerning the site of dolphin echolocation click production. Much has been accomplished on the analysis of bat neural structure and function. The intense effort directed toward understanding the structure, connections, and functional properties of parallel auditory pathways and the parallel and hierarchical processing of information by the mustached bat, has lead to dramatic breakthroughs in understanding brain function.

Thirteen years have gone by since the first international meet ing on Animal Sonar Systems was held in Frascati, Italy, in 1966. Since that time, almost 900 papers have been published on its theme. The first symposium was vital as it was the starting point for new research lines whose goal was to design and develop technological systems with properties approaching optimal biological systems. There have been highly significant developments since then in all domains related to biological sonar systems and in their appli cations to the engineering field. The time had therefore come for a multidisciplinary integration of the information gathered, not only on the evolution of systems used in animal echolocation, but on systems theory, behavior and neurobiology, signal-to-noise ratio, masking, signal processing, and measures observed in certain species against animal sonar systems. Modern electronics technology and systems theory which have been developed only since 1974 now allow designing sophisticated sonar and radar systems applying principles derived from biological systems. At the time of the Frascati meeting, integrated circuits and technol ogies exploiting computer science were not well enough developed to yield advantages now possible through use of real-time analysis, leading to, among other things, a definition of target temporal char acteristics, as biological sonar systems are able to do. All of these new technical developments necessitate close co operation between engineers and biologists within the framework of new experiments which have been designed, particularly in the past five years.

In recent years there has been a rapid increase in the understanding of communication between animals and this is perhaps especially true of bio-acoustics. In the last 35 years a completely new branch of bio acoustics, involving ultrasounds, has been made possible by technical developments that now allow these inaudible sounds to be detected and studied. This subject has a personal fascination for the authors, perhaps because of the novelty of 'listening in' to these previously unknown sig nals, perhaps because of the wide variety of ways in which different animals use them. Many studies of different aspects of animal ultrasound have now been published and a review of them all seems to be timely. Ultrasound is is biologically arbitrary; other animals defined in human terms and may produce similar signals at lower frequencies for similar purposes. This book attempts to be comprehensive but the limits of the subject are rather difficult to define. It should be read in conjunction with other books on audible bio-acoustics. Each chapter has been written and may be read as a separate entity, although there is considerable cross-referencing. Chapters 1 and 2 form a common introduction and may help in understanding the later sections. The Appendix is not essential but is included for those who may be interested in the quanti tative aspects of the echo-location phenomena described in Chapters 3 and 8.

Sonar isn’t just used by submarines—many animals use it, too. Biosonar is a kind of sonar produced and used by animals such as dolphins. Readers discover the biology behind biosonar and are introduced to other animals that also have this amazing adaptation, including bats and shrews. Bright photographs of these animals are presented alongside a variety of fun facts and a helpful graphic organizer. Informative, engaging text touches on essential science curriculum topics, such as animal adaptations, predator-prey relationships, and the science of sound.

The extraordinary ability of dolphins to echolocate has fascinated scientists and the public since its discovery in the late 1950's. This is the first book to summarize modern research in this area, and presents a broad synthesis of this very interdisciplinary subject. The author is an internationally-recognized expert on dolphin sonar and is thus in a unique position to bring together research on the physiological, mathematical and engineering aspects of the subject. Of interest to auditory researchers, electrical engineers, acoustical physicists, and mammalian physiologists.

Two groups of animals, bats and odontocetes (toothed whales), have independently developed the ability to orient and detect prey by biosonar (echolocation). This active mechanism of orientation allows these animals to operate under low light conditions. Biosonar is a conceptual overview of what is known about biosonar in bats and odontocetes. Chapters are written by bat and odontocetes experts, resulting in collaborations that not only examine data on both animals, but also compare and contrast mechanisms. This book provides a unique insight that will help improve our understanding of biosonar in both animal groups.