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The Tetragnatha—a genus of the Epeira family, and known also in England—are small spiders found on the margin of streams. Their bodies are slender, oblong, and resembling a canoe in shape; and when they sit lengthwise on a stem or blade of grass, their long, hair-like legs arranged straight before and behind them, it is difficult to detect them, so closely do they resemble a discoloured stripe on the herbage. A species of Tetragnatha with a curious modification of structure abounds on the pampas. The long leg of this spider is no thicker than a bristle from a pig's back, but at the extremity it is flattened and broad, giving it a striking resemblance to an oar. These spiders are only found in herbage overhanging the borders of streams: they are very numerous, and, having a pugnacious temper, are incessantly quarrelling; and it frequently happens that in these encounters, or where they are pursuing each other through the leaves, they drop into the water below. I believe, in fact, that they often drop themselves purposely into it as the readiest means of escape when hard pressed. When this happens, the advantage of the modified structure of the legs is seen. The fallen spider, sitting boat-like on the surface, throws out its long legs, and, dipping the broad ends into the water, literally rows itself rapidly to land.
The gossamer-spider, most spiritual of living things, of which there are numerous species, some extremely beautiful in colouring and markings, is the most numerous of our spiders. Only when the declining sun flings a broad track of shiny silver light on the plain does one get some faint conception of the unnumbered millions of these buoyant little creatures busy weaving their gauzy veil over the earth and floating unseen, like an ethereal vital dust, in the atmosphere.
This spider carries within its diminutive abdomen a secret which will possibly serve to vex subtle intellects for a long time to come; for it is hard to believe that merely by mechanical force, even aided by currents of air, a creature half as big as a barley grain can instantaneously snoot out filaments twenty or thirty inches long, and by means of which it floats itself in the air.
Naturalists are now giving a great deal of attention to the migrations of birds in different parts of the world: might not insect and spider migrations be included with advantage to science in their observations? The common notion is that the gossamer makes use of its unique method of locomotion, only to shift its quarters, impelled by want of food or unfavourable conditions—perhaps only by a roving disposition. I believe that besides these incessant flittings about from place to place throughout the summer the gossamer-spiders have great periodical migrations which are, as a rule, in-visible, since a single floating web cannot be remarked, and each individual rises and floats away by itself from its own locality when influenced by the instinct. When great numbers of spiders rise up simultaneously over a large area, then, sometimes, the movement forces itself on our attention; for at such times the whole sky may be filled with visible masses of floating web. All the great movements of gossamers I have observed have occurred in the autumn, or, at any rate, several weeks after the summer solstice; and, like the migrations of birds at the same season of the year, have been in a northerly direction. I do not assert or believe that the migratory instinct in the gossamer is universal. In a moist island, like England, for instance, where the condition of the atmosphere is seldom favourable, and where the little voyagers would often be blown by adverse winds to perish far out at sea, it is difficult to believe that such migrations take place. But where they inhabit a vast area of land, as in South America, extending without interruption from the equator to the cold Magellanic regions, and where there is a long autumn of dry, hot weather, then such an instinct as migration might have been developed. For this is not a faculty merely of a few birds: the impulse to migrate at certain seasons affects birds, insects, and even mammals. In a few birds only is it highly developed, but the elementary feeling, out of which the wonderful habit of the swallow has grown, exists widely throughout animated nature. On the continent of Europe it also seems probable that a great autumnal movement of these spiders takes place; although, I must confess, I have no grounds for this statement, except that the floating gossamer is called in Germany "Der fliegender Summer"—the flying or departing summer.
I have stated that all migrations of gossamers I have witnessed have been in the autumn; excepting in one instance, these flights occurred when the weather was still hot and dry. The exceptionally late migration was on March 22—a full month after the departure of martins, humming-birds, flycatchers, and most other true bird-migrants. It struck me as being so remarkable, and seems to lend so much force to the idea I have suggested, that I wish to give here an exact copy of the entries made at the time and on the spot in my notebook.
"March 22. This afternoon, while I was out shooting, the gossamer-spiders presented an appearance quite new to me. Walking along a stream (the Conchitas, near Buenos Ayres), I noticed a broad white line skirting the low wet ground. This I found was caused by gossamer web lying in such quantities over the earth as almost to hide the grass ad thistles under it. The white zone was about twenty yards wide, and outside it only a few scattered webs were visible on the grass; its exact length I did not ascertain, but followed it for about two miles without finding the end. The spiders were so numerous that they continually baulked one another in their efforts to rise in the air. As soon as one threw out its lines they would become entangled with those of another spider, lanced out at the same moment; both spiders would immediately seem to know the cause of the trouble, for as soon as their lines fouled they would rush angrily towards each other, each trying to drive the other from the elevation. Notwithstanding these difficulties, numbers were continually floating off on the breeze which blew from the south.
"I noticed three distinct species: one with a round scarlet body; another, velvet black, with large square cephalothorax and small pointed abdomen; the third and most abundant kind were of different shades of olive green, and varied greatly in size, the largest being fully a quarter of an inch in length. Apparently these spiders had been driven up from the low ground along the stream where it was wet, and had congregated along the borders of the dry ground in readiness to migrate.
"25th. Went again to visit the spiders, scarcely expecting to find them, as, since first seeing them, we have had much wind and rain. To my surprise I found them in greatly increased numbers: on the tops of cardoons, posts, and other elevated situations they were literally lying together in heaps. Most of them were large and of the olive-coloured species; their size had probably prevented them from getting away earlier, but they were now floating off in great numbers, the weather being calm and tolerably dry. To-day I noticed a new species with a grey body, elegantly striped with black, and pink legs—a very pretty spider.
"26th. Went again to-day and found that the whole vast army of gossamers, with the exception of a few stragglers sitting on posts and dry stalks, had vanished. They had taken advantage of the short spell of fine weather we are now having, after an unusually wet and boisterous autumn, to make their escape."
Here it seemed to me that a conjunction of circumstances—first, the unfavourable season preventing migration at the proper time, and secondly, the strip of valley out of which the spiders had been driven to the higher ground till they were massed together—only served to make visible and evident that a vast annual migration takes place which we have only to look closely for to discover.
One of the most original spiders in Buenos Ayres—mentally original, I mean—is a species of Pholcus; a quiet, inoffensive creature found in houses, and so abundant that they literally swarm where they are not frequently swept away from ceilings and obscure corners. Certainly it seems a poor spider after the dynamical and migratory gossamer; but it happens, curiously enough, that a study of the habits of this dusty domestic creature leads us incidentally into the realms of fable and romance. It is remarkable for the extreme length of its legs, and resembles in colour and general appearance a crane fly, but is double the size of that insect. It has a singular method of protecting itself: when attacked or approached even, gathering its feet together and fastening them to the centre of its web, it swings itself round and round with the velocity of a whirligig, so that it appears like a mist on the web, offering no point for an enemy to strike at. "When a fly is captured the spider approaches it cautiously and spins a web round it, continually narrowing the circle it describes, until the victim is inclosed in a cocoon-like covering. This is a common method with spiders; but the intelligence—for I can call it by no other word—of the Pholcus has supplemented this instinctive procedure with a very curious and unique habit. The Pholcus, in spite of its size, is a weak creature, possessing little venom to despatch its prey with, so that it makes a long and laborious task of killing a fly. A fly when caught in a web is a noisy creature, and it thus happens that when the Daddylonglegs—as Anglo-Argentines have dubbed this species—succeeds in snaring a captive the shrill outrageous cries of the victim are heard for a long time—often for ten or twelve minutes. This noise greatly excites other spiders in the vicinity, and presently they are seen quitting their webs and flurrying to the scene of conflict. Sometimes the captor is driven off, and then the strongest or most daring spider carries away the fly. But where a large colony are allowed to continue for a long time in undisturbed possession of a ceiling, when one has caught a fly he proceeds rapidly to throw a covering of web over it, then, cutting it away, drops it down and lets it hang suspended by a line at a distance of two or three feet from the ceiling. The other spiders arrive on the scene, and after a short investigation retreat to their own webs, and when the coast is clear our spider proceeds to draw up the captive fly, which is by this time exhausted with its struggles."
Now, I have repeatedly remarked that all spiders, when the shrill humming of an insect caught in a web is heard near them, become agitated, like the Pholcus, and will, in the same way, quit their own webs and hurry to the point the sound proceeds from. This fact convinced me many years ago that spiders are attracted by the sound of musical instruments, such as violins, concertinas, guitars, &c., simply because the sound produces the same effect on them as the shrill buzzing of a captive fly. I have frequently seen spiders come down walls or from ceilings, attracted by the sound of a guitar, softly played; and by gently touching metal strings, stretched on a piece of wood, I have succeeded in attracting spiders on to the strings, within two or three inches of my fingers; and I always noticed that the spiders seemed to be eagerly searching for something which they evidently expected to find there, moving about in an excited manner and looking very hungry and fierce. I have no doubt that Pelisson's historical spider in the Bastille came down in a mood and with a manner just as ferocious when the prisoner called it with musical sounds to be fed.
The spiders I have spoken of up till now are timid, inoffensive creatures, chiefly of the Epeira family; but there are many others exceedingly high-spirited and, like some of the most touchy hymenopteras, always prepared to "greatly quarrel" over matters of little moment. The Mygales, of which we have several species, are not to be treated with contempt. One is extremely abundant on the pampas, the Mygale fusca, a veritable monster, covered with dark brown hair, and called in the vernacular aranea peluda—hairy spider. In the hot month of December these spiders take to roaming about on the open plain, and are then everywhere seen travelling in a straight line with a slow even pace. They are very great in attitudes, and when one is approached it immediately throws itself back, like a pugilist preparing for an encounter, and stands up so erect on its four hind feet that the under surface of its body is displayed. Humble-bees are commonly supposed to carry the palm in attitudinizing; and it is wonderful to see the grotesque motions of these irascible insects when their nest is approached, elevating their abdomens and two or three legs at a time, so that they resemble a troupe of acrobats balancing themselves on their heads or hands, and kicking their legs about in the air. And to impress the intruder with the dangerous significance of this display they hum a shrill warning or challenge, and stab at the air with their naked stings, from which limpid drops of venom are seen to exude. These threatening gestures probably have an effect. In the case of the hairy spider, I do not think any creature, however stupid, could mistake its meaning when it stands suddenly up, a figure horribly grotesque; then, dropping down on all eights, charges violently forwards. Their long, shiny black, sickle-shaped falces are dangerous weapons. I knew a native woman who had been bitten on the leg, and who, after fourteen years, still suffered at intervals acute pains in the limb.
The king of the spiders on the pampas is, however, not a Mygale, but a Lycosa of extraordinary size, light grey in colour, with a black ring round its middle. It is active and swift, and irritable to such a degree that one can scarcely help thinking that in this species nature has overshot her mark.
When a person passes near one—say, within three or four yards of its lurking-place—it starts up and gives chase, and will often follow for a distance of thirty or forty yards. I came once very nearly being bitten by one of these savage creatures Riding at an easy trot over the dry grass, I suddenly observed a spider pursuing me, leaping swiftly along and keeping up with my beast. I aimed a blow with my whip, and the point of the lash struck the ground close to it, when it instantly leaped upon and ran up the lash, and was actually within three or four inches of my hand when I flung the whip from me.
The gauchos have a very quaint ballad which tells that the city of Cordova was once invaded by an army of monstrous spiders, and that the townspeople went out with beating drums and flags flying to repel the invasion, and that after firing several volleys they were forced to turn and fly for their lives. I have no doubt that a sudden great increase of the man-chasing spiders, in a year exceptionally favourable to them, suggested this fable to some rhyming satirist of the town.
In conclusion of this part of my subject, I will describe a single combat of a very terrible nature I once witnessed between two little spiders belong-ing to the same species. One had a small web against a wall, and of this web the other coveted possession. After vainly trying by a series of strategic movements to drive out the lawful owner, it rushed on to the web, and the two envenomed httle duellists closed in mortal combat. They did nothing so vulgar and natural as to make use of their falces, and never once actually touched each other, but the fight was none the less deadly. Rapidly revolving about, or leaping over, or passing under, each other, each endeavoured to impede or entangle his adversary, and the dexterity with which each avoided the cunningly thrown snare, trying at the same time to entangle its opponent, was wonderful to see. At length, after this equal battle had raged for some time, one of the combatants made some fatal mistake, and for a moment there occurred a break in his motions; instantly the other perceived his advantage, and began leaping backwards and forwards across his struggling adversary with such rapidity as to confuse the sight, producing the appearance of two spiders attacking a third one lying between them. He then changed his tactics, and began revolving round and round his prisoner, and very soon the poor vanquished wretch—the aggressor, let us hope, in the interests of justice—was closely wrapped in a silvery cocoon, which, unlike the cocoon the caterpillar weaves for itself, was also its winding-sheet.
In the foregoing pages I have thrown together some of the most salient facts I have noted; but the spider-world still remains to me a wonderland of which I know comparatively nothing. Nor is any very intimate knowledge of spiders to be got from books, though numberless lists of new species are constantly being printed; for they have not yet had, like the social bees and ants, many loving and patient chroniclers of their ways. The Hubens and Lubbocks have been many; the Moggridges few. But even a very slight study of these most versatile and accomplished of nature's children gives rise to some interesting reflections. One fact that strikes the mind very forcibly is the world-wide distribution of groups of species possessing highly developed instincts. One is the zebra-striped Salticus, with its unique strategy—that is to say, unique amongst spiders. It is said that the Australian savage approaches a kangaroo in the open by getting up in sight of its prey and standing perfectly motionless till he is regarded as an inanimate object, and every time the animal's attention wanders advancing a step or two until sufficiently near to hurl his spear. The Salticus approaches a fly in the same manner, till near enough to make its spring. Another is the Trapdoor spider. Another the Dolomedes, that runs over the surface of the water in pursuit of its prey, and dives down to escape from its enemies; and, strangest of all, the Argyroneta, that has its luminous dwelling at the bottom of streams; and just as a mason carries bricks and mortar to its building, so does this spider carry down bubbles of air from the surface to enlarge its mysterious house, in which it lays its eggs and rears its young. Community of descent must be supposed of species having such curious and complex instincts; but how came these feeble creatures, unable to transport themselves over seas and continents like the aerial gossamer, to be so widely distributed, and inhabiting regions with such different conditions? This can only be attributed to the enormous antiquity of the species, and of this antiquity the earliness in which the instinct manifests itself in the young spiders is taken as evidence.
A more important matter, the intelligence of spiders, has not yet received the attention it deserves. The question of insect intelligence—naturalists are agreed that insects do possess intelligence—is an extremely difficult one; probably some of our conclusions on this matter will have to be reconsidered. For instance, we regard the Order Hymenoptera as the most intelligent because most of the social insects are included in it; but it has not yet been proved, probably never will be proved, that the social instincts resulted from intelligence which has "lapsed." Whether ants and bees were more intelligent than other insects during the early stages of their organic societies or not, it will hardly be disputed by any naturalist who has observed insects for long that many solitary species display more intelligence in their actions than those that live in communities.
The nature of the spider's food and the difficulties in the way of providing for their wants impose on them a life of solitude: hunger, perpetual watchfulness, and the sense of danger have given them a character of mixed ferocity and timidity. But these very conditions, which have made it impossible for them to form societies like some insects and progress to a state of things resembling civilization in men, have served to develop the mind that is in a spider, making of him a very clever barbarian-The spider's only weapon of defence—-his falces—are as poor a protection against the assaults of his insect foes as are teeth and finger-nails in man employed against wolves, bears, and tigers. And the spider is here even worse off than man, since his enemies are winged and able to sweep down instantly on him from above; they are also protected with an invulnerable shield, and are armedwith deadly stings. Like man, also, the spider has a soft, unprotected body, while his muscular strength, compared with that of the insects he has to contend with, is almost nil. His position in nature then, with relation to his enemies, is like that of man; only the spider has this disadvantage, that he cannot combine with others for protection. That he does protect himself and maintains his place in nature is due, not to special instincts, which are utterly insufficient, but to the intelligence which supplements them. At the same time this superior cunning is closely related with, and probably results indirectly from, the web he is provided with, and which is almost of the nature of an artificial aid. Let us take the imaginary case of a man-like monkey, or of an arboreal man, born with a cord of great length attached to his waist, which could be either dragged after him or carried in a coil. After many accidents, experience would eventually teach him to put it to some use; practice would make him more and more skilful in handling it, and, indirectly, it would be the means of developing his latent mental faculties. He would begin by using it, as the monkey does its prehensile tail, to swing himself from branch to branch, and finally, to escape from an enemy or in pursuit of his prey, he would be able by means of his cord to drop himself with safety from the tallest trees, or fly down the steepest precipices. He would coil up his cord to make a bed to lie on, and also use it for binding branches together when building himself a refuge. In a close fight, he would endeavour to entangle an adversary, and at last he would learn to make a snare with it to capture his prey. To all these, and to a hundred other uses, the spider has put his web. And when we see him spread his beautiful geometric snare, held by lines fixed to widely separated points, while he sits concealed in his web-lined retreat amongst the leaves where every touch on the far-reaching structure is telegraphed to him by the communicating line faithfully as if a nerve had been touched, we must admire the wonderful perfection to which he has attained in the use of his cord. By these means he is able to conquer creatures too swift and strong for him, and make them his prey. When we see him repairing damages, weighting his light fabric in windy weather with pebbles or sticks, as a fisher weights his net, and cutting loose a captive whose great strength threatens the destruction of the web, then we begin to suspect that he has, above his special instinct, a reason that guides, modifies, and in many ways supplements it. It is not, however, only on these great occasions, when the end is sought by unusual means, that spiders show their intelligence; for even these things might be considered by some as merely parts of one great complex instinct; but at all times, in all things, the observer who watches them closely cannot fail to be convinced that they possess a guiding principle which is not mere instinct. What the stick or stone was to primitive man, when he had made the discovery that by holding it in his hand he greatly increased the force of his blow, the possession of a web has been to the spider in developing that spark of intellect which it possesses in common with all animal organisms.
CHAPTER XV.
THE DEATH-FEIGNING INSTINCT.
Most people are familiar with the phenomenon of "death-feigning," commonly seen in coleopterous insects, and in many spiders. This highly curious instinct is also possessed by some vertebrates. In insects it is probably due to temporary paralysis occasioned by sudden concussion, for when beetles alight abruptly, though voluntarily, they assume that appearance of death, which lasts for a few moments. Some species, indeed, are so highly sensitive that the slightest touch, or even a sudden menace, will instantly throw them into this motionless, death-simulating condition. Curiously enough, the same causes which produce this trance in slow-moving species, like those of Scarabseus for example, have a precisely contrary effect on species endowed with great activity. Rapacious beetles, when disturbed, scuttle quickly out of sight, and some water-beetles spin about the surface, in circles or zigzag lines, so rapidly as to confuse the eye. Our common long-legged spiders (Pholcus) when approached draw their feet together in the middle of the web, and spin the body round with such velocity as to resemble a whirligig.
Certain mammals and birds also possess the death-simulating instinct, though it is hardly possible to believe that the action springs from the same immediate cause in vertebrates and in insects. In the latter it appears to be a purely physical instinct, the direct result of an extraneous cause, and resembling the motions of a plant. In mammals and birds it is evident that violent emotion, and not the rough handling experienced, is the final cause of the swoon.
Passing over venomous snakes, skunks, and a few other species in which the presence of danger excites only anger, fear has a powerful, and in some cases a disabling, effect on animals; and it is this paralyzing effect of fear on which the death-feigning instinct, found only in a few widely-separated species, has probably been built up by the slow cumulative process of natural selection.
I have met with some curious instances of the paralyzing effect of fear. I was told by some hunters in an outlying district of the pampas of its effect on a jaguar they started, and which took refuge in a dense clump of dry reeds. Though they could see it, it was impossible to throw the lasso over its head, and, after vainly trying to dislodge it, they at length set fire to the reeds. Still it refused to stir, but lay with head erect, fiercely glaring at them through the flames. Finally it disappeared from sight in the black smoke; and when the fire had burnt itself out, it was found, dead and charred, in the same spot.
On the pampas the gauchos frequently take the black-necked swan by frightening it. When the birds are feeding or resting on the grass, two or three men or boys on horseback go quietly to leeward of the flock, and when opposite to it suddenly wheel and charge it at full speed, uttering loud shouts, by which the birds are thrown into such terror that they are incapable of flying, and are quickly despatched.
I have also seen gaucho boys catch the Silver-bill (Lichenops perspicillata) by hurling a stick or stone at the bird, then rushing at it, when it sits perfectly still, disabled by fear, and allows itself to be taken. I myself once succeeded in taking a small bird of another species in the same way.
Amongst mammals our common fox (Canis azarae), and one of the opossums (Didelphys azarae), are strangely subject to the death-simulating swoon. For it does indeed seem strange that animals so powerful, fierce, and able to inflict such terrible injury with their teeth should also possess this safeguard, apparently more suited to weak inactive creatures that cannot resist or escape from an enemy and to animals very low down in the scale of being. When a fox is caught in a trap or run down by dogs he fights savagely at first, but by-and-by relaxes his efforts, drops on the ground, and apparently yields up the ghost. The deception is so well carried out, that dogs are constantly taken in by it, and no one, not previously acquainted with this clever trickery of nature, but would at once pronounce the creature dead, and worthy of some praise for having perished in so brave a spirit. Now, when in this condition of feigning death, I am quite sure that the animal does not altogether lose consciousness. It is exceedingly difficult to discover any evidence of life in the opossum; but when one withdraws a little way from the feigning fox, and watches him very attentively, a slight opening of the eye may be detected; and, finally, when left to himself, he does not recover and start up like an animal that has been stunned, but slowly and cautiously raises his head first, and only gets up when his foes are at a safe distance. Yet I have seen gauchos, who are very cruel to animals, practise the most barbarous experiments on a captive fox without being able to rouse it into exhibiting any sign of life. This has greatly puzzled me, since, if death-feigning is simply a cunning habit, the animal could not suffer itself to be mutilated without wincing. I can only believe that the fox, though not insensible, as its behaviour on being left to itself appears to prove, yet has its body thrown by extreme terror into that benumbed condition which simulates death, and during which it is unable to feel the tortures practised on it.
The swoon sometimes actually takes place before the animal has been touched, and even when the exciting cause is at a considerable distance. I was once riding with a gaucho, when we saw, on the open level ground before us, a fox, not yet fully grown, standing still and watching our approach. All at once it dropped, and when we came up to the spot it was lying stretched out, with eyes closed, and apparently dead. Before passing on my companion, who said it was not the first time he had seen such a thing, lashed it vigorously with his whip for some moments, but without producing the slightest effect.
The death-feigning instinct is possessed in a very marked degree by the spotted tinamou or common partridge of the pampas (Nothura maculosa). When captured, after a few violent struggles to escape, it drops its head, gasps two or three times, and to all appearances dies. If, when you have seen this, you release your hold, the eyes open instantly, and, with startling suddenness and a noise of wings, it is up and away, and beyond your reach for ever. Possibly, while your grasp is on the bird it does actually become insensible, though its recovery from that condition is almost instantaneous. Birds when captured do sometimes die in the hand, purely from terror. The tinamou is excessively timid, and sometimes when birds of this species are chased—for gaucho boys frequently run them down on horseback—and when they find no burrows or thickets to escape into, they actually drop down dead on the plain. Probably, when they feign death in their captor's hand, they are in reality very near to death.
CHAPTER XVI.
HUMMING-BIRDS.
Humming-birds are perhaps the very loveliest things in nature, and many celebrated writers have exhausted their descriptive powers in vain efforts to picture them to the imagination. The temptation was certainly great, after describing the rich setting of tropical foliage and flower, to speak at length of the wonderful gem contained within it; but they would in this case have been wise to imitate that modest novel-writer who introduced a blank space on the page where the description of his matchless heroine should have appeared. After all that has been written, the first sight of a living humming-bird, so unlike in its beauty all other beautiful things, comes like a revelation to the mind. To give any true conception of it by means of mere word-painting is not more impossible than it would be to bottle up a supply of the "living sunbeams" themselves, and convey them across the Atlantic to scatter them in a sparkling shower over the face of England.
Doubtless many who have never seen them in a state of nature imagine that a tolerably correct idea of their appearance can be gained from Gould's colossal monograph. The pictures there, however, only represent dead humming-birds. A dead robin is, for purposes of bird-portraiture, as good as a live robin; the same may be said of even many brilliant-plumaged species less aerial in their habits than humming-birds. In butterflies the whole beauty is seldom seen until the insect is dead, or, at any rate, captive. It was not when Wallace saw the Ornithoptera croesus flying about, but only when he held it in his hands, and opened its glorious wings, that the sight of its beauty overcame him so powerfully. The special kind of beauty which makes the first sight of a humming-bird a revelation depends on the swift singular motions as much as on the intense gem-like and metallic brilliancy of the plumage.
The minute exquisite form, when the bird hovers on misty wings, probing the flowers with its coral spear, the fan-like tail expanded, and poising motionless, exhibits the feathers shot with many hues; and the next moment vanishes, or all but vanishes, then reappears at another flower only to vanish again, and so on successively, showing its splendours not continuously, but like the intermitted flashes of the firefly—this forms a picture of airy grace and loveliness that baffles description. All this glory disappears when the bird is dead, and even when it alights to rest on a bough. Sitting still, it looks like an exceedingly attenuated kingfisher, without the pretty plumage of that bird, but retaining its stiff artificial manner. No artist has been so bold as to attempt to depict the bird as it actually appears, when balanced before a flower the swift motion of the wings obliterates their form, making them seem like a mist encircling the body; yet it is precisely this formless cloud on which the glittering body hangs suspended, which contributes most to give the humming-bird its wonderful sprite-like or extra-natural appearance. How strange, then, to find bird-painters persisting in their efforts to show the humming-bird flying! When they draw it stiff and upright on its perch the picture is honest, if ugly; the more ambitious representation is a delusion and a mockery.
Coming to the actual colouring—the changeful tints that glow with such intensity on the scale-like feathers, it is curious to find that Gould seems to have thought that all difficulties here had been successfully overcome. The "new process" he spoke so confidently about might no doubt be used with advantage in reproducing the coarser metallic reflections on a black plumage, such as we see in the corvine birds; but the glittering garment of the humming-bird, like the silvery lace woven by the Epeira, gemmed with dew and touched with rainbow-coloured light, has never been and never can be imitated by art.
On this subject one of the latest observers of humming-birds, Mr. Everard im Thurn, in his work on British Guiana, has the following passage:—"Hardly more than one point of colour is in reality ever visible in any one humming-bird at one and the same time, for each point only shows its peculiar and glittering colour when the light falls upon it from a particular direction. A true representation of one of these birds would show it in somewhat sombre colours, except just at the one point which, when the bird is in the position chosen for representation, meets the light at the requisite angle, and that point alone should be shown in full brilliance of colour. A flowery shrub is sometimes seen surrounded by a cloud of humming-birds, all of one species, and each, of course, in a different position. If someone would draw such a scene as that, showing a different detail of colour in each bird, according to its position, then some idea of the actual appearance of the bird might be given to one who had never seen an example."
It is hardly to be expected that anyone will carry out the above suggestion, and produce a monograph with pages ten or fifteen feet wide by eighteen feet long, each one showing a cloud of humming-birds of one species flitting about a flowery bush; but even in such a picture as that would be, the birds, suspended on unlovely angular projections instead of "hazy semicircles of indistinctness," and each with an immovable fleck of brightness on the otherwise sombre plumage, would be as unlike living humming-birds as anything in the older monographs.
Whether the glittering iridescent tints and singular ornaments for which this family is famous result from the cumulative process of conscious or voluntary sexual selection, as Darwin thought, or are merely the outcome of a superabundant vitality, as Dr. A. R.. Wallace so strongly maintains, is a question which science has not yet answered satisfactorily. The tendency to or habit of varying in the direction of rich colouring and beautiful or fantastic ornament, might, for all we know to the contrary, have descended to humming-birds from some diminutive, curiously-shaped, bright-tinted, flying reptile of arboreal habits that lived in some far-off epoch in the world's history. It is not, at all events, maintained by anyone that all birds sprang originally from one reptilian stock; and the true position of humming-birds in a natural classification has not yet been settled, for no intermediate forms exist connecting them with any other group, To the ordinary mind they appear utterly unlike all other feathered creatures, and as much entitled to stand apart as, for instance, the pigeon and ostrich families. It has been maintained by some writers that they are anatomically related to the swifts, although the differences separating the two families appear so great as almost to stagger belief in this notion. Now, however, the very latest authority on this subject, Dr. Schufeldt, has come to the conclusion that swifts are only greatly modified Passeres, and that the humming-birds should form an order by themselves.
Leaving this question, and regarding them simply with the ornithological eye that does not see far below the surface of things, when we have sufficiently admired the unique beauty and marvellous velocity of humming-birds, there is little more to be said about them. They are lovely to the eye—indescribably so; and it is not strange that Gould wrote rapturously of the time when he was at length "permitted to revel in the delight of seeing the humming-bird in a state of nature." The feeling, he wrote, which animated him with regard to these most wonderful works of creation it was impossible to describe, and could only be appreciated by those who have made natural history a study, and who "pursue the investigations of her charming mysteries with ardour and delight." This we can understand; but to what an astonishing degree the feeling was carried in him, when, after remarking that enthusiasm and excitement with regard to most things in life become lessened and eventually deadened by time in most of us, he was able to add, "not so, however, I believe, with those who take up the study of the Family of Humming-birds!" It can only be supposed that he regarded natural history principally as a "science of dead animals—a necrology," and collected humming-birds just as others collect Roman coins, birds' eggs, old weapons, or blue china, their zeal in the pursuit and faith in its importance increasing with the growth of their treasures, until they at last come to believe that though all the enthusiasms and excitements which give a zest to the lives of other men fade and perish with time, it is not so with their particular pursuit. The more rational kind of pleasure experienced by the ornithologist in studying habits and disposition no doubt results in a great measure from the fact that the actions of the feathered people have a savour of intelligence in them. Whatever his theory or conviction about the origin of instincts may happen to be, or even if he has no convictions on the subject, it must nevertheless seem plain to him that intelligence is, after all, in most cases, the guiding principle of life, supplementing and modifying habits to bring them into closer harmony with the environment, and enlivening every day with countless little acts which result from judgment and experience, and form no part of the inherited complex instincts. The longer he observes any one species or individual, the more does he find in it to reward his attention; this is not the case, however, with humming-birds, which possess the avian body but do not rank mentally with birds. The pleasure one takes in their beauty soon evaporates, and is succeeded by no fresh interest, so monotonous and mechanical are all their actions; and we accordingly find that those who are most familiar with them from personal observation have very little to say about them. A score of hummingbirds, of as many distinct species, are less to the student of habits than one little brown-plurnaged bird haunting his garden or the rush-bed of a neighbouring stream; and, doubtless, for a reason similar to that which makes a lovely human face uninformed by intellect seem less permanently attractive than many a homelier countenance. He grows tired of seeing the feathered fairies perpetually weaving their aerial ballet-dance about the flowers, and finds it a relief to watch the little finch or wren or flycatcher of shy temper and obscure protective colouring. Perhaps it possesses a graceful form and melodious voice to give it aesthetic value, but even without such accessories he can observe it day by day with increasing interest and pleasure; and it only adds piquancy to the feeling to know that the little bird also watches him with a certain amount of intelligent curiosity and a great deal of suspicion, and that it studiously endeavours to conceal from him all the little secrets its life which he is bent on discovering.
It has frequently been remarked that humming birds are more like insects than birds in disposition. Some species, on quitting their perch, perform wide bee-like circles about the tree before shooting away in a straight line. Their aimless attacks on other species approaching or passing near them, even on large birds like hawks and pigeons, is a habit they have in common with many solitary wood-boring bees. They also, like dragon-flies and other insects, attack each other when they come together while feeding; and in this case their action strangely resembles that of a couple of butterflies, as they revolve about each other and rise vertically to a great height in the air. Again, like insects, they are undisturbed at the presence of man while feeding, or even when engaged in building and incubation; and like various solitary bees, wasps, &c., they frequently come close to a person walking or standing, to hover suspended in the air within a few inches of his face; and if then struck at they often, insect-like, return to circle round his head. All other birds, even those which display the least versatility, and in districts where man is seldom seen, show as much caution as curiosity in his presence; they recognize in the upright unfamiliar form a living being and a possible enemy. Mr. Whiteley, who observed humming-birds in Peru, says it is an amusing sight to watch the Lesbia nuna attempting to pass to a distant spot in a straight line during a high wind, which, acting on the long tail feathers, carries it quite away from the point aimed at. Insects presenting a large surface to the wind are always blown from their course in the same way, for even in the most windy districts they never appear to learn to guide themselves; and I have often seen a butterfly endeavouring to reach an isolated flower blown from it a dozen times before it finally succeeded or gave up the contest. Birds when shaping their course, unless young and inexperienced, always make allowance for the force of the wind. Humming-birds often fly into open rooms, impelled apparently by a fearless curiosity, and may then be chased about until they drop exhausted or are beaten down and caught, and, as Gould says, "if then taken into the hand, they almost immediately feed on any sweet, or pump up any liquid that may be offered to them, without betraying either fear or resentment at the previous treatment." Wasps and bees taken in the same way endeavour to sting their captor, as most people know from experience, nor do they cease struggling violently to free themselves; but the dragon-fly is like the humming-bird, and is no sooner caught after much ill-treatment, than it will greedily devour as many flies and mosquitoes as one likes to offer it. Only in beings very low in the scale of nature do we see the instinct of self-preservation in this extremely simple condition, unmixed with reason or feeling, and so transient in its effects. The same insensibility to danger is seen when humming-birds are captured and confined in a room, and when, before a day is over, they will flutter about their captor's face and even take nectar from his lips.
Some observers have thought that hummingbirds come nearest to humble-bees in their actions. I do not think so. Mr. Bates writes: "They do not proceed in that methodical manner which bees follow, taking the flowers seriatim, but skip about from one part of a tree to another in the most capricious manner." I have observed humble-bees a great deal, and feel convinced that they arc among the most highly intelligent of the social hymenoptera. Humming-birds, to my mind, have a much closer resemblance to the solitary wood-boring bees and to dragon-flies. It must also be borne in mind that insects have very little time in which to acquire experience, and that a large portion of their life, in the imago state, is taken up with the complex business of reproduction.
The Trochilidae, although confined to one continent, promise to exceed all other families—even the cosmopolitan finches and warblers—in number of species. At present over five hundred are known, or as many as all the species of birds in Europe together; and good reasons exist for believing that very many more—not less perhaps than one or two hundred species—yet remain to be discovered. The most prolific region, and where humming-birds are most highly developed, is known to be West Brazil and the eastern slopes of the Bolivian and Peruvian Andes. This is precisely the least known portion of South America; the few naturalists and collectors who have reached it have returned laden with spoil, to tell us of a region surpassing all others in the superabundance and beauty of its bird life. Nothing, however, which can be said concerning these vast unexplored areas of tropical mountain and forest so forcibly impresses us with the idea of the unknown riches contained in them as the story of the Loddigesia mirabilis. This is perhaps the most wonderful humming-bird known, and no one who had not previously seen it figured could possibly form an idea of what it is like from a mere description. An outline sketch of it would probably be taken by most people as a fantastic design representing a bird-form in combination with leaves, in size and shape resembling poplar leaves, but on leaf-stalks of an impossible length, curving and crossing each other so as to form geometrical figures unlike anything in nature. Yet this bird (a single specimen) was obtained in Peru half a century ago, and for upwards of twenty years after its discovery Gould tried to obtain others, offering as much as fifty pounds for one; but no second specimen ever gladdened his eyes, nor was anything more heard of it until Stolzmann refound it in the year 1880.
The addition of many new species to the long list would, however, be a matter of small interest, unless fresh facts concerning their habits and structure were at the same time brought to light; but we can scarcely expect that the as yet unknown species will supply any link connecting the Trochilidae with other existing families of birds. The eventual conclusion will perhaps be that this family has come down independently from an exceedingly remote past, and with scarcely any modification. While within certain very narrow limits humming-birds vary more than other families, outside of these limits they appear relatively stationary; and, conversely, other birds exhibit least variability in the one direction in which humming-birds vary excessively. On account of a trivial difference in habit they have sometimes been separated in two sub-families: the Phaethornithinae, found in shady tropical forests; and the Trochilinae, comprising humming-birds which inhabit open sunny places—and to this division they mostly belong. In both of these purely arbitrary groups, however, the aerial habits and manner of feeding poised in the air are identical, although the birds living in shady forests, where flowers are scarce, obtain their food principally from the under surfaces of leaves. In their procreant habits the uniformity is also very great. In all cases the nest is small, deep, cup-shaped, or conical, composed of soft felted materials, and lined inside with vegetable down. The eggs are white, and never exceed two in number. Broadly speaking, they resemble each other as closely in habits as in structure; the greatest differences in habit in the most widely separated genera being no greater than may be found in two wrens or sparrows of the same genus.
This persistence of character in humming-birds, both as regards structure and habit, seems the more remarkable when we consider their very wide distribution over a continent so varied in its conditions, and where they range from the lowest levels to the limit of perpetual snow on the Andes, and from the tropics to the wintry Magellanic district; also that a majority of genera inhabit very circumscribed areas—these facts, as Dr. Wallace remarks, clearly pointing to a very high antiquity.
It is perhaps a law of nature that when a species (or group) fits itself to a place not previously occupied, and in which it is subject to no opposition from beings of its own class, or where it attains so great a perfection as to be able easily to overcome all opposition, the character eventually loses its original plasticity, or tendency to vary, since improvement in such a case would be superfluous, and becomes, so to speak, crystallized in that form which continues thereafter unaltered. It is, at any rate, clear that while all other birds rub together in the struggle for existence, the humming-bird, owing to its aerial life and peculiar manner of seeking its food, is absolutely untouched by this kind of warfare, and is accordingly as far removed from all competition with other birds as the solitary savage is removed from the struggle of life affecting and modifying men in crowded communities. The lower kind of competition affecting hummingbirds, that with insects and, within the family, of species with species, has probably only served to intensify their unique characteristics, and, perhaps, to lower their intelligence.
Not only are they removed from that indirect struggle for existence which acts so powerfully on other families, but they are also, by their habits and the unequalled velocity of their flight, placed out of reach of that direct war waged on all other small birds by the rapacious kinds—birds, mammals, and reptiles. One result of this immunity is that humming-birds are excessively numerous, albeit such slow breeders; for, as we have seen, they only lay two eggs, and not only so, but the second egg is often dropped so long after incubation has begun in the first that only one is really hatched. Yet Belt expressed the opinion that in Nicaragua, where he observed humming-birds, they out-numbered all the other birds together. Considering how abundant birds of all kinds are in that district, and that most of them have a protective colouring and lay several eggs, it would be impossible to accept such a statement unless we believed that humming-birds have, practically, no enemies.
Another result of their immunity from persecution is the splendid colouring and strange and beautiful feather ornaments distinguishing them above all other birds; and excessive variation in this direction is due, it seems to me, to the very causes which serve to check variation in all other directions. In their plumage, as Martin long ago wrote, nature has strained at every variety of effect and revelled in an infinitude of modifications. How wonderful their garb is, with colours so varied, so intense, yet seemingly so evanescent!—the glittering mantle of powdered gold; the emerald green that changes to velvet black; ruby reds and luminous scarlets; dull bronze that brightens and burns like polished brass, and pale neutral tints that kindle to rose and lilac-coloured flame. And to the glory of prismatic colouring are added feather decorations, such as the racket-plumes and downy muffs of Spathura, the crest and frills of Lophornis, the sapphire gorget burning on the snow-white breast of Oreotrochilus, the fiery tail of Cometes, and, amongst grotesque forms, the long pointed crest-feathers, representing horns, and flowing-white beard adorning the piebald goat-like face of Oxypogon.
Excessive variation in this direction is checked in nearly all other birds by the need of a protective colouring, few kinds so greatly excelling in strength and activity as to be able to maintain their existence without it. Bright feathers constitute a double danger, for not only do they render their possessor conspicuous, but, just as the butterfly chooses the gayest flower, so do hawks deliberately single out from many obscure birds the one with brilliant plumage; but the rapacious kinds do not waste their energies in the vain pursuit of hummingbirds. These are in the position of neutrals, free to range at will amidst the combatants, insulting all alike, and flaunting their splendid colours with impunity. They are nature's favourites, endowed with faculties bordering on the miraculous, and all other kinds, gentle or fierce, ask only to be left alone by them.
CHAPTER XVII.
THE CRESTED SCREAMER.
(Chalina chavarria.)
Amongst the feathered notables from all parts of the world found gathered at the Zoological Gardens in London is the Crested Screamer from South America. It is in many respects a very singular species, and its large size, great strength, and majestic demeanour, with the surprising docility and intelligence it displays when domesticated, give it a character amongst birds somewhat like that of the elephant amongst mammals. Briefly and roughly to describe it: in size it is like a swan, in shape like a lapwing, only with a powerful curved gallinaceous beak. It is adorned with a long pointed crest and a black neck-ring, the plumage being otherwise of a pale slaty blue, while the legs and the naked skin about the eyes are bright red. On each wing, in both sexes, there are two formidable spurs; the first one, on the second joint, is an inch and a half long, nearly straight, triangular, and exceedingly sharp; the second spur, on the last joint, being smaller, broad, and curved, and roughly resembling in shape and size a lion's claw. There is another stinking peculiarity. The skin is emphysematous—that is, bloated and yielding to pressure. It crackles when touched, and the surface, when the feathers are removed, presents a swollen bubbly appearance; for under the skin there is a layer of air-bubbles extending over the whole body and even down the legs under the horny tesselated skin to the toes, the legs thus having a somewhat massive appearance.
And now just a few words about the position of the screamer in systematic zoology. It is placed in the Family Palamedeidae, which contains only three species, but about the Order it belongs to there is much disagreement. It was formerly classed with the rails, and in popular books of Natural History still keeps its place with them. "Now the rail-tribe," says Professor Parker, speaking on this very matter, "has for a long time been burdened (on paper) with a very false army list. Everything alive that has had the misfortune to be possessed of large unwieldy feet has been added to this feeble-minded cowardly group, until it has become a mixed multitude with discordant voices and with manners and customs having no consonance or relation." He takes the screamer from the rail-tribe and classes it with the geese (as also does Professor Huxley), and concludes his study with these words:—"Amongst living birds there is not one possessing characters of higher interest, none that I am acquainted with come nearer, in some important points, to the lizard; and there are parts of the organization which make it very probable that it is one of the nearest living relations of the marvellous Archaeopteryx"—an intermediate form between birds and reptiles belonging to the Upper Jurassic period.
The screamer's right to dwell with the geese has not been left unchallenged. The late Professor Garrod finds that "from considerations of pterylosis, visceral anatomy, myology, and osteology the screamer cannot be placed along with the Anserine birds." He finds that in some points it resembles the ostrich and rhea, and concludes: "It seems therefore to me that, summing these results, the screamer must have sprung from the primary avian stock as an independent offshoot at much the same time as did most of the other important families." This time, he further tells us, was when there occurred a general break-up of the ancient terrestrial bird-type, when the acquisition of wings brought many intruders into domains already occupied, calling forth a new struggle for existence, and bringing out many special qualities by means of natural selection.
With this archaeological question I have little to do, and only quote the above great authorities to show that the screamer appears to be nearly the last descendant of an exceedingly ancient family, with little or no relationship to other existing families, and that its pedigree has been hopelessly lost in the night of an incalculable antiquity. I have only to speak of the bird as a part of the visible world and as it appears to the non-scientific lover of nature; for, curiously enough, while anatomists nave been laboriously seeking for the screamer's affinities in that "biological field which is as wide as the earth and deep as the sea," travellers and ornithologists have told us almost nothing about its strange character and habits.
Though dressed with Quaker-like sobriety, and without the elegance of form distinguishing the swan or peacock, this bird yet appeals to the aesthetic feelings in man more than any species I am acquainted with. Voice is one of its strong points, as one might readily infer from the name: nevertheless the name is not an appropriate one, for though the bird certainly does scream, and that louder than the peacock, its scream is only a powerful note of alarm uttered occasionally, while the notes uttered at intervals in the night, or in the day-time, when it soars upwards like the lark of some far-off imaginary epoch in the world's history when all tilings, larks included, were on a gigantic scale, are. properly speaking, singing notes and in quality utterly unlike screams. Sometimes when walking across Regent's Park I bear the resounding cries of the bird confined there attempting to sing; above the concert of cranes, the screams of eagles and macaws, the howling of dogs and wolves and the muffled roar of lions, one can hear it all over the park. But those loud notes only sadden me. Exile and captivity have taken all joyousness from the noble singer, and a moist climate has made him hoarse; the long clear strains are no more, and he hurries through his series of confused shrieks as quickly as possible, as if ashamed of the performance. A lark singing high up in a sunny sky and a lark singing in a small cage hanging against a shady wall in a London street produce very different effects; and the spluttering medley of shrill and harsh sounds from the street singer scarcely seems to proceed from the same kind of bird as that matchless melody filling the blue heavens. There is even a greater difference in the notes of the crested screamer when heard in Regent's Park and when heard on the pampas, where the bird soars upwards until its bulky body disappears from sight, and from that vast elevation pours down a perpetual rain of jubilant sound.
Screamer being a misnomer, I prefer to call the bird by its vernacular name of chaja, or chakar, a more convenient spelling.
With the chakar the sexes are faithful, even in very large flocks the birds all being ranged in couples. When one bird begins to sing its partner immediately joins, but with notes entirely different in quality. Both birds have some short deep notes, the other notes of the female being long powerful notes with a trill in them; but over them sounds the clear piercing voice of the male, ringing forth at the close with great strength and purity. The song produces the effect of harmony, but, comparing it with human singing, it is less like a duo than a terzetto composed of bass, contralto, and soprano.
At certain times, in districts favourable to them, the chakars often assemble in immense flocks, thousands of individuals being sometimes seen congregated together, and in these gatherings the birds frequently all sing in concert. They invariably—though without rising—sing at intervals during the night, "counting the hours," as the gauchos say; the first song being at about nine o'clock, the second at midnight, and the third just before dawn, but the hours vary in different districts.
I was once travelling with a party of gauchos when, about midnight, it being intensely dark, a couple of chakars broke out singing right ahead of us, thus letting us know that we were approaching a watercourse, where we intended refreshing our horses. We found it nearly dry, and when we rode down to the rill of water meandering over the broad dry bed of the river, a flock of about a thousand chakars set up a perfect roar of alarm notes, all screaming together, with intervals of silence after; then they rose up with a mighty rush of wings. They settled down again a few hundred yards off, and all together burst forth in one of their grand midnight songs, making the plains echo for miles around.
There is something strangely impressive in these spontaneous outbursts of a melody so powerful from one of these large flocks, and though accustomed to hear these birds from childhood, I have often been astonished at some new effect produced by a large multitude singing under certain conditions. Travelling alone one summer day, I carne at noon to a lake on the pampas called Kakel—a sheet of water narrow enough for one to see across. Chakars in countless numbers were gathered along its shores, but they were all ranged in well-defined flocks, averaging about five hundred birds in each flock. These flocks seemed to extend all round the lake, and had probably been driven by the drought from all the plains around to this spot. Presently one flock near me began singing, and continued their powerful chant for three or four minutes; when they ceased the next flock took up the strains, and after it the next, and so on until the notes of the flocks on the opposite shore came floating strong and clear across the water—then passed away, growing fainter and fainter, until once more the sound approached me travelling round to my side again. The effect was very curious, and I was astonished at the orderly way with which each flock waited its turn to sing, instead of a general outburst taking place after the first flock had given the signal. On another occasion I was still more impressed, for here the largest number of birds I have ever found congregated at one place all sung together. This was on the southern pampas, at a place called Gualicho, where I had ridden for an hour before sunset over a marshy plain where there was still much standing water in the rushy pools, though it was at the height of the dry season. This whole plain was covered with an endless flock of chakars, not in close order, but scattered about in pairs and small groups. In this desolate spot I found a small rancho inhabited by a gaucho and his family, and I spent the night with them. The birds were all about the house, apparently as tame as the domestic fowls, and when I went out to look for a spot for my horse to feed on, they would not fly away from me, but merely moved, a few steps out of my path About nine o'clock we were eating supper in the rancho when suddenly the entire multitude of birds covering the marsh for miles around burst forth into a tremendous evening song. It is impossible to describe the effect of this mighty rush of sound; but let the reader try to imagine half-a-million voices, each far more powerful than that one which makes itself heard all over Regent's Park, bursting forth on the silent atmosphere of that dark lonely plain. One peculiarity was that in this mighty noise, which sounded louder than the sea thundering on a rocky coast, I seemed to be able to distinguish hundreds, even thousands, of individual voices. Forgetting my supper, I sat motionless and overcome with astonishment, while the air, and even the frail rancho, seemed to be trembling in that tempest of sound. When it ceased my host remarked with a smile, "We are accustomed to this, senor—every evening we have this concert." It was a concert well worth riding a hundred miles to hear. But the chakar country is just now in a transitional state, and the precise conditions which made it possible for birds so large in size to form such immense congregations are rapidly passing away. In desert places, the bird subsists chiefly on leaves and seeds of aquatic plants; but when the vast level area of the pampas was settled by man, the ancient stiff grass-vegetation gave place to the soft clovers and grasses of Europe, and to this new food the birds took very kindly. Other circumstances also favoured their increase. They were never persecuted, for the natives do not eat them, though they are really very good—the flesh being something like wild goose in flavour. A higher civilization is changing all this: the country is becoming rapidly overrun with emigrants, especially by Italians, the pitiless enemies of all bird-life.
The chakars, like the skylark, love to soar upwards when singing, and at such times when they have risen till their dark bulky bodies appear like floating specks on the blue sky, or until they disappear from sight altogether, the notes become wonderfully etherealized by distance to a soft silvery sound, and it is then very delightful to listen to them.
It seems strange that so ponderous a fowl with only six feet and a half spread of wings should possess a power of soaring equal to that of vultures and eagles. Even the vulture with its marvellous wing power soars chiefly from necessity, and when its crop is full finds no pleasure in "scaling the heavens by invisible stairs." The chakar leaves its grass-plot after feeding and soars purely for recreation, taking so much pleasure in its aerial exercises that in bright warm weather, in winter and spring, it spends a great part of the day in the upper regions of the air. On the earth its air is grave and its motions measured and majestic, and it rises with immense labour, the wings producing a sound like a high wind. But as the bird mounts higher, sweeping round as it ascends, just as vultures and eagles do, it gradually appears to become more buoyant, describing each succeeding circle with increasing grace. I can only account for this magnificent flight, beginning so laboriously, by supposing that the bubble space under the skin becomes inflated with an air lighter than atmospheric air, enabling a body so heavy with wings disproportionately short to float with such ease and evident enjoyment at the vast heights to which the bird ascends. The heavenward flight of a large bird is always a magnificent spectacle; that of the chakar is peculiarly fascinating on account of the resounding notes it sings while soaring, and in which the bird seems to exult in its sublime power and freedom.
I was once very much surprised at the behaviour of a couple of chakars during a thunderstorm. On a still sultry day in summer I was standing watching masses of black cloud coming rapidly over the sky, while a hundred yards from me stood the two birds also apparently watching the approaching storm with interest. Presently the edge of the cloud touched the sun, and a twilight gloom fell on the earth. The very moment the sun disappeared the birds rose up and soon began singing their long' resounding notes, though it was loudly thundering at the time, while vivid flashes of lightning lit the black cloud overhead at short intervals. I watched their flight and listened to their notes, till suddenly as they made a wide sweep upwards they disappeared in the cloud, and at the same moment their voices became muffled, and seemed to come from an immense distance. The cloud continued emitting sharp flashes of lightning, but the birds never reappeared, and after six or seven minutes once more their notes sounded loud and clear above the muttering thunder. I suppose they had passed through the cloud into the clear atmosphere above it, but I was extremely surprised at their fearlessness; for as a rule when soaring birds see a storm coming they get out of its way, flying before it or stooping to the earth to seek shelter of some kind, for most living things appear to have a wholesome dread of thunder and lightning.
When taken young the chakar becomes very tame and attached to man, showing no inclination to go back to a wild life. There was one kept at an estancia called Mangrullos, on the western frontier of Buenos Ayres, and the people of the house gave me a very curious account of it. The bird was a male, and had been reared by a soldier's wife at a frontier outpost called La Esperanza, about twenty-five miles from Mangrullos. Four years before I saw the bird the Indians had invaded the frontier, destroying the Esperanza settlement and all the estancias for some leagues around. For some weeks after the invasion the chakar wandered about the country, visiting all the ruined estancias, apparently in quest of human beings, and on arriving at Mangrullos, which had not been burnt and was still inhabited, it settled down at ones and never afterwards showed any disposition to go away. It was extremely tame, associating by day with the poultry, and going to roost with them at night OH a high perch, probably for the sake of companionship, for in a wild state the bird roosts on the ground. It was friendly towards all the members of the household except one, a peon, and against this person from the first the bird always displayed the greatest antipathy, threatening him with its wings, puffing itself out, and hissing like an angry goose. The man had a swarthy, beardless face, and it was conjectured that the chakar associated him in its mind with the savages who had destroyed its early home.
Close to the house there was a lagoon, never dry, which was frequently visited by flocks of wild chakars. Whenever a flock appeared the tame bird would go out to join them; and though the chakars are mild-tempered birds and very rarely quarrel, albeit so well provided with formidable weapons, they invariably attacked the visitor with great fury, chasing him back to the house, and not ceasing their persecutions till the poultry-yard was reached. They appeared to regard this tame bird that dwelt with man as a kind of renegade, and hated him accordingly.
Before he had been long at the estancia it began to be noticed that he followed the broods of young chickens about very assiduously, apparently taking great interest in their welfare, and even trying to entice them to follow him. A few newly-hatched chickens were at length offered to him as an experiment, and he immediately took charge of them with every token of satisfaction, conducting them about in search of food and imitating all the actions of a hen. Finding him so good a nurse, large broods were given to him, and the more the foster-chickens were the better he seemed pleased. It was very curious to see this big bird with thirty or forty little animated balls of yellow cotton following him about, while he moved majestically along, setting down his feet with the greatest care not to tread on them, and swelling himself up with jealous anger at the approach of a cat or dog.
The intelligence, docility, and attachment to man displayed by the chakar in a domestic state, with perhaps other latent aptitudes only waiting to be developed by artificial selection, seem to make this species one peculiarly suited for man's protection, without which it must inevitably perish. It is sad to reflect that all our domestic animals have descended to us from those ancient times which we are accustomed to regard as dark or barbarous, while the effect of our modern so-called humane civilization has been purely destructive to animal life. Not one type do we rescue from the carnage going on at an ever-increasing rate over all the globe. To Australia and America, North and South, we look in vain for new domestic species, while even from Africa, with its numerous fine mammalian forms, and where England has been the conquering colonizing power for nearly a century, we take nothing. Even the sterling qualities of the elephant, the unique beauty of the zebra, appeal to us in vain. We are only teaching the tribes of that vast continent to exterminate a hundred noble species they would not tame. With grief and shame, even with dismay, we call to mind that our country is now a stupendous manufactory of destructive engines, which we are rapidly placing in the hands of all the savage and semi-savage peoples of the earth, thus ensuring the speedy destruction of all the finest types in the animal kingdom.
CHAPTER XVIII.
THE WOODHEWER FAMILY.
(Dendrocolaptidae.)
The South American Tree-creepers, or Woodhewers, as they are sometimes called, although confined exclusively to one continent, their range extending from Southern Mexico to the Magellanic islands, form one of the largest families of the order Passeres; no fewer than about two hundred and ninety species (referable to about forty-six genera) having been already described. As they are mostly small, inconspicuous, thicket-frequenting birds, shy and fond of concealment to excess, it is only reasonable to suppose that our list of this family is more incomplete than of any other family of birds known. Thus, in the southern Plata and north Pata-gonian districts, supposed to be exhausted, where my observations have been made, and where, owing to the open nature of the country, birds are more easily remarked than in the forests and marshes of the tropical region, I have made notes on the habits of five species, of which I did not preserve specimens, and which, as far as I know, have never been described and named. Probably long before the whole of South America has been "exhausted," there will be not less than four to five hundred Dendrocolaptine species known. And yet with the exception of that dry husk of knowledge, concerning size, form and colouration, which classifiers and cataloguers obtain from specimens, very little indeed scarcely anything, in fact is known about the Tree-creepers; and it would not be too much to say that there are many comparatively obscure and uninteresting species in Europe, any one of which has a larger literature than the entire Tree-creeper family. No separate work about these birds has seen the light, even in these days of monographs; but the reason of this comparative neglect is not far to seek. In the absence of any knowledge, except of the most fragmentary kind, of the life-habits of exotic species, the monograph-makers of the Old World naturally take up only the most important groups i.e. the groups which most readily attract the traveller's eye with their gay conspicuous colouring, and which have acquired a wide celebrity. We thus have a succession of splendid and expensive works dealing separately with such groups as woodpeckers, trogons, humming-birds, tanagers, king-fishers, and birds of paradise; for with these, even if there be nothing to record beyond the usual dreary details and technicalities concerning geographical distribution, variations in size and markings of different species, &c., the little interest of the letter-press is compensated for in the accompanying plates, which are now produced on a scale of magnitude, and with so great a degree of perfection, as regards brilliant colouring, spirited attitudes and general fidelity to nature, that leaves little further improvement in this direction to be looked for. The Tree-creepers, being without the inferior charm of bright colour, offer no attraction to the bird-painter, whose share in the work of the pictorial monograph is, of course, all-important. Yet even the very slight knowledge we possess of this family is enough to show that in many respects it is one richly endowed, possessing characters of greater interest to the student of the instincts and mental faculties of birds, than any of the gaily-tinted families I have mentioned.
There is, in the Dendrocolaptidae, a splendid harvest for future observers of the habits of South American birds: some faint idea of its richness may perhaps be gathered from the small collection of the most salient facts known to us about them I have brought together and put in order in this place. And I am here departing a little from the plan usually observed in this book, which is chiefly occupied with matters of personal knowledge, seasoned with a little speculation; but in this case I have thought it best to supplement my own observations with those of others [Footnote: Azara; D'Orbigny; Darwin; Bridges; Frazer; Leotaud; Gaumer; Wallace; Bates; Cunningham; Stolzmann; Jelski; Durnford; Gibson; Burrows; Doering; White, &c.] who have collected and observed birds in South America, so as to give as comprehensive a survey of the family as I could.
It is strange to find a Passerine family, numerous as the Tree-creepers, uniformly of one colour, or nearly so; for, with few exceptions, these birds have a brown plumage, without a particle of bright colour. But although they possess no brilliant or metallic tints, in some species, as we shall see, there are tints approaching to brightness. Notwithstanding this family likeness in colour, any person, not an ornithologist, looking at a collection of specimens comprising many genera, would hear with surprise and almost incredulity that they all belonged to one family, so great is the diversity exhibited in their structure. In size they vary from species smaller than the golden-crested wren to others larger than the woodcock; but the differences in size are as nothing compared with those shown in the form of the beak. Between the minute, straight, conical, tit-like beaks of the Laptasthenura—a tit in appearance and habits—and the extravagantly long, sword-shaped bill of Nasica, or the excessively attenuated, sickle-shaped organ in Xiphorynchus, the divergence is amazing, compared with what is found in other families; while between these two extremes there is a heterogeneous assemblage of birds with beaks like creepers, nuthatches, finches, tyrant-birds, woodpeckers, crows, and even curlews and ibises. In legs, feet and tails, there are corresponding differences. There are tails of all lengths and all forms; soft and stiff, square, acuminated, broad and fan-like, narrow and spine-like, and many as in the woodpeckers, and used as in that bird to support the body in climbing. An extremely curious modification is found in Sittosoma: the tail-feathers in this genus are long and graduated, and the shafts, projecting beyond the webs at the ends, curve downwards and form stiff hooks. Concerning the habits of these birds, it has only been reported that they climb on the trunks of trees: probably they are able to run vertically up or down with equal facility, and even to suspend themselves by their feather-hooks when engaged in dislodging insects. Another curious variation is found in Sylviothorhynchus, a small wren-like bird and the only member known of the genus, with a tail resembling that of the lyre-bird, the extravagantly long feathers being so narrow as to appear almost like shafts destitute of webs. This tail appears to be purely ornamental.
This extreme variety in structure indicates a corresponding diversity in habits; and, assuming it to be a true doctrine that habits vary first and structure afterwards, anyone might infer from a study of their forms alone that these birds possess a singular plasticity, or tendency to vary, in their habits—or, in other words, that they are exceptionally intelligent; and that such a conclusion would be right I believe a study of their habits will serve to show.
The same species is often found to differ in its manner of life in different localities. Some species of Xenops and Magarornis, like woodpeckers, climb vertically on tree-trunks in search of insect prey, but also, like tits, explore the smaller twigs and foliage at the extremity of the branches; so that the whole tree, from its root to its topmost foliage, is hunted over by them. The Sclerurus, although an inhabitant of the darkest forest, and provided with sharply-curved claws, never seeks its food on trees, but exclusively on the ground, among the decaying fallen leaves; but, strangely enough, when alarmed it flies to the trunk of the nearest tree, to which it clings in a vertical position, and, remaining silent and motionless, escapes observation by means of its dark protective colour. The Drymornis, a large bird, with feet and tail like a woodpecker, climbs on tree-trunks to seek its food; but also possesses the widely-different habit of resorting to the open plain, especially after a shower, to feed on larvae and earthworms, extracting them from a depth of three or four inches beneath the surface with its immense curved probing beak.
Again, when we consider a large number of species of different groups, we find that there is not with the Tree-creepers, as with most families, any special habit or manner of life linking them together; but that, on the contrary, different genera, and, very frequently, different species belonging to one genus, possess habits peculiarly their own. In other families, even where the divergence is greatest, what may be taken as the original or ancestral habit is seldom or never quite obsolete in any of the members. This we see, for instance, in the woodpeckers, some of which have acquired the habit of seeking their food exclusively on the ground in open places, and even of nesting in the banks of streams. Yet all these wanderers, even those which have been structurally modified in accordance with their altered way of life, retain the primitive habit of clinging vertically to the trunks of trees, although the habit has lost its use. With the tyrant birds—a family showing an extraordinary amount of variation—it is the same; for the most divergent kinds are frequently seen reverting to the family habit of perching on an elevation, from which to make forays after passing insects, returning after each capture to the same stand. The thrushes, ranging all over the globe, afford another striking example. Without speaking of their nesting habits, their relationship appears in their love of fruit, in their gait, flight, statuesque attitudes, and abrupt motions.
With the numerous Dendrocolaptine groups, so widely separated and apparently unrelated, it would be difficult indeed to say which, of their most striking habits is the ancestral one. Many of the smaller species live in trees or bushes, and in their habits resemble tits, warblers, wrens, and other kinds that subsist on small caterpillars, spiders, &c., gleaned from the leaves and smaller twigs. The Anumbius nests on trees, but feeds exclusively on the ground in open places; while other ground-feeders seek their food among dead leaves in dense gloomy forests. Coryphistera resembles the lark and pipit in its habits; Cinclodes, the wagtail; Geobates a Saxicola; Limnornis lives in reed beds growing in the water; Henicornis in reed beds growing out of the water; and many other ground species exist concealed in the grass on dry plains; Homorus seeks its food by digging in the loose soil and dead leaves about the roots of trees; while Geo-sitta, Furnarius, and Upercerthia obtain a livelihood chiefly by probing in the soil. It would not be possible within the present limits to mention in detail all the different modes of life of those species or groups which do not possess the tree-creeping habit; after them comes a long array of genera in which this habit is ingrained, and in which the greatly modified feet and claws are suited to a climbing existence. As these genera comprise the largest half of the family, also the largest birds in it, we might expect to find in the tree-creeping the parental habit of the Dendrocolaptidae, and that from these tropical forest groups have sprung the widely-diverging thicket, ground, marsh, sea-beach, and rock-frequenting groups. It happens, however, that these birds resemble each other only in their climbing feet; in the form of their beaks they are as wide apart as are nuthatches, woodpeckers, crows, and curlews. They also differ markedly in the manner of seeking their food. Some dig like woodpeckers in decayed wood; others probe only in soft rotten wood; while the humming-bird-billed Xiphorhynchus, with a beak too long and slender for probing, explores the interior of deep holes in the trunks to draw out nocturnal insects, spiders, and centipedes from their concealment. Xiphoco-laptes uses its sword-like beak as a lever, thrusting it under and forcing up the loose bark; while Dendrornis, with its stout corvine beak, tears the bark off.
In the nesting habits the diversity is greatest. Some ground species excavate in the earth like kingfishers, only with greater skill, making cylindrical burrows often four to five feet deep, and terminating in a round chamber. Others build a massive oven-shaped structure of clay on a branch or other elevated site. Many of those that creep on trees nest in holes in the wood. The marsh-frequenting kinds attach spherical or oval domed nests to the reeds; and in some cases woven grass and clay are so ingeniously combined that the structure, while light as a basket, is perfectly impervious to the wet and practically indestructible. The most curious nests, however, are the large stick structures on trees and bushes, in the building and repairing of which the birds are in many cases employed more or less constantly all the year round. These stick nests vary greatly in form, size, and in other respects. Some have a spiral passage-way leading from the entrance to the nest cavity, and the cavity is in many cases only large enough to accommodate the bird; but in the gigantic structure of Homorus gutturalis it is so large that, if the upper half of the nest or dome were removed, a condor could comfortably hatch her eggs and rear her young in it. This nest is spherical. The allied Homorus lophotis builds a nest equally large, but with a small cavity for the eggs inside, and outwardly resembling a gigantic powder-flask, lying horizontally among the lower branches of a spreading tree. Pracellodomtis sibila-trix, a bird in size like the English house sparrow, also makes a huge nest, and places it on the twigs at the terminal end of a horizontal branch from twelve to fifteen feet above the ground; but when finished, the weight of the structure bears down the branch-end to within one or two feet of the surface. Mr. Barrows, who describes this nest, says: "When other branches of the same tree are similarly loaded, and other trees close at hand bear the same kind of fruit, the result is very picturesque." Synallaxis phryganophila makes a stick nest about a foot in depth, and from the top a tubular passage, formed of slender twigs interlaced, runs down the entire length of the nest, like a rain-pipe on the wall of a house, and then becoming external slopes upward, ending at a distance of two to three feet from the nest. Throughout South America there are several varieties of these fruit-and-stem or watering-pot shaped nests; they are not, however, all built by birds of one genus, while in the genus Synallaxis many species have no tubular passageways attached to their nests. One species—erythro thorax—in Yucatan, makes so large a nest of sticks, that the natives do not believe that so small a bird can be the builder. They say that when the tzapatan begins to sing, all the birds in the forest repair to it, each one carrying a stick to add to the structure; only one, a tyrant-bird, brings two sticks, one for itself and one for the urubu or vulture, that bird being considered too large, heavy, and ignorant of architecture to assist personally in the work.
In the southern part of South America, where scattered thorn trees grow on a dry soil, these big nests are most abundant. "There are plains," Mr. Barrows writes, "within two miles of the centre of this town (Concepcion, Argentine Republic), where I have stood and counted, from one point within a radius of twenty rods, over two hundred of these curious nests, varying in size from that of a small pumpkin to more than the volume of a barrel. Often a single tree will contain half a dozen nests or more; and, not unfrequently, the nests of several different species are seen crowding each other out of shape on the same bush or tree."
It would be a mistake to think that the widely different nesting habits I have mentioned are found in different genera. I have just spoken of the big stick nests, with or without passage-ways, of the Synallaxes, yet the nest of one member of this group is simply a small straight tube of woven grass, the aperture only large enough to admit the finger, and open at both ends, so that the bird can pass in and out without turning round. Another species scoops a circular hollow in the soil, and builds over it a dome of fine woven grass. It should be mentioned that the nesting habits of only about fifteen out of the sixty-five species comprised in this genus are known to us. In the genus Furnarius the oven-shaped clay structure is known to be made by three species; a fourth builds a nest of sticks in a tree; a fifth burrows in the side of a bank, like a kingfisher.
The explanation of the most striking features of the Dendrocolaptidae, their monotonous brown plumage, diversity of structure, versatile habits, and the marvellous development of the nest-making instinct which they exhibit is to be found, it appears to me, in the fact that they are the most defenceless of birds. They are timid, unresisting creatures, without strength or weapons; their movements arc less quick and vigorous than those of other kinds, and their flight is exceedingly feeble. The arboreal species flit at intervals from one tree to another; those that frequent thickets refuse to leave their chosen shelter; while those inhabiting grassy plains or marshes study concealment, and, when forced to rise, flutter away just above the surface, like flying-fish frightened from the water, and, when they have gone thirty or forty yards, dip into the grass or reeds again. Their life is thus one of perpetual danger in a far greater degree than with other passerine families, such as warblers, tyrants, finches, thrushes, &c.; while an exclusively insect diet, laboriously extracted from secret places, and inability to change their climate, contribute to make their existence a hard one. It has been with these birds as with human beings, bred in "misfortune's school," and subjected to keen competition. One of their most striking characteristics is a methodical, plodding, almost painful diligence of manner while seeking their food, so that when viewed side by side with other species, rejoicing in a gayer plumage and stronger flight, they seem like sober labourers that never rest among holiday people bent only on enjoyment. That they are able not only to maintain their existence, but to rise to the position of a dominant family, is due to an intelligence and adaptiveness exceeding that of other kinds, and which has been strengthened, and perhaps directly results from the hard conditions of their life. |
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