164 LIFE HISTORIES OF NORTH AMERICAN BIRDS. 



surprised to find that skins taken by me in the vicinity of Fort Klamath, Oregon, 

 and now in the United States National Museum collection, are almost indistin- 

 guishable from tvpical specimens from the eastern United States; they certainly 

 approach the eastern bird far more closely than the lighter-colored western 

 subspecies. The same remarks apply to specimens from southern British 

 Columbia, Washington, and northern California. Along the respective borders 

 of their ranges the two forms overlap sometimes for considerable distances, the 

 present species occupying the outskirts of the better-timbered tracts, while the 

 western race is principally restricted to the more open prairie country. 



The Nighthawk is generally a common summer resident throughout the 

 eastern United States north of latitude 35°, while south of this it is more irreg- 

 ularly distributed, but breeds, to some extent at least, in all of our Southern 

 States, excepting perhaps Florida and the immediate vicinity of the Gulf coast. 

 Its common name is somewhat of a misnomer; it is by no means nocturnal in 

 its habits; intact, it is diurnal and crepuscular, and it is not at all unusual to see 

 numbers of these birds on the wing on bright sunny days; but it does most of 

 its hunting in cloudy weather and in the early mornings and evenings, retiring 

 to rest soon after it becomes dark; but during bright moonlight nights it 

 keeps up its flight somewhat later and 1 have heard its calls as late as eleven 

 o'clock. 



It is one of our most graceful birds on the wing and its aerial evolutions 

 are truly wonderful; one moment it may be seen soaring through space without 

 any apparent movement of its pinions, and again its swift flight is accompanied 

 by a good deal of rapid flapping of the wings, like that of our Falcons, and 

 this is constantly more or less varied by numerous twistings and turnings. 

 While suddenly darting here and there in pursuit of its prey I have seen one 

 of these birds shoot almost perpendicularly upward with the swiftness of an 

 arrow in pursuit of some insect. Its tail appears to assist it greatly in these 

 sudden zigzag changes, being partly expanded during most of its complicated 

 movements. I know of no more interesting sight than to watch a number of 

 Xighthawks while engaged in feeding, skimming close to the ground or over 

 the waters of some pond or lake, gliding swiftly along in all kinds of serpentine 

 gyrations with the utmost grace and ease, and no matter how limited the space 

 may be and how numerous the birds, none will ever get in the way of each 

 other; all their movements seem to be accomplished in the most harmonious 

 manner. 



The Nighthawk is a social bird while on the wing, and I have seen fully a 

 hundred at one time hawking over a small mountain meadow or a pond, and 

 they certainly seemed to enjoy each other's company. While on the wing their 

 querulous and squeaky call note, sounding like "seh-eek, adi-eek" or "speek- 

 speek," is repeated at different intervals. Mr. W. E. Grover describes this note 

 as a sharp, mowing "mueike," and it is also said to resemble the word "beard," 

 uttered in a whisper. When disturbed while sitting on its eggs it usually utters 

 a low, purring or chuckling sound; and during early spring the male frequently 



