174 THE MIGRATION OF BIRDS. 



through which their fiy-hnes extend has its own 

 Raptorial birds waiting to levy tribute as the 

 migrants hurry by. Hawks have also been observed 

 to pay long visits to islands lying on routes of 

 migration, to prey upon the passing birds, and 

 even to hunt for small migrants in the rays of the 

 lanterns. Many of these birds of prey themselves 

 are migratory, and are careful to make their own 

 seasons of passage correspond with those of their 

 unfortunate victims. The arrival of the Peregrine 

 [Falco peregrinus), for instance, in the Arctic 

 regions, takes place simultaneously with that of 

 the Ducks ; the Hobby [Fcdco subbuteo) does not 

 appear until late in spring, when the woods are full 

 of small birds ; but the Merlin (Fa/co cpsalon) 

 follows the very first few venturesome migrants 

 northwards. 



We must not overlook another very fertile source 

 of danger to migrating birds, and that is the fatal 

 attraction of lighthouses and light-ships. The 

 brilliant light of the various beacons that stud the 

 coasts of the civilized world, along the direct route 

 of countless migrants, allure birds from their direct 

 course, especially during cloudy weather, and great 

 numbers kill themselves as they fly dazed and 

 bewildered against the glass. It has been univers- 

 ally remarked by light-keepers, that birds strike 

 most frequently on dark cloudy nights, with fog, 

 haze, or rain. Instances of birds striking on clear 

 nights are exceedingly rare. Again, light-ships are 

 more attractive to birds than lighthouses on islands 



