﻿482 PROCEEDINGS OF THE NATIONAL MUSEUM vol. loo 



SPECIMEN COLLECTED 



1 ? , Cantaura, June 1, 1948; gonads slightly enlarged; brood patch evident; 

 iris brown; gizzard contained tiny insects. 



An adult in good plumage, agreeing very well with another from 

 British Guiana. 



This tiny nighthawk was recorded over the savanna and woods edge 

 during March and June. It was undoubtedly present in other months 

 but not recorded, as the collector experienced considerable difficulty 

 in distinguishing it with any certainty from the Chordeiles. 



The example collected was one of three which were chasing one 

 another over the savanna, giving a (vocal?) beep note as they passed. 



Local name, "aguaitacamino." 



CHORDEILES ACUTIPENNIS ACUTIPENNIS (Hermann) 



Caprimulgus acutipennis Hermann, Tabula aflSnitatum animalium, 1783, p. 230 

 (Cayenne). 



SPECIMENS COLLECTED 



1 cf, 4 9 , Cantaura, September 1, 1947, May 22, August 20, September 24, 

 and October 6, 1948; gonads greatly enlarged in the May 22 bird, small in all 

 the others. 



1 cT (labeled ?, but cf in plumage), November 7, 1947; gonads small; iris 

 brown; gizzard contained "stink bugs." 



The Cantaura male had the bill black, iris dark brown, feet brown; 

 its gizzard contained small beetles and winged ants. It was shot 

 from a flock of about 25 birds, all apparently of the same kind. The 

 females also had black bills, brown irides and feet, and their gizzards 

 also contained small beetles and winged ants. 



The size variations in this bird are so great that one is almost 

 led to wonder if there may not be two very similar species, one smaller 

 and one larger, that occur together. Thus three of the Cantaura 

 females have wing lengths of 142.5, 145, and 147.3 mm., respectively, 

 while the fourth one has a wing 162 mm. long. A similar situation 

 was reported for this species in another collection (Friedmann, Proc. 

 U. S. Nat. Mus., vol. 97, 1948, p. 412) where two males from the 

 Orinoco were found to have wings measuring 156 mm. in length while 

 a third one from the same place measured 166 mm. However, it 

 seems best to look upon this nighthawk as a very variable single 

 entity. 



Comparison of these Venezuelan birds with a long series from 

 northern Colombia (Bolivar, Magdalena, Santa Marta, Santander del 

 Norte) shows that Colombian females average larger than the Ven- 

 ezuelan birds seen, the limits of variation in wing length of the Colom- 

 bian birds being 152 to 181 mm. Of eight Colombian females four 

 were below the upper limits of Venezuelan ones, and four were much 

 larger, while of the four Venezuelan birds three were smaller than the 



