600 KEPORT OF NATIONAL MUSEUM, 1893. 



3.70-3.80, culinen 0.85-0.90, tarsus 1.15-1.25. Young male entirely 

 blackish, with distinct gloss only on wings, etc.; the lower parts, back, 

 etc., without bronzy luster. Adult, female : Above dark brownish gray, 

 the feathers sometimes showing distinct dusky shaft streaks. Length 

 about 8-8.50, wing about 4.10, tail 3.25, culmen 0.75, tarsus 1.05. 



Geographical range. — Mexico and Central America, north to southern 

 Texas, south to Panama. 



The breeding range of the Red-eyed or Bronzed Cowbird, a larger 

 and darker colored species than the two preceding, coincides with its 

 geographical distribution in the United States, and extends, as far as 

 known, north and eastward only to Bexar County, Tex., where Mr. H. 

 P. Attwater reports it as a rare summer resident near San Antonio, 

 and found one of its eggs in the nest of a Bullock's Oriole in that 

 vicinity. 



We are indebted to Dr. James C. Merrill, U. S. Army, for the addi- 

 tion of this interesting species to our fauna, who first recorded it in the 

 Bulletin of the iSTuttall Ornithological Club, Vol. i, 1876, p. 88, as an 

 abundant summer resident in the vicinity of Fort Brown, Tex. A full 

 account of the breeding habits of this species by Dr. Merrill may be 

 found in the above-mentioned bulletin, Vol. ii, 1877, pp. 85-87, from 

 which I extract the most interesting notes : 



My first specimeus were taken at Hidalgo, oa the Rio Grande, 70 miles northwest 

 of Fort Brown, where, however, they are not so abundant as lower down the river. 

 Here they are common throughout the year, a small proportion going south in winter 

 Those that remain gather in large flocks with the Long-tailed Grackles, common 

 Cowbirds, and Brewers, Red-winged, and Yellow-headed Blackbirds; they become 

 very tame, and the abundance of food about the picket lines attracts them for miles 

 around. C. rohustus is readily distinguishable in these mixed gatherings from the 

 other species by its blood-red iris and its peculiar top-heavy appearance, caused by 

 its habit of puffing out the feathers of the head and neck. 



This habit is most marked during the breeding season and in the male, but is seen 

 throughout the year. 



About the middle of April the common Cowbird, Brewer's, and Yellow-headed 

 Blackbirds leave for the north ; the Long-tailed Grackles have formed their colonies 

 in favorite clumps of mesquite trees; the Redwings that remain to breed have 

 selected sites for their nests; the Dwarf Cowbirds, MoJoihvns pecorls ohscurus, arrive 

 from the south, and CaVothnis robustiis gather in flocks by themselves and wait for 

 their victims to build. The males have now a variety of notes, somewhat resembling 

 those of the common Cowbird Molothrus pecoris, but more harsh. During the day 

 they scatter over the surrounding country in little companies of one or two females 

 and half a dozen males, returning at nightfall to the A'iclnity of the picket lines. 

 While the females are feeding or resting in the shade of a bush the males are eagerly 

 paying their addresses by puffing out their feathers, as above noted, strutting up and 

 down, and nodding and bowing in a very odd manner. Every now and then one of 

 the males rises in the air, and poising himself 2 or 3 feet above the female, flutters 

 for a minute or two, following her if she moves away, and then descends to resume 

 his puffing and bowing. This habit of fluttering in the air was what first attracted 

 my attention to the species. In other respects their habits seem to be like those of 

 the eastern Cowbird (J/, pecoris). 



My first egg of C. rohustus was taken on May 14, 1876, in a Cardinal's nest. A few 

 days before this a soldier brought me a similar egg, saying he found it in a Scissors- 

 tail's {Milvulus) nest. Not recognizing it at the time, I paid little attention to him, 



