64 REPORT ON THE MIGRATION OF BIRDS. 



the bulk of the immigrants. Others, as Ruticilla phoenicurusy the 

 SaxicolcBy and other soft-billed insect-eaters, although coming 

 from the eastward, persistently follow the coast-line to the south. 

 All the Limicolce and other shore birds, as well as the Geese, 

 Ducks, Divers, Gulls, and sea-fowl generally, move from north to 

 south as a general rule, the sea-fowl at some distance at sea, the 

 waders along the coast. Although so far we have no stations, 

 excepting Heligoland, on the European coast of the North Sea, 

 we may, I think, fairly presume that there is similarly another 

 stream of birds passing down the coast-line of Em'ope. Migration 

 as observed on that island for many years points to the undoubted 

 fact that the line followed by birds is, as a rule, from E. to W., 

 and doubtless some portion of these Heligoland birds keep moving 

 westward or south-westward, till eventually they strike our east 

 coast. There are, however, many species which make Heligoland 

 the western boundary of their autumn wanderings, and crossing, 

 as they do, that island in enormous numbers, must eventually 

 follow the coast-hne to the south, for the simple reason that they 

 never occur on our own coast, except as very rare or occasional 

 wanderers ; such are Motacilla alba and Jiava, Ruticilla suecica, 

 Emheriza hortulana, Plectrophanes lapponiciis, Anthus Richardi, 

 and, in a less degree, Miiscicapa luctuosa and Otocorys alpestris. 

 These all, then, must pass southward along the European coast, 

 as do doubtless an immense majority of those countless Sparrow- 

 hawks, Siskins, and more familiar birds which cross the island in 

 the autumn migration ; and just as occasionally some species, 

 whose line of migration lies farther to the eastward still, turn up 

 as wanderers to the old rock from the regular track, so do 

 occasionally now one and now another of the regular Heligoland 

 immigrants get blow^n across to om- side. 



The observations taken at some of our southern stations both 

 in 1879 and 1880 show that, in the autumn, there is what may 

 be called a double stream of birds crossing each other near the 

 entrance of the English Channel, that is, from the Essex and Kent 

 coast towards the S.E. on to the French and Belgian coast, and 

 again in the opposite direction frofn the Belgian land to the coast of 

 Kent. During the severe weather in the early part of 1881, as well 

 as in December, flocks of birds came to us direct from the French 

 coast, or from the south to the north. These must be considered 

 purely local migrations, caused by outbui'sts of severe weather. 



