Page:Popular Science Monthly Volume 55.djvu/846

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824
POPULAR SCIENCE MONTHLY.

on the upper Mississippi River and its numerous tributaries. They occur only as stragglers on the Pacific coast west of the Cascade and Sierra Nevada Mountains. The most northern point at which they have been known to breed is the neighborhood of Little Slave Lake in southern Athabasca. In the autumn the majority of these birds migrate to southern Mexico, although a considerable number remain in our Southern States, and a few occasionally tarry for the winter even as far north as New England and southern Michigan.

The male cowbird looks like a well-dressed gentleman—and may have even a slightly clerical air—in his closely fitting suit of glossy black, with its greenish and purplish iridescence, and his cloak of rich metallic brown covering his head, neck, and chest. He makes a poor shift as a musician, but his failure is not due to lack of effort, for during courtship days he does his level best to sing a variety of tunes, expanding and distorting his throat, fluffing up his feathers, spreading out his wings and tail, his purpose evidently being to make himself as fascinating as possible in the eyes of his lady love. One of his calls sounds like the word "spreele," piped in so piercing a key that it seems almost to perforate your brain.

One observer maintains that the cowbirds are not only parasitical in their habits, but are also absolutely devoid of conjugal affection, practicing polyandry, and seldom even mating. This is a serious charge, but it is doubtless true, for even during the season of courtship and breeding these birds live in flocks of six to twelve, the males almost always outnumbering the females. However, if their sexual relations are somewhat irregular, no one can accuse them of engaging in family brawls, as so many other birds do, for both males and females seem to be on the most cordial terms with one another, and are, to all appearances, entirely free from jealousy. Who has ever seen two cowbirds fighting a duel like the orioles, meadow larks, and robins? Their domestic relations seem to be readily adjusted, perhaps all the more so on account of their lax standards of sexual virtue.

In obtruding her eggs into the nests of other birds Madame Cowbird is sly and stealthy. She does not drive the rightful owners from their nests, but simply watches her opportunity to drop her eggs into them when they are unguarded. No doubt she has been on the alert while her industrious neighbors have been constructing their domiciles, and knows where every nest in the vicinity is hidden. Says Major Charles Bendire: "In rare instances only will a fresh cowbird's egg be found among incubated ones of the rightful owners. I have observed this only on a single occasion." From one to seven eggs of the parasite are found in the nests of the dupes. In most cases the number is two, but in the case of