BIRDS OF PENNSYLVANIA. 181 



dish white and brown ; wing quills quite uniformly brown ; the five outer prima- 

 ries with a white blotch midway between the tip and carpal joint, not extending on 

 the outer web of the outer quill ; tail with a terminal white patch. 



Female without the caudal white patch, the white of the throat mixed with red- 

 dish. Length about 9^ inches ; extent about 23 ; wing about 8 inches. 



Habitat. Northern and eastern North America, east of the Great Plains, south 

 through tropical America to Buenos Ayres. 



The Nighthawk occurs in Pennsylvania as a common summer resident. 

 It usually arrives from its southern winter resorts, a few days after the 

 Whip-poor-wills have made their appearance. The note of the Night- 

 hawk is a short, sharp squeak. During the breeding season this bird 

 has a curious habit, when flying, of falling through the air with a loud 

 booming sound, which, as Nuttall has truly said, resembles the noise pro- 

 duced by blowing into the bung-hole of an empty hogshead. This pe- 

 culiar booming or whirring sound, which can be heard oftentimes to the 

 distance of a quarter of a mile or over, is produced, it is stated, by the 

 air rushing through the stiff wing feathers. The Nighthawk never 

 breeds in woods or thickets, but deposits her two eggs on the bare 

 ground or rocks in open situations ; the favorite breeding places are bar- 

 ren and rocky lands, though sometimes they have been known to de- 

 posit their eggs on roofs of buildings in large cities and towns, over 

 which these birds all day long may be seen or heard flying in pursuit 

 of their favorite insect prey. 



The eggs, elliptical in shape and about the same size as those of the 

 Whip-poor-will, so closely resemble the ground or pieces of rock on which 

 they are deposited, that they are frequently overlooked by persons 

 accustomed to search for them. The Nighthawk, like the Whip-poor- 

 will, manifests great affection for her eggs and young, and will re- 

 sort to numerous devices to induce you to follow her, when these treas- 

 urers are approached or discovered. It is stated that birds of this fam- 

 ily have a common habit, when their eggs or young are disturbed, of 

 removing them in their capacious mouths, to different localities. I have 

 known the Nighthawk to move its eggs a distance of over two hundred 

 yards, in less than one hour after I had examined them. In the breed- 

 ing season especially, these birds are frequently seen sitting lengthwise 

 on fences or on the limbs of high trees, in the vicinity of their breeding 

 grounds. Several pairs of Nighthawks may often be found breeding 

 within a few yards of each other. The Nighthawk, although oftentimes 

 observed flying about during the daytime, is particularly active in the 

 afternoon and in cloudy weather. This bird when on the wing, if not 

 too distant, can easily be recognized by the white spot on the primaries, 

 which is commonly spoken of as a "hole in the wing." During the lat- 

 ter part of August, these birds collect in large bands and leisurely pro- 

 ceed to winter quarters in Mexico, Central America and portions of 

 South America, etc. 



The somewhat prevalent idea that Nighthawks are destroyers of 



