194 BIRDS IN THEIR RELATIONS TO MAN. 



nearly half of the cuckoos' fare. These birds are unique in 

 having a taste for insects that other birds reject. Most birds 

 are ready to devour a smooth caterpillar that comes in their 

 way, but they leave the hairy varieties severely alone. The 

 cuckoos, however, make a specialty of devouring such unpal- 

 atable creatures : even stink-bugs and the poisonous spiny 

 larvae of the Io moth are freely taken. About six per cent, 

 of the food for the year consists of beetles, among which are 

 a few potato-beetles. No preference for any particular sort of 

 beetle is apparent : probably any beetles found crawling over 

 branches of trees would be eaten. Investigation has shown 

 scarcely more bugs (Hemiptera) than beetles, probably for the 

 same reason, — both live principally on the ground, — those 

 that were found being largely cicadas, which dwell almost 

 wholly in trees. Grasshoppers, katydids, and tree-crickets are 

 eaten to a considerable extent, orthopterous insects amount- 

 ing to about thirty per cent, of the year's food. Flies, ants, and 

 other hymenopterous insects are taken in small quantities. 



The nestling birds are fed chiefly with smooth caterpillars 

 and grasshoppers, their stomachs probably being unable to 

 endure the hairy caterpillars. 



All in all, the cuckoos are of the highest economic value. 

 They do no harm and accomplish great good. If the orchardist 

 could colonize his orchards with them, he would escape much 

 loss. 



That curious member of the cuckoo family known in the 

 Southwest as the Chaparral Cock, or Roadrunner, is especially 

 noted for its speed on foot and its droll manner of darting 

 about in pursuit of its food. Its economic interest lies 

 wholly in what it eats. Insects, snails, lizards, small birds, 

 and snakes are food for it. It is even credited as an enemy 

 of the rattlesnake. It is occasionally tamed and allowed to 

 go at will about the premises to wage war on mice and other 

 household pests, though it generally becomes so mischievous 

 that it proves a nuisance rather than a benefit. 



