40-2 



SYSTEMATIC SYNOPSIS.— PASSEBES— OSCINES. 



has lately been added ; there are several others in the warmer parts of America, all of the same 

 irregular and objectionable tendencies. 



Analysis of Species and Varieties. 



(f, steely black with browu Lead. 



Larger: J", wing over 4.00 ; tail over 3.00 : 9, wing about 3.75; tail about 2.75 ater 313 



Smaller: ^f, size of $ of the foregoing obscurus 314 



(f, brassy black, including head ; eyesred; wing near 5.00; tail nearly 4.00 ceneus 315 



313. M. a'ter. (Lat. atec, black. Fig. 258.) Common Cowbied. Cuckold. (J, adult: Lus- 

 trous green-black, with steel-blue, purple, and violet iridescence. Head and neck deep wood- 

 brown, witli some purplish lustre. Bill and feet black. Length 7.50-8.00; extent 13.50; 

 wing about 4.50, at least over 4.00 ; tail about 3.25 ; bill 0.70 ; tarsus 1.00-1.10. ? , adult : 

 An obscure-looking bird, dusky grayish-brown, nearly uniform, but paler below than above, 

 where most t)f the feathers have dusky centres, and most of those of the under parts with dark 

 shaft lines ; giving a somewhat streaky appearance. There is some gloss on the upper parts, 

 particularly (m the wings and tail, where a slight greenish lustre is usually evident. Bill 

 blackish-hrowu, paler below ; feet lilackish-brown. Smaller than the (J. Length 7.00-7.50; 

 wing about 3.75; tail 2.75. Young g 9 : Similar to the ? adult; still duller, and more 



-_ variegated ; upper parts dusky brown, the 



^, - ^ ^tSBTTP feathers skirted with gray, producing a set 



■^^ ^ '' ^5^ ^^^^B °^ semicircles on the back ; below, pale 



Jtia^B^Pf?^ 'SF griiyish, or even ochrey-brown, everywhere 



•a^s.' 1"' ■ ttS streaked with dusky. The sexual difference 

 in size soon appreciable, and the black of 



A the $ soon begins to appear in patches. 



i'*""'<^S«**'>rt7''3B^^^**'^*'***^'vV'^n ^' ■'^™' ^'^ l'"'S<' ; migi-atory, abundant, 

 " "'^ " " " ^J^ W'^l • * 'Jx*^ "-s!^ gregarious, polygamous, parasitic. The 



5 "—'J^ '"" *~'?Cr»/^iteicS .singular habits of this bird, shared by others 



/ — ».'',,_'*°^» i^^^s ^ — ^ "' ''"^ genus, form one of the most inter- 



"" ><■' '••!,]lC!!&i. > ^^_^^i^^^^'^^ esting chapters in ornithology. Like the 



^ European cuckoo, it builds no nest, laying 



Fig. 258. — Cowbird, reduced. (Sheppard del. its eggs by stealth in the nests of various 

 Nichols Bc.) other birds, especially warblers, vireos, and 



sparrows ; and it appears to constitute, furthermore, a remarkable exception to the rule of 

 conjugal affection and fidelity among birds. A wonderful provision for the pei-pctuation of the 

 species is seen in its instinctive selection of smaller birds as the foster-parents of its offspring; 

 for the larger egg receives the greater share of warmth during incubation, and the lustier young 

 cowbird asserts its precedence in the nest ; while the foster-birds, however reluctant to incu- 

 bate the strange egg (their devices to avoid the duty are sometimes astonishing), become assid- 

 uous in their care of the foundling, even to the neglect of their <.iwn young. The cowbird's 

 egg is said to hatch sooner than that of most birds : this would obviously confer additional 

 advantage. The list of birds in whose nests cowbirds' eggs have been found includes a large 

 number of finches, warblers, greenlets, flycatchers, etc. ; there seems to be really little choice. 

 While small species are usually ^'ictimized, this is not always the ease. I have found eggs in 

 nests of the kingbird and towhee bunting. In the West, where cowbirds swarm about the ranches 

 and settlements, it is the rule, I almost said, to find their eggs in nests of the prairie Frin- 

 gillidcE, etc. The egg is usually single ; sometimes 2, 3, even 4 are found in a nest ; they 

 range from 0.80-1.00 in length, by 0.65-0.70 in breadth, and are white, fully speckled and 

 dashed with browns and neutral tints. 



314. M. a. obscu'rus. (Lat. 0&scMn<s, dark.) DwAEF CowBlRD. Similar; smaller; (J the size 

 of 9 M. ater: 9 under 7-00; wing 3.33; tail 2.33. The difi'erence is strongly marked, and 



