40 



usually be seen and heard in great numbers about any large 

 city as they circle high in the air or sweep in graceful 

 curves over the tops of the buildings. In the country they 

 frequent the edges of woods or burned areas where flying 

 insects are the most easily secured. They are very sociable 

 birds and often hunt in large flocks. I have watched fully 

 a hundred of them at a time as they swept back and forth 

 across a large field^ curving, skimming and cavorting about 

 in a perfect maze; with never a falter they crossed and re- 

 crossed paths, each seeming to read the other's mind per- 

 fectly so that imminent collisions were always averted. 



Nighthawk bills are very small but the mouth opens to 

 a point below the eyes so that the gape is enormous. Their 

 food is entirely caught while on the wing, — either by snap- 

 ping up individual moths or beetles or by dashing through 

 swarms of gnats, with wide-open mouths gathering them in 

 by the hundreds. 



During the mating season the males often perform won- 

 derful evolutions in the air. Sometimes they make perpen- 

 dicular descents from high altitudes shooting downwards 

 with folded wings at bullet-like speed and turning upward 

 so suddenly that the air rushing through their wings pro- 

 duces a hollow "booming." On a warm, still evening during 

 earl}^ June and the latter part of May, these "boomings" 

 may very frequently be heard. 



Although so exceedingly expert in aerial evolutions, 

 Nighthawks are very awkward when on the ground. Their 

 small, weak feet give them a very wobbly gait so that they 

 often require the services of their wings to keep their bal- 

 ance. When roosting on the limbs of trees and fence rails 

 they almost invariably sit lengthwise, their mottled plumage 

 and motionless attitudes rendering them very inconspicious. 



They build no nest at all, — just l^v their two mottled 

 eggs on the bare ground, usually choosing a small sandy 

 spot in a pasture or in very open woods; frequently they 

 are laid in hollows on rocks or even (very commonly) on 



