Bird Migration 6i 



The absorbingly interesting subject of bird migration 

 is one than cannot be dealt with in a few cursory notes, or 

 in any wise scantily treated, for whatever theory is 

 advanced the idea baffles the most devoted student of 

 natural history. 



An excellent authority very ably puts it thus — and this 

 view is the one now generallj 7 adopted on this question : — 

 1 ' Originally birds lived in latitudes which supplied 

 them throughout the whole year with everything neces- 

 sary to their existence ; that in process of time some 

 of them accidentally came to stray so far beyond the 

 northern limit of their home that on the approach of 

 winter they were compelled to retrace their path thither 

 in order not to succumb to cold and hunger : that a 

 habit of migration was developed from such accidental 

 erratic wanderings, and that this habit, together with 

 the experiences made on these journeys, had been passed 

 on by inheritance from the old birds to their young." 

 He further states that the flock of migrants generally 

 had for their leaders older and stronger individuals : that 

 the young were not possessed of an inborn consciousness 

 of the necessity of migration, but had to learn all this from 

 their parents. 



The roads frequently travelled over by these old birds 

 consisted of a succession of spots favourable for taking 

 rest ; or feeding grounds on which they were dependent, 

 and the so-called routes of migration were determined by 

 the geographical situation of such places. Such young 

 birds again, as travel alone, are further credited with the 

 possession of a so-called local sense or local memory. 

 This is acquired at first by their getting to know such 

 feeding grounds as are situated in the immediate vicinity 

 of their nests, impressing these upon their memory, then 

 discovering others further removed, and so on. Sup- 

 ported by this knowledge of stations where food may be 

 obtained, the young birds are now left to their own re- 

 sources to find the way to their winter quarters. 



It may not be out of place here to refer to the inexplic- 

 able manner in which dogs are able to find their way back 

 to their homes from very long distances. A friend of the 



