In the case of the modified into a melodious love song. feathers, by which the drumming, whistling, or roaring noises are produced, we know that some birds during their courtship flutter, shake, or rattle their unmodified feathers together; and Fig. 45. Secondary wing-feathers of Pipra deliciosa (from Mr. Sclater, in Proc. ZocL Soc. 1860). The three upper feathers, a, b, c, from the male; the three lower corre sponding feathers, d, e, f, from the female. a and d, fifth secondary wing-feather of male and female, upper surface. b and e, sixth secondary, upper surface. c and f, seventh secondary, lower surface. if the females were led to select the best performers, the males which possessed the strongest or thickest, or most attenuated feathers, situated on any part of the body, would be the most successful; and thus by slow degrees the feathers might be modified to almost any extent. The females, of course, would not notice each slight successive alteration in shape, but only the sounds thus produced. It is a curious fact that in the same class of animals, sounds so different as the drumming of the snipe's tail, the tapping of the woodpecker's beak, the harsh trumpet-like cry of certain water-fowl, the cooing of the turtledove, and the song of the nightingale, should all be pleasing to the females of the several species. But we must not judge of the tastes of distinct species by a uniform standard; nor must we judge by the standard of man's taste. Even with man, we should remember what discordant noises, the beating of tomtoms and the shrill notes of reeds, please the ears of savages. Sir S. Baker remarks,58 that “as the stomach of the Arab prefers "the raw meat and reeking liver taken hot from the animal, so "does his ear prefer his equally coarse and discordant music to "all other." Love-Antics and Dances.-The curious love gestures of some birds have already been incidentally noticed; so that little need here be added. In Northern America, large numbers of a grouse, the Tetrao phasianellus, meet every morning during the breedingseason on a selected level spot, and here they run round and round in a circle of about fifteen or twenty feet in diameter, so that the ground is worn quite bare, like a fairy-ring. In these Partridge-dances, as they are called by the hunters, the birds assume the strangest attitudes, and run round, some to the left and some to the right. Audubon describes the males of a heron (Ardea herodias) as walking about on their long legs with great dignity before the females, bidding defiance to their rivals. With one of the disgusting carrion-vultures (Cathartes jota) the same naturalist states that "the gesticulations and parade of the "males at the beginning of the love-season are extremely "ludicrous." Certain birds perform their love antics on the wing, as we have seen with the black African weaver, instead of on the ground. During the spring our little white-throat (Sylvia cinerea) often rises a few feet or yards in the air above some bush, and "flutters with a fitful and fantastic motion, singing all “the while, and then drops to its perch." The great English bustard throws himself into indescribably odd attitudes whilst courting the female, as has been figured by Wolf. An allied Indian bustard (Otis bengalensis) at such times "rises perpendicularly into the air with a hurried flapping of his wings, raising his crest and puffing out the feathers of his neck and "breast, and then drops to the ground;" he repeats this manœuvre several times, at the same time humming in a peculiar tone. Such females as happen to be near obey this 68 The Nile Tributaries of Abyssinia,' 1867, p. 203. saltatory summons," and when they approach he trails his wings and spreads his tail like a turkey-cock.59 6" But the most curious case is afforded by three allied genera of Australian birds, the famous Bower-birds,--no doubt the codescendants of some ancient species which first acquired the strange instinct of constructing bowers for performing their love-antics. The bowers (fig. 46), which, as we shall hereafter sec, are decorated with feathers, shells, bones, and leaves, are built on the ground for the sole purpose of courtship, for their uests are formed in trees. Both sexes assist in the erection of the bowers, but the male is the principal workman. So strong is this instinct that it is practised under confinement, and Mr Strange has described " the habits of some Satin Bower-birds which he kept in an aviary in New South Wales. "At times "the male will chase the female all over the aviary, then go to "the bower, pick up a gay feather or a large leaf, utter a curious "kind of note, set all his feathers erect, run round the bower and "become so excited that his eyes appear ready to start from his head; he continues opening first one wing then the other, uttering a low, whistling note, and, like the domestic cock, seems to be picking up something from the ground until at "last the female goes gently towards him." Captain Stokes has described the habits and "play-houses" of another species, the Great Bower-bird, which was seen amusing itself by flying "backwards and forwards, taking a shell alternately from each "side, and carrying it through the archway in its mouth." These curious structures, formed solely as halls of assemblage, where both sexes amuse themselves and pay their court, must cost the birds much labour. The bower, for instance, of the Fawn-breasted species, is nearly four feet in length, eighteen inches in height, and is raised on a thick platform of sticks. 66 Decoration.-I will first discuss the cases in which the males are ornamented either exclusively or in a much higher degree than the females, and in a succeeding chapter those in which both sexes are equally ornamented, and finally the rare cases in which the female is somewhat more brightly-coloured than the 81 Sec remarks to this effect, on the Feeling of Beauty among male. As with the artificial ornaments used by savage and civilised men, so with the natural ornaments of birds, the head is the chief seat of decoration. The ornaments, as mentioned 61 Animals,' by Mr. J. Shaw, in the Fig 46. Bower-bird. Chlamydera maculata, with bower (from Brehm). at the commencement of this chapter, are wonderfully diversified. The plumes on the front or back of the head consist of variously-shaped feathers, sometimes capable of erection or expansion, by which their beautiful colours are fully displayed. Elegant ear-tufts (see fig. 39, ante) are occasionally present. The head is sometimes covered with velvety down, as with the pheasant; or is naked and vividly coloured. The throat, also, is sometimes ornamented with a beard, wattles, or caruncles. Such appendages are generally brightly-coloured, and no doubt servo as ornaments, though not always ornamental in our eyes; for whilst the male is in the act of courting the female, they often swell and assume vivid tints, as in the male turkey. At such times the fleshy appendages about the head of the male Tragopan pheasant (Ceriornis Temminckii) swell into a large lappet on the throat and into two horns, one on each side of the splendid top-knot; and these are then coloured of the most intense blue which I have ever beheld.62 The African hornbill (Bucora.c ubyssinicus) inflates the scarlet bladder-like wattle on its neck, and with its wings drooping and tail expanded “makes quite a grand appearance.” 63 Even the iris of the eye is sometimes more brightly-coloured in the male than in the female; and this is frequently the case with the beak, for instance, in our common blackbird. In Buceros corrugatus, the whole beak and immense casque are coloured more conspicuously in the male than in the female; and "the oblique grooves upon the sides of the lower "mandible are peculiar to the male sex."" 66 65 The head, again, often supports fleshy appendages, filaments, and solid protuberances. These, if not common to both sexes, are always confined to the males. The solid protuberances have been described in detail by Dr. W. Marshall, who shews that they are formed either of cancellated bone coated with skin, or of dermal and other tissues. With mammals true horns are always supported on the frontal bones, but with birds various bones have been modified for this purpose; and in species of the same group the protuberances may have cores of bone, or be quite destitute of them, with intermediate gradations connecting these two extremes. Hence, as Dr. Marshall justly remarks, variations of the most different kinds have served for the development through sexual selection of these ornamental appendages. Elongated feathers or plumes spring from almost 62 See Dr. Murie's account with coloured figures in Proc. Zoolog. Soc. 1872, p. 730. 6 Mr. Monteiro, 1862, p. 339. Ibis, vol. iv. 6 Land and Water,' 1868, p. 217. 65 Ueber die Schädelhöcker,' &c., • Niederländischen Archiv für Zoologie,' B. I. Heft. 2. 1872. |