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Perceptual strategies in active and passive hearing of neotropical bats [Elektronische Ressource] / vorgelegt von Holger R. Goerlitz

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Perceptual strategies in active andpassive hearing of neotropical batsHolger R. GoerlitzMarch 2008MünchenPerceptual strategies in active andpassive hearing of neotropical batsHolger R. GoerlitzDissertationan der Fakultät für Biologieder Ludwig–Maximilians–UniversitätMünchenzur Erlangung des Grades eines Doktorsder Naturwissenschaftenvorgelegt vonHolger R. Goerlitzaus StuttgartMünchen, den 27.03.2008Erstgutachter: PD. Dr. Lutz WiegrebeZweitgutachter: Prof. Dr. Benedikt GrotheTag der mündlichen Prüfung: 22.10.2008ContentsList of figures and tables ixList of abbreviations xiZusammenfassung xiiiSummary xv1 General introduction 31.1 Bats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.2 Hearing and echolocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61.3 Perception and action in the context of sensory physiology and sensory ecology 132 Comparing Passive and Active Hearing: Spectral Analysis of Transient Sounds 192.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192.2 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212.2.1 Phyllostomus discolor . . . . . . . . . . . . . . . . . . . . . . . . . . 212.2.2 Animal housing and training procedure . . . . . . . . . . . . . . . . 222.2.3 Experiment 1: passive hearing . . . . . . . . . . . . . . . . . . . . . 222.2.4 Expt 2: echolocation . . . . . . . . . . . . . . . . . . . . .

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Perceptual strategies in active and
passive hearing of neotropical bats
Holger R. Goerlitz
March 2008
MünchenPerceptual strategies in active and
passive hearing of neotropical bats
Holger R. Goerlitz
Dissertation
an der Fakultät für Biologie
der Ludwig–Maximilians–Universität
München
zur Erlangung des Grades eines Doktors
der Naturwissenschaften
vorgelegt von
Holger R. Goerlitz
aus Stuttgart
München, den 27.03.2008Erstgutachter: PD. Dr. Lutz Wiegrebe
Zweitgutachter: Prof. Dr. Benedikt Grothe
Tag der mündlichen Prüfung: 22.10.2008Contents
List of figures and tables ix
List of abbreviations xi
Zusammenfassung xiii
Summary xv
1 General introduction 3
1.1 Bats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Hearing and echolocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.3 Perception and action in the context of sensory physiology and sensory ecology 13
2 Comparing Passive and Active Hearing: Spectral Analysis of Transient Sounds 19
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.2 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.2.1 Phyllostomus discolor . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.2.2 Animal housing and training procedure . . . . . . . . . . . . . . . . 22
2.2.3 Experiment 1: passive hearing . . . . . . . . . . . . . . . . . . . . . 22
2.2.4 Expt 2: echolocation . . . . . . . . . . . . . . . . . . . . . . . 25
2.2.5 Echolocation call recording and analysis . . . . . . . . . . . . . . . . 26
2.2.6 Analysis and statistics . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2.3.1 Training performance . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2.3.2 Experiment 1: perceptual compensation during passive hearing . . . 29
2.3.3 Expt 2: spectral processing during echolocation . . . . . . . . 30
2.3.4 Effect of the roving level . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.3.5 Echolocation calls . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
2.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
2.4.1 Experiment 1: perceptual compensation during passive hearing . . . 34
2.4.2 Expt 2: spectral processing during echolocation . . . . . . . . 34
2.4.3 Effect of the roving level . . . . . . . . . . . . . . . . . . . . . . . . . 35
2.4.4 Echolocation calls . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
2.4.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Appendix: Transponder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383 Detection of Jittering Real Targets by Passive Listening and Echolocation 41
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.1.1 Experiments on temporal accuracy . . . . . . . . . . . . . . . . . . . 42
3.1.2 Objections to the jitter experiments . . . . . . . . . . . . . . . . . . 44
3.1.3 Aim of this study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
3.2 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
3.2.1 Glossophaga soricina . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
3.2.2 Housing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
3.2.3 Experimental setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
3.2.4 Description of the stimuli . . . . . . . . . . . . . . . . . . . . . . . . 49
3.2.5 Experimental paradigm . . . . . . . . . . . . . . . . . . . . . . . . . 50
3.2.6 Call recordings and simulation of the perceived temporal jitter . . . 52
3.2.7 Statistical methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
3.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
3.3.1 Echo-acoustic detection of temporal jitter in Glosso2 and Glosso3 . . 55
3.3.2 Detection of jitter in Glosso1 . . . . . . . . . . . . . . . . . . . . . . 55
3.3.3 The use of passive acoustic cues . . . . . . . . . . . . . . . . . . . . 57
3.3.4 Simulation of the perceived temporal jitter . . . . . . . . . . . . . . 60
3.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
3.4.1 Potential cues in the current jitter detection experiment . . . . . . . 63
3.4.2 Discussion of the measured thresholds . . . . . . . . . . . . . . . . . 66
3.4.3 The use of echolocation versus passive listening . . . . . . . . . . . . 68
3.4.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
4 Orientation Response of Wild Free-Flying Bats to Real and Virtual Objects 73
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
4.2 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
4.2.1 Study site and animals . . . . . . . . . . . . . . . . . . . . . . . . . . 77
4.2.2 Playback and video-recording setup . . . . . . . . . . . . . . . . . . 77
4.2.3 Test and control stimuli . . . . . . . . . . . . . . . . . . . . . . . . . 80
4.2.4 Experimental procedure and stimulus presentation . . . . . . . . . . 81
4.2.5 Video analysis and flight path extraction . . . . . . . . . . . . . . . 82
4.2.6 Evaluation of flyways and statistics . . . . . . . . . . . . . . . . . . . 83
4.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
4.3.1 Behavioural observations . . . . . . . . . . . . . . . . . . . . . . . . 84
4.3.2 Control recordings of undisturbed flight paths . . . . . . . . . . . . . 85
4.3.3 Orientation response to real objects . . . . . . . . . . . . . . . . . . 88
4.3.4 Orien response to virtual objects . . . . . . . . . . . . . . . . . 92
4.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
4.4.1 Real objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
4.4.2 Virtual objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
4.4.3 Methodological discussion . . . . . . . . . . . . . . . . . . . . . . . . 101
4.4.4 Conclusion and outlook . . . . . . . . . . . . . . . . . . . . . . . . . 102
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103Contents
5 General discussion 105
5.1 Comparison of methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
5.2 Sensory physiology: Spectral and temporal processing . . . . . . . . . . . . 107
5.2.1 Auditory receiver models in echolocation . . . . . . . . . . . . . . . . 108
5.3 The context of sensory ecology . . . . . . . . . . . . . . . . . . . . . . . . . 110
5.4 The end... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
References 111
Acknowledgments 133
Curriculum vitae 135
List of publications 137
Ehrenwörtliche Erklärung 139
viiList of figures and tables
List of figures
1.1 The impulse response and the generation of echoes . . . . . . . . . . . . . . 14
1.2 Perception-action-loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.1 Echolocation call of Phyllostomus discolor . . . . . . . . . . . . . . . . . . . 21
2.2 Y-shaped training platform . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2.3 Amplitude spectra of the filters and of example stimuli . . . . . . . . . . . . 24
2.4 Block diagram of Experiment 1 (passive hearing) . . . . . . . . . . . . . . . 25
2.5 Block diagram of Expt 1 (echolocation) . . . . . . . . . . . . . . . . . 26
2.6 Learning curves of Bats 4 and 5 . . . . . . . . . . . . . . . . . . . . . . . . . 28
2.7 Experiment 1 (passive hearing): Classification of filtered impulses . . . . . . 29
2.8 Expt 2 (echolocation): of filtered calls . . . . . . . . . . 30
2.9 Experiment 2 (echolo Influence of the roving level . . . . . . . . . . 31
2.10 Call parameters of Phyllostomus discolor in Experiment 2 (echolocation) . . 33
2.11 Calculated influences on the frequency centroid . . . . . . . . . . . . . . . . 36
3.1 Echolocation calls of Glossophaga soricina . . . . . . . . . . . . . . . . . . . 46
3.2 Experimental chamber of the jitter experiment . . . . . . . . . . . . . . . . 47
3.3 Sketch of the setup and the feeders . . . . . . . . . . . . . . . . . . . . . . . 48
3.4 Impulse response of the vibrating speaker membrane . . . . . . . . . . . . . 50
3.5 Sketch of the control-setup . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
3.6 Perceived jitter depending on vibration frequency and pulse interval . . . . 53
3.7 Temporal jitter detection functions . . . . . . . . . . . . . . . . . . . . . . . 55
3.8 Jitter detection function for Glosso1 . . . . . . . . . . . . . . . . . . . . . . 56
3.9 Initial test, control and retraining performance of Glosso2 . . . . . . . . . . 58
3.10 Sound recordings of the vibrating membranes . . . . . . . . . . . . . . . . . 59
3.11 Training and control performance of Glosso3 . . . . . . . . . . . . . . . . . 60
3.12 Call sequences of Glossophaga soricina . . . . . . . . . . . . . . . . . . . . . 61
3.13 Simulated perceived jitter at threshold . . . . . . . . . . . . . . . . . . . . . 63
3.14 Bat-pollinated flowers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
4.1 Hypothetical flight paths around the virtual object . . . . . . . . . . . . . . 76
4.2 Tamana Cave, Trinidad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
4.3 Block diagram of the experimental setup . . . . . . . . . . . . . . . . . . . . 79
4.4 Camera-only control: Example flight paths without any object . . . . . . . 86List of tables
4.5 Camera-only control: Flight paths and flyways without any object . . . . . 87
4.6 Real object: Example flight paths . . . . . . . . . . . . . . . . . . . . . . . . 89
4.7 Real object: Flight paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
4.8 Real object: Flyways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
4.9 Real object: Reaction distances . . . . . . . . . . . . . . . . . . . . . . . . . 92
th4.10 Virtual objects: Interpolated flight paths, overview of December 09 . . . . 93
th4.11 objects: Interp flight overview ofber 10 . . . . 94
th4.12 Virtual objects: Interpolated flight paths, overview December of 15 . . . . 95
th4.13 objects: Flyways of December 09 . . . . . . . . . . . . . . . . . . . 96
th4.14 Virtual objects: Flyways ofber 10 . . . . . . . . . . . . . . . . . . . 97
th4.15 objects: Flyways of December 15 . . . . . . . . . . . . . . . . . . . 98
List of tables
1.1 Systematics of the studied species . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1 Published distance discrimination thresholds . . . . . . . . . . . . . . . . . 42
3.2 jitter detection thresholds . . . . . . . . . . . . . . . . . . . . . . 43
3.3 Pulse intervals of call sequences . . . . . . . . . . . . . . . . . . . . . . . . . 62
4.1 Impulse response parameters . . . . . . . . . . . . . . . . . . . . . . . . . . 81
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