Mystery of migration 3
Historical accounts 3
Advantages of migration 4
Theories of causes of migration 5
When birds migrate 7
Movements of species and groups 8
Nocturnal and diurnal migration 11
How birds migrate 13
Speed of flight andspeed of migration 13
Altitudes at which birds travel 22
Orientation 23
Segregation during migration 25
Where birds migrate 27
Distances of migration vary 27
Short and undetermined migration 27
Variable migrations wi thin species 28
Fall flights not far south of breeding ranges 29
Long-distance migrations 30
Routes of migration 33
Wide and narrow migration lanes 34
Atlantic oceanic route 39
Atlantic coast route and tributaries 42
Mackenzie Valley-Great Lakes-Mississippi Valley
route and tributaries 45
Pacific coast route 47
Pacific oceanic route 49
Arctic routes 52