THE BIRDS OF HELIGOLAND 363 



neighbouring isle of England, where this Lark likewise belongs to the 

 very rare occurrences, although it nests in fair abundance on the 

 other side of the English Channel and in Holland. This inequality 

 of distribution is probably to be explained by the fact that the bird 

 has an aversion to crossing the sea, and that such individuals as are 

 found to breed in small numbers in the south of Sweden remain 

 there the whole year. In Norway the species is represented by 

 only three examples, which were observed at Drontheim, in 1880 

 (Collett, Norges Fuglefauna). 



This Lark is distributed as a breeding species from Portugal 

 through central and southern Europe and Asia as far as China. In 

 the north I have met with it in East Friesland. 



168. Shore Lark [BKKGLERCHE]. 

 ALAUDA ALPESTRIS, Linn. 1 



Heligolandish : Berg Lortsk = Mountain Lark. 



Alauda alpestris. Naumann, iv. 149. 



Shore LarL Dresser, iv. 387. 



Alouette a hausse-col-noir. Temminck, Manuel,\. 279, iii. 201. 



The question of the gradual extension of the breeding range of 

 some birds has much occupied the present generation of ornitholo- 

 gists. Alexander von Homeyer has attempted to establish the 

 advance of the Serin Finch (Fringilla serinus), and everybody 

 knows that the Little Bustard has, a number of years since, taken 

 up a fixed abode in some districts of Thuringia, and nests there in 

 annually increasing numbers. Again, Pallas' Grey Shrike (Lanius 

 major) has been undoubtedly likewise engaged, during a number of 

 years, in extending its area of distribution from east to west, as has 

 been more fuUy discussed under the description of that species; while 

 the same fact finds more or less striking expression in the case of 

 several other birds. There is, however, probably no species which 

 has so rapidly and in such numbers advanced the limits of its dis- 

 tribution as this Lark has done in the course of the last fifty years, 

 and nowhere are its annually increasing migratory flocks displayed 

 so abundantly, as at present is regularly the case in Heligoland 

 during the autumn and spring migrations. 



Until the autumn of 1847 the Shore Lark was known here 

 only from the examples shot by the brothers Aeuckens some ten 

 years before that date ; during the October and November of the 

 latter year, however, the birds all of a sudden appeared in such large 



1 Otocorys alpestri/i (Linn.)- 



