CONTENTS xi 



PAGES 



Pelicans, Darters, and Frigate Birds The 

 Screamers, Flamingoes, Swans, Geese, Ducks, 

 and Mergansers The Finfoots and Rails The 

 Cranes, Trumpeters, Screamers, and Sun Bitterns 

 The Game Birds The Sand-Grouse The Pigeons 

 The Plovers and Snipes, &c. The Gulls, Terns, 

 Skuas The Auks The Birds of Prey The 

 Coraciiformes The Parrots The Cuckoos and 

 Plan tain- Eaters The Passeriformes or Perching 

 Birds 103-142 



CHAPTER IV 



THEIR MEANS OF DISPERSAL AND MIGRATIONS 



The dispersal of birds Fortuitous dispersal Ancient 

 land-surfaces Polar dispersal Equatorial disper- 

 sal The law of dispersal Obstacles to dispersal 

 Discontinuous areas of dispersal Influence 

 of climate upon species Species increasing 

 their range during present time The migration 

 of birds Misconceptions concerning migration 

 Transmutation and Hibernation Migration and 

 Instinct Migration not universal in certain species 

 The Cause of Migration Migration due to range 

 expansion or colonisation Cause of migration in 

 autumn Length of journey variable The Philo- 

 sophy of Migration The wings of migrants 

 Moulting of migrants Course of autumn migra- 

 tion How birds find their way on migration 

 Migration across seas General aspects of migra- 

 tion Duration of migration The speed of migra- 

 tion flight The height at which migrating birds 

 fly The perils of migration Lost birds at 

 lighthouses Various kinds of migration Vertical 

 migration Local movements of birds Nomadic 

 migration Irruptic movements . . . 143-177 



