Bird Flight

Contents
Foreword v
Preface vii
Acknowledgements ix
Bird flight - S Dhawan xi
1 Introduction 1
1.1 Evolution 1
1.2 Species 2
1.3 Occurrence 2
1.4 Pioneers of flight 5
1.5 The scientists 6
2 What it takes to fly 7
2.1 The structure adapted for flight 7
2.2 Wings and feathers 7
2.3 The muscles 10
2.4 Flight control and navigation 11
3 Types of bird flight 13
3.1 Flapping flight – “power-on” 13
3.2 Detailed observations of wing motion 17
3.3 Take-off and landing 21
3.4 Propeller action 22
3.5 Illustrations of flapping kinematics 24
3.6 Hovering flight 24
3.7 Gliding and soaring 26
4 Production of aerodynamic forces by the wings 29
4.1 Flow patterns and forces on airfoils 29
4.2 Circulation and lift 31
4.3 The finite wing 32
4.4 Downwash and induced drag 32
4.5 Linearised theory 32
4.6 Flapping amplitudes and frequency 34
4.7 Summary of discussion 35
4.8 Velocity and forces 35
iii5 Flight mechanics of the bird 37
5.1 Estimates of lift 38
5.2 Estimates of drag 38
5.3 Power required for flight 41
5.4 Discussion 42
5.5 Power for hovering flight 44
5.6 Transition to and from hovering flight to forward flight 44
5.7 Gliding and soaring 45
5.8 Discussion 47
5.9 Effects of head and tail winds 49
5.10 Soaring flight 49
5.11 Turning flight 50
5.12 Dynamic soaring 51
6 Power available 53
6.1 Metabolic rate 53
6.2 Muscle power 54
6.3 Fuel and oxygen 55
6.4 Structure and action of muscles 56
6.5 Muscle action during flight 56
6.6 Wing frequency 58
6.7 Economy during gliding 58
6.8 Power output from muscles 58
7 Flight performance of birds 63
7.1 Flight characteristics 63
7.2 Performance estimates 64
7.3 Endurance and range 66
8 Effects of size and shape 71
8.1 Scaling laws 72
8.2 Discussion 73
8.3 Wing shape 75
9 Conclusion 77
Appendices 107