BIRDS OF AKGENTINA, PARAGUAY, URUGUAY, AND CHILE 387 

 MOLOTHRUS BADIUS BADIUS (Vieillot) 



Agelaius hadius Vieillot, Nouv. Diet. Hist. Nat., vol. 34, 1819. p. 535. 

 (Paraguay and Rio de la Plata.) 



The bay-winged cowbird was widely distributed, as the following 

 records indicate : Las Palmas, Chaco, July 17 to 30, 1920 (two males 

 July 17) ; Kilometer 110, west of Puerto Pinasco, Paraguay, Septem- 

 ber 23; Lavalle, Buenos Aires, October 23 to November 1 (female, 

 October 2.5, male, November 1) ; Victorica, Pampa, December 23 to 

 29 (male, December 24) ; San Vicente, Uruguay, January 27 to 31, 

 1921 (juvenile male, January 27, juvenile female, January 31) ; Laz- 

 cano, Uruguay, February 5 to 8 ; Rio Negro, Uruguay, February 17 

 (juvenile female) to 19; Potrerillos, Mendoza, March 21; Tunuyan, 

 Mendoza, March 25 to 28; Tapia, Tucuman, April to 14 . Speci- 

 mens taken do not offer any marked variation. 



Hellmayr" has named a form of this species from northern and 

 central Bolivia (type locality, Chuquisaca) as Molothnis badius 

 holivianus, distinguished by larger size and somewhat browner shade 

 above. A skin in the United States National ISIusuem from Men- 

 doza is somewhat browner above than others and may represent an 

 approach to holivianus though it is no larger than others from the 

 Province of Buenos Aires. A male taken at Jujuy, July 29, 1922, by 

 D. S. Bullock, is also somewhat broAvner above than the average, but 

 has a wing length of onlj^ 91 mm. I have seen skins from northern 

 Buenos Aires with the wing 95 mm. long, a greater size than indi- 

 cated by Hellmayr in the paper mentioned for the typical form. 

 The shortened wing tip of Molothrus Radius distinguishes it struc- 

 turally from other cowbirds and warrants the use of Agelaioides 

 Cassin"'^ as a subgenus at least. Further investigation may reveal 

 other differences that will warrant generic separation. The question 

 has been discussed briefly by Mr. Ridgway.'^ 



Stempelmann and Schulz *° in a list of the birds found in Cordoba 

 have included this species as Deinelioteucus badius, without com- 

 ment as to the source of the generic name used. Demelioteucus thus 

 appears to be new here since I have not yet found it at any other 

 place. At this point it is a synonym of Agelaioides Cassin. 



The breeding season for this bird apparently extends from Decem- 

 ber to January. At the end of December, in the stunted open forest 

 about Victorica, Pampa, these cowbirds were found in twos and 

 threes about large, deserted stick nests of various tracheophones 

 and showed considerable solicitude as I approached. At the end of 



"Verb. Orn. Gks. Bayern, vol. 13, Feb. 25, 1917, p. 108. 



™ A'jclaioules Oassin, Proc. Acad. Nat. Sci. Philadelphia, vol. 18, 1866, p. 15. Type 

 Agelaius badius Vieillot. 



"» Birds North and Middle America, vol. 2, 1902, pp. 205, 206, and 207. 

 «"Bol. .icad. Nac. Cienc. Cordoba, vol. 10, 1890, p. 399. 



