250 
BIRD-LIFE. 
are not the sole agents employed in this matter, 
for the Corviclce are scarcely less useful, especially 
one member of the family,—the common Rook. This 
bird is the chief enemy of the cockchaffer, and in destroy¬ 
ing untold numbers of this insect, as also snails, &c., 
does us no small service. Buzzards, Kestrels, and Owls, 
are not less instrumental in preserving to man those 
plants which are most necessary to his existence. These 
three creatures ought to be as sacred to us as the Ibis 
was to the Egyptians, for they are the most active and 
untiring adversaries of the universally destructive field- 
mouse. They all, in some way or another, contribute to 
the general service ! A single Buzzard can devour some 
twenty field-mice in a forenoon, without any fear of an 
attack of indigestion; and a pair of these birds will, in 
the breeding-season, carry over a hundred of these little 
mammals to their young in a day. Owls and Kestrels 
are quite as useful in proportion to their size. One may 
rest assured that these birds will not be long before they 
find out and frequent a field over-run by these pests, and 
there carry out the work for which they were created. It 
is a veritable sin, a crime committed against agricultural 
interests, when the ignorant boor destroys them, and 
nails to his barn-door a crushing evidence of his folly 
and stupidity. In seasons when plagues of field-mice 
occur, these useful birds—they might almost be called 
angels—arrive, from whence no one can tell, and destroy 
them so long as one is to be found. The Snowy Owl has 
been known, from observation, to follow the Lemming, in 
its migration, for miles. 
Of late years our attention has been attracted to 
another work, in which birds prove their utility to man. 
Not a few of them contribute greatly to keep down 
