256 BULLETIN 15 5, UNITED STATES NATIONAL MUSEUM 



gravel-surfaced knolls bearing little vegetation. Apparently they 

 were located on their breeding grounds with nesting about to begin, 

 as males swung back and forth through the air in zigzag course, 

 fifty yards from the earth, each one confining himself to a limited 

 area which apparently was his chosen nesting territory. As they 

 flew they called chitty-chit chitty-chit chitty-chit, a rasping note 

 that in tone and utterance sounded almost exactly like the call of a 

 katydid. At intervals they swept suddenly down through the air, 

 turning just before reaching the earth to produce a whirring boom 

 that was higher pitched, weaker, and less resonant than that of the 

 nighthawks of the minor group in the United States. To keen ears 

 this was barely audible at fifty yards. 



In the summer of 1927 Danforth reported nighthawks at Les 

 Cayes. Poole and Perrygo recorded a dozen at Plaine Mapou on 

 Gonave Island March 3 to 14, 1929 but did not collect specimens. 



After careful comparison it appears that two forms of nighthawk 

 come to Hispaniola of which the Cuban bird appears in passage to 

 or from nesting grounds elsewhere, while the breeding bird as shown 

 by Abbott's specimens is the Bahaman nighthawk, G. m. vicinus. 

 Specimens from Tortue and Port a 1'Ecu, and a male taken by Wet- 

 more at Hinche, five in all, agree with vicinus from the Bahama 

 Islands in being pale above and lighter below than the Cuban bird. 

 In fact they average slightly lighter than most Bahaman birds. 

 Measurements are as follows (in millimeters) : 



One male, wing 169.5, tail 90.8, culmen from base 7.0 and tarsus 

 13.4. 



Four females, wing 167.5-175,0 (172.5); tail 87.6-94.3 (91.5): 

 culmen from base 7.0-7.7 (7.2) ; tarsus 13.4-14.2 (13.8). 



As a matter of convenience here all records in literature are cited 

 under vicinus though part may refer to the other form. Since the 

 breeding bird of Hispaniola proves to be vicinus that is probably the 

 race that nests on Porto Rico, instead of gundlachii as has been 

 supposed. 



The relationship of the Cuban bird gundlachii and the Bahaman 

 form vicinus to the nighthawks of the minor type of North America 

 is puzzling. From all appearances the birds of the Greater An- 

 tilles and Bahamas are merely geographic races of the continental 

 type yet the calls of the two from observations made by Wetmore 

 in Haiti (where he collected both vicinus and gundlachii) are radi- 

 cally and entirely different. The call of North American minor in 

 its various geographic races is a loud almost raucous peent or pe-ernt 

 that announces the presence of these birds at a great distance, while 

 the boom of the male is a resonant, roaring sound that may be heard 

 likewise over a wide radius. The katydidlike chitty-chit of the 



