Inhalt: | 1. What is ultrasound? -- The discovery of animal ultrasound -- The properties of ultrasound -- 2. Methods of detection and analysis -- Ultrasonic microphones -- Cathode-ray oscilloscopes -- Tape-recording and analysis -- Bat detectors -- 3. Bats -- The biology of bats -- The echo-location signals of bats -- Short-pulse echo-location in Megachiroptera -- Frequency sweep pulses in Microchiroptera -- Constant frequencies in Microchiroptera -- Mixed signals in Microchiroptera -- Sound production and emission in Microchiroptera -- Frequency-sweep bats -- Constant frequency bats -- Nose-leaves -- Hearing in the Microchiroptera -- Other senses and social use of ultrasound in Microchiroptera -- 4. Countermeasures by insects -- Noctuidae -- The evasive behaviour of noctuid moths -- Acoustic sensitivity of the tympanic organ -- Directionality -- Central co-ordination -- Arctiidae, Notodontidae and Ctenuchidae -- Pyralididae -- Sphingidae -- Geometridae -- Neuroptera -- Evolution -- 5. The songs of bush crickets (Tettigoniidae) -- The physics of strigilation in general -- The mechanism of sound production in tettigoniids -- The ultrasonic songs of tettigoniids -- The acoustic behaviour of tettigoniids -- The ability of tettigoniids to hear ultrasonic sounds -- Some further considerations -- 6. Other insects -- Gryllidae, crickets -- Gryllotalpidae, mole crickets -- Acrididae, grasshoppers and locusts -- Insects of other groups -- 7. Ultrasound in rodents -- The ultrasonic calls of infant rodents -- The physical characteristics of the calls -- The motivation for the emission of ultrasonic calls by infant rodents -- The role of infant distress calls in adult-young relationships -- Ultrasound and aggressive behaviour -- Rats -- Other myomorph rodents -- Social significance -- Ultrasound and mating behaviour -- Mice -- Rats -- Other myomorph rodents -- Social significance -- Other situations involving ultrasound emission in rodents -- The mechanism of ultrasound production in rodents -- The ability of rodents to hear high frequency sounds -- 8. Other vertebrate groups -- Birds -- Cetacea -- The sounds of odontocetes -- The site of sound production -- The ear of odontocetes -- Hearing in odontocetes -- Evidence for echo-location in odontocetes -- Other marine mammals -- Insectivora -- 9. Review and speculations -- Appendix Some formulae summarizing the rules of echo-location -- References -- Indexes. 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. |
