RIO GRANDE REDWING 157 



AGELAIUS PHOENICEUS MEGAPOTAMUS Oberholser 



Rio Grande Redwing 

 HABITS 



Oberholser (1919a) describes this redwing as "similar to Agelaius 

 phoeniceus richmondi from southern Vera Cruz and Tabasco, Mexico, 

 but larger; female more grayish above and less ochraceus below." He 

 gives as its distribution — 



central southern Texas and northeastern Mexico. Breeds north to central Texas ; 

 west to eastern Coahuila; south to Nuevo Leon and northern Vera Cruz; and east 

 to Tamaulipas and the Brazos River in Texas. 



* * * This new subspecies differs from Agelaius phoeniceus phoeniceus in some- 

 what longer wing, rather shorter bill, and much lighter coloration of the female; 

 from Agelaius phoeniceus sonoriensis and Agelaius phoeniceus for lis in very much 

 smaller size; and from Agelaius phoeniceus neutralis in greatly inferior size and 

 paler female. Birds belonging to this geographic race have hitherto been referred 

 to Agelanis phoeniceus richmondi, but they are so different from typical representa- 

 tives of the latter that subspecific separation seems desirable. It is a larger and 

 less brownish edition of Agelaius phoeniceus richmondi, and replaces that form in 

 Texas, Tamaulipas, and Nuevo Leon. It seems to be more or less permanently 

 resident, as no specimens have been taken outside of its breeding range. 



Southward it passes into Agelaius phoeniceus richmondi somewhere in the 

 northern part of the State of Vera Cruz; westward through central western Texas 

 into Agelaius phoeniceus neutralis; northward in central northern Texas into 

 Agelaius phoeniceus predatorius; and along the coast of southeastern Texas beyond 

 the Brazos River into Agelaius phoeniceus phoeniceus of the southeastern United 

 States. 



In considering Oberholser's names, as used above, allowance must be 

 made for some changes that have been made since his paper was 

 written. 



Nesting. — Although he did not recognize it as a subspecies, George 

 B. Sennett (1878) was the first to give any information on the nesting 

 habits of this blackbird in the vicinity of Brownsville, Tex.; he 

 writes ; 



"I found this species breeding in great numbers along the Lower 

 Rio Grande. They usually build their nests low, among the rank 

 growth of weeds and willows that spring up in the resaca beds after 

 the annual overflows of the river. One nest, however, I found at least 

 20 feet high in a mczquite-tree. It was composed of bleached grasses 

 and attached to a leaning branch; it was partly pensile, and looked 

 like a large nest of the Orchard Oriole, Icterus spurius. I was deceived 

 into climbing for it." 



On May 23, 1923, near Brownsville, I found a number of nests of the 

 Rio Grande redwing, containing from three to four eggs, placed from 3 



