5 
If birds are protected and encouraged to nest about the farm and gar- 
den, they will do their share in destroying noxious insects and weeds, 
and a few hours spent in putting up boxes for bluebirds, martins, and 
wrens will prove a good investment. Birds are protected by law in 
many States, but it remains for the agriculturists to see that the laws 
are faithfully observed. 
THE CUCKOOS. 
(Coccyzus americanus and C. erythrophthalmus.) 
Two species of cuckoos, the yellow-billed (fig. 1) and the black-billed, 
are common in the United States cast of the Plains, and a subspecies 
of the yellow-billed extends westward to the Pacific. While the two 
species are quite distinct, they do not differ greatly in food habits, and 
their economic status is practically the same. 
Wi 
* hho fy 
Fia. 1.—Yellow-billed cuckoo. 
An examination of 155 stomachs has shown that these cuckoos are 
much given to eating caterpillars, and, unlike most birds, do not reject 
those covered with hair. In fact, euckoos eat so many hairy cater- 
pillars that the hairs pierce the inner lining of the stomach and remain 
there, so that when the stomach is opened and turned inside out, it 
appears to be lined with a thin coating of fur. 
An examination of the stomachs of 46 black-billed cuckoos, taken 
during the summer months, showed the remains of 906 caterpillars, 44 
beetles, 96 grasshoppers, 100 sawflies, 30 stink bugs, and 15 spiders. In 
all probability more individuals than these were represented, but their 
remains were too badly broken for recognition. Most of the cater- 
pillars were hairy, and many of them belonged to a genus that lives in 
colonies and feeds on the leaves of trees, including the apple tree. 
One stomach was filled with larva of a caterpillar belonging to the 
