364 THE NESTS AND EGGS OF BRITISH BIRDS. 



in number ; in unfavourable seasons the clutches are 

 small, in dry and warm ones large. They are creamy- 

 white in ground colour, profusely and handsomely 

 blotched and spotted with rich reddish or crimson- 

 brown, or even blackish-brown. The markings are very 

 numerous, and cover most of the shell ; but as the 

 colour, especially on newly-laid eggs, is very easily 

 rubbed, much of the beauty is frequently destroyed by 

 contact with the parent. Average measurement, i'8 

 inch in length, by V2$ inch in breadth. Incubation, 

 performed by the female, lasts twenty-four days. 



Diagnostic characters : The size, rich colour, and 

 profusion of the markings, readily distinguish the eggs 

 of the Red Grouse from those of allied species, except 

 perhaps from those of the Ptarmigan : the latter eggs, 

 however, are more buff, and not so profusely marked. 



Family THASIANID^. Genus Lagopus. 



Sub- family TETRAONIN.E. 



PTARMIGAN. 



Lagopus mutus {Movtin). 

 Single Brooded. Laying season, May ; late seasons, early June. 



British breeding area : The Ptarmigan is another 

 very local species, confined principally to the loftiest 

 mountains of the Highlands, as far south as the moun- 

 tains of Islay, Jura, and Arran, and extending west- 

 wards to Skye, Harris, and Lewis, but not to the Ork- 

 neys nor the Shetlands. 



Breeding habits : The Ptarmigan is resident in the 

 British Islands, and subject to remarkably little local 

 movement, except when driven to lower levels by 

 prolonged bad weather. Its breeding-haunts are the 



