Nearly all the rapacious animals, even the stupid vultures, are monogamous. The conjugal union of the bald-headed eagle appears even to last till the death of one of the partners. This is indeed monogamic and indissoluble marriage, though without legal constraint.[42] Golden eagles live in couples, and remain attached to each other for years without even changing their domicile.[43] But these instances, honourable as they are, have nothing exceptional in them; strong conjugal attachment is a sentiment common to many birds.
With the female Illinois parrot (Psittacus pertinax) widowhood and death are synonymous, a circumstance rare enough in the human species, yet of which birds give us more than one example. When, after some years of conjugal life, a wheatear happens to die, his companion hardly survives him a month. The male and female of the panurus are always perched side by side. When they fall asleep, one of them, generally the male, tenderly spreads its wing over the other. The death of one, says Brehm, is fatal to its companion. The couples of golden wood-peckers, of doves, etc., live in a perfect union, and in case of widowhood experience a violent and lasting grief. The male of a climbing wood-pecker, having seen his mate die, tapped day and night with his beak to recall the absent one; then at length, discouraged and hopeless, he became silent, but never recovered his gaiety (Brehm). These examples of a fidelity that stands every test, and of the religion of memory, although much more frequent in the unions of birds than in those of human beings, are not, however, the unfailing rule. With birds, as with men, there seems to be a good number of irregular cases—individuals of imperfect moral development and of fickle disposition. This may be inferred from the facility with which, among certain species of monogamous birds, the dead partner is replaced. Jenner, who introduced vaccination, relates that in Wiltshire he has seen one of a couple of magpies killed seven days in succession, and seven times over immediately replaced. Analogous facts have been observed of jays, falcons, and starlings. Now, when it concerns animals that are paired, each substitution must correspond to a desertion, the more so as the observations were made in the same locality and in the height of the breeding season.[44]
Very peculiar fancies sometimes arise in the brains of certain birds. Thus we see birds of distinct species pairing, and this even in a wild state. These illegitimate unions have been observed between geese and barnacle geese, and between black grouse and pheasants.
Darwin relates a case of this kind of passion suddenly appearing in a wild duck. The fact is related by Mr. Hewitt as follows:—“After breeding a couple of seasons with her own mallard, she at once shook him off on my placing a male pintail in the water. It was evidently a case of love at first sight, for she swam about the new-comer caressingly, though he appeared evidently alarmed and averse to her overtures of affection. From that hour she forgot her old partner. Winter passed by, and the next spring the pintail seemed to have become a convert to her blandishments, for they nested and produced seven or eight young ones.”[45] It is difficult not to attribute such deviations as these to motives similar to those by which we are ourselves actuated—to passion, caprice, or depravity. They certainly cannot be accounted for by the theory of mechanical and immutable instinct. Such facts clearly prove that animal psychology, although less complicated than our own, does not differ essentially from it, and consequently throws much light on our present investigation. The adventure of the wild duck, for example, may, without any alteration, be read as a human adventure, proving for the hundred-thousandth time that the heart, or what we call by that name, is versatile; that conjugal fidelity does not always resist a strong impression arising from a chance encounter; that novelty has a disturbing effect; and, finally, that indifference and coldness can rarely hold out against the persistent advances of one who loves ardently enough not to yield to discouragement. Dante has already made this last reflection in his celebrated line—
“Amor ch’a nullo amato amar perdona.”
To quote Dante à propos of the illicit amours of a pintail and a wild duck may shock the learned, but the aptness of the quotation proves once more the essential identity of the animal and human organisms.
III. The Family amongst Animals.
If the study of the modes of sexual union amongst animals is not useless to the sociologist, that of the animal family is at least quite as interesting. This latter confirms the inductions of theorists relative to the primitive form of the human family. The animal family is especially maternal. The female of birds, immediately she has laid her eggs, experiences a sort of intoxication; to sit becomes for her an imperious need, which completely transforms her moral nature. In January 1871, during the bombardment of Paris, a German shell, bursting in the loft of a house inhabited by one of my friends, was powerless to disturb a female pigeon absolutely enchained by the passion of incubation.
It is amongst birds that the animal family is best constituted; this, however, differs much according to the species, especially as regards the participation of the male in the rearing of the young.
Amongst ducks, the male has no care for his progeny. The male eider resembles the duck in this respect (Audubon). Male turkeys do much worse: they often devour the eggs of their females, and thus oblige the latter to hide them.[46] Female turkeys join each other with their young ones for greater security, and thus form troops of from sixty to eighty individuals, led by the mothers, and carefully avoiding the old males, who rush on the young ones and kill them by violent blows on the head with their beaks.[47]