198 THE MIGRATION OF BIRDS 



bushes ; whilst at midnight the birds commit suicide 

 against the lighthouse. When we consider that this has 

 been going on for a quarter of a century, and that the 

 results have been most carefully chronicled for that 

 length of time, the wonder is not that so many species of 

 birds have occurred on Heligoland, but that so many 

 have hitherto escaped detection. This must be accounted 

 for on the theory that, after all, the appearance of birds 

 on Heligoland is only accidental. Comparatively little 

 migration is observed by the casual visitor who frequents 

 the restaurant to enjoy the oysters and the lobsters, or 

 rows across to Sandy Island to bathe on the shore, and 

 take a constitutional on the "dunes." Now and then a 

 flock of waders may be detected hurrying pas: ; flocks of 

 pipits occasionally land on the island, feed for an hour or 

 two, and then pass on ; and sometimes a scattered and 

 straggling stream of hooded crows, of heavy and 

 laborious flight, will continue all day long. But by far 

 the most important migration will be found to have 

 taken place "while men slept." Every flock which 

 passes over probably drops a few tired or hungry birds, 

 and a walk through the potato-fields in the morning after 

 a migration night sometimes turns up the most curious 

 and interesting variety of species which have sought the 

 only cover on the island to feed or rest. Perhaps the 

 first bird you flush is a skylark ; the report of your gun 

 starts a golden plover, or a jack snipe ; then you observe 

 some small birds skulking in the potatoes, and you pre- 

 sently secure a little bunting, an aquatic warbler, and a 

 shore-lark. Your next shot may be a corncrake, followed 

 by a ring ousel or a Richard's pipit. 



Every night, however, is not a migration night. 

 Sometimes for a week together you may diligently tramp 

 the potatoes without finding a bird. Migration is a 



