ECONOMIC VALUE OF BIRDS. 7 
Birds digest their food so rapidly, that it is difficult to 
estimate from the contents of a bird’s stomach at a given 
time how much it eats during the day. The stomach of a 
Yellow-billed Cuckoo, shot at six o’clock in the morning, 
contained the partially digested remains of forty-three 
tent caterpillars, but how many it would have eaten be- 
fore night no one can say. 
Mr. E. H. Forbush, Ornithologist of the Board of 
Agriculture of Massachusetts, states that the stomachs 
of four Chickadees contained one thousand and twenty- 
eight eggs of the cankerworm. The stomachs of four 
other birds of the same species contained about six 
hundred eggs and one hundred and five female moths 
of the cankerworm. The average number of eggs 
found in twenty of these moths was one hundred and 
eighty-five; and as it is estimated that a Chickadee may 
eat thirty female cankerworm moths per day during 
the twenty-five days which these moths crawl up trees, 
it follows that in this period each Chickadee would de- 
stroy one hundred and thirty-eight thousand seven hun- 
dred and fifty eggs of this noxious insect. 
Professor Forbes, Director of the Illinois State Lab- 
oratory of Natural History, found one hundred and 
seventy-five larvee of Bibio—a fly which in the larval 
stage feeds on the roots of grass—in the stomach of a 
single Robin, and the intestine contained probably as 
many more. 
Many additional cases could be cited, showing the 
intimate relation of birds to insect-life, and emphasizing 
the necessity of protecting and encouraging these little. 
appreciated allies of the agriculturist. 
The service rendered man by birds in killing the 
small rodents so destructive to crops is performed by 
Hawks and Owls—birds the uninformed farmer con- 
siders his enemies. The truth is that, with two excep- 
