CHORDEILES VIRGINIANUS. 13 



The Nacunda breeds in October, and makes no nest, but lays two 

 eggs on a scraped place on the open plain. Mr. Dalgleish says of the 

 eggs : " They are oval-shaped, and resemble much in appearance those 

 of the Nightjar, except that the markings, which are similar in character 

 to those of the latter, are of a reddish-brown or port-wine colour/' 



After the breeding-season they are sometimes found in flocks of 

 forty or fifty individuals, and will spend months on the same spot, 

 returning to it in equal numbers every year. One summer a flock of 

 about two hundred individuals frequented a meadow near my house, 

 and one day I observed them rise up very early in the evening and 

 begin soaring about like a troop of swallows preparing to migrate. I 

 watched them for upwards of an hour; but they did not scatter as on 

 previous evenings to seek for food, and after a while they began to rise 

 higher and higher, still keeping close together, until they disappeared 

 from sight. Next morning I found that they had gone. 



In Entrerios, Mr. Barrows tells us, this Goatsucker is an abundant 

 summer resident, arriving early in September, and departing again in 

 April. It is strictly crepuscular or nocturnal, never voluntarily taking 

 wing by daylight. In November it lays a pair of spotted eggs in a hollow 

 scooped in the soil of the open plain. These in shape and markings 

 resemble eggs of the Nighthawk (Chordeiles virginianus) somewhat, but 

 are of course much larger, and have a distinct reddish tinge. We 

 found the birds not uncommon near Bahia Blanca, February 17, 1881, 

 but elsewhere on the Pampas we did not observe them. 



243. CHORDEILES VIRGINIANUS (Om.). 

 (WHIP-POOR-WILL.) 



Chordeiles virginianus, Scl. et Salv. Nomencl. p. 96; Barrows, Auk, 1884, 

 p. 24 (Entrerios) ; Berlepsch, J.f. O. 1887, p. 120 (Paraguay). 



Description. Above black, varied and mottled with brown ; wings black, 

 with a broad white bar across the bases of the five outer primaries ; tail black, 

 with brown cross bands and a broad white subapical bar : beneath white, with 

 dense blackish cross bands ; breast blacker ; broad throat-band white ; bill 

 black ; feet pale brown : whole length 8*5 inches, wing 7*8, tail 4*0. Female 

 similar, but throat-band tawny and no white band on the tail. 



Hab. North and South America. 



The well-known " Whip-poor-Will " of the U. S. appears to extend 

 its winter-migration into Northern Argentina. Mr. Barrows has re- 

 corded the capture of two specimens of this species at Concepcion in 



