HOW CAUSED. 149 



" Nine or ten years ago the Fjall-Ripa on Lofoden and 

 Westeraalen thus fell down to the coast, and were killed in 

 such numbers throughout the whole w r inter as to be sold 

 for 2 skillings, or Id., each, the usual price being 6 skill- 

 ings, or 3d. They were then mostly used as food for 

 servants. Of late years, however, these migrations of 

 the Fjall-Ilipa have been of less frequent occurrence 

 than formerly, when they usually took place at intervals 

 of only a few years. 



"The cause of the migrations in question is believed 

 to be, that during the years when they occur the f jails 

 are covered with dense masses of snow, which, instead of 

 drifting in places, as usually happens, has fallen in. calm 

 weather and rested evenly everywhere ; and from its 

 surface having subsequently frozen, the llipa are prevented 

 from obtaining access not only to the crakeberry their 

 favourite food, which, as said, remains green all the 

 winter but to the dwarf birch and willow, on the buds 

 and tender shoots of which, when the crakeberry is 

 debarred them, they also feed." 



These periodical migrations of the Fjall-Ripa from 

 their alpine homes to the lowlands would not seem to be 

 confined to the Lofoden islands, for Nilsson informs us 

 that, when at Upper Hallingdal, in Norway, he was told 

 by the people there that " on the occurrence of heavy 

 snow-storms, these birds would descend from the fjalls, 

 and perch on the birch-trees in such numbers that they 

 seemed clad in white." 



Again : " This year, 1863," writes M. Widmark from 

 Qvickjock, in Lapland, " there are unusually few Fjall- 

 Ripa on the Lulea fjalls. This may possibly be owing to 

 the enormous quantity of snow that fell during the past 

 winter, which drove them down from their proper haunts 

 the Skoysbryn, or upper edge of the birch region 

 to the forest region, even to the forest itself, and to 



