576 THE BIRDS OF HELIGOLAND 



in August ; of individuals of the latter migration season, only the 

 first arrivals wear the pure breeding plumage, those which appear 

 towards the end of the month being all more or less advanced in the 

 moulting condition. This Diver is shot most frequently during the 

 shooting season for Kittiwake Gulls in autumn, when both young 

 and old individuals disport the winter plumage. Occasionally this 

 bird occurs in inconceivable quantities, as, for instance, on the 2nd 

 and 3rd of December 1879, Avhen there was a moderate east 

 wind, with about 13 F. of frost ( 6 R). The air was clear, but 

 a snowstorm set in towards evening. Hundreds of thousands of 

 Ducks, Geese, Swans, Curlews, Oystercatchers and Dunlins were 

 migrating in astonishing multitudes from east to west. During the 

 whole of the forenoon, moreover, from early morning, these Divers 

 migrated in numbers before unequalled, and since that time never 

 even approached. At a distance of about two miles from the 

 island, as far as the eye or the telescope could reach, these birds 

 were seen moving in one incessant stream, all of them, strange to 

 say, travelling towards the north-east. This migration lasted till 

 about noon, and was repeated on the next day in the same manner 

 and in the same gigantic proportions. Whence all these birds 

 could have come, and whither they Avere going, are questions 

 which it is difficult, if not impossible, to answer ; equally difficult is 

 it to find a cause which could have induced so enormous a 

 number of birds, neve*r seen in companies under ordinary condi- 

 tions, to congregate for one common purpose on this particular 

 occasion. Contrary to the habits of its two larger congeners, this 

 Diver shows a preference for flying, almost all the hundreds of in- 

 dividuals which are killed here during late autumn being shot 

 on the wing; such individuals as are at any time seen to dive 

 or swim near the island are invariably found to be emaciated 

 and out of condition. Their flight, however, is not a regular 

 migratory movement proceeding in a definite direction, but ap- 

 parently a mere aimless roving about, confined almost without 

 exception to solitary individuals. Sometimes one may succeed, by 

 imitating its strange call-note, to decoy one of these birds within 

 shooting range. 



The Red- throated Diver is found breeding from Greenland and 

 Iceland down to the Hebrides, Orkney and Shetland Islands ; also in 

 northern Scandinavia, Spitzbergen, Nova Zembla ; and towards the 

 east, throughout northern Asia, and the whole of Arctic America. 



Guillemots Uria. The Guillemots are the most prominent of 

 the few birds which make this island their regular annual breed- 



