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.