156 TREE WOUNDS AND DISEASES 



hawthorn, suffer much from attacks of the 

 pigeon, and during the spring of 1916 the 

 depredations in the case of the lilac and haw- 

 thorn were so considerable in the Metropolis 

 that special preventive measures had in some 

 cases to be adopted. 



The crossbill feeds on the seeds of several 

 coniferous trees, principally those of the Scotch 

 pine and spruce, and when large flocks of the 

 bird appear the injury done is considerable. 

 In pine plantations in the north of Ireland, 

 the crossbill committed such an amount of 

 damage some years ago that reduction of their 

 numbers had to be resorted to by shooting. 

 Comparatively speaking, the crossbill is a rare 

 bird and of local distribution. 



The capercaillie, blackcock, and moorfowl 

 or ptarmigan are all inhabitants of secluded 

 heathery moors and pine plantations. They 

 feed on the buds and shoots of the Scotch pine 

 and other coniferous and hard-wooded trees, 

 and frequently whilst these are in the nursery 

 border. Both the blackcock and the red grouse 

 feed largely where the heather and whortle- 

 berry abound, and when food is scarce they 



