TEXAS NIGHTHAWK 251 



In general the vocul utterances of tbe Texas Nighthawk are of three kinds : 

 first a low soft cluck, repeated slowly ; second, a louder, querulous, nasal cry, 

 repeated more rapidly and used when two or more of the birds are together ; 

 third, a series of throaty staccato notes delivered in monotone so rapidly as 

 to be almost continuous, sustained for several seconds at a time and resumed 

 after a short pause as if for breath. This trill is usually given from the 

 ground, but sometimes also while flying. [The foregoing sentence was in- 

 correctly printed and was revised in a letter to the author.] It is used only 

 when the birds are undisturbed and is not ordinarily heard at close range. 

 While the tone is soft, the carrying power is great, and sometimes on summer 

 evenings when several of the nighthawks are about, the air seems filled with 

 an indefinable vibration. 



Alden H, Miller (1937) recognizes four main types of vocal notes: 



(1) Long-continued guttural trills, well characterized by Dawson as am- 

 phibian-like, but also remindful of the sound of a motor at a distance ; (2) 

 a twing like the picking of a banjo (Dawson) or, more prosaically, like the 

 twang of a jew's-harp; (3) staccato clucks; and (4) melodious trills of vary- 

 ing intensity, similar to those of western screech owls (Grinnell and Storer), 

 except for cadence. The twang and melodious trill may follow one another 

 in rapid succession. The guttural trill seemed not to enter into the courtship 

 on the wing. I could not be certain that this note was given on the wing at 

 all; its source always seemed stationary. The melodious trill was occasion- 

 ally given by birds perched in mesquite trees in the heat of midday. 



M. W. deLaubenfels (1925) heard an unusual note, both in Arizona 

 and again in Texas, which he described as "a loud ringing whistle — 

 whee-ee^y-poor-will. The notes were not at all like those of the 

 "Whip-poor-will, which are repressed and muffled by comparison." 



Dr. Merrill (1878) says: "The notes are a mewing call, and a very 

 curious call that is with difficulty described. It is somewhat like the 

 distant and very rapid tapping of a large woodpecker, accompanied 

 by a humming sound, and it is almost impossible to tell in what 

 direction or at what distance the bird is that makes the noise. Both 

 these notes are uttered on the wing or on the ground, and by both 

 sexes." 



Field marks. — The most conspicuous character by which the Texas 

 nighthawk can be distinguished from the nighthawks of the minor 

 group is the position of the white band (buffy in the female) in the 

 wing; in 7ninor this is about midway between the bend of the wing 

 and the tip; in acutipennis it is nearer the tip than the bend. The 

 Texas nighthawk is also somewhat smaller, rather browner, and has 

 a somewhat shorter and broader wing. But perhaps the most satis- 

 factory means of identifying the two species in the field is the decided 

 difference in the notes, as described under each; from the Texas 

 nighthawk one never hears the harsh, rasping peent note or sees the 

 plunging "booming" flight. 



Winter. — Dickey and van Rossem (1938) record this nighthawk 

 as an — 



