NIGHTHA WKS 347 



Texas Nighthawk. Chordeiles acutipennis texensis Lawrence 



Field characters. — Same as those for Pacific >.'ightha\vk (which see), but narrow 

 white band across long flight feathers (primaries) scarcely more than its own length 

 from end of wing; in other words this white bar is well beyond middle of wing rather 

 than close to midway. Voice: A mellow, long-continued, rolling trill. 



Occurrence. — Common summer visitant to Lower Sonoran Zone. Seen in vicinity of 

 Snclling and near Lagrange. Active during evening and morning twilight and during 

 the night. Forages close over ground, rarely rising over .50 feet into the air. Rests 

 during the day on ground in shade of bush or in open gravelly situation. 



The Texas Nighthawk is a summer visitant to the w^armer parts of the 

 southwestern United States and in the Yosemite section it was observed 

 only at our lowest stations, west of the foothills. On the evening of 

 May 25, 1915, 3 were noted in flight over the river bottom near Snelling, 

 the first at 7 :15 p.m., well after sundown. The next evening 2 were abroad 

 at about the same hour, 'hawking' over the alfalfa fields and doubtless in 

 search of the night-flying insects to be found there. 



When we established camp on a gravelly bench beside the Tuolumne 

 River below Lagrange on the evening of May 5, 1919, it was evident at 

 once that we had closely invaded the special domain of this nighthawk, 

 for two pairs were coursing about activety at 6:30 p.m. (sun-time). The 

 mellow trilling notes of the males were heard off and on throughout the 

 succeeding night, so the birds must have been active during most of the 

 hours of darkness. And on the following morning they were flying around 

 now and then until about 8 o'clock. 



It was the height of the nesting season and the birds were courting 

 actively. A male, distinguished by the larger and whiter bands on his 

 wings and the more conspicuously Avhite chin patch, was pursuing a 

 female. The male always followed, but at close range, rarely more than 

 two lengths behind the female. Occasionally a second male joined in 

 the pursuit, but evidently with only partial interest, for he frequently 

 circled off by himself. Less often the two male birds pursued one another, 

 weaving an irregular course up and down, in and out, but never rising 

 much if any over 50 feet above the ground. The progress through the 

 air was ea.sy yet swift, a few strokes of the long wings .sufficing to carry 

 the birds through a long glide. Often as they pa.ssed close over the observer 

 the barred pattern of the under surface was clearly visible, as was also 

 the broad subterminal band of white on the lower side of the tail. While 

 the males were on the wing their low crooning trills were heard almost 

 continually, swelling and diminishing as the birds approached or departed. 

 When they rested on the ground between flights they gave the same notes, 

 prolonged but also with longer intervals of quiet. One trill lasted 25 



