SOME MODERN VIEWS 17 



In this respect their patriotism, if we may so term it, is 

 pronouncedly parochial, for the returning migrants seek 

 the very neighbourhood (even the very field, wood, etc.) 

 in which the old home is situated, and return to it 

 regularly, year after year. There are many instances 

 on record of this remarkable constancy on the part of 

 migratory birds. 



The periodic physiological changes in progress at the 

 approach of spring in the shape of the development of the 

 reproductive organs, with their corollary, the reviving 

 instinct of procreation, must prove an overpowering 

 incentive to seek the accustomed breeding haunts. 

 These physiological developments, too, no doubt regu- 

 late the date at which the departure to the breeding 

 grounds should take place for particular races, and will 

 account for the late emigration from the winter home of 

 those species which breed in the far north, where the 

 land does not assume its summer aspect until com- 

 paratively late in the season.^ Another important factor 

 is that the southern and tropical regions (the main 

 winter resorts) are not suited for a nursery for the young 

 of the hardy northern species, and if they attempted to 

 nest there the result would be disastrous — their race 

 would become extinct. On the approach of the southern 

 winter — our spring — the question of food might become 

 an important incentive to emigration, though, personally, 

 I do not attach much importance to it. 



Thus the necessity for different summer and winter 

 quarters, through breeding and feeding requirements, has 

 resulted in the migratory habit becoming an integral 

 part of the lives of a vast number of birds inhabiting the 

 arctic and north temperate regions : while, on the other 



1 See Plate III. 

 I. B 



