102 THE MIGRATION OF BIRDS. 



fact that most of the migration by this route has 

 ceased. 



We have only instanced the most important 

 coast routes of migration, but there are innumerable 

 others in all parts of the world, both of seas and 

 large lakes, which are followed by various species 

 during passage. Witness the vast number of 

 migrants that pass the coast-lines of the British 

 Islands, or follow the shores of the Bothnian Gulf, 

 the Baltic, the White, Mediterranean, Black, and 

 Caspian Seas in the western Palccarctic region ; the 

 shores of Lake Baikal, and the Great Lakes of North 

 America. It would require a chapter to particu- 

 larize them all. The coast routes are more especially 

 the migration highways of great numbers of 

 Waders (Charadriid-e) and Ducks (Axatid.e) ; 

 the abundance of food is probably the chief reason 

 for this choice. As soon as the breeding season 

 is over these birds begin to congregate on or off 

 the nearest coasts, and gradually move south along 

 them^ many species remaining on them all the 

 winter in the far south, and passing north again 

 by exactly the same route. That a vast number 

 of land birds, especially Passeres, follow coast-lines, 

 is also equally certain ; but these must take such 

 routes primarily for the sake of an unfailing guide 

 which trends in the precise direction they wish to 

 go, rather than from any partiality for littoral 

 haunts. Coast routes, then, are the recognized 

 Highways of Migration, followed by hosts of birds- 

 throughout the world. Great numbers of these 



