SOME MODERN MEWS 23 



could be obtained. Few birds, I think, could accomplish 

 the journey under such conditions. By crossing at 

 night, all these difficulties are obviated. That the birds 

 have evidently fasted for some time ere they reach our 

 shores is manifest from an examination of their stomachs. 

 I have examined the stomachs of many birds captured 

 at the lantern of the Fair Isle lighthouse, and in not one 

 of them have I found even a trace of food. 



It has been suggested that birds migrate by night to 

 escape the attacks of gulls, which often pounce down upon 

 and destroy migrants, especially solitary ones, when they 

 come across them at sea during the daytime. This theory 

 is scarcely worthy of serious consideration, because 

 such powerful birds as Cranes and Storks, among 

 others, migrate during the hours of darkness, though 

 surely not to escape the attention of Gulls. Then great 

 overland passages also take place at night, in regions 

 where there are certainly no Gulls awaiting the voyagers. 



We see comparatively little of night - migration, 

 because during clear weather it passes entirely unnoticed, 

 even at the most favourably situated stations. Now 

 and then the weather comes to our aid during a great 

 migration, and we get a glimpse of how vast these move- 

 ments are, and we learn something about the weather 

 conditions which make their observation possible, some 

 of which are noticed in the chapter on the author's 

 experiences at the Eddystone. 



Dangers encountered en Route. — It must not be 

 supposed that these journeys are free from dangers. Far 

 from it ; the perils are many and varied. The following 

 are a few of them. To begin with, many migrants perish 

 at sea. Favourable weather may prevail at the point of 

 embarkation, say in southern Norway, and induce the 



