PREFACE. 
The native birds are one of our nation’s most yal- 
uable assets. Destroy them, and in a comparatively 
few years the insects will have multiplied to such an 
extent that trees will be denuded of their foliage, 
plants will cease to thrive and crops cannot be rais- 
ed. This is not fancy but plain facts. Look at the 
little Chickadee on the side of this page. She was 
photographed while entering a bird box, with about 
twenty-five plant lice to feed her seven young; about 
two hundred times a day, either she or her mate, 
made trips with similar loads to feed the growing 
youngsters. 
It has been found, by observation and dissection, 
that a Cuckoo consumes daily from 50 to 400 cater- 
pillars or their equivalent, while a Chickadee will 
eat from 200 to 500 insects, or up to 4000 insect or 
worm eggs. 100 insects a day is a conservative esti- 
mate of the quantity consumed by each individual 
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