296 A HISTORY OF BIRDS 



The Dunlin {Tringa alpina) is, as we have already re- 

 marked, an extremely variable species, and in its wing measure- 

 ments it is no less so : — 



These measurements are the more striking when compared 

 with similar ones in allied species, such as the following : — 

 Common Sandpiper — 



Average length wing . . . 4*30 



Longest „ ... 4-47 



Shortest „ ... 4'i2 



Percentage of variation . 8. 



