LOVE-CHARMS AND LOVE-CALLS
The same reasoning applies to the music of animals, vocal and instrumental, on which Darwin lays great stress. In his opinion, the music of some male animals serves to charm the females æsthetically, and thus gives to the best musicians special advantages through Sexual Selection. But the instances cited by him hardly warrant this conclusion, and seem rather to point to the inference that the function of animal music is chiefly to facilitate courtship, by making it easy for the females to discover the whereabouts of a male of the same species. The evidence tends to show that it is not the male whose voice is most mellow and melodious that catches the female, but rather the one who is most vigorous and persistent and has the loudest organ. As Jaques says in As You Like It: “Sing it: ’tis no matter how it be in tune, so it make noise enough!”
Darwin himself quotes a naturalist’s statement, that “the stridulation produced by some of the Locustidæ is so loud that it can be heard during the night at the distance of a mile;” and such cases as “the drumming of the snipe’s tail, the tapping of the woodpecker’s beak, the harsh, trumpetlike cry of certain water-fowl,” though Darwin tries to dispose of them on the ground of a difference in æsthetic taste, nevertheless incline one to the belief that the music of the forest troubadours is not so much intended to gratify the æsthetic taste of the female as to guide her to the spot where the male awaits her; for, contrary to common opinion, it is the female in these cases that searches for a male and not vice versâ. Montagu, for instance, asserts that “males of song-birds and of many others do not in general search for the female, but, on the contrary, their business in spring is to perch on some conspicuous spot, breathing out their full and amorous notes, which, by instinct, the female knows, and repairs to the spot to choose her mate.” And Dr. Hartman, speaking of the American Cicada septemdecim, says: “The drums are now heard in all directions. This I believe to be the marital summons from the males. Standing in thick chestnut sprouts about as high as my head, where hundreds were around me, I observed the females coming around the drumming males.” And, says Darwin, “the spel of the blackcock certainly serves as a call to the female, for it has been known to bring four or five females from a distance to a male under confinement; but as the blackcock continues his spel for hours during successive days, and in the case of the capercailzie ‘with an agony of passion,’ we are led to suppose that the females which are present are thus charmed.”
There appears to be no direct evidence, however, that female birds are more charmed by one male than another, and prefer him on account of his superior song, as the theory of Sexual Selection postulates. And when we remember that likewise there is no evidence that birds, etc., are ever influenced in their choice by the superior colours of certain males, and that in fact it is the rule for the female to follow passively the most vigorous and victorious male, we are brought back to the conclusion with which we set out—that it is not the superior songster who wins the female by charming her, but the loudest and most persistent songster, by guiding her to the courting-place.
Darwin himself evidently felt the weakness of his position, for he constantly speaks of “love-charms or love-calls” in the same sentence. Thus, “the true song of most birds and various strange cries are uttered chiefly during the breeding-season, and serve as a charm, or merely as a call-note, to the other sex.” Again: “It is often difficult to conjecture whether the many strange cries and notes uttered by male birds during the breeding-season serve as a charm or merely as a call to the female.” The distinction between love “charms” and mere “calls” is of course of the utmost importance. For if male song charms the females and influences them in their choice, we have Sexual-æsthetic-female Selection. But if the male song merely serves as a call to the female and as a sign of species-recognition, then Natural Selection accounts for everything, because the most vigorous, loudest, and most persistent male will have the choice of the most numerous females brought to his side by his musical efforts.