CHAPTER X. 



THE SPRING MIGRATION OF BIRDS. 



The Dominating Impulse of Spring Migration — General 

 Aspects of Spring jNIigration — The Greatest Travellers 

 generally the Latest Starters — Avian Waves of Spring 

 Migrants — Spring Routes sometimes different from Autumn 

 Routes — Intensity of Migration — Spring Migration of 

 Turtle Dove and Common Sandpiper — Day and Night 

 INIigration reversed according to Season — Minor Streams 

 of Spring Migrants — Abnormal Direction of Fly-lines — ■ 

 Migration of Rose-coloured Pastor, Scarlet Rose Finch, 

 and Black-headed Bunting — Spring Migration gradual in 

 Southern Zones — Sudden Spring Migration in Arctic 

 Regions — Arrival of Birds in Northern Europe — Arrival 

 of Birds in Siberia — Rush of Birds across the Arctic 

 Circle — Migration of Geese — Arrival of Waders — Various 

 Routes to the Tundra from the South — Spring Migration 

 in High Arctic Latitudes — In Grinnell Land — In Arctic 

 America — Table of Spring Migrants — Return of Birds to 

 Old Haunts — Migration and Reproduction. 



The Great Spring Migration of Birds may be said 

 to commence when the sun has performed about 

 a third of his journey towards the Tropic of Cancer, 

 or, in other words, about the middle of February. 

 Migration flows and ebbs with the sun. The 

 spring migration advances in the w^ake of the sun, 

 on his apparent northward course, and in the same 

 way retreats to follow that great central luminary to 



