16 STUDIES IN BIRD-MIGRATION 



remarkable to relate, were proceeding from south-east 

 to north-west : proceeding north ere they sought the 

 south ! but this was exceptional, and the movements 

 were never important. 



It will have been noticed that the species recorded 

 as participating in these great east-to-west movements 

 are comparatively few in number — at any rate, those 

 observed during the daytime. At the Eddystone, like- 

 wise, a few species only cross the Channel by day, but 

 a great variety at night. May not the same be the 

 case at the Kentish Knock ? I am decidedly of opinion 

 that this is so. I am inclined to think that we have 

 here the true explanation of what takes place. The phe- 

 nomena of migration as witnessed at this station are, 

 however, exceedingly complicated, as has already been 

 stated, and it was found impossible to determine from 

 actual observation whence came the birds that were so 

 abundantly noticed during the hours of darkness. The 

 occurrence of such characteristic east-to-west migrants 

 as Rooks and Jackdaws at night, also favours this 

 opinion. I shall return to this subject anon when 

 discussing the night movements. 



The reason why the movements of these species 

 are performed so largely during the daytime, instead of 

 entirely at night, as is the case of most over-sea 

 migrations, may be the comparative shortness of the 

 passage (about i8o miles at most), if direct east to west 

 in the latitude of this lightship. The few hours 

 necessary for its accomplishment would not interfere 

 unduly with the time that must be devoted to the daily 

 search for food- — a most important consideration for all 

 migrating birds. 



It is a fact worthy of mention that each of the flocks, 



