Migration 



what these figures mean, but on this occasion when I 

 say thousands were killed I do not exaggerate in the 

 slightest." 



Some of the early theories concerning bird migration are 

 vastly humorous, in the light of our present-day know- 

 ledge, scanty though it be. That birds did migrate was 

 known in Biblical times ; that they migrated to the moon 

 was a surmise of a later date. A theory that was widespread, 

 still later, assumed that birds must be classed among the 

 hibernating animals. Swallows had been seen in reed-beds, 

 preparatory to their autumn flight ; the day arrived when 

 the swallows had disappeared they must have hiberr.ated 

 in the water ! Often a sudden fall of temperature at this 

 season would result in the death or stupor of a number of 

 birds and their discovery in this state was looked upon as 

 confirmation of the hibernation theory. That the stronger 

 birds carried the weaker on their backs during migration 

 was another common fallacy. 



Migration is merely a habit and one that has been 

 slowly acquired with the expenditure of much labour and 

 many failures. For thousands of years these journeys 

 have been undertaken, till now, as we have said, it is a 

 deeply rooted habit. This habit probably originated 

 owing to changes on the face of the earth. Once the 

 polar regions were fertile lands with a large resident bird 

 population. Then when the earth changed her position 

 and an ice-cap was formed, lack of food drove the birds 

 southward. This all occurred during a very long period, 

 sufficiently long to implant the migratory habit in birds. 

 When the glacial epoch passed and the snows began to melt 

 and the ice to drift back, the birds returned farther and 

 farther north. Age after age the journey became longer, 

 till it attained the dimensions of the present day. Water 

 birds travel farther than land birds, for the latter are 

 practically confined to the limits of forest growth. It 

 is of interest to note that many migrants follow the 

 direction of ancient coast-lines, which are now buried 



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