STRANGE DWELLINGS. 
42 
The birds that have hitherto been mentioned are either bur- 
rowers into the earth, or adopters of burrows which have been 
made and deserted by fossorial mammalia. Those which now 
come before us are burrowers into wood, and either form their 
tunnels with their own beaks, or adapt to their purposes the 
excavations made by other creatures, and the hollows formed 
by natural decay. 
The first in order of these birds are necessarily the Wood- 
peckers, examples of which are found in most parts of the 
world. They are easily distinguished from any other birds by 
the peculiar construction of the beak, the feet, and the tail; the 
beak enabling them to chip away the bark and wood, the feet 
giving them the power of clinging to the tree- trunk, and the tail 
helping to support them in the attitude which gives to their 
strokes the greatest force. Their beaks are long, powerful, 
straight and pointed; their feet are formed for grasping, and 
are set far back upon the body; and their tails are short and 
stiff, and act as props when pressed against the rough bark. 
As is well known, this bird makes its nest in a tunnel which 
it hollows in the tree, and to a superficial observer might easily 
be reckoned among the enemies of the forest. If it were to 
burrow into sound timber, as is often supposed to be the case, 
it would certainly rank among the deadliest foes of our trees ; 
for in the spots where it still resides, its burrows may be seen 
in plenty, perforating the trunks and branches of the fines^ and 
most picturesque trees. But, in point of fact, none of the 
British Woodpeckers are able to cut so deep a tunnel into 
sound and growing wood, and are perforce obliged to choose 
timber which is already dead, and which has begun to decay. 
Sometimes the bird selects a spot where a branch has been 
blown down, leaving a hollow in which the rain has lodged and 
eaten its way deeply into the stem. In such places the wood 
is so soft that it can be broken away with the fingers, or scraped 
out with a stick ; and in many a noble tree, which seems to the 
eye to be perfectly sound, the very heart-wood is being slowly 
dissolved by the action of water, which has gained access 
through some unsuspected hole. Water, when thus admitted 
