26 THE TUNDRA AND ITS FAUNA 



agony of the last march of de Long and his companions 

 after the wreck of the Jeannette, it was by the help of 

 the ptarmigan and reindeer shot that the final cata- 

 strophe was postponed so long. After Nansen and his 

 companions arrived in safety at the east coast of 

 Greenland, their crossing of the inland ice completed, 

 they whiled away their months of waiting for a ship by 

 the help of ptarmigan shooting. Sverdrup and his 

 companions shot many for food during their Arctic 

 expedition, and similarly almost every expedition which 

 has landed in tundra regions has noted the presence 

 and characters of the birds. 



The ptarmigan share with the Arctic fox, the stoat 

 or ermine, and not a few other northern forms the 

 peculiarity of displaying a seasonal change of colour. 

 This change doubtless aids these varied animals in 

 escaping from their enemies, or in stealing unperceived 

 upon their prey. Like many other tundra animals also, 

 the ptarmigan is social, being found in flocks, except 

 at the pairing season. This is no doubt associated with 

 the fact that food is only obtainable in certain areas, 

 separated by extensive barren regions. Though in most 

 favourable tundra regions ptarmigan are to be found 

 throughout the year, a certain amount of migration 

 occurs. Thus in Greenland they are commoner in the 

 south in winter than in summer. Needless to say, 

 ptarmigan are not peculiar to the tundra, for they 

 extend far to the south of the region. 



The only songster of the tundra is the snow-bunting 

 (Plectrophenax nivalis), which is very widely distributed, 

 and is spoken of by most explorers, who welcome its 

 twittering song in spring. There is no doubt that it is 

 largely a migrant, nesting in the north, and turning 

 southwards in the autumn. Occasionally, however, 



