288 BLACKBIRDS, ORIOLES, ETC. 



sparrows, vireos, wrens, and warblers, the birds most frequently 

 imposed upon are so small that the cowbird's big, crowding nestling 

 will be the one to survive when it is a question of size and resisting 

 power." {Birds of Village and Field.) 



495a. M. a. obscurus (GmeL). Dwarf Cowbird. 



Similar to M. ater, but smaller. Male : length (skins) 6.00-7.10, wing 

 3.78-4.10, tail 2.43-2.87, bill .{j2-.70. Female : length (skins) 5.61-6.30, 

 wing 3.37-3.70, tail 2.27-2.62, bill .55-.62. 



Distribution. — Breeds from southern Texas to southwestern Arizona, 

 and south to Lower California and Mexico. 



Eggs. — Deposited in nests of other birds, similar to those of M. ater. 



GENUS CALLOTHRUS. 



496. Callothrusrobustus(Ca6.). Red-eyed Cowbird. 



Bill shorter than head, stout, conical, distinctly ridged, upper outline 

 slightly curved ; neck with soft, dense, erectile ruff ; four outer primaries 

 with inner webs curiously sinuated and emarginated. Adult male : iris 

 bright red ; body and erectile ruff black, with soft bronzy luster ; wings 

 and tail glossed with bluish, greenish, and purplish. Adult female : dull 

 black, somewhat glossed with bluish green ; neck ruffs much smaller than 

 in male. Young male : sooty black, under parts with feathers edged with 

 paler. Young female : paler and grayer than young male. Male : length 

 (skins) 7.75-8.80, wino- 4.40-4.73, tail 2.98-3.24, bill .88-.94. Female: 

 length (skins) 6.50-8.10, wing 3.84-4.16, tail 2.52-2.94, bill .78-.84. 



Distribution. — Breeds from southern Texas south through eastern Mex- 

 ico to Central America ; migrates to Panama. 



Eggs. — Deposited in nests of other birds, usually 4, pale bluish green, 

 unspotted. 



On the coast prairies of the Rio Grande Valley in Texas the red- 

 eyed cowbird may be seen on the roadside fences. His strikingly 

 red eyes and handsome glossy black coat mark him at a glance from 

 the other cowbirds, and when he raises his neck ruff he seems indeed 

 a distinguished personage. 



GENUS XANTHOCEPHALUS. 



497. Xanthocephalus xanthocephalus {Bonap.}. Yellow- 



headed Blackbird. 



Bill decidedly shorter than head, its depth through base less than half 

 the length of the exposed culmen ; culmen straight, flattened ; sexes dif- 

 ferent in size ; wing long and pointed ; tarsus nearly one fourth as long 

 as wing ; claws large, lateral ones reaching beyond base of middle one. 

 Adult male in summer : black except for yellow or orange of head, throat, 

 and chest, and white patch on wings. Adult male in winter : similar, but 

 yellow of top of head obscured by brownish tips to feathers. Adult 

 female : brownish, throat and chest dull yellowish, breast mixed with 

 white. Young male in first winter : similar to female, but larger and deeper 

 colored. Male : length (skins) 8.(>0-U).10, wing 5.32-5.73. tail 3.66-4.27, 

 bill .83-.99. Female : length (skins) 7.50-8.30. wing 4.33-4.64, tail 3.10- 

 3.45, bill .77-83. 



Distribution. — Western North America from British Columbia and Hud- 



