How great their adaptiveness and variability must be when we find that every portion of the South American continent is occupied by them; for there is really no climate, and no kind of soil or vegetation, which does not possess its appropriate species, modified in colour, form, and habits to suit the surrounding conditions. In the tropical region, so rich in bird life of all kinds, in forest, marsh, and savanna, they are everywhere abundant—food is plentiful there; but when we go to higher elevations avd cold sterile deserts, where their companion families of the tropics dwindle away and disappear, the creepers are still present, for they are evidently able to exist where other kinds would starve. On the stony plateaus of the Andes, and on the most barren spots in Patagonia, where no other bird is seen, there are small species of Synallaxis, which, in their obscure colour and motions on the ground, resemble mice rather than birds; indeed, the Quichua name for one of these Synallaxes is ukatchtuka, or mouse-bird. How different is the life habit here from what we see in the tropical groups—the large birds with immense beaks, that run vertically on the trunks of the great forest trees!

At the extreme southern extremity of the South American continent we find several species of Cin-clodes, seeking a subsistence like sandpipers on the beach; they also fly out to sea, and run about on the floating kelp, exploring the fronds for the small marine animals on which they live. In the dreary forests of Tierra del Fuego another creeper, Uxyurus, is by far the commonest bird. "Whether high up or low down, in the most gloomy, wet, and scarcely penetrable ravines," says Darwin, "this little bird is to be met with;" and Dr. Cunningham also relates that in these wintry, savage woods he was always attended in his walks by parties of these little creepers, which assembled to follow him out of curiosity.

To birds placed at so great a disadvantage, by a feeble flight and other adverse circumstances, in the race of life bright colours would certainly prove fatal. It is true that brown is not in itself a protective colour, and the clear, almost silky browns and bright chestnut tints in several species are certainly not protective; but these species are sufficiently protected in other ways, and can afford to be without a strictly adaptive colour, so long as they are not conspicuous. In a majority of cases, however, the colour is undoubtedly protective, the brown hue being of a shade that assimilates very closely to the surroundings. There are pale yellowish browns, lined and mottled, in species living amidst a sere, scanty vegetation; earthy browns, in those frequenting open sterile or stony places; while the species that creep on trees in forests are dark brown in colour, and in many cases the feathers are mottled in such a manner as to make them curiously resemble the bark of a tree. The genera Lochmias and Sclerurus are the darkest, the plumage in these birds being nearly or quite black, washed or tinged with rhubarb yellow. Their black plumage would render them conspicuous in the sunshine, but they pass their lives in dense tropical forests, where the sun at noon sheds only a gloomy twilight.

If "colour is ever tending to increase and to appear where it is absent," as Dr. Wallace believes, then we ought to find it varying in the direction of greater brightness in some species in a family so numerous and variable as the Dendrocolaptidae, however feeble and in need of a protective colouring these birds may be in a majority of pases. And this in effect we do find. In many of the dark-plumaged species that live in perpetual shade some parts are a very bright chestnut; while in a few that live in such close concealment as to be almost independent of protective colouring, the lower plumage has become pure white. A large number of species have a bright or nearly bright guiar spot. This is most remarkable in Synallaxis phryganophila, the chin being sulphur-yellow, beneath which is a spot of velvet-black, and on either side a white patch, the throat thus having three strongly contrasted colours, arranged in four divisions. The presence of this bright throat spot in so many species cannot very well be attributed to voluntary sexual selection, although believers in that theory are of course at liberty to imagine that when engaged in courtship, the male bird, or rather male and female both, as both sexes possess the spot, hold up their heads vertically to exhibit it. Perhaps it would be safer to look on it as a mere casual variation, which, like the exquisitely pencilled feathers and delicate tints on the concealed sides and under surfaces of the wings of many species possessing outwardly an obscure protective colouring, is neither injurious nor beneficial in any way, either to the birds or to the theory. It is more than probable, however, that in such small feeble-winged, persecuted birds, this spot of colour would prove highly dangerous on any conspicuous part of the body. In some of the more vigorous, active species, we can see a tendency towards a brighter colouring on large, exposed surfaces. In Auto-malus the tail is bright satiny rufous; in Pseudo-colaptes the entire under surface is rufous of a peculiar vivid tint, verging on orange or red; in Magarornis the bosom is black, and beautifully ornamented with small leaf-shaped spots of a delicate straw-colour. There are several other very pretty birds in this homely family; but the finest of all is Thripodectes flammulatus, the whole body being tortoise-shell colour, the wings and tail bright chesnut. The powerful tanager-like beak of this species seems also to show that it has diverged from its timid shade-loving congeners in another direction by becoming a seed and fruit eater.

Probably the sober and generally protective colouring of the tree-creepers, even with the variability and adaptiveness displayed in their habits superadded, would be insufficient to preserve such feeble birds in the struggle of life without the further advantage derived from their wonderful nests. It has been said of domed nests that they are a danger rather than a protection, owing to their large size, which makes it easy for carnivorous species that prey on eggs and young birds to find them; while small open nests are usually well concealed. This may be the case with covered nests made of soft materials, loosely put together; but it cannot be said of the solid structure the tree-creeper bnilds, and which, as often as not, the bird erects in the most conspicuous place it can find, as if, writes Azara, it desired all the world to admire its work. The annual destruction of adult birds is very great—more than double that, I believe, which takes place in other passerine families. Their eggs and young are, however, practically safe in their great elaborate nests or deep burrows, and, as a rule, they lay more eggs than other kinds, the full complement being seldom less than five in the species I am acquainted with, while some lay as many as nine. Their nests are also made so as to keep out a greater pest than their carnivorous or egg-devouring enemies—namely, the parasitical starlings (Molo-thrus), which are found throughout South America, and are excessively abundant and destructive to birds' nests in some districts. In most cases, in the big, strong-domed nest or deep burrow, all the eggs are hatched and all the young reared, the thinning, out process commencing only after the brood has been led forth into a world beset with perils. With other families, on the contrary, the greatest amount of destruction falls on the eggs or fledglings. I have frequently kept a dozen or twenty pairs of different species—warblers, finches, tyrants, starlings, &c.—under observation during the breeding season, and have found that in some cases no young-were reared at all; in other cases one or two young; while, as often as not, the young actually reared were only parasitical starlings after all.

I have still to speak of the voice of the tree-creepers, an important point in the study of these birds; for, though not accounted singers, some species emit remarkable sounds; moreover, language in birds is closely related to the social instinct. They seem to be rather solitary than gregarious; and this seems only natural in birds so timid, weak-winged, and hard pressed. It would also be natural to conclude from what has been said concerning their habits that they are comparatively silent; for, as a rule, vigorous social birds are loquacious and loud-voiced, while shy solitary kinds preservo silence, except in the love season. Nevertheless the creepers are loquacious and have loud resonant voices; this fact, however, does not really contradict a well-known principle, for the birds possess the social disposition in an eminent degree, only the social habit is kept down in them by the conditions of a life which makes solitude necessary. Thus, a large proportion of species are found to pair for life; and the only reasonable explanation of this habit in birds—one which is not very common in the mammalia—is that such species possess the social temper or feeling, and live in pairs only because they cannot afford to live in flocks. Strictly gregarious species pair only for the breeding season. In the creepers the attachment between the birds thus mated for life is very great, and, as Azara truly says of Anumbius, so fond of each other's society are these birds, that when one incubates the other sits at the entrance to the nest, and when one carries food to its young the other accompanies it, even if it has found nothing to cany. In these species that live in pairs, when the two birds are separated they are perpetually calling to each other, showing how impatient of solitude they are; while even from the more solitary kind, a high-pitched call-note is constantly heard in the woods, for these birds, debarred from associating together, satisfy their instinct by conversing with one another over long distances.

The foregoing remarks apply to the Dendrocolap-tidae throughout the temperate countries of South America—the birds inhabiting extensive grassy plains and marshes, and districts with a scanty or scattered tree and bush vegetation. In the forest areas of the hotter regions it is different; there the birds form large gatherings or "wandering bands," composed of all the different species found in each district, associated with birds of other families—wood-peckers, tyrant-birds, bush shrikes, and many others. These miscellaneous gatherings are not of rare occurrence, but out of the breeding season are formed daily, the birds beginning to assemble at about nine or ten o'clock in the morning, their number increasing through the day until it reaches its maximum between two and four o'clock in the afternoon, after which it begins to diminish, each bird going off to its customary shelter or dwelling-place. Mr. Bates, who first described these wandering bands, says that he could always find the particular band belonging to a district any day he wished, for when he failed to meet with it in one part of the forest he would try other paths, until he eventually found it. The great Amazonian forests, he tells us, appear strangely silent and devoid of bird life, and it is possible to ramble about for whole days without seeing or hearing birds. But now and then the surrounding trees and bushes appear suddenly swarming with them. "The bustling crowd loses no time, and, always moving in concert, each bird is occupied on its own account in searching bark, or leaf, or twig. In a few moments the host is gone, and the forest path remains deserted and silent as before." Stolzmann, who observed them in Peru, says that the sound caused by the busy crowd searching through the foliage, and the falling of dead leaves and twigs, resembles that produced by a shower of rain. The Indians of the Amazons, Mr. Bates writes, have a curious belief to explain these bird armies; they say that the Papa-uira, supposed to be a small grey bird, fascinates all the others, and leads them on a weary perpetual dance through the forest. It seems very wonderful that birds, at other times solitary, should thus combine daily in large numbers, including in their bands scores of widely different species, and in size ranging from those no larger than a wren to others as big as a magpie. It is certainly very advantageous to them. As Belt remarks, they play into each other's hands; for while the larger creepers explore the trunks of big trees, others run over the branches and cling to the lesser twigs, so that every tree in their route, from its roots to the topmost foliage, is thoroughly examined, and every spider and caterpillar taken, while the winged insects, driven from their lurking-places, are seized where they settle, or caught flying by the tyrant birds.

I have observed the wandering bands only in Patagonia, where they are on a very small scale compared with those of the tropical forests. In the Patagonia thickets the small tit-like creeper, Laptas-thenura, is the prime mover; and after a considerable number of these have gathered, creepers of other species and genera unite with them, and finally the band, as it moves through the thickets, draws to itself other kinds—flycatchers, finches, &c.—many of the birds running or hopping on the ground to search for insects in the loose soil or under dead leaves, while others explore the thorny bushes. My observations of these small bands lead me to believe that everywhere in South America the Dendrocolaptidae are the first in combining to act in concert, and that the birds of other families follow their march and associate with them, knowing from experience that a rich harvest may be thus reaped. In the same way birds of various kinds follow the movements of a column of hunting ants, to catch the insects flying up from the earth to escape from their enemies; swallows also learn to keep company with the traveller on horseback, and, crossing and recrossing just before the hoofs, they catch the small twilight moths driven up from the grass.

To return to the subject of voice. The tree-creepers do not possess melodious, or at any rate mellow notes, although in so numerous a family there is great variety of tone, ranging from a small reedy voice like the faint stridulation of a grasshopper, to the resounding, laughter-like, screaming concerts of Homorus, which may be heard distinctly two miles away. As a rule, the notes are loud ringing calls; and in many species the cry, rapidly reiterated, resembles a peal of laughter. With scarcely an exception, they possess no set song; but in most species that live always in pairs there are loud, vehement, gratulatory notes uttered by the two birds in concert when they meet after a brief separation. This habit they possess in common with birds of other families, as, for instance, the tyrants; but, in some creepers, out of this confused outburst of joyous sound has been developed a. musical performance very curious, and perhaps unique among birds. On meeting, the male and female, standing close together and facing each other, utter their clear ringing concert, one emitting loud single measured notes, while the notes of its fellow are rapid, rhythmical triplets; their voices have a joyous character, and seem to accord, thus producing a kind of harmony. This manner of singing is perhaps most perfect in the oven-bird, Furnarias, and it is very curious that the young birds, when only partially fledged, are constantly heard in the nest or oven apparently practising these duets in the intervals when the parents are absent; single measured notes, triplets, and long concluding trills are all repeated with wonderful fidelity, although these notes are in character utterly unlike the hunger cry, which is like that of other fledglings. I cannot help thinking that this fact of the young birds beginning to sing like the adults, while still confined in their dark cradle, is one of very considerable significance, especially when we consider the singular character of the performance; and that it might even be found to throw some light on the obscure question of the comparative antiquity of the different and widely separated Dendrocolaptine groups. It is a doctrine in evolutionary science that the early maturing of instincts in the young indicates a high antiquity for the species or group; and there is no reason why this principle should not be extended, in the case of birds at any rate, to language. It is true that Daines Barrington's notion that young song-birds learn to sing only by imitating the adults still holds its ground; and Darwin gives it his approval in his Descent of Man. It is perhaps one of those doctrines which are partially true, or which do not contain the whole truth; and it is possible to believe that, while many singing birds do so learn their songs, or acquire a greater proficiency in them from hearing the adults, in other species the song comes instinctively, and is, like other instincts and habits, purely an "inherited memory."

The case of a species in another order of birds—Crypturi—strikes me as being similar to this of the oven-bird, and seems to lend some force to the suggestion I have made concerning the early development of voice in the young.

Birds peculiar to South America are said by anatomists to be less specialized, lower, more ancient, than the birds of the northern continents, and among those which are considered lowest and most ancient are the Tinamous (rail and partridge like in their habits), birds that lead a solitary, retiring life, and in most cases have sweet melancholy voices. Rhynchotus rufescens, a bird the size of a fowl, inhabiting the pampas, is perhaps the sweetest-voiced, and sings with great frequency. Its song or call is heard oftenest towards the evening, and is composed of five modulated notes, flute-like in character, very expressive, and uttered by many individuals answering each other as they sit far apart concealed in the grass. As we might have expected, the faculties and instincts of the young of this species mature at a very early period; when extremely small, they abandon their parents to shift for themselves in solitude; and when not more than one-fourth the size they eventually attain, they acquire the adult plumage and are able to fly as well as an old bird. I observed a young bird of this species, less than a quail in size, at a house on the pampas, and was told that it had been taken from the nest when just breaking the shell; it had, therefore, never seen or heard the parent birds. Yet this small chick, every day at the approach of evening, would retire to the darkest corner of the dining room, and, concealed under a piece of furniture, would continue uttering its evening song for an hour or longer at short intervals, and rendering it so perfectly that I was greatly surprised to hear it; for a thrush or other songster at the same period of life, when attempting to sing, only produces a chirping sound.

The early singing of the oven-bird fledgling is important, owing to the fact that the group it belongs to comprises the least specialized forms in the family. They are strong-legged, square-tailed, terrestrial birds, generally able to perch, have probing beaks, and build the most perfect mud or stick nests, or burrow in the ground. In the numerous tree-creeping groups, which, seem as unrelated to the oven-bird as the woodpecker is to the hoopoe, we find a score of wonderfully different forms of beak; but many of them retain the probing character, and are actually used to probe in rotten wood on trees, and to explore the holes and deep crevices in the trunk. We have also seen that some of these tree-creepers revert to the ancestral habit (if I may so call it) of seeking their food by probing in the soil. In others, like Dendrornis, in which the beak has lost this character, and is used to dig in the wood or to strip off the bark, it has not been highly specialized, and, compared with the woodpecker's beak, is a very imperfect organ, considering the purpose for which it is used. Yet, on the principle that "similar functional requirements frequently lead to the development of similar structures in animals which are otherwise very distinct"—as we see in the tubular tongue in honey-eaters and humming birds—we might have expected to find in the Dendrocolaptidae a better imitation of the woodpecker in so variable an organ as the beak, if not in the tongue.

Probably the oven-birds, and their nearest relations—generalized, hardy, builders of strong nests, and prolific—represent the parental form; and when birds of this type had spread over the entire continent they became in different districts frequenters of marshes, forests, thickets and savannas. With altered life-habits the numerous divergent forms originated; some, like Xiphorynchus, retaining a probing beak in a wonderfully modified form, attenuated in an extreme degree, and bent like a sickle; others diverging more in the direction of nuthatches and woodpeckers.

This sketch of the Dendrocolaptidae, necessarily slight and imperfect, is based on a knowledge of the habits of about sixty species, belonging to twenty-eight genera: from personal observation I am acquainted with less than thirty species. It is astonishing to find how little has been written about these most interesting birds in South America. One tree-creeper only, Furnarius rufus, the oven-bird par excellence, has been mentioned, on account of its wonderful architecture, in almost every general work of natural history published during the present century; yet the oven-bird does not surpass, or even equal in interest, many others in this family of nearly three hundred members.



CHAPTER XIX.

MUSIC AND DANCING IN NATURE.

In reading books of Natural History we meet with numerous instances of birds possessing the habit of assembling together, in many cases always at the same spot, to indulge in antics and dancing performances, with or without the accompaniment of music, vocal or instrumental; and by instrumental music is here meant all sounds other than vocal made habitually and during the more or less orderly performances; as, for instance, drumming and tapping noises; smiting of wings; and humming, whip-cracking, fan-shutting, grinding, scraping, and horn-blowing sounds, produced as a rule by the quills.

There are human dances, in which only one person performs at a time, the rest of the company looking on; and some birds, in widely separated genera, have dances of this kind. A striking example is the Rupicola, or cock of-the-rock, of tropical South America. A mossy level spot of earth surrounded by bushes is selected for a dancing-place, and kept well cleared of sticks and stones; round this area the birds assemble, when a cock-bird, with vivid orange-scarlet crest and plumage, steps into it, and, with spreading wings and tail, begins a series of movements as if dancing a minuet; finally, carried away with excitement, he leaps and gyrates in the most astonishing manner, until, becoming exhausted, he retires, and another bird takes his place.

In other species all the birds in a company unite in the set performances, and seem to obey an impulse which affects them simultaneously and in the same degree; but sometimes one bird prompts the others and takes a principal part. One of the most curious instances I have come across in reading is contained in Mr. Bigg-Wither's Pioneering in South Brazil. He relates that one morning in the dense forest his attention was roused by the unwonted sound of a bird singing—songsters being rare in that district. His men, immediately they caught the sound, invited him to follow them, hinting that he would probably witness a very curious sight. Cautiously making their way through the dense undergrowth, they finally came in sight of a small stony spot of ground, at the end of a tiny glade; and on this spot, some on the stone and some on the shrubs, were assembled a number of little birds, about the size of tom-tits, with lovely blue plumage and red top-knots. One was perched quite still on a twig, singing merrily, while the others were keeping time with wings and feet in a kind of dance, and all twittering an accompaniment. He watched them for some time, and was satisfied that they were having a ball and concert, and thoroughly enjoying themselves; they then became alarmed, and the performance abruptly terminated, the birds all going off in different directions. The natives told him that these little creatures were known as the "dancing birds."

This species was probably solitary, except when assembling for the purpose of display; but in a majority of cases, especially in the Passerine order, the solitary species performs its antics alone, or with no witness but its mate. Azara, describing a small finch, which he aptly named Oscilador, says that early and late in the day it mounts up vertically to a moderate height; then, flies off to a, distance of twenty yards, describing a perfect curve in its passage; turning, it flies back over the imaginary line it has traced, and so on repeatedly, appearing like a pendulum swung in space by an invisible thread.

Those who seek to know the cause and origin of this kind of display and of song in animals are referred to Darwin's Descent of Man for an explanation. The greater part of that work is occupied with a laborious argument intended to prove that the love-feeling inspires the animals engaged in these exhibitions, and that sexual selection, or the voluntary selection of mates by the females, is the final cause of all set musical and dancing performances, as well as of bright and harmonious colouring, and of ornaments.

The theory, with regard to birds is, that in the love-season, when the males are excited and engage in courtship, the females do not fall to the strongest and most active, nor to those that are first in the field; but that in a large number of species they are endowed with a faculty corresponding to the aesthetic feeling or taste in man, and deliberately select males for their superiority in some aesthetic quality, such as graceful or fantastic motions, melody of voice, brilliancy of colour, or perfection of ornaments. Doubtless all birds were originally plain-coloured, without ornaments and without melody, and it is assumed that so it would always have been in many cases but for the action of this principle, which, like natural selection, has gone on accumulating countless small variations, tending to give a greater lustre to the species in each case, and resulting in all that we most admire in the animal world—the Rupicola's flame-coloured mantle, the peacock's crest and starry train, the joyous melody of the lark, and the pretty or fantastic dancing performances of birds.

My experience is that mammals and birds, with few exceptions—probably there are really no exceptions—possess the habit of indulging frequently in more or less regular or set performances, with or without sound, or composed of sound exclusively; and that these performances, which in many animals are only discordant cries and choruses, and uncouth, irregular motions, in the more aerial, graceful, and melodious kinds take immeasurably higher, more complex, and more beautiful forms. Among the mammalians the instinct appears almost universal; but their displays are, as a rule, less admirable than those seen in birds. There are some kinds, it is true, like the squirrels and monkeys, of arboreal habits, almost birdlike in their restless energy, and in the swiftness and certitude of their motions, in which the slightest impulse can be instantly expressed in graceful or fantastic action; others, like the Chinchillidae family, have greatly developed vocal organs, and resemble birds in loquacity; but mammals generally, compared with birds, are slow and heavy, and not so readily moved to exhibitions of the kind I am discussing.

The terrestrial dances, often very elaborate, of heavy birds, like those of the gallinaceous kind, are represented in the more volatile species by performances in the air, and these are very much more beautiful; while a very large number of birds—hawks, vultures, swifts, swallows, nightjars, storks, ibises, spoonbills, and gulls—circle about in the air, singly or in flocks. Sometimes, in serene weather, they rise to a vast altitude, and float about in one spot for an hour or longer at a stretch, showing a faint bird-cloud in the blue, that does not change its form, nor grow lighter and denser like a flock of starlings; but in the seeming confusion there is perfect order, and amidst many hundreds each swift- or slow-gliding figure keeps its proper distance with such exactitude that no two ever touch, even with the extremity of the long-wings, flapping or motionless:—such a multitude, and such miraculous precision in the endless curving motions of all the members of it, that the spectator can lie for an hour on his back without weariness watching this mystic cloud-dance in the empyrean.

The black-faced ibis of Patagonia, a bird nearly as large as a turkey, indulges in a curious mad performance, usually in the evening when feeding-time is over. The birds of a flock, while winging their way to the roosting-place, all at once seem possessed with frenzy, simultaneously dashing downwards with amazing violence, doubling about in the most eccentric manner; and when close to the surface rising again to repeat the action, all the while making the air palpitate for miles around with their hard, metallic cries. Other ibises, also birds of other genera, have similar aerial performances.

The displays of most ducks known to me take the form of mock fights on the water; one exception is the handsome and loquacious whistling widgeon of La Plata, which has a pretty aerial performance. A dozen or twenty birds rise up until they appear like small specks in the sky, and sometimes disappear from sight altogether; and at that great altitude they continue hovering in one spot, often for an hour or longer, alternately closing and separating; the fine, bright, whistling notes and flourishes of the male curiously harmonizing with the grave, measured notes of the female; and every time they close they slap each other on the wings so smartly that the sound can be distinctly heard, like applauding hand-claps, even after the birds have ceased to be visible.

The rails, active, sprightly birds with powerful and varied voices, are great performers; but owing to the nature of the ground they inhabit and to their shy, suspicious character, it is not easy to observe their antics. The finest of the Platan rails is the ypecaha, a beautiful, active bird about the size of the fowl. A number of ypecahas have their assembling place on a small area of smooth, level ground, just above the water, and hemmed in by dense rush beds. First, one bird among the rushes emits a powerful cry, thrice repeated; and this is a note of invitation, quickly responded to by other birds from all sides as they hurriedly repair to the usual place. In a few moments they appear, to the number of a dozen or twenty, bursting from the rushes and running into the open space, and instantly beginning the performance. This is a tremendous screaming concert. The screams they utter have a certain resemblance to the human voice, exerted to its utmost pitch and expressive of extreme terror, frenzy, and despair. A long, piercing shriek, astonishing for its vehemence and power, is succeeded by a lower note, as if in the first the creature had well nigh exhausted itself: this double scream is repeated several times, and followed by other sounds, resembling, as they rise and fall, half smothered cries of pains and moans of anguish. Suddenly the unearthly shrieks are renewed in all their power. While screaming the birds rush from side to side, as if possessed with madness, the wings spread and vibrating, the long-beak wide open and raised vertically. This exhibition lasts three or four minntes, after which the assembly peacefully breaks up.

The singular wattled, wing-spurred, and long-, toed jacana has a remarkable performance, which seems specially designed to bring out the concealed beauty of the silky, greenish-golden wing-quills-The birds go singly or in pairs, and a dozen or fifteen individuals may be found in a marshy place feeding within sight of each other. Occasionally, in response to a note of invitation, they all in a moment leave off feeding and fly to one spot, and, forming a close cluster, and emitting short, excited, rapidly repeated notes, display their wings, like beautiful flags grouped loosely together: some hold the wings up vertically and motionless; others, half open and vibrating rapidly, while still others wave them up and down with a slow, measured motion.

In the ypecaha and jacana displays both sexes take part. A stranger performance is that of the spur-winged lapwing of the same region—a species resembling the lapwing of Europe, but a third larger, brighter coloured, and armed with spurs. The lapwing display, called by the natives its "dance," or "serious dance"—by which they mean square dance—requires three birds for its performance, and is, so far as I know, unique in this respect. The birds are so fond of it that they indulge in it all the year round, and at frequent intervals during the day, also on moonlight nights. If a person watches any two birds for some time—for they live in pairs—he will see another lapwing, one of a neighbouring couple, rise up and fly to them, leaving his own mate to guard their chosen ground; and instead of resenting this visit as an unwarranted intrusion on their domain, as they would certainly resent the approach of almost any other bird, they welcome it with notes and signs of pleasure. Advancing to the visitor, they place themselves behind it; then all three, keeping step, begin a rapid march, uttering resonant drumming notes in time with their movements; the notes of the pair behind being emitted in a stream, like a drum-roll, while the leader utters loud single notes at regular intervals. The march ceases; the leader elevates his wings and stands erect and motionless, still uttering loud notes; while the other two, with puffed-out plumage and standing exactly abreast stoop forward and downward until the tips of their beaks touch the ground, and, sinking their rhythmical voices to a murmur, remain for some time in this posture. The performance is then over and the visitor goes back to his own ground and mate, to receive a visitor himself later on.

In the Passerine order, not the least remarkable displays are witnessed in birds that are not accounted songsters, as they do not possess the highly developed vocal organ confined to the suborder Oscines. The tyrant-birds, which represent in South America the fly-catchers of the Old World, all have displays of some kind; in a vast majority of cases these are simply joyous, excited duets between male and female, composed of impetuous and more or less confused notes and screams, accompanied with beating of wings and other gestures. In some species choruses take the place of duets, while in others entirely different forms of display have been developed. In one group—Cnipolegus—the male indulges in solitary antics, while the silent, modest-coloured female keeps in hiding. Thus, the male of Cnipolegus Hudsoni, an intensely black-plumaged species with a concealed white wing-band, takes his stand on a dead twig on the summit of a bush. At intervals he leaves his perch, displaying the intense white on the quills, and producing, as the wings are thrown open and shut alternately, the effect of successive flashes of light. Then suddenly the bird begins revolving in the air about its perch, like a moth wheeling round and close to the flame of a candle, emitting a series of sharp clicks and making a loud humming with the wings. While performing this aerial waltz the black and white on the quills mix, the wings appearing like a grey mist encircling the body. The fantastic dance over, the bird drops suddenly on to its perch again; and, until moved to another display, remains as stiff and motionless as a bird carved out of jet.

The performance of the scissors-tail, another tyrant-bird, is also remarkable. This species is grey and white, with black head and tail and a crocus-yellow crest. On the wing it looks like a large swallow, but with the two outer tail-feathers a foot long. The scissors-tails always live in pairs, but at sunset several pairs assemble, the birds calling excitedly to each other; they then mount upwards, like rockets, to a great height in the anand, after wheeling about for a few moments, pro-cipitate themselves downwards with amazing violence in a wild zigzag, opening and shutting the long tail-feathers like a pair of shears, and producing loud whirring sounds, as of clocks being wound rapidly up, with a slight pause after each turn of the key. This aerial dance over, they alight in separate couples on the tree tops, each couple joining in a kind of duet of rapidly repeated, castanet-like sounds.

The displays of the wood-hewers, or Dendrocolap-tidae, another extensive family, resemble those of the tyrant-birds in being chiefly duets, male and female singing excitedly in piercing or resonant voices, and with much action. The habit varies somewhat in the cachalote, a Patagonian species of the genus Homorus, about the size of the missel-thrush. Old and young birds live in a family together, and at intervals, on any fine day, they engage in a grand screaming contest, which may be heard distinctly at a distance of a mile and a half. One bird mounts on to a bush and calls, and instantly all the others hurry to the spot, and burst out into a chorus of piercing cries that sound like peals and shrieks of insane laughter. After the chorus, they all pursue each other wildly about among the bushes for some minutes.

In some groups the usual duet-like performances have developed into a kind of harmonious singing, which is very curious and pleasant to hear. This is pre-eminently the case with the oven-birds, as D'Orbigney first remarked. Thus, in the red oven-bird, the first bird, on the appearance of its mate flying to join it, begins to emit loud, measured notes, and sometimes a continuous trill, somewhat metallic in sound; but immediately on the other bird striking in this introductory passage is changed to triplets, strongly accented on the first note, in a tempo vivace; while the second bird utters loud single notes in the same time. While thus singing they stand facing each other, necks outstretched and tails expanded, the wings of the first bird vibrating rapidly to the rapid utterance, while those of the second bird beat measured time. The finale consists of three or four notes, uttered by the second bird alone, strong and clear, in an ascending scale, the last very piercing.

In the melodists proper the displays, in a majority of cases, are exclusively vocal, the singer sitting still on his perch. In the Troupials, a family of starling-like birds numbering about one hundred and forty species, there are many that accompany singing with pretty or grotesque antics. The male screaming cow-bird of La Plata, when perched, emits a hollow-sounding internal note that swells at the end into a sharp metallic ring, almost bell-like: this is uttered with wings and tail spread and depressed, the whole plumage being puffed out as in a strutting turkey-cock, while the bird hops briskly up and down on its perch as if dancing. The bell-like note of the male is followed by an impetuous scream from the female, and the dance ends. Another species, the common Argentine cow-bird of La Plata, when courting puffs out his glossy rich violet plumage, and, with wings vibrating, emits a succession of deep internal notes, followed by a set song in clear, ringing tones; and then, suddenly taking wing, he flies straight away, close to the surface, fluttering like a moth, and at a distance of twenty to thirty yards turns and flies in a wide circle round the female, singing loudly all the time, hedging her in with melody as it were.

Many songsters in widely different families possess the habit of soaring and falling alternately while singing, and in some cases all the aerial postures and movements, the swift or slow descent, vertical, often, with oscillations, or in a spiral, and sometimes with a succession of smooth oblique lapses, seem to have an admirable correspondence with the changing and falling voice—melody and motion being united in a more intimate and beautiful way than in the most perfect and poetic forms of human dancing.

One of the soaring singers is a small yellow field-finch of La Plata—Sycalis luteola; and this species, like some others, changes the form of its display with the seasons. It lives in immense flocks, and during the cold season it has, like most finches, only aerial pastimes, the birds wheeling about in a cloud, pursuing each other with lively chirpings. In August, when the trees begin to blossom, the flock betakes itself to a plantation, and, sitting on the branches, the birds sing in a concert of innumerable voices, producing a great volume of sound, as of a high wind when heard at a distance. Heard near, it is a great mass of melody; not a confused tangle of musical sounds as when a host of Troupials sing in concert, but the notes, although numberless, seem to flow smoothly and separately, producing an effect on the ear similar to that which rain does on the sight, when the sun shines on and lightens up the myriads of falling drops all falling one way. In this manner the birds sing for hours, without intermission, every day. Then the passion of love infects them; the pleasant choir breaks up, and its ten thousand members scatter wide over the surrounding fields and pasture lands. During courtship the male has a feeble, sketchy music, but his singing is then accompanied with very charming love antics. His circlings about the hen-bird; his numberless advances and retreats, and little soarings above her when his voice swells with importunate passion; his fluttering lapses back to earth, where he lies prone with outspread, tremulous wings, a suppliant at her feet, his languishing voice meanwhile dying down to lispings—all these apt and graceful motions seem to express the very sickness of the heart. But the melody during this emotional period is nothing. After the business of pairing and nest-building is over, his musical displays take a new and finer form. He sits perched on a stalk above the grass, and at intervals soars up forty or fifty yards high; rising, he utters a series of long melodious notes; then he descends in a graceful spiral, the set of the motionless wings giving him the appearance of a slowly-falling parachute; the voice then also falls, the notes coming lower, sweeter, and more expressive until he reaches the surface. After alighting the song continues, the strains becoming longer, thinner, and clearer, until they dwindle to the finest threads of sound and faintest tinklings, as from a cithern touched by fairy fingers. The great charm of the song is in this slow gradation from the somewhat throaty notes emitted by the bird when ascendino-to the excessively attenuated sounds at the close.

In conclusion of this part I shall speak of one species more—the white-banded mocking-bird of Patagonia, which greatly excels all other songsters known to me in the copiousness, variety and brilliant character of its music. Concealed in the foliage this bird will sing by the half-hour, reproducing with miraculous fidelity the more or less melodious set songs of a score of species—a strange and beautiful performance; but wonderful as it seems while it lasts, one almost ceases to admire this mimicking bird-art when the mocker, as if to show by contrast his unapproachable superiority, bursts into his own divine song, uttered with a power, abandon and joyousness resembling, but greatly exceeding, that of the skylark "singing at heaven's gate;" the notes issuing in a continuous torrent; the voice so brilliant and infinitely varied, that if "rivalry and emulation" have as large a place in feathered breasts as some imagine all that hear this surpassing melody might well languish ever after in silent despair.

In a vast majority of the finest musical performances the same notes are uttered in the same order, and after an interval the song is repeated without any variation: and it seems impossible that we could in any other way have such beautiful contrasts and harmonious lights and shades—the whole song, so to speak, like a "melody sweetly played in tune." This seeming impossibility is accomplished in the mocking-bird's song: the notes never come in the same order again and again, but, as if inspired, in a changed order, with variations and new sounds: and here again it has some resemblance to the skylark's song, and might be described as the lark's song with endless variations and brightened and spiritualized in a degree that cannot be imagined.

This mocking-bird is one of those species that accompany music with appropriate motions. And just as its song is, so to speak, inspired and an im-provization, unlike any song the bird has ever uttered, so its motions all have the same character of spontaneity, and follow no order, and yet have a grace and passion and a perfect harmony with the music unparalleled among birds possessing a similar habit. While singing he passes from bush to bush, sometimes delaying a few moments on and at others just touching the summits, and at times sinking out of sight in the foliage: then, in an access of rapture, soaring vertically to a height of a hundred feet, with measured wing-beats, like those of a heron: or, mounting suddenly in a wild, hurried zigzag, then slowly circling downwards, to sit at last with tail outspread fanwise, and vans, glistening white in the sunshine, expanded and vibrating, or waved languidly up and down, with, a motion like that of some broad-winged butterfly at rest on a flower.

I wish now to put this question: What relation that we can see or imagine to the passion of love and the business of courtship, have these dancing and vocal performances in nine cases out of ten? In such cases, for instance, as that of the scissors-tail tyrant-bird, and its pyrotechnic evening displays, when a number of couples leave their nests containing eggs and young to join in a wild aerial dance: the mad exhibitions of ypecahas and ibises, and the jacanas' beautiful exhibition of grouped wings: the triplet dances of the spur-winged lapwing, to perform which two birds already mated are compelled to call in a third bird to complete the set: the harmonious duets of the oven-birds, and the duets and choruses of nearly all the wood-hewers, and the wing-slapping aerial displays of the whistling widgeons—will it be seriously contended that the female of this species makes choice of the male able to administer the most vigorous and artistic slaps?

The believer in the theory would put all these cases lightly aside, to cite that of the male cow-bird practising antics before the female and drawing a wide circle of melody round her; or that of the jet-black, automaton-like, dancing tyrant-bird; and concerning this species he would probably say that the plain-plumaged female went about unseen, critically watching the dancing of different males, to discover the most excellent performer according to the traditional standard. And this was, in substance, what Darwin did. There are many species in which the male, singly or with others, practises antics or sings during the love-season before the female; and when all such cases, or rather those that are most striking and bizarre, are brought together, and when it is gratuitously asserted that the females do choose the males that show off in the best manner or that sing best, a case for sexual selection seems to be made out. How unfair the argument is, based on these carefully selected cases gathered from all regions of the globe, and often not properly reported, is seen when we turn from the book to nature and closely consider the habits and actions of all the species inhabiting any one district. We see then that such cases as those described and made so much of in the Descent of Man, and cases like those mentioned in this chapter, are not essentially different in character, but are manifestations of one instinct, which appears to be almost universal among the animals. The explanation I have to offer lies very much on the surface and is very simple indeed, and, like that of Dr. Wallace with regard [Footnote: It is curious to find that Dr. Wallace's idea about colour has been independently hit upon by Ruskin. Of stones he writes in Frondes Agrestis:—"I have often had occasion to allude to the apparent connection of brilliancy of colour with vigour of life and purity of substance. This is pre-eminently the case in the mineral kingdom. The perfection with which the particles of any substance unite in crystallization, corresponds in that kingdom to the vital power in organic nature."] to colour and ornaments covers the whole of the facts. We see that the inferior animals, when the conditions of life are favourable, are subject to periodical fits of gladness affecting them powerfully and standing out in vivid contrast to their ordinary temper. And we know what this feeling is—this periodic intense elation which even civilized man occasionally experiences when in perfect health, more especially when young. There are moments when he is mad with joy, when he cannot keep still, when his impulse is to sing and shout aloud and laugh at nothing, to run and leap and exert himself in some extravagant way. Among the heavier mammalians the feeling is manifested in loud noises, bellowings and screamings, and in lumbering, uncouth motions—throwing up of heels, pretended panics, and ponderous mock battles.

In smaller and livelier animals, with greater celerity and certitude in their motions, the feeling shows itself in more regular and often in more complex ways. Thus, Felidae when young, and, in very agile, sprightly species like the Puma, throughout life, simulate all the actions of an animal hunting its prey—sudden, intense excitement of discovery, concealment, gradual advance, masked by intervening objects, with intervals of watching, when they crouch motionless, the eyes flashing and tail waved from side to side; finally, the rush and spring, when the playfellow is captured, rolled over on his back and worried to imaginary death. Other species of the most diverse kinds, in which voice is greatly developed, join in noisy concerts and choruses; many of the cats may be mentioned, also dogs and foxes, capybaras and other loquacious rodents; and in the howling monkeys this kind of performance rises to the sublime uproar of the tropical forest at eventide.

Birds are more subject to this universal joyous instinct than mammals, and there are times when some species are constantly overflowing with it; and as they are so much freer than mammals, more buoyant and graceful in action, more loquacious, and have voices so much finer, their gladness shows itself in a greater variety of ways, with more regular and beautiful motions, and with melody. But every species, or group of species, has its own inherited form or style of performance; and, however rude and irregular this may be, as in the case of the pretended stampedes and fights of wild cattle, that is the form in which the feeling will always be expressed. If all men, at some exceedingly remote period in their history, had agreed to express the common glad impulse, which they now express in such an infinite variety of ways or do not express at all, by dancing a minuet, and minuet-dancing had at last come to be instinctive, and taken to spontaneously by children at an early period, just as they take to walking "on their hind legs," man's case would be like that of the inferior animals.

I was one day watching a flock of plovers, quietly feeding on the ground, when, in a moment, all the birds were seized by a joyous madness, and each one, after making a vigorous peck at his nearest neighbour, began running wildly about, each trying in passing to peck other birds, while seeking by means of quick doublings to escape being pecked in turn. This species always expresses its glad impulse in the same way; but how different in form is this simple game of touch-who-touch-can from the triplet dances of the spur-winged lapwings, with their drumming music, pompous gestures, and military precision of movement! How different also from the aerial performance of another bird of the same family—the Brazilian stilt—in which one is pursued by the others, mounting upwards in a wild, eccentric flight until they are all but lost to view; and back to earth again, and then, skywards once more; the pursued bird when overtaken giving place to another individual, and the pursuing pack making the air ring with their melodious barking cries! How different again are all these from the aerial pastimes of the snipe, in which the bird, in its violent descent, is able to produce such wonderful, far-reaching sounds with its tail-feathers! The snipe, as a rule, is a solitary bird, and, like the oscillating finch mentioned early in this paper, is content to practise its pastimes without a witness. In the gregarious kinds all perform together: for this feeling, like fear, is eminently contagious, and the sight of one bird mad with joy will quickly make the whole flock mad. There are also species that always live in pairs, like the scissors-tails already mentioned, that periodically assemble in numbers for the purpose of display. The crested screamer, a very large bird, may also be mentioned: male and female sing somewhat harmoniously together, with voices of almost unparalleled power: but these birds also congregate in large numbers, and a thousand couples, or even several thousands, may be assembled together: and, at intervals, both by day and night, all sing in concert, their combined voices producing a thunderous melody which seems to shake the earth. As a rule, however, birds that live always in pairs do not assemble for the purpose of display, but the joyous instinct is expressed by duet-like performances between male and female. Thus, in the three South American Passerine families, the tyrant-birds, wood-hewers, and ant-thrushes, numbering together between eight and nine hundred species, a very large majority appear to have displays of this description.

In my own experience, in cases where the male and female together, or assembled with others, take equal parts in the set displays, the sexes arc similar, or differ little; but where the female takes no part in the displays the superiority of the male in brightness of colour is very marked. One or two instances bearing on this point may be given.

A scarlet-breasted troupial of La Plata perches conspicuously on a tall plant in afield, and at intervals soars up vertically, singing, and, at the highest ascending point, flight and song end in a kind of aerial somersault and vocal flourish at the same moment. Meanwhile, the dull-plumaged female is not seen and not heard: for not even a skulking crake lives in closer seclusion under the herbage—so widely have the sexes diverged in this species. Is the female, then, without an instinct so common r—has she no sudden fits of irrepressible gladness? Doubtless she has them, and manifests them down in her place of concealment in lively chirpings and quick motions—the simple, primitive form in which gladness is expressed in the class of birds. In the various species of the genus Cnipolegus, already mentioned, the difference in the sexes is just as great as in the case of the troupial: the solitary, intensely black, statuesque male has, we have seen, a set and highly fantastic performance; but on more than one occasion I have seen four or five females of one species meet together and have a little simple performance all to themselves—in form a kind of lively mock fight.

It might be objected that when a bird takes its stand and repeats a set finished song at intervals for an hour at a stretch, remaining quietly perched, such a performance appears to be different in character from the irregular and simple displays which are unmistakably caused by a sudden glad impulse. But we are familiar with the truth that in organic nature great things result from small beginnings—a common flower, and our own bony skulls, to say nothing of the matter contained within them, are proofs of it. Only a limited number of species sing in a highly finished manner. Looking at many species, we find every gradation, every shade, from the simple joyous chirp and cry to the most perfect melody. Even in a single branch of the true vocalists we may see it—from the chirping bunting, and noisy but tuneless sparrow, to linnet and goldfinch and canary. Not only do a large majority of species show the singing instinct, or form of display, in a primitive, undeveloped state, but in that state it continues to show itself in the young of many birds in which melody is most highly developed in the adult. And where the development has been solely in the male the female never rises above that early stage; in her lively chirpings and little mock fights and chases, and other simple forms which gladness takes in birds, as well as in her plainer plumage, and absence of ornament, she represents the species at some remote period. And as with song so with antics and all set performances aerial or terrestrial, from those of the whale and the elephant to those of the smallest insect.

Another point remains to be noticed, and that is the greater frequency and fulness in displays of all kinds, including song, during the love season. And here Dr. Wallace's colour and ornament theory helps us to an explanation. At the season of courtship, when the conditions of life are most favourable vitality is at its maximum, and naturally it is then that the proficiency in all kinds of dancing-antics, aerial and terrestrial, appears greatest, and that melody attains its highest perfection. This applies chiefly to birds, but even among birds there are exceptions, as we have seen in the case of the field-finch, Sycalis luteola. The love-excitement is doubtless pleasurable to them, and it takes the form in which keenly pleasurable emotions are habitually expressed, although not infrequently with variations due to the greater intensity of the feeling. In some migrants the males arrive before the females, and no sooner have they recovered from the effects of their journey than they burst out into rapturous singing; these are not love-strains, since the females have not yet arrived, and pairing-time is perhaps a mouth distant; their singing merely expresses their overflowing gladness. The forest at that season is vocal, not only with the fine melody of the true songsters, but with hoarse cawings, piercing cries, shrill duets, noisy choruses, drummings, boomings, trills, wood-tappings—every sound with which different species express the glad impulse; and birds like the parrot that only exert their powerful voices in screamings—because "they can do no other"—then scream their loudest. When courtship begins it has in many cases the effect of increasing the beauty of the performance, giving added sweetness, verve, and brilliance to the song, and freedom and grace to the gestures and motions. But, as I have said, there are exceptions. Thus, some birds that are good melodists at other times sing in a feeble, disjointed manner during courtship. In Patagonia I found that several of the birds with good voices—one a mocking bird—were, like the robin at home, autumn and winter songsters.

The argument has been stated very binefly: but little would be gained by the mere multiplication of instances, since, however many, they would bo selected instances—from a single district, it is true, while those in the Descent of Man were brought together from an immeasurably wider field; but the principle is the same in both cases, and to what I have written it may be objected that, if, instead of twenty-five, I had given a hundred cases, taking them as they came, they might have shown a larger proportion of instances like that of the cow-bird, in which the male has a set performance practised only during the love-season and in the presence of the female.

It is, no doubt, true that all collections of facts relating to animal life present nature to us somewhat as a "fantastic realm"—unavoidably so, in a measure, since the writing would be too bulky, or too dry, or too something inconvenient, if we did not take only the most prominent facts that come before us, remove them from their places, where alone they can be seen in their proper relations to numerous other less prominent facts, and rearrange them patch work-wise to make up our literature. But I am convinced that any student of the subject who will cast aside his books—supposing that they have not already bred a habit in his mind of seeing only "in accordance with verbal statement"—and go directly to nature to note the actions of animals for himself—actions which, in many cases, appear to lose all significance when set down in writing—the result of such independent investigation will be a conviction that conscious sexual selection on the part of the female is not the cause of music and dancing performances in birds, nor of the brighter colours and ornaments that distinguish the male. It is true that the females of some species, both in the vertebrate and insect kingdoms, do exercise a preference; but in a vast majority of species the male takes the female he finds, or that he is able to win from other competitors; and if we go to the reptile class we find that in the ophidian order, which excels in variety and richness of colour, there is no such thing as preferential mating; and if we go to the insect class, we find that in butterflies, which surpass all creatures in their glorious beauty, the female gives herself up to the embrace of the first male that appears, or else is captured by the strongest male, just as she might be by a mantis or some other rapacious insect.



CHAPTER XX.

BIOGRAPHY OF THE VIZCACHA.

(Lagostomus Trichodactylus.)

The vizcacha is perhaps the most characteristic of the South American Rodentia, [Footnote: "According to Mr. Waterhouse, of all rodents the vizcacha is most nearly related to marsupials; but in the points in which it approaches this order its relations are general, that is, not to any one marsupial species more than to another. As these points of affinity are believed to be real and not merely adaptive, they must be due in accordance with our view to inheritance from a common progenitor. Therefore wo must suppose either that all rodents, including the vizcacha, branched off from some ancient marsupial, which will naturally have been more or less intermediate in character with respect to all existing marsupials; or, that both lodents and marsupials branched off from a common progenitor. ... On either view we must suppose that the vizcacha has retained, by inheritance, more of the characters of its ancient progenitor than have other rodents."—DARWIN; Origin of Species.] while its habits, in some respects, are more interesting than those of any other rodent known: it is, moreover, the most common mammal we have on the pampas; and all these considerations have induced me to write a very full account of its customs. It is necessary to add that since the following pages were written at my home on the pampas a great war of extermination has been waged against this animal by the landowners, which has been more fortunate in its results—or unfortunate if one's sympathies are with the vizcacha—than the war of the Australians against their imported rodent—the smaller and more prolific rabbit.

The vizcachas on the pampas of Buenos Ayres live in societies, usually numbering twenty or thirty members. The village, which is called Vizcachera, is composed of a dozen or fifteen burrows or mouths; for one entrance often serves for two or more distinct holes. Often, where the ground is soft, there are twenty or thirty or more burrows in an old vizcachera; but on stony, or "tosca" soil even an old one may have no more than four or five burrows. They are deep wide-mouthed holes, placed very close together, the entire village covering an area of from one hundred to two hundred square feet of ground.

The burrows vary greatly in extent; and usually in a vizcachera there are several that, at a distance of from four to six feet from the entrance, open into large circular chambers. From these chambers other burrows diverge in all directions, some running horizontally, others obliquely downwards to a maximum depth of six feet from the surface: some of these burrows or galleries communicate with those of other burrows. A vast amount of loose earth is thus brought up, and forms a very irregular mound, fifteen to thirty inches above the surrounding level.

It will afford some conception of the numbers of these vizcacheras on the settled pampas when I say that, in some directions, a person might ride five hundred miles and never advance half a mile without seeing one or more of them. In districts where, as far as the eye can see, the plains are as level and smooth as a bowling-green, especially in winter when the grass is close-cropped, and where the rough giant-thistle has not sprung up, these mounds appear like brown or dark spots on a green surface. They are the only irregularities that occur to catch the eye, and consequently form an important feature in the scenery. In some places they are so near together that a person on horseback may count a hundred of them from one point of view.

The sites of which the vizcacha invariably makes choice to work on, as well as his manner of burrow-ing, adapt him peculiarly to live and thrive on the open pampas. Other burrowing species seem always to fix upon some spot where there is a bank or a sudden depression in the soil, or where there is rank herbage, or a bush or tree, about the roots of which to begin their kennel. They are averse to commence digging on a clear level surface, either because it is not easy for them where they have nothing to rest their foreheads against while scratching, or because they possess a wary instinct that impels them to place the body in concealment whilst working on the surface, thus securing the concealment of the burrow after it is made. Certain it is that where large hedges have been planted on the pampas, multitudes of opossums, weasels, skunks, armadillos, &c., come and make their burrows beneath them; and where there are no hedges or trees, all these species make their kennels under bushes of the perennial thistle, or where there is a shelter of some kind. The vizcacha, on the contrary, chooses an open level spot, the cleanest he can find to burrow on. The first thing that strikes the observer when viewing the vizcachera closely is the enormous size of the entrance of the burrows, or, at least, of several of the central ones in the mound; for there are usually several smaller outside burrows. The pit-like opening to some of these principal burrows is often four to six feet across the mouth, and sometimes deep enough for a tall man to stand up waist-deep in. How these large entrances can be made on a level surface may be seen when the first burrow or burrows of an incipient vizcachera are formed. It is not possible to tell what induces a vizcacha to be the founder of a new community; for they increase very slowly, and furthermore are extremely fond of each other's society; and it is invariably one individual that leaves his native village to found a new and independent one. If it were to have better pasture at hand, then he would certainly remove to a considerable distance; but he merely goes from forty to fifty or sixty yards off to begin his work. Thus it is that in desert places, where these animals are rare, a solitary vizcachera is never seen; but there are always several close together, though there may be no others on the surrounding plain for leagues. When the vizcacha has made his habitation, it is but a single burrow, with only himself for an inhabitant, perhaps for many months. Sooner or later, however, others join him: and these will be the parents of innumerable generations; for they construct no temporary lodging-place, as do the armadillos and other species, but their posterity continues in the quiet possession of the habitations bequeathed to it; how long, it is impossible to say. Old men who have lived all their lives in one district remember that many of the vizcacheras around them existed when they were children. It is invariably a male that begins a new village, and makes his burrow in the following manner, though he does not always observe the same method. He works very straight into the earth, digging a hole twelve or fourteen inches wide, but not so deep, at an angle of about 25 degrees with the surface. But after he has progressed inwards a few feet, the vizcacha is no longer satisfied with merely scattering away the loose earth he fetches up, but cleans it away so far in a straight line from the entrance, and scratches so much on this line (apparently to make the slope gentler), that he soon forms a trench a foot or more in depth, and often three or four feet in length. Its use is, as I have inferred, to facilitate the conveying of the loose earth as far as possible from the entrance of the burrow. But after a while the animal is unwilling that it should accumulate even at the end of this long passage; he therefore proceeds to make two additional trenches, that form an acute, sometimes a right angle, converging into the first, so that when the whole is completed it takes the form of a capital Y.

These trenches are continually deepened and lengthened as the burrow progresses, the angular segment of earth between them, scratched away, until by degrees it has been entirely conveyed off, and in its place is the one deep great unsymmetrical mouth I have already described. There are soils that will not admit of the animals working in this manner. Where there are large cakes of "tosca" near the surface, as in many localities on the southern pampas, the vizcacha makes its burrow as best he can, and without the regular trenches. In earths that crumble much, sand or gravel, he also works under great disadvantages.

The burrows are made best in the black and red moulds of the pampas; but even in such soils the entrances of many burrows are made differently. In some the central trench is wanting, or is so short that there appear but two passages converging directly into the burrow; or these two trenches may be so curved inwards as to form the segment of a circle. Many other forms may also be noticed, but usually they appear to be only modifications of the most common Y-shaped system.

As I have remarked that its manner of burrowing has peculiarly adapted the vizcacha to the pampas, it may be asked what particular advantage a species that makes a wide-mouthed burrow possesses over those that excavate in the usual way. On a declivity, or at the base of rocks or trees, there would be none; but on the perfectly level and shelterless pampas, the durability of the burrow, a circumstance favourable to the animal's preservation, is owing altogether to its being made in this way, and to several barrows being made together. The two outer trenches diverge so widely from the mouth that half the earth brought out is cast behind instead of before it, thus creating a mound of equal height about the entrance, by which it is secured from water during great rainfalls, while the cattle avoid treading over the great pit-like entrances. But the burrows of the dolichotis, armadillo, and other species, when made on perfectly level ground, are soon trod on and broken in by cattle; in summer they are choked up with dust and rubbish; and, the loose earth having all been thrown up together in a heap on one side, there is no barrier to the water which in eveiy great rainfall flows in and obliterates the kennel, drowning or driving out the tenant.

I have been minute in describing the habitations of the vizcacha, as I esteem the subject of prime importance in considering the zoology of this portion of America. The vizcacha does not benefit himself alone by his perhaps unique style of burrowing; but this habit has proved advantageous to several other species, and has been so favourable to two of our birds that they are among the most common species found here, whereas without these burrows they would have been exceedingly rare, since the natural banks in which they breed are scarcely found anywhere on the pampas. I refer to the Minera (Geositta cunicularia), which makes its breeding-holes in the bank-like sides of the vizcacha's burrow, and to the little swallow (Atticora cyanoleuca) which breeds in these excavations when forsaken by the Minera. Few old vizcacheras are seen without some of these little parasitical burrows in them.

Birds are not the only beings in this way related to the vizcachas: the fox and the weasel of the pampas live almost altogether in them. Several insects also frequent these burrows that are seldom found anywhere else. Of these the most interesting are:—a large predacious nocturnal bug, shining black, with red wings; a nocturnal Cicindela, a beautiful insect, with dark green striated wing-cases and pale red legs; also several diminutive wingless wasps. Of the last I have counted six species, most of them marked with strongly contrasted colours, black, red, and white. There are also other wasps that prey on the spiders found on the vizcachera. All these and others are so numerous on the mounds that dozens of them might there be collected any summer day; but if sought for in other situations they are exceedingly rare. If the dry mound of soft earth which the vizcacha elevates amidst a waste of humid, close-growing grass is not absolutely necessary to the existence of all these species, it supplies them with at least one favourable condition, and without doubt thereby greatly increases their numbers: they, too, whether predacious or preyed on, have so many relations with other outside species, and these again with still others, that it would be no mere fancy to say that probably hundreds of species are either directly or indirectly affected in their struggle for existence by the vizcacheras so abundantly sprinkled over the pampas.

In winter the vizcachas seldom leave their burrows till dark, but in summer come out before sunset; and the vizcachera is then a truly interesting spectacle. Usually one of the old males first appears, and sits on some prominent place on the mound, apparently in no haste to begin his evening meal. When approached from the front he stirs not, but eyes the intruder with a bold indifferent stare. If the person passes to one side, he deigns not to turn his head.

Other vizcachas soon begin to appear, each one quietly taking up his station at his burrow's mouth, the females, known by their greatly inferior size and lighter grey colour, sitting upright on their haunches, as if to command a better view, and indicating by divers sounds and gestures that fear and curiosity struggles in them for mastery; for they are always wilder and sprightlier in their motions than the males. With eyes fixed on the intruder, at intervals they dodge the head, emitting at the same time an internal note with great vehemence; and suddenly, as the danger comes nearer, they plunge simultaneously, with a startled cry, into their burrows. But in some curiosity is the strongest emotion; for, in spite of their fellow's contagious example, and already half down the entrance, again they start up to scrutinize the stranger, and will then often permit him to walk within five or six paces of them.

Standing on the mound there is frequently a pair of burrowing owls (Pholeoptynx cunicularia). These birds generally make their own burrows to breed in, or sometimes take possession of one of the lesser outside burrows of the village; but their favourite residence, when not engaged in tending their eggs or young, is on the vizcachera. Here a pair will sit all day; and I have often remarked a couple close together on the edge of the burrow; and when the vizcacha came out in the evening, though but a hand's breadth from them, they did not stir, nor did he notice them, so accustomed are these creatures to each other. Usually a couple of the little burrowing Geositta are also present. They are lively creatures, running with great rapidity about the mound and bare space that surrounds it, suddenly stopping and jerking their tails in a slow deliberate manner, and occasionally uttering their cry, a trill, or series of quick short clear notes, resembling somewhat the shrill excessive laughter of a child. Among the grave, stationary vizcachas, of which they take no heed, perhaps half a dozen or more little swallows (Atticora cyanoleuca) are seen, now clinging altogether to the bank-like entrance of a burrow, now hovering over it in a moth-like manner, as if uncertain where to alight, and anon sweeping about in circles, but never ceasing their low and sorrowful notes.

The vizcachera with all its incongruous inhabitants thus collected upon it is to a stranger one of the most novel sights the pampas afford.

The vizcacha appears to be a rather common species over all the extensive Argentine territory; but they are so exceedingly abundant on the pampas inhabited by man, and comparatively so rare in the desert places I have been in, that I was at first much surprised at finding them so unequally distributed. I have also mentioned that the vizcacha is a tame familiar creature. This is in the pastoral districts, where they are never disturbed; but in wild regions, where he is scarce, he is exceedingly wary, coming forth long after dark, and plunging into his burrow on the slightest alarm, so that it is a rare thing to get a sight of him. The reason is evident enough; in desert regions the vizcacha has several deadly enemies in the larger rapacious mammals. Of these the puma or lion (Felis concolor) is the most numerous, as it is also the swiftest, most subtle, and most voracious; for, as regards these traits, the jaguar (F. onca) is an inferior animal. To the insatiable bloody appetite of this creature nothing comes amiss; he takes the male ostrich by surprise, and slays that wariest of wild things on his nest; He captures little birds with the dexterity of a cat, and hunts for diurnal armadillos; he comes unawares upon the deer and huanaco, and, springing like lightning on them, dislocates their necks before their bodies touch the earth. Often after he has thus slain them, he leaves their bodies untouched for the Polyborus and vulture to feast on, so great a delight does he take in destroying life. The vizcacha falls an easy victim to this subtle creature; and it is not to be wondered at that it becomes wild to excess, and rare in regions hunted over by such an enemy, even when all other conditions are favourable to its increase. But as soon as these wild regions are settled by man the pumas are exterminated, and the sole remaining foe of the vizcacha is the fox, comparatively an insignificant one.

The fox takes up his residence in a vizcachera, and succeeds, after some quarrelling (manifested in snarls, growls, and other subterranean warlike sounds), in ejecting the rightful owners of one of the burrows, which forthwith becomes his. Certainly the vizcachas are not much injured by being compelled to relinquish the use of one of their kennels for a season or permanently; for, if the locality suits him, the fox remains with them always. Soon they grow accustomed to the unwelcome stranger; he is quiet and unassuming in demeanour, and often in the evening sits on the mound in their company, until they regard him with the same indifference they do the burrowing owl. But in spring, when the young vizcachas are large enough to leave their cells, then the fox makes them his prey; and if it is a bitch fox, with a family of eight or nine young to provide for, she will grow so bold as to hunt her helpless quarry from hole to hole, and do battle with the old ones, and carry off the young in spite of them, so that all the young animals in the village are eventually destroyed. Often when the young foxes are large enough to follow their mother, the whole family takes leave of the vizcachera where such cruel havoc has been made to settle in another, there to continue their depredations. But the fox has ever a relentless foe in man, and meets with no end of bitter persecutions; it is consequently much more abundant in desert or thinly settled districts than in such as are populous, so that in these the check the vizcachas receive from the foxes is not appreciable.

The abundance of cattle on the pampas has made it unnecessary to use the vizcacha as an article of food. His skin is of no value; therefore man, the destroyer of his enemies, has hitherto been the greatest benefactor of his species. Thus they have been permitted to multiply and spread themselves to an amazing extent, so that the half-domestic cattle on the pampas are not nearly so familiar with man, or so fearless of his presence as are the vizcachas. It is not that they do him no injury, but because they do it indirectly, that they have so long enjoyed immunity from persecution. It is amusing to see the sheep-farmer, the greatest sufferer from the vizcachas, regarding them with such indifference as to permit them to swarm on his "run," and burrow within a stone's throw of his dwelling with impunity, and yet going a distance from home to persecute with unreasonable animosity a fox, skunk, or opossum on account of the small annual loss it inflicts on the poultry-yard. That the vizcacha has comparatively no adverse conditions to war with wherever man is settled is evident when we consider its very slow rate of increase, and yet see them in such incalculable numbers. The female has but one litter in the year of two young, sometimes of three. She becomes pregnant late in April, and brings forth in September; the period of gestation is, I think, rather less than five months.

The vizcacha is about two years growing. A full-sized male measures to the root of the tail twenty-two inches, and weighs from fourteen to fifteen pounds; the female is nineteen inches in length, and her greatest weight nine pounds. Probably it is a long-lived, and certainly it is a very hardy animal. Where it has any green substance to eat it never drinks water; but after a long summer drought, when for months it has subsisted on bits of dried thistle-stalks and old withered grass, if a shower falls it will come out of its burrows even at noonday and drink eagerly from the pools. It has been erroneously stated that vizcachas subsist on roots. Their food is grass and seeds; but they may also sometimes eat roots, as the ground is occasionally seen scratched up about the burrows. In March, when the stalks of the perennial cardoon or Castile thistle (Cynara cardunculus) are dry, the vizcachas fell them by gnawing about their roots, and afterwards tear to pieces the great dry flower-heads to get the seeds imbedded deeply in them, of which they seem very fond. Large patches of thistle are often found served thus, the ground about them literally white with the silvery bristles they have scattered. This cutting down tall plants to get the seeds at the top seems very like an act of pure intelligence; but the fact is, the vizcachas cut down every tall plant they can. I have seen whole acres of maize destroyed by them, yet the plants cut down were left untouched. If posts be put into the ground within range of their nightly rambles they will gnaw till they have felled them, unless of a wood hard enough to resist their chisel-like incisors.

The strongest instinct of this animal is to clear the ground thoroughly about its burrows; and it is this destructive habit that makes it necessary for cultivators of the soil to destroy all the vizcachas in or near their fields. On the uninhabited pampas, where the long grasses grow, I have often admired the vizcachera; for it is there the centre of a clean space, often of half an acre in extent, on which there is an even close-shaven turf: this clearing is surrounded by the usual rough growth of herbs and giant grasses. In such situations this habit of clearing the ground is eminently advantageous to them, as it affords them a comparatively safe spot to feed and disport themselves on, and over which they can fly to their burrows without meeting any obstruction, on the slightest alarm.

Of course the instinct continues to operate where it is no longer of any advantage. In summer, when the thistles are green, even when growing near the burrows, and the giant thistle (Carduus mariana) springs up most luxuriantly right on the mound, the vizcachas will not touch them, either disliking the strong astringent sap, or repelled by the thorns with which they are armed. As soon as they dry, and the thorns become brittle, they are levelled; afterwards, when the animal begins to drag them about and cut them up, as his custom is, he accidentally discovers and feasts on the seed: for vizcachas are fond of exercising their teeth on hard substances, such as sticks and bones, just as cats are of "sharpening their claws" on trees.

Another remarkable habit of the vizcacha, that of dragging to and heaping about the mouth of his burrow every stalk he cuts down, and every portable object that by dint of great strength he can carry, has been mentioned by Azara, Darwin, and others. On the level plains it is a useful habit; for as the vizcachas are continually deepening and widening their burrows, the earth thrown out soon covers up these materials, and so assists in raising the mound. On the Buenos-Ayrean pampas numbers of vizcacheras would annually be destroyed by water in the great sudden rainfalls were the mounds loss high. But this is only an advantage when the animals inhabit a perfectly level country subject to flooding rains; for where the surface is unequal they invariably prefer high to low ground to burrow on, and are thus secured from destruction by water; yet the instinct is as strong in such situations as on the level plains. The most that can be said of a habit apparently so obscure in its origin and uses is, that it appears to be part of the instinct of clearing the ground about the village. Every tall stalk the vizcacha cuts down, every portable object he finds, must be removed to make the surface clean and smooth; but while encumbered with it he does not proceed further from his burrows, but invariably re-tires towards them, and so deposits it upon the mound. So well known is this habit, that whatever article is lost by night—whip, pistol, or knife—the loser next morning visits the vizcacheras in the vicinity, quite sure of finding it there. People also visit the vizcacheras to pick up sticks for firewood.

The vizcachas are cleanly in their habits; and the fur, though it has a strong earthy smell, is kept exceedingly neat. The hind leg and foot afford a very beautiful instance of adaptation. Propped by the hard curved tail, they sit up erect, and as firmly on the long horny disks on the undersides of the hind legs as a man stands on his feet. Most to be admired, on the middle toe the skin thickens into a round cushion, in which the curved teeth-like bristles are set; nicely graduated in length, so that "each particular hair" may come into contact with the skin when the animal scratches or combs itself. As to the uses of this appendage there can be no difference of opinion, as there is about the serrated claw in birds. It is quite obvious that the animal cannot scratch himself with his hind paw (as all mammals do) without making use of this natural comb. Then the entire foot is modified, so that this comb shall be well protected, and yet not be hindered from performing its office: thus the inner toe is pressed close to the middle one, and so depressed that it comes under the cushion of skin, and cannot possibly get before the bristles, or interfere their coming against the skin in scratching, as certainly be the case if this toe were free as outer one.

Again, the vizcachas appear to form the deep trenches before the burrows by scratching the earth violently backwards with the hind claws. Now these straight, sharp, dagger-shaped claws, and especially the middle one, are so long that the vizcacha is able to perform all this rough work without the bristles coming into contact with the ground, and so getting worn by the friction. The Tehuelcho Indians in Patagonia comb their hair with a brush-comb very much like that on the vizcacha's toe, but in their case it does not properly fulfil its office, or else the savages make little use of it. Vizcachas have a remarkable way of dusting themselves: the animal suddenly throws himself on his back, and, bringing over his hind legs towards his head, depresses them till his feet touch the ground. In this strange posture he scratches up the earth with great rapidity, raising a little cloud of dust, then rights himself with a jerk, and, after an interval, repeats the dusting. Usually they scratch a hole in the ground to deposit their excrements in. Whilst opening one of the outside burrows that had no communication with the others, I once discovered a vast deposit of their dung (so great that it must have been accumulating for years) at the extremity. To ascertain whether this be a constant, or only a casual habit, it would be necessary to open up entirely a vast number of vizcacheras. When a vizcacha dies in his burrow the carcass is, after some days, dragged out and left upon the mound.

The language of the vizcacha is wonderful for its variety. When the male is feeding he frequently pauses to utter a succession of loud, percussive, and somewhat jarring cries; these he utters in a leisurely manner, and immediately after goes on feeding. Often he utters this cry in a low grunting tone. One of his commonest expressions sounds like the violent hawking of a man clearing his throat. At other times he bursts into piercing tones that may be heard a mile off, beginning like the excited and quick-repeated squeals of a young pig, and growing longer, more attenuated, and quavering towards the end. After retiring alarmed into the burrows, he repeats at intervals a deep internal moan. All these, and many other indescribable guttural, sighing, shrill, and deep tones, are varied a thousand ways in strength and intonation, according to the age, sex, or emotions of the individual; and I doubt if there is in the world any other four-footed thing so loquacious, or with a dialect so extensive. I take great pleasure in going to some spot where they are abundant, and sitting quietly to listen to them; for they are holding a perpetual discussion, all night long, which the presence of a human being will not interrupt.