208 



NATURAL HISTORY OF BIRDS. 



changing their summer plumage at the approach of winter, to one of a pure white. 

 They dwell among the snow-clad hills and peaks, are monogamous, both sexes devoting 

 themselves to the care of the young ; and but one brood is raised, as a rule, in a season. 

 The eggs are about a dozen in number, varying in color from buff to a bright rufous, 

 thickly spotted and blotched with black. While the hen is incubating, the male re- 

 mains in the vicinity and keeps a bright look-out for enemies of every kind. One 

 species is restricted to the New World, L. leucurus ; three to the Old World, L. sco- 

 ticus, of Great Britain and Ireland, L. hemileucurus, doubtfully distinct from L. rupes- 



FlG. 98. Lagopus aibus, ptarmigan, in winter plumage. 



tris, from Spitzbergen, and L. mutus ; while L. albus and L. rupestris are inhabitants 

 of both hemispheres. They go in flocks, are not wild when not much hunted, and 

 their flesh is tolerably good for food. An exception may be made for the Scotch 

 grouse, whose flesh is excellent, but this species, from causes perhaps incident to its insu- 

 lar existence, has lost some of the ptarmigan traits, and adopted others pertaining more 

 to those of the true grouse. Although apparently nearest allied to the L. albus, of 

 which it may be considered an island form, it does not turn white in winter, and is 

 chiefly a bird of the moors, ascending at times, however, to the base of the higher 

 peaks. It varies in the colors of its plumage according to the localities it frequents, 

 those individuals inhabiting rocky ground being usually lightest in hue. 



