In a well-known mystic book occurs an aphorism which has become celebrated—“Love is strong as death.” The expression is not exaggerated; we may even say that love is stronger than death, since it makes us despise it. This is perhaps truer with animals than with man, and is all the more evident in proportion as the rational will is weaker, and prudential calculations furnish no check to the impetuosity of desire. For the majority of insects to love and to die are almost synonymous, and yet they make no effort to resist the amorous frenzy which urges them on. But however short may be their sexual career, one fact has been so generally observed in regard to many of them, that it may be considered as the expression of a law—the law of coquetry. With the greater number of species that are slightly intelligent, the female refuses at first to yield to amorous caresses. This useful practice may well have arisen from selection, for its result has invariably been to excite the desire of the male, and arouse in him latent or sleeping faculties. However brief, for example, may be the life of butterflies, their pairing is not accomplished without preliminaries; the males court the females during entire hours, and for a butterfly hours are years.
We can easily imagine that the coquetry of females is more common amongst vertebrates. When the season of love arrives, many male fishes, who are then adorned with extremely brilliant colours, make the most of their transient beauty by spreading out their fins, and by executing leaps, darts, and seductive manœuvres around the females.
Among fishes we begin already to observe another sexual law, at least as general as the law of coquetry, which Darwin has called the law of battle. The males dispute with each other for the females, and must triumph over their rivals before obtaining them. Thus, whilst the female sticklebacks are very pacific, their males are of warlike humour, and engage in furious combats in their honour. In the same way the male salmon, whose lower jaw lengthens into a crook during the breeding season, are constantly fighting amongst each other.[3]
The higher we ascend in the animal kingdom the more frequent and more violent become two desires in the males—the desire of appearing beautiful, and that of driving away rivals. In South America, the males of the Analis cristellatus, a fissilingual saurian, have terrible battles in the breeding season, the vanquished habitually losing his tail, which is bitten off by the victor. An old observer also describes the amorous male alligator as “swollen to bursting, the head and tail raised, spinning round on the surface of the water, and appearing to assume the manner of an Indian chief relating his exploits.”[4]
But it is particularly among birds that the sentiment, or rather the passion, of love breaks out with most force and even poetry. It is especially to birds that the celebrated Darwinian theory of sexual selection applies. It is difficult, indeed, not to attribute to this influence the production of the offensive and defensive arms, the armaments, the organs of song, the glands of odoriferous secretion of many male birds, also their courage, the warlike instinct of many of them, and lastly, the coquetry of the females. Let us listen to Audubon, as he relates the loves of the skylark:—“Each male is seen to advance with an imposing and measured step, swinging his tail, spreading it out to its full extent, then closing it again like a fan in the hands of a fine lady. Their brilliant notes are more melodious than ever; they repeat them oftener than usual as they rest on the branch or summit of some tall meadow reed. Woe to the rival who dares to enter the lists, or to the male who simply comes in sight of another male at this moment of veritable delirium: he is suddenly attacked, and, if he is the weaker, chased beyond the limits of the territory claimed by the first occupant. Sometimes several birds are seen engaged in these rude combats, which rarely last more than two or three minutes: the appearance of a single female suffices to put an instant end to their quarrel, and they all fly after her as if mad. The female shows the natural reserve of her sex, without which, even among larks, every female would probably fail to find a male [this is a little too flattering for larks, and even for men]. When the latter,” continues Audubon, “flies towards her, sighing forth his sweetest notes, she retreats before her ardent admirer in such a way that he knows not whether he is repulsed or encouraged.”[5]
In this little picture the author has noted all the striking traits of the love of birds—the courage and jealousy of the male, his efforts to charm the female by his beauty and the sweetness of his song, and finally, the coquetry of the female, who retreats, and thus throws oil on the fire. The combats of the amorous males among many species of birds have been observed and described minutely. “The large blue male herons,” says Audubon, “attack each other brutally, without courtesy; they make passes with their long beaks and parry them like fencing masters, often for half-an-hour at a time, after which the vanquished one remains on the ground, wounded or killed.”[6]
The male Canadian geese engage in combats which last more than half-an-hour; the vanquished sometimes return to the charge, and the fight always takes place in an enclosed field, in the middle of a circle formed by the band or clan of which the rivals form part.
But it is especially among the gallinaceæ that love inspires the males with warlike fury. In this order of birds nearly all the males are of bellicose temperament. Our barn-door cock is the type of the gallinaceæ—vain, amorous, and courageous. Black cocks are also always ready for a fight, and their females quietly look on at their combats, and afterwards reward the conqueror. We may observe analogous facts, only somewhat masked, in savage, and even in civilised humanity. The conduct of certain females of the Tetras urogallus is still more human. According to Kowalewsky, they take advantage of a moment when the attention of the old cocks is entirely absorbed by the anxiety of the combat, to run off with a younger male.[7]
If we may believe certain authors, these amorous duels must not always be taken seriously. They are often nothing more than parades, tourneys, or courteous jousts, merely giving the males an opportunity of showing their beauty, address, or strength. This is the case, according to Blyth, with the Tetras umbellus.[8] In the same way, the grouse of Florida (Tetras cuspido) are said to assemble at night to fight until the morning with measured grace, and then to separate, having first exchanged formal courtesies.[9]
But among animals, as well as men, love has more than one string to his bow. It is especially so with birds, who are the most amorous of vertebrates. They use several æsthetic means of attracting the female, such as beauty of plumage and the art of showing it, and also sweetness of song. Strength seems often to be quite set aside, and the eye and ear are alone appealed to by the love-stricken males.