FOOD OP SOME WELL-KNOWN BIEDS. 13 



here and there may be killed. "Wlien the injury is more extensive, 

 as it often is, the tree may be completely girdled, and of course dies. 

 Holes made by sapsuckers go clear through the bark and often into 

 the wood. Generally they are made in rings, or partial rings, around 

 the trunk or limbs, but they often fall into vertical series, and they 

 may be either vertically or horizontally connected. This type of 

 woodpecker work is familiar to everyone who has been much in 

 orchards and woods. 



Sapsucker pecking disfigures ornamental trees, giving rise to pitch 

 streams, gummy excrescences, and deformities of the trunks. Small 

 fruit trees, especially apple, are often killed, and whole young or- 

 chards have been destroyed by these birds. Sapsuckers are known to 

 attack no fewer than 258 kinds of trees, shrubs, and vines in the 

 United States, 63 of which are often seriously injured and 32 have 

 been killed. 



However, the killing of trees outright is by no means the greatest 

 damage done by sapsuckers. Indeed, in the aggregate these birds 

 inflict much greater financial loss by producing defects in the wood 

 of the far larger number of trees which they work upon but do not 

 kill. Blemishes reducing the value appear in the lumber from such 

 trees and in the various articles into which it is manufactured. These 

 defects consist of distortion of the grain, formation of knotty growths 

 and cavities in the wood, extensive staining, fat streaks, resin de- 

 posits, and other blemishes. All of these result from injuries to the 

 cambium, their variety being due to differences in the healing. 



Hickory trees are favorites of the sapsucker and defects in the 

 wood, though severe, may be used to illustrate the general character 

 of this form of damage and also the resulting loss. Blemishes in 

 hickory due to sapsucker work consist of open black checks, varying 

 in size up to two by four inches, sometimes walled with rotten wood 

 or partly filled with spongy growth, and frequently connected with 

 gnarly fissures, up to two inches in length, which usually extend to- 

 ward the bark. These are surrounded by brown or black stains, 

 called iron streaks, which penetrate more or less wood adjoining the 

 wound and follow the grain sometimes for many feet, making condi- 

 tions favorable for checking and rendering the wood harder to work. 

 The abundance and extensiveness of stains and gnarly growth in 

 hickory spoil the wood for many of its most important uses. A 

 large proportion of hickory trees are attacked by sapsuckers, and it 

 is estimated that about 10 per cent of the merchantable material is 

 left in the woods on account of bird pecks. On this basis the an- 

 nual loss on hickory is about $600,000. To this must be added the 

 loss on timber graded out by the manufacturer and that suffered by 

 the manufacturer himself because of culling out a certain proportion 



506 



