ABOVE THE PINE-ZONE 37 



adaptation of plumage is really a change in the in- 

 dividual feathers, and not a process of moulting. 

 In northern Europe the change is quicker and 

 more complete than in Scotch birds, which are 

 only purely white in severe winters. 



British ptarmigan have but few enemies, whilst 

 those of Arctic countries have many. Among these 

 are the great snowy owl, Iceland falcon, silver fox, 

 and numerous fur-bearing animals; and the white 

 winter covering here serves a double purpose, as it 

 protects the birds directly from its enemies, and in- 

 directly from the cold. Nevertheless they love the 

 snow, and at night sleep in a scraped-out hollow 

 under the lee-side of a boulder. Their tendency is 

 towards the tops of the mountains, except during 

 the severest weather, when, being unable to obtain 

 their usual supply of food, they descend to the 

 shoulders of the hills. In their every adaptation 

 ptarmigan are truly children of the mist, and find 

 their home at a high altitude. Several attempts 

 have been made to naturalise them to lower land, 

 and even to keep them in confinement, but these 

 attempts have invariably failed. The bird is subject 

 to the same disease as grouse, though only on the 

 lower grounds. The afforesting of land for deer has 

 done much to lessen the once famous ptarmigan 

 " shoots," as forests cannot now be disturbed for 

 the smaller game. There is something in common 



