CONTENTS 



CHAPTER I 



Introduction 3 



Historical Account 4 



Theories of Migration 15 



Superstitious Beliefs 15 



Scientific Hypotheses of Migration 21 



CHAPTER II 



Nocturnal and Diurnal Migration 39 



Altitudes at which Migrating Birds Travel ... 46 



Weather and Migration 52 



Speed of Flight in Birds 58 



The Sense of Direction in Birds 62 



CHAPTER III 



Regularity of Migration 73 



Segregation during Migration 79 



Migration Among Supposedly Resident Birds . . 84 



Irregular or Vagrant Migration 89 



Casual Records 99 



CHAPTER IV 



Altitudinal or Vertical Migration 106 



Rapidity of Migration Movement no 



Distances Travelled by Migrants 115 



Mortality Among Migrant Birds 121 



9 Q o o Q 



