The Making of Species

by Douglas Dewar; Frank Finn

Similarly, Finn records, in The Country-Side for August 29th, 1908, that the male Globose Curassow (Crax globicera) in the London Zoological Gardens, which bred with the female Heck’s Curassow (C. hecki), as related on p. 104, selected the hen of this very distinctly coloured form or species in preference to any of the typical hens of his own kind.

Male Attractiveness

The cases on record of cocks being in a position to select their mates are comparatively rare, while instances of selection on the part of the hens are far more numerous.

Hence it would seem that the sex, which is in a minority, and so has the opportunity of selecting a mate, does exert a choice and prefer one particular individual; and that, for the reasons pointed out by Darwin, it is in most cases the female who is in the position of being able to pick and choose her mate. It is, as Darwin truly said, far more difficult to decide what qualities determine the choice of the female. He believed that it is “to a large extent the external attractions of the male, though no doubt his vigour, courage, and other mental qualities come into play.”

Darwin argued that it is the love of hen birds for “external attractions” in cock birds that has brought into being all the wonderful plumes that characterise such birds as the peacock. “Many female progenitors of the peacock,” he writes, on page 661 of The Descent of Man (ed. 1901), “during a long line of descent, have appreciated this superiority, for they have unconsciously, by the continued preference of the most beautiful males, rendered the peacock the most splendid of living birds.”

This conclusion has been vigorously attacked. It is argued, with some show of reason, that it is absurd to credit birds with æsthetic tastes equal, if not superior, to those of the most refined and civilised of human beings.

Is it likely, it is asked, that a bird, which will nest in an old shoe cast off by a tramp, can appreciate beauty of plumage?

As Geddes and Thomson say (page 29 of The Evolution of Sex), “When we consider the complexity of the markings of the male bird or insect, and the slow gradations from one step of perfection to another, it seems difficult to credit birds or butterflies with a degree of æsthetic development exhibited by no human being without special æsthetic acuteness and special training. Moreover, the butterfly, which is supposed to possess this extraordinary development of psychological subtlety, will fly naively to a piece of white paper on the ground, and is attracted by the primary æsthetic stimulus of an old-fashioned wall-paper, not to speak of the gaudy and monotonous brightness of some of our garden flowers. Thus we have the further difficulty, that we must suppose the female butterfly to have a double standard of taste, one for the flowers which she and her mate both visit, the other for the far more complex colourings and markings of the males. And even among birds, if we take those unmistakable hints of real awakening of the æsthetic sense which are exhibited by the Australian bower-bird or by the common jackdaw in its fondness for bright objects, how very rude is his taste compared with the critical examination of infinitesimal variations of plumage on which Darwin relies. Is not, therefore, his essential supposition too glaringly anthropomorphic?

“Again, the most beautiful males are often extremely combative; and on the conventional view this is a mere coincidence, yet a most unfortunate one for Mr Darwin’s view. Battle thus constantly decides the question of pairing, and in cases where, by hypothesis, the female should have most choice, she has simply to yield to the victor.”

Darwin, with characteristic fairness, quotes some instances which appear to be opposed to the theory that the hen selects the most beautiful of her suitors. He informs us that Messrs Hewitt, Tegetmeier, and Brent, who have all had a long experience of domesticated birds, “do not believe that the females prefer certain males on account of the beauty of their plumage. . . . Mr Tegetmeier is convinced that a game-cock, though disfigured by being dubbed and with his hackles trimmed, would be accepted as readily as a male retaining all his natural ornaments. Mr Brent, however, admits that the beauty of the male probably aids in exciting the female; and her acquiescence is necessary. Mr Hewitt is convinced that the union is by no means left to mere chance, for the female almost invariably prefers the most vigorous, defiant, and mettlesome male”; and, in consequence, when there is a game-cock in the farmyard, the hens will all resort to him in preference to the cock of their own breed. Darwin thinks that “some allowance must be made for the artificial state in which these birds have long been kept,” and cites in his favour the case of Mr Cupples’ female deerhound that thrice produced puppies, and on each occasion showed a marked preference for one of the largest and handsomest, but not the most eager, of four deerhounds living with her, all in the prime of life.