150 BRITISH BIRDS. 



light to a bird overhead over a very small area, while 

 the ordinary navigation lights that ninety per cent, of 

 ships carry must be to all intents and purposes invisible. 

 The same, most likely, applies to foggy weather, but we 

 only twice experienced fog in the Mediterranean during 

 the migration seasons. When burning searchlights at 

 night, birds are frequently attracted to the beam, which 

 resembles that from a lighthouse or lightship. If the 

 birds made their passage at night at low altitudes, it 

 would seem probable that the rows of lights from the 

 ports of a man-of-war should attract a small percentage 

 of birds; the fact that it is not so must have a bearing on 

 the mode of passage at night across the Mediterranean. 



In the day time, where rushes such as that described 

 off the Grecian coast are concerned, the time presumably 

 has a relation to the hours of normal passage of the various 

 species across the Mediterranean, but times of strayed 

 birds, as birds which come singly on board ship seem 

 undoubtedly to be, can have no significance except to 

 show by their very nature that they are the outcome of 

 abnormal conditions. 



