THE RELATIONS OF BIRDS TO MAN. 3 



hatches and creepers, look after the insects on and beneath 

 the bark of both the trunk and branches ; the chickadees and 

 warblers and vireos and kinglets are always scrutinizing the 

 leaves for their inhabitants, and are assisted in the case of 

 the caterpillars and larger insects by the bluebirds, thrushes, 

 cherry-birds, and many others. 



The air is no less thoroughly supervised by our feathered 

 allies than are the grasses and the trees. Most insects at one 

 stage of their existence are aerial : by day the butterflies, the 

 beetles, some of the moths, the grasshoppers, the hosts of 

 two-winged flies, and many others are upon the wing ; while 

 by night an even greater host of moths, fire-flies and other 

 beetles, bugs, and many other insects are abroad. To keep 

 in check these hordes of flying things there are certain well- 

 marked groups of birds : 

 by day the swallows of 

 many species and the chim- 

 ney-swifts are constantly 

 patrolling the larger spaces 

 of the air, over both land 

 and water, capturing mil- 

 lions of these aerial insects ; 

 the kingbird, pewee, and 

 other fly-catchers, as well 

 as to a -more limited de- 

 gree the cedar-bird and 

 bluebird, capture the in- 

 sects that pass within their 

 range of vision as they 

 perch upon fence or stump 

 or tree; the warblers and 

 vireos catch those insects 



flying in the immediate vicinity of the green-leaved trees, 

 while the redstarts have well been named the fly-catchers 

 of the inner tree-tops ; by night the nighthawks and whip- 



