This book is a collection of original research papers given at a symposium entitled "Sensory Systems and Behavior of Aquatic Mammals", hosted by the USSR Academy of Sciences. The meeting was held in Moscow from 16 to 25 October, 1991 and involved nearly 100 scientists from around the world. The major headings of the book correspond to the session topics at the symposium. This meeting was not the first dedicated to problems of sensory systems in aquatic mammals. Experts in this field met several times previously to discuss important problems of sensory functions in echolocating animals. symposia on biosonar systems were held in Frascati, Italy in 1966, then in Jersey, France in 1978, and in Helsingor, Denmark in 1986. Papers presented at these meetings were pUblished in books that advanced significantly the understanding of sensory systems (Busnel and Fish, 1980; Nachtigall and Moore, 1988). Initially, echolocating bats were the main subjects of consideration. However, studies on echolocating aquatic mammals, whales and dolphins, increased from one meeting to the next. Indeed, aquatic mammals are of exceptional interest for studying the adaptation of sensory functions for echolocation in specific aquatic environments. As a natural consequence of these developments, the 1989 symposium in Rome was devoted specifically to the sensory systems of cetaceans (Thomas and Kastelein, 1990). This symposium was held within the Fifth International Theriological Congress and was attended by many scientists.

This book is actually a product of efforts of many people, not only of the authors. W ide investigations of marine mammals began in Russia (that time, in the former Soviet Union) in the 1960s when a few teams of enthusiasts founded in captivity experimental stations intended for keeping dolphins and seals and for performing experimental studies of these fascinating animals. It was a time when attention of many people throughout the world was attracted to dolphins and other marine mammals due to appearance of oceanariums and dolphinariums, which demonstrated unique capabilities of these animals. So scientists in many countries concentrated on studies of them. There was much to learn about the morphology, physiology, and psychology of marine mammals, and investigators spending their time and efforts on studies in this field were rewarded by a number of surprising findings. The authors of this book represent one of such research teams focused on the neuro- and sensory physiology of marine mammals. A few decades of studies naturally resulted in the idea to summarize in a book both the results of these studies and a large body of data in adjacent fields. Our goal was to synthesize the many research findings and the present knowledge on sensory capabilities and mechanisms of sensory systems of aquatic mammals. We realize, however, that the appearance of this book was made possible due to the help and assistance of many colleagues.

This book is actually a product of efforts of many people, not only of the authors. W ide investigations of marine mammals began in Russia (that time, in the former Soviet Union) in the 1960s when a few teams of enthusiasts founded in captivity experimental stations intended for keeping dolphins and seals and for performing experimental studies of these fascinating animals. It was a time when attention of many people throughout the world was attracted to dolphins and other marine mammals due to appearance of oceanariums and dolphinariums, which demonstrated unique capabilities of these animals. So scientists in many countries concentrated on studies of them. There was much to learn about the morphology, physiology, and psychology of marine mammals, and investigators spending their time and efforts on studies in this field were rewarded by a number of surprising findings. The authors of this book represent one of such research teams focused on the neuro- and sensory physiology of marine mammals. A few decades of studies naturally resulted in the idea to summarize in a book both the results of these studies and a large body of data in adjacent fields. Our goal was to synthesize the many research findings and the present knowledge on sensory capabilities and mechanisms of sensory systems of aquatic mammals. We realize, however, that the appearance of this book was made possible due to the help and assistance of many colleagues.