THE BIRDS OF HELIGOLAND 459 



frost or snowfall, couutlcss Hocks of Uicso birds, together with 

 Golden Plovers, Lapwings and Trincjcr will bo seen, on the niglit 

 preceding the advent of such weather here, migrating over the 

 island, amid great haste and noise, on an east-to-west line of flight ; 

 in fact their numbers are, on such occasions, so immense that one 

 might almost believe that no autumn migration had as yet taken 

 place. Thus, for instance, on the niglit intervening between the 

 19th and 20th December 1878, from S a.m., my journal records: — 

 ' IMyriads of N. arqucdus, mixed with countless numbers of smaller 

 Waders.' IMany other instances of a similar kind might bo quoted. 

 Solitary individuals are also seen here during the winter, and, what 

 is particularly remarkable, in the hardest frosts. No doubt, at such 

 times the birds must be in sore straits, many of them probably 

 perishing ; in fact, on occasions like this, countless dead Curlews 

 have been seen drifting on the sea between Hehgoland and the 

 estuary of the Elbe. 



The spring migration of this species commences very early : in 

 1885, with the advent of mild weather, it was observed to pass here 

 as early as the 3rd of February, accompanied by CIiiav. auratiia, 

 immense numbers of Skylarks, many Greenfinches and Linnets, 

 Blackbirds and Redwings, and even a few Song Thrushes ; these 

 were followed, on the next day, with a southerly wind, by a flock 

 of at least a hundred Rooks. The weather continued mild through- 

 out the whole month, so that the spring migration, after having 

 once begun, proceeded without any substantial interruptions. The 

 young birds of the year, which arc the real inaugurators of the 

 autumn migration, frequentlj' arrive here as early as the middle 

 of July. 



I have been struck by a peculiar tendency which these birds, 

 and, more particularly, the smaller species next to be discussed, 

 display in the manner of their flight, especially during their spring 

 passage ; that is, from travelling in flocks without regular order 

 or system, they will form themselves into an oblique line, termi- 

 nated by a short curve. Often, also, an irregular flight of from 

 fifty to eighty of the small species (Whimbrel) will form into 

 several scattered lines of greater or less length, which subsequently 

 unite into one single column. In this latter formation their rate 

 uf flight is so tremendous that there is little doubt of their 

 accomplishing the distance from the island to the oyster-bank — 

 22,000 feet to the east — in little more than a minute ; while the 

 dune, at a distance of 4000 feet, to which they may be followed 

 by the eye, is actually reached in a few seconds. 



The Curlew occurs as breeding bird in Scotland, central 

 Scandinavia, northern Germany, Poland; and, within the same 



