184 FRIENDS WORTH KNOWING. 
It is commonly observed that scarcely any small birds 
are seen in the depths of a forest, but they become abun- 
dant as one approaches the neighborhood of settlements. 
Travellers through Siberia know that they are coming near. 
a village when they begin to hear the voices of birds, which’ 
are absent from the intervening solitudes. Every ornithol- 
ogist has proved these facts in his own experience, and ex- 
plorers who go to uninhabited and primeval regions have 
learned not to expect there the chorus that greets their 
ears from the great army of songsters thronging the fields 
in populous countries. 
The song-birds—the small denizens of our summer 
groves, pastures, and meadows—seem, then, to recognize 
the presence of man’s civilization as a blessing, and have 
taken advantage of it, both from love of human society and 
for more solid and prosaic reasons. 
The settlement of a country implies the felling of for- 
ests, the letting in upon the ground of light and warmth, 
the propagation of seed-bearing cereals, weeds, and grasses 
enormously in excess of a natural state of things, the de- 
struction of noxious quadrupeds and reptiles, and the intro- 
duction of horses and eattle. Each of these alterations of 
nature (except in some few cases, like that of the relation 
of the woodpecker to the cutting away of timber) is a di- 
