244 BULLETIN 17 6, UNITED STATES NATIONAL MUSEUM 



Dr. H. C. Oberholser (1914) describes it as "resembling Chordeiles 

 virginianus sennetti^ but decidedly smaller; general tone of upper 

 parts lighter and more ochraceous, the light areas more buffy or 

 ochraceous (less grayish or whitish) and somewhat more extensive; 

 and the dark brown areas of anterior lower surface less grayish." 

 He remarks further: "This heretofore unrecognized race seems to 

 be in color most nearly like Chordeiles virginianus sennetti^ though 

 in this respect also near Chordeiles virginianus howelli and probably 

 in reality most closely resembling this form, which it adjoins 

 geographically." 



Mr. Cherrie's type specimen seems to have been lost; at least, 

 neither he nor Dr. Oberholser have been able to locate it, but the 

 full description of the type convinced Dr. Oberholser that "there is 

 no doubt that Mr. Cherrie had in hand a male nighthaAvk of the 

 virginianus style in fully grown juvenal or first autumn plumage, 

 not adult, as he supposed. Allowing for this immaturity, the char- 

 acters that Mr. Cherrie gives are just those distinguishing the small, 

 pale race which summers in southern Texas." 



The nesting habits, eggs, food, and behavior of this nighthawk 

 probably do not differ materially from those of other races living in 

 similar environment. The measurements of 43 eggs average 29.3 by 

 21.4 millimeters; the eggs showing the four extremes measure 32.5 

 by 22.5, 27.1 by 21.3, and 28.4 by 20.6 millimeters. 



CHORDEILES ACUTIPENNIS TEXENSIS Lawrence 

 TEXAS NIGHTHAWK 



Plates 37-39 

 HABITS 



The Texas nighthawk is a large, pale race of the species Chordeiles 

 acutipennis, which is divided into additional races in Central and 

 South America. Our 1931 Check-list states that it "breeds in the 

 Lower Austral Zone from north-central California, southern Nevada, 

 southern Utah, and central Texas south to about lat. 30° in Lower Cali- 

 fornia, and to south-central Mexico." 



The Texas nighthawk is a common summer resident in the warmer 

 portions of the Southwestern United States; we found it generally 

 distributed throughout the arid desert regions of Arizona, along the 

 river bottoms and dry washes, and, in the more fertile regions, about 

 the sloughs and coursing over the alfalfa fields, H. S. Swarth 

 (1920) writes: "In all the valley towns of southern Arizona the 

 Texas nighthawk is a familiar sight. It has not, as yet, acquired the 

 habit of its eastern relative of nesting upon the flat roofs of build- 

 ings, but throughout the summer the birds may be seen in numbers 



