82 Bird Comrades 



are two other species of cowbirds in the Argentine coun- 

 try the screaming cowbird (Molothrus rufoaxillaris) 

 and the bay- winged cowbird (Molothrus badius). The 

 latter is only partly a trencher on the rights of other birds 

 only half a parasite. Indeed, it sometimes builds its 

 own nest, which is quite a respectable affair ; but, as if to 

 prove that it still has some remnants of cowbird deprav- 

 ity in its nature, it frequently drives other birds- -from 

 their rightful possessions, appropriates the quarters thus 

 acquired, lays its eggs into them, and proceeds to the per- 

 formance of its domestic duties like its respectable neigh- 

 bors. Its virtue is that it never imposes the work of 

 incubation and brood rearing on any of its feathered 

 associates, even though it does sometimes eject, them 

 from their premises. 



But what is to be said of the screaming cowbird? 

 Instead of inflicting its eggs on its more distant avian 

 relatives, it watches its chance and slyly drops them into 

 the domicile of its bay-winged cousins, and actually makes 

 them hatch and rear its offspring! This seems to be 

 carrying imposture to the extreme of refinement, or possi- 

 bly developing it into a fine art, and reminds one of those 

 human good-f or-naughts who " sponge" off their relatives 

 rather than go among strangers. 



Before closing this chapter I must call attention to 

 one of the most surprising discoveries ever made by an 

 American observer of bird ways. It was reported some 

 time after my article on the cowbird was first published 

 in Apple ton's " Popular Science Monthly." The observer 



