MOLOTHRUS BONARIENSIS. 



73 



shyer, inconspicuous individuals should be in such a minority; but the 

 reason is perhaps that the male eggs of the Cow- bird are harder-shelled 

 than the female eggs, and escape destruction oftener, when the parent 

 bird exercises its disorderly and destructive habit of pecking holes in 

 all the eggs it finds in the nests into which it intrudes. 



The Cow-birds are sociable to a greater degree than most species, 

 their companies not breaking up during the laying-season; for, as 

 they are parasitical, the female merely steals away to drop her egg in 

 any nest she can find, after which she returns to the flock. They 

 feed on the ground^ where in their movements and in the habit 

 the male has of craning out its neck when disturbed, they resemble 

 Starlings. The male has also a curious habit of carrying his tail raised 

 vertically while feeding. They follow the domestic cattle about the 

 pastures, and frequently a dozen or more birds may be seen perched 

 along the back of a cow or horse. When the animal is grazing they 

 group themselves close to its mouth, like chickens round a hen when 

 she scratches up the ground, eager to snatch up the small insects 

 exposed where the grass is cropped close. In spring they also follow 

 the plough to pick up worms and grubs. 



The song of the male, particularly when making love, is accompanied 

 with gestures and actions somewhat like those of the domestic Pigeon. 

 He swells himself out, beating the ground with his wings, and uttering 

 a series of deep internal notes, followed by others loud and clear ; and 

 occasionally, when uttering them, he suddenly takes wing and flies 

 directly away from the female to a distance of fifty yards, and performs 

 a wide circuit about her in the air, singing all the time. The homely 

 object of his short-lived passion always appears utterly indifferent to 

 this curious and pretty performance ; yet she must be even more 

 impressionable than most female birds, since she continues scattering 

 about her parasitical and often wasted eggs during four months in 

 every year. Her language consists of a long note with a spluttering 

 sound, to express alarm or curiosity, and she occasionally chatters in a 

 low tone as if trying to sing. In the evening, when the birds congre- 

 gate on the trees to roost they often continue singing in concert until 

 it is quite dark ; and when disturbed at night the males frequently 

 utter their song while taking flight, reminding one of the Icterus 

 pyrrhopterus , which has only its usual melody to express fear and other 

 painful emotions. On rainy days, when they are driven to the shelter 

 of trees, they will often sing together for hours without intermission, 

 the blending of innumerable voices producing a rushing sound as of 

 a high wind. At the end of summer they congregate in flocks of tens 

 of thousands, so that the ground where they are feeding seems carpeted 



