Animal Sonar : Processes and Performance

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.

Memories and Reflections on Biosonars.- Section 1: Echolocation Signals and Their Production.- Echolocation Signal Types of Odontocetes.- The Production of Echolocation Signals by Bats and Birds.- Propagation of Beluga Echolocation Signals.- Nasal Pressure and Sound Production in an Echolocating White Whale, Delphinapterus leucas.- The Study of the Sound Production Apparatus in the Harbour Porpoise, Phocoena phocoena, and the Jacobita, Cephalorhynchus commersoni by Means of Serial Cryo-Microtome Sectioning and 3-D Computer Graphics.- The Anatomy of Acoustic Structures in the Spinner Dolphin Forehead as Shown by X-Ray Computed Tomography and Computer Graphics.- Whale Heads, Magnetic Resonance Images, Ray Diagrams and Tiny Bubbles.- Individual Variation in Vocal Tract Resonance May Assist Oilbirds in Recognizing Echoes of Their Own Sonar Clicks.- Midbrain Areas as Candidates for Audio-Vocal Interface in Echolocating Bats.- The Sounds of Sperm Whale Calves.- Apparent Sonar Clicks from a Captive Bottlenosed Dolphin, Tursiops truncatus, When 2, 7 and 38 Weeks Old.- Ontogeny of Vocal Signals in the Big Brown Bat, Eptesicus fuscus.- Observations on the Development of Echolocation in Young Bottlenose Dolphins.- The Short-Time-Duration Narrow-Bandwidth Character of Odontocete Echolocation Signals.- Section 2: Auditory Systems of Echolocating Animais.- Parallel-Hierarchical Processing of Biosonar Information in the Mustached Bat.- Dolphin Echolocation and Audition.- Parallel Auditory Pathways I: Structure and Connections.- Parallel Auditory Pathways II: Functional Properties.- Cochlear Physiology and Anatomy in Bats.- Ascending Pathways to the Inferior Colliculus via the Superior Olivary Complex in the Rufous Horseshoe Bat, Rhinolophus rouxii.- Pattern of Projections to the 60 KHz Isofrequency Region of the Mustache Bat’s Inferior Colliculus.- Target Range Processing Pathways in the Auditory System of the Mustached Bat.- Processing of Paired Biosonar Signals in the Cortices of Rhinolophus rouxi and Pteronotus P. parnellii: A Comparative Neurophysiological and Neuroanatomical Study.- Central Control of Frequency in Biosonar Emissions of the Mustached Bat.- Frontal Auditory Space Representation in the Cerebellar Vermis of Echolocating Bats.- Directional Emission and Time Precision as a Function of Target Angle in the Echolocating Bat Carollia perspicillata.- The Jaw-Hearing Dolphin: Preliminary Behavioral and Acoustical Evidence.- Acoustical Aspects of Hearing and Echolocation in Bats.- The Perception of Complex Echoes by an Echolocating Dolphin.- Morphometric Analysis of Cochlear Structures in the Mustached Bat, Pteronotus p. parnellii.- The Efferent Auditory System in Doppler-Shift Compensating Bats.- Some Comparative Aspects of Auditory Brainstem Cytoarchitecture in Echolocating Mammals: Speculations on the Morphological Basis of Time-Domain Signal Processing.- Temporal Order Discrimination within the Dolphin Critical Interval.- Detection Abilities and Signal Characteristics of Echolocating False Killer Whales (Pseudorca crassidens).- Binaural Neurons in the Mustache Bat’s Inferior Colliculus: Physiology, Functional Organization, and Behavioral Implications.- Ontogeny of the Echolocation System in Rhinolophoid CF-FM Bats: Audition and Vocalization in Early Postnatal Development.- Lightmicroscopic Observation of Cochlear Development in Horseshoe Bats (Rhinolophus rouxi).- Only One Nucleus in the Brainstem Projects to the Cochlea in Horseshoe Bats: The Nucleus Olivo-Cochlearis.- Section 3: Performance of Animal Sonar Systems.- The Performance of Echolocation: Acoustic Images Perceived by Echolocating Bats.- Designing Critical Experiments on Detection and Estimation in Echolocating Bats.- Target Discrimination and Target Classification in Echolocating Bats.- Target Detection by Echolocating Bats.- Sonar Target Detection and Recoginition by Odontocetes.- Prey Interception: Predictive and Nonpredictive Strategies.- A Mechanism for Horizontal and Vertical Target Localization in the Mustache Bat (Pteronotus p. parnellii).- Echoes of Fluttering Insects.- Encoding of Natural Insect Echoes and Sinusoidally Modulated Stimuli by Neurons in the Auditory Cortex of the Greater Horseshoe Bat, Rhinolophus ferrumeauinum.- Do Signal Characteristics Determine a Bat’s Ability to Avoid Obstacles?.- Greater Horseshoe Bats Learn to Discrimate Simulated Echoes of Insects Fluttering with Different Wingbeat Rates.- Predictive Tracking of Horizontally Moving Targets by the Fishing Bat, Noctilio leporinus.- Discrimination of Target Surface Structure in the Echolocating Bat, Megaderma lyra.- A Time Window for Distance Information Processing in the Bats, Noctilio albiventris and Rhinolophus rouxi.- Section 4: Natural History of Echolocation.- Natural History Aspects of Marine Mammal Echolocation: Feeding Strategies and Habitat.- Behaviour and Foraging Ecology of Echolocating Bats.- Interaction between Echolocating Bats and Their Prey.- Loud Impulse Sounds in Odontocete Predation and Social Behavior.- Harmonic Structure of Bat Echolocation Signals.- Acoustical VS. Visual Orientation in Neotropical Bats.- Echolocation Strategies of Aerial Insectivorous Bats and Their Influence on Prey Selection.- Foraging Behavior, Prey Selection and Echolocation in Phyllostomine Bats (Phyllostomidae).- Variation in Foraging Strategies in Five Species of Insectivorous Bats — Implications for Echolocation Call Design.- Detection of Prey in Echocluttering Environments.- How the Bat, Pipistrellus kuhli Hunts for Insects.- The Communication Role of Echolocation Calls in Vespertilionid Bats.- Auditory Input to the Dorsal Longitudinal Flight Motor Neurons of a Noctuid Moth.- Disrupting Foraging Bats: The Clicks of Arctiid Moths.- The Echolocation Assemblage: Acoustic Ensembles in a Neotropical Habitat.- Microbat Vision and Echolocation in an Evolutionary Context.- Future Directions.- Section 5: Echolocation and Cognition.- On the Evolution of Acoustic Communication Systems in Vertebrates Part I: Historical Aspects.- On the Evolution of Acoustic Communication Systems in Vertebrates Part II: Cognitive Aspects.- Cognitive Aspects of Echolocation.- Cognition and Echolocation of Dolphins.- Loud Sounds during Feeding in Indian Ocean Bottlenose Dolphins.- Attention and Detection in Dolphin Echolocation.- Odontocete Sonar Systems Research — Future Directions from a Ethologist’s Personal Point of View.- Section 6: Echolocation Theory and Applications.- Some Theoretical Concepts for Echolocation.- Detection and Recognition Models of Dolphin Sonar Systems.- A Brief History of Bionic Sonars.- Biosonar Signal Processing Applications.- Take off Signals Emitted by Myotis mystacinus: Theory of Receivers and Modelling.- Noseleaves and Bat Pulses.- Time-Frequency Processing of Bat Sonar Signals.- Echoes from Insects Processed Using Time Delayed Spectrometry (TDS).- Sonar Discrimination of Metallic Plates by Dolphins and Humans.- Echoes from Solid and Hollow Metallic Spheres.- Target Identification in a Natural Environment: A Statistical View of the Inverse Problem.- An Automatic Target Recognition Algorithm Using Time-Domain Features.- A Matched Filter Bank for Time Delay Estimation in Bats.- Participants.