THE GEEEN WOODPECKER. 129 



could be inserted. This shows that the woodpecker's task 

 was not quite such a laborious one as it at first appeared ; 

 but nevertheless the bird had to perforate several inches of 

 solid and healthy wood, in order to get at the softened parts 

 within. 



This explanation brings up an interesting question. 

 Could the bird tell, before commencing its burrow, that the 

 heart of the tree it had chosen was decaying, whilst the 

 exterior was sound ? If so, how ? I believe there is only 

 one method ; viz., by percussion. The woodpecker is most 

 perfect in this art, which must prove an invaluable assist- 

 ance to it in many ways. Just as the carpenter uses his 

 hammer to find w^here lath and plaster ends, and brickwork 

 begins, so does the woodpecker utilize his sturdy bill, and 

 easily detects the difference between the note produced by 

 percussing the solid oak and that by " tapping the hollow 

 beech tree." I ought to mention that the oak under con- 

 sideration does not stand upright, and the bird made its 

 burrow on that side which was nearest to the ground. Thus, 

 it will be seen, no rain could enter. Does this not show 

 something in the woodpecker near akin to reason ? 



It is often stated that the bird removes the discarded 

 chips of wood from the spot where it makes its burrow ; but 

 this is by no means always the case, as they often serve as 

 the first indication of the nest. The bird generally makes 

 a new nesting hole every year, the old ones being used for 

 roosting purposes. Standing close to a large house, not far 

 from Clifton, there is a tree having a hole in which a green 

 woodpecker was seen to retire regularly every evening. It 

 has roosted there for some years, and for all I know to the 

 contrary, still continues to do so. 



I alluded just now to the pertinacity with which the bird 

 clings to its home. I have lately come across a striking 



