446 LIFE HISTORIES OF NORTH AMERICAN BIRDS. 



ovate. They are pale bluish green in color and unspotted, resembling the eggs 

 of the Black-throated Sparrow and Blue Grosbeak in this respect, but are much 

 larger. 



The average measurement of thirty-eight specimens in the United States 

 National Museum collection is 23.11 by 18.29 millimetres, or 0.91 by 0.72 inch. 

 The largest egg of the series measures 24.64 by 18.80 millimetres, or 0.97 by 

 0.74 inch; the smallest, 21.84 by 16.76 millimetres, or 0.86 by 0.66 inch. 



The type specimen, No. 26349 (PL 6, Fig. 9), from the Ralph collection, 

 taken from a nest of Audubon's Oriole containing three eggs and also three of 

 the Red-eyed Cowbird's, was obtained on May 8, 1893, in Cameron County, 

 Texas, and represents about .an average egg of this species. 



173. Xanthocephalus xanthocephalus (Bonapartej. 



YELLOW-HEADED BLACKBIRD. 



Icterus xanthocephalus Bonaparte, Journal Academy Natural Sciences, Phila., V, 1826, 223. 

 Xanthocephalus xanthocephalus Jordan, Manual of Vertebrates, ed. 4, 1884, 92. 

 (B 404, C 213, R 260, C 319, U 497.) 



Geographical range: Western North America; from northern Mexico and Lower 

 California, through Texas, New Mexico, Arizona, and California, north to southern British 

 Columbia, and iu the interior of the Dominion of Canada, in the Provinces of Athabasca 

 and Keewatin, to about latitude 58° 30' N; east to Manitoba, and in the United States 

 regularly to Wisconsin, northern Illinois, northwestern Indiana, Missouri, and the Indian 

 Territory. Casually to Ontai'io and Quebec, Canada, Pennsylvania, New York, the New 

 England States, the District of Columbia, South Carolina, Florida, and Louisiana. Acci- 

 dental in the Island of Cuba and in Greenland. 



The breeding range of the Yellow-headed Blackbird is, I believe, coex- 

 tensive with its regular geographical distribution, although we "have no positive 

 information that it breeds in Texas and in the Indian Territory. It is a well- 

 known and abundant winter resident, however, along the Gulf coast and in 

 the lower Rio Grande Valley, in Texas, and it.has been observed there up to the 

 latter part of April. In looking over the series of eggs of this species I find 

 that the United States National Museum contains a set of three, originally part 

 of Dr. Berlandier's collection, made in the vicinity of Matamoras, Mexico, and 

 received from Lieutenant Couch, in 1858, which, although in a poor state of 

 preservation, can readily be identified as belonging to this bird. But in the 

 almost impenetrable tangle and undergrowth with which many of the lagoons in 

 that section of country are surrounded, which localities are mainly resorted to 

 by these birds during the breeding season, it is an easy matter to overlook even 

 such extensive colonies as are occasionally found at that time of year on its 

 regular breeding grounds farther north, and I therefore believe that it will yet 

 be found nesting in Texas. 



The Yellow-headed Blackbird, while common in suitable localities during 

 the breeding season throughout portions of our Northern and Western States, is 



