1 64 THE MIGRATION OF BIRDS. 



suitable places throughout the extreme North 

 Atlantic), where it is a partial resident, but numbers 

 wander about a good deal in winter ; and at that 

 season it occasionally appears off the British coasts 

 as a nomadic migrant. 



The phenomenon of Nomadic Migration has 

 been little studied in the Antarctic region ; but 

 there can be little doubt that it exists among the 

 few peculiar species of birds that dwell on the 

 borders of the glaciated South Polar lands. We 

 cannot expect to find it so frequent or so marked 

 a movement as in the Arctic regions, for obvious 

 reasons, still the movement would well repay careful 

 study, for I am of opinion that it throws much 

 light on the origin of the more regular and ex- 

 tended migrations of birds. 



The facts to be derived from a study of Nomadic 

 Migration are of great value in assisting us to 

 understand the origin of regular migration. Many 

 of these nomadic migrants are probably descend- 

 ants of those species that dwelt on the fringe of the 

 glacial ice during the Post-Pliocene Glacial Epoch, 

 the birds that wandered least from their devastated 

 Polar haunts. There is not a single trace of their 

 migrations ever having been Inter-Polar. In their 

 wandering movements during present time they 

 are profoundly interesting examples of migration in 

 its incipient stage ; they illustrate very vividly the 

 rudimentary portion of that grand migration flight 

 which now takes place almost from Pole to Pole. 

 That some few birds remained in as high latitudes 



