THE COVVBIRDS. 623 



incongruity and unfitness as we iiud in nests into wliicli other para- 

 sites intrude, there is no reason here to regard the foster parents' aftec- 

 tion as blind and stupid, tlie similarity beiug close enough to batSe 

 the keenest sagacity. Nor can the instinct here appear in the light of 

 an outrage on the maternal affection, for the young 71/. rufoaxillaris 

 possesses no advantage over its foster brothers. It is not endowed 

 with greater strength and voracity to monopolize the attentions of the 

 foster parent or to eject the real offspring; but being in every particu- 

 lar precisely like them, it has only an equal chance of being preserved. 

 To this wonderful parasitical instinct we may well ai)ply Darwin's 

 words, when speaking of the architecture of the hive bee, "Beyond 

 this stage of perfection natural selection could not lead." 



MOLOTHRUS BADIUS, Vieill. liay-winyed C'owbird. 



Mololhrus hadiiis, Bukm., La-Plata Ueise, n, p. 495 (Parana and Tiicixmau). ScL. 

 et Salv., Nomenel., p. 37; Hudson, P. Z. S., 1874, p. 163 (Bueuos Ayres) ; 

 DuRNKORD, Ibis, 1877, p. 174 (Buenos Ayres); Scl., Cat. B., xi., p. 338. 



Description. — Dull gray, beneath rather paler; wings chestnut; tips 

 of primaries, inner portions of secondaries, and tail blackish; bill and 

 feet black; total length, 7.5 inches; wing, 3. a; tail, o. Female similar. 



Habitat. — Argentina, Paraguay, and Bolivia. 



In this species the sexes are alike; the plumage of the body is gray- 

 drab color, with a black spot between the eye and beak; tail dark, the 

 quills cinnamon color; beak and legs black. Azara, describing it under 

 the name of Tordo pardo ro.iiso, says it is a rare bird, so that it has 

 probably increased since his time, as it is now quite common in the Plata 

 district. 



The Bay-wings usually go in small flocks, numbering from 10 to 30 

 individuals, and are not migratory, but in winter they travel about a 

 great deal from place to place without extending their journeys more 

 than a few miles in any direction. They are fond of coining about 

 houses, and are frequently seen pecking at the fresh meat hanging out 

 of doors; and, like otlier birds of the same tribe, feed chiefly on the 

 ground. They spend a great portion of their time on trees, are familiar 

 with man, and inactive, and in their motions singularly slow and delib- 

 erate. Their hmguage is varied. Curiosity or alarm is expressed by 

 trilling notes, and before <iuitting a tree all the birds of a flock cere- 

 moniously invite each other to fiy with long clear notes, powerful enough 

 to be heard a (juarter of a mile away. 



They also sing a great deal m all seasons, the song being composed 

 of soft, clear, rather sweet notes, variously modulated, uttered in a 

 leisurely manner, and seeming to express a composed frame of mind, 

 all the birds in a flock singing m concert. During the cold season the 

 flock always finds some sheltered sunny spot on the north side of a 

 wood pile or hedge, where they spend several hours every day, sitting 

 still and singiiig in their usual quiet, soft style. 



