THE GROUSE SUBFAMILY 21 



vegetation is at all times scanty, it is a matter for comment indeed 

 that it contrives to secure a sufficiency even during the plenty of 

 summer and autumn. Heather and ling, and the birch and conifers, 

 which so largely supply the needs of the former birds, grow at lower 

 altitudes than the ptarmigan frequents, and still more remote are the 

 bounteous fruits of autumn furnished by the corn-fields. The fruits 

 and leaves of alpine plants, and the fruit and leaves of blaeberry, 

 blackbear-berry, and small red cranberry, form their staple diet : when 

 these are to be had in plenty, indeed, they will eat nothing else. 

 Insects during the summer furnish a welcome variety. True, 

 Naumann l assures us that ptarmigan eats the buds of birch and 

 other trees, and the needles of conifers, but these statements need 

 confirmation, as also does the statement of Mr. Howard Saunders that 

 the tops of ling are eaten. 



That the conditions of existence at these high altitudes are 

 severe, and that this bird is not able to adapt itself readily to new 

 conditions, is shown by the fact that its range is steadily decreasing 

 in Great Britain. It seems never to have inhabited Ireland, and its 

 supposed occurrence in Wales in times past is doubtful. Long since 

 it occurred on the fells of Westmorland and Cumberland, but is now 

 entirely confined to Scotland (see p. 10). There also its range has 

 diminished, and is diminishing. It would seem, as we have suggested, 

 that the ptarmigan is lacking in plasticity, and is in consequence 

 unable not only to extend, but even to maintain its range. The 

 curiously specialised nature, the inherent inability to adapt itself to 

 new conditions, which the ptarmigan displays, make the avoidance 

 of its enemies a difficult matter. Its chief foes are the golden eagle and 

 the hill fox. But of late years a new enemy has arisen in the common 

 and other gulls, which make merciless raids upon its eggs. Against 



1 Ptarmigan shot in Norway contained in crop leaves of birch and sallow, and tops and 

 berries of crowberry. Dwarf birch and sallow crawl about the rocks like ivy on the high 

 ptarmigan ground in Norway. Willow-grouse shot in same district contained whortleberry 

 (blaeberry) leaves and berries, also leaves and young catkins of birch, and a few heather tops 

 (species of heather not noticed). [W. R. OGILVIE-GRANT.] 



