THE BIRDS OF HELIGOLAND 539 



fifty to ahundi-ed, and often even nmch larger numbers, frequenting 

 the sea at a short distance from tlic island. Such flocks consist 

 almost excUisively of very handsome old males, with double 

 tufts on the head formed by the peculiarly elongated loose 

 hanging feathers of the occiput. Females and younger birds 

 are found nearer to the island, where they dive about after food ; 

 these never congregate into companies, but invariably follow 

 their occupati,ons apart from their follows. Solitary examples 

 make their appearance very early in the winter, whereas the large 

 flocks of old males only arrive after three or four weeks of severe 

 and persistent frost. Among the birds with rust-coloured heads one 

 often meets with very small individuals, so that one almost feels 

 tempted to regard them as belonging to a separate species, which, 

 however, is not the case. 



It is more diflicult, in the case of the present species than even 

 in that of the preceding, to explain whj' it is not seen here regularly 

 every autumn and winter, seeing that it nests numerously through- 

 out the whole of Norway, from the North Cape down to its southern- 

 most exti'emity. It also occurs as a breeding species m Sweden 

 and Finland, as well as throughout Asia and the north of America, 

 and also in Iceland and the north of Scotland, and the islands 

 skirting its coasts. 



344. — Smew [Kleiner Sagetaucher]. 



MERGUS ALBELLUS, Linn. 



Heligolandish : Lutj witt Seel)oliii = /SH!(iM White Seacock. 



Mergus albellus. Naumann, xii. 314. 



Smew. Dresser, vi. 699. 



Harle piette. Temminck, Manuel, ii. 847, iv. 559. 



This diver, in its simple and yet most elegant dress of snowy 

 white and deep velvety black, is of extremely rare occurrence in 

 Heligoland ; only now and again, after prolonged frost, does one 

 meet with a solitary female or young bird which may be followed 

 later by a pair of old males ; and only on two occasions have as many 

 as five and three been seen together. A male in perfect plumage 

 has only been shot here once ; but birds with rust-coloured head 

 have been killed on five or six occasions. 



My journal for 1847 has some interesting notes with regard to 

 the appearance of winter visitants of this kind from the far East. 

 Until the middle of December of that year the weather had been 



