COURSE OF MIGRATION IN HELIGOLAND 19 



evidently proves that all these birds were still engaged on their 

 normal autumn migration from east to west. 



Matters, however, assume a vastly different aspect if, instead 

 of a mild temperature, frost and a sharp east wind set in in the 

 beginning of the month. Under these conditions all of the birds 

 belonging to the before-named species as well as the Curlews, 

 Golden Plovers, Oyster-catchers, and Sandpipers, which have until 

 then tarried in their summer habitations rush in one night 

 towards their winter quarters ; during the day countless flocks of 

 Swans, Geese, Ducks, and Mergansers are seen migrating across 

 the sea. Sea Eagles, numerous Common Buzzards, and solitary 

 Harriers are frequently observed; and now and again a Stone 

 Curlew may be seen under similar conditions. The old birds of 

 the Purple Sandpiper, Sanderling, and Knot appear in more or less 

 considerable numbers. On the sea the Slavonian Grebe may be 

 seen rather frequently ; likewise old birds of the Black Guillemot, 

 Black-throated Diver, and pretty often, too, Great Northern Diver. 

 The Common Gull is abundant ; young birds of the Glaucous Gull 

 are fairly common, and the Iceland Gull is shot occasionally. The 

 Long-tailed Duck dives merrily among the rocks to the north of 

 the Dune, while solitary females of the Common Scoter may be 

 seen swimming round the cliff. 



If this sudden frost is accompanied by a heavy fall of snow, 

 hundreds of thousands of Skylarks, Twites, Linnets, and Green- 

 finches, Goldfinches, and Mealy Redpoles arrive during the early 

 morning and forenoon of the following day, and literally cover all 

 such places on the island as are still free from snow. If the snowy 

 weather lasts for any considerable time, and is accompanied by a 

 strong east wind and severe cold, all the species of the northern 

 diving Ducks very soon congregate in fairly large numbers on the 

 sea. In addition to the females and young of the Common Scoter, 

 scattered young examples of the Red-breasted Merganser are 

 amongst the first to arrive. These are soon followed by young 

 Golden-eyes, smaller or larger companies of which dive about in 

 search of food quite near to the foot of the cliffs. 



Scaups next make their appearance at a somewhat greater 

 distance from the island ; these keep together in large flocks and 

 consist in great part of males in perfect plumage, in exceptional 

 cases, and are, later, accompanied by one or several examples of the 

 Pochard. The Goosander now begins his excursions, either singly 

 or in companies of from three, seven, up to ten individuals, most of 

 the birds being fine old males; the females, with rust-coloured 

 heads, are more frequently met with swimming. During this 

 stage of the bird-life of winter, a good sportsman, provided with 



