WILD LIFE OF ORCHARD AND FIELD 



search with great diligence, in the ground, at the 

 roots of plants, in orchards and meadows, as well 

 as among buds, leaves, and blossoms; and from 

 their known voracity the multitudes of these in- 

 sects which they destroy must be immense. Let 

 me illustrate this fact by a short computation: 

 If we suppose each bird on an average to devour 

 fifty of these larvae in a day (a very moderate al- 

 lowance), a single pair in four months, the usual 

 time such food is sought after, will devour upward 

 of twelve thousand. It is believed that not less than 

 a million pairs of these birds are distributed over 

 the whole extent of the United States in summer, 

 whose food, being nearly the same, would swell the 

 amount of vermin destroyed to twelve billions. But 

 the number of young birds may be fairly estimated 

 at double that of their parents; and as these are 

 constantly fed on larvae for three weeks, making 

 only the same allowance for them as for the older 

 ones, their share would amount to 4^ billions, 

 making a grand total of i6i billions of noxious 

 insects destroyed in the space of four months by 

 this single species I The combined ravages of 

 such a hideous host of vermin would be sufficient 

 to spread famine and desolation over a wide extent 

 of the richest, best-cultivated country on the earth." 



138 



