Naturally one would expect to find some other eccentricities in this aberrant family besides that of parasitism, and in this expectation one is not disappointed. There are two other species of cowbirds in the Argentine country--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 depravity 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 performance of its domestic duties like its respectable neighbors. 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 possibly developing it into a fine art, and reminds one of those human good-for-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 Appleton's "Popular Science Monthly." The observer was Joseph F. Honecker, whose statement was printed in "American Ornithology" for June, 1902, and runs as follows:
"As ornithologists and all bird students think and believe that the cowbird will build no nest, but always lays in the nests of other birds, I am glad to give the results of my experiments. In order to get the desired results, in the spring of 1899 I secured a pair of cowbirds and placed them in a large cage, cared well for them, and supplied them with plenty of nesting material. To my surprise, the female built a nest, laid four eggs, hatched them, and reared the young, and on July twenty-eighth, young and old were given their freedom. This will show that the cowbird will build a nest and care for its young in captivity, while in its wild life it has never been known to do so."