150 TREE WOUNDS AND DISEASES 



The great woodpecker will attack healthy 

 as well as diseased trees, and encircle the stems 

 with rings of holes, which are arranged hori- 

 zontally. When the trees are badly pierced 

 with lines of holes arranged shelf-like, one 

 above the other, the trunk frequently snaps 

 across during stormy weather, and several such 

 cases were observed in a Kentish plantation 

 during the past season. In the same wood- 

 land, however, unhealthy and insect-infested 

 trees of the Scotch and cluster pines were also 

 attacked, and telephone and telegraph poles by 

 the roadside. The holes are usually two inches 

 in diameter, and extend inwards according to 

 the depth at which insects are to be found. In 

 some cases, as will be seen in the accompanying 

 illustration, the timber of the attacked tree 

 has been entirely removed by the woodpecker, 

 leaving only the bark intact. 



Although hurtful by picking holes in living 

 tree stems, it would appear that the utility of 

 the woodpecker, in destroying injurious beetles 

 in unhealthy trees, outweighs any harm it may 

 do in attacking healthy specimens. 



Birds undoubtedly do much injury, but the 



