34 THE BIRDS OF HELIGOLAND 



after having traversed this peninsula, they are in face of the North 

 Sea, with every coast soon out of sight, what further guide is there 

 left them for the rest of their journey ? No doubt observers watch- 

 ing successive droves of migrants flying above the shore in the 

 direction of the coast-line regarded these in the sense of one far- 

 stretching host or stream of migration, little thinking that they 

 themselves might possibly be stationed in the centre of a broad 

 migration column extending for miles on either side to sea and 

 land. Such, nevertheless, was undoubtedly the case : in proof of this 

 assumption we may again cite the case of the Hooded Crows, which 

 in endless hosts pass the island every autumn on an east-to-west 

 course. The breadth of the migration column in this case may be 

 estimated from the following considerations : According to observa- 

 tions from fishing-boats stationed seven miles north of the island 

 it had not reached its limit at that distance ; while from the Weser 

 steamer the birds were seen in undiminished numbers, and all 

 pursuing the same westerly course, during the whole of her passage 

 to the opposite coast, a distance of about six German or twenty- 

 four geographical miles to the south. No doubt, had any of the 

 above observers happened to be on any one of the islands on that 

 coast, such as Wangeroog, Norderney, or Borkum, on a day like 

 this, they would have at once appealed to their experience as 

 furnishing a striking proof for their hypothesis that migrants 

 use shore-lines as marked-out migration routes, little thinking that 

 they were really in the midst of a broad column or belt of migra- 

 tion extending from the point of their observation from thirty-two 

 to forty geographical miles northwards out to sea, and an equal if 

 not greater distance inland to the south. 



Another example of an autumn migration proceeding in a broad 

 front westwards was furnished by the Golden-crested Wren in Octo- 

 ber 1882. During the whole time of its migration the bird travelled 

 past Heligoland in extraordinary large, in some cases quite 

 uncountable multitudes. Observations made simultaneously at 

 all the lighthouses, lightships, and many land-stations on the east 

 coast of England and Scotland, proved that on the 7th, 8th, and 

 9th, among other days of the above-named month, innumerable 

 hosts of this little bird were migrating westwards at all these 

 points, from Guernsey northwards as far as Bressay, in the middle 

 of the Shetland group. Thus, then, we have a migration column 

 embracing nearly eleven degrees of latitude, or about 640 geogra- 

 phical miles ; nor is there any reason to doubt that this enormous 

 column may riot have extended still further south, inasmuch as the 

 breeding zone of the Golden-crested Wren by no means reaches its 

 southern limit in the latitude of Guernsey i.e. 49 N. latitude. 



