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Armadillo killing Snake.
captures mice; when preying on snakes it proceeds in another manner. A friend of mine, a careful observer, who was engaged in cattle-breeding amongst the stony sierras near Cape Corrientes, described to me an encounter he witnessed between an armadillo and a poisonous snake. While seated on the hillside one day he observed a snake, about twenty inches in length, lying coiled up on a stoue five or six yards beneath him. By-and-by, a hairy
Some curious Animal Weapons.73
armadillo appeared trotting directly towards it. Apparently the snake perceived and feared its approach, for it quickly uncoiled itself and began gliding away. Instantly the armadillo rushed on to it, and, squatting close down, began swaying its body backward and forward with a regular sawing motion, thus lacerating its victim with the sharp, deep-cut edges of its bony covering. The snake struggled to free itself, biting savagely at its aggressor, for its head and neck were disengaged. Its bites made no impression, and very soon it dropped its head, and when its enemy drew off, it was dead and very much mangled. The armadillo at once began its meal, taking the tail in its mouth and slowly progressing towards the head; but when about a third of the snake still remained it seemed satisfied, and, leaving that portion, trotted away.
Altogether, in its rapacious and varied habits this armadillo appears to have some points of resemblance with the hedgehog; and possibly, like the little European mammal it resembles, it is not harmed by the bite of venomous snakes.
I once had a cat that killed every snake it found, purely for sport, since it never ate them. It would jump nimbly round and across its victim, occasionally dealing it a blow with its cruel claws. The enemies of the snake are legion. Burrowing owls feed largely on them; so do herons and storks, killing them with a blow of their javelin beaks, and swallowing them entire. The sulphur tyrant-bird picks up the young snake by the tail, and, flying to a branch or stone, uses it like a flail till its life is battered out. The bird is highly com-
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mended in consequence, reminding one of very ancient words: "Happy shall he be that taketh thy little ones and dasheth them against the stones." In arraying such a variety of enemies against the snake, nature has made ample amends for having endowed it with deadly weapons. Besides, the power possessed by venomous snakes only seems to us disproportionate; it is not really so, except in occasional individual encounters. Venomous snakes are always greatly outnumbered by non-venomous ones in the same district; at any rate this is the case on the pampas. The greater activity of the latter counts for more in the result than the deadly weapons of the former.
The large teguexin lizard of the pampas, called iguana by the country people, is a notable snake-killer. Snakes have in fact, no more formidable enemy, for he is quick to see, and swift to overtake them. He is practically invulnerable, and deals them sudden death with his powerful tail. The gauchos say that dogs attacking the iguana are sometimes known to have their legs broken, and I do not doubt it. A friend of mine was out riding one day after his cattle, and having attached one end of his lasso to the saddle, He let it trail on the ground. He noticed a large iguana lying apparently asleep in the sun, and though he rode by it very closely, it did not stir; but no sooner had he passed it, than it raised its head, and fixed its attention on the forty feet of lasso slowly trailing by. Suddenly it rushed after the rope, and dealt it a succession of violent blows with its tail. When the whole of the lasso, several yards of which had been pounded in vain, had been
Sonic curious Animal Weapons.75
dragged by, the lizard, with uplifted head, continued gazing after it with the greatest astonishment. Never had such a wonderful snake crossed its path before!
Molina, in hisNatural History of Chill,says the vizcacha uses its tail as a weapon; but then Molina is not always reliable. I have observed vizcachas all my life, and never detected them making use of any weapon except their chisel teeth. The tail is certainly very curious, being straight at the base, then curving up outwardly, and slightly down again at the tip, resembling the spout of a china teapot. The under surface of the straight portion of the base is padded with a thick, naked, corneous skin; and, when the animal performs the curious sportive antics in which it occasionally indulges, it gives rapid loud-sounding blows on the ground with this part of the tail. The peculiar form of the tail also makes it a capital support, enabling the vizcacha to sit erect, with ease and security.
The frog is a most timid, inoffensive creature, saving itself, when pursued, by a series of saltatory feats unparalleled amongst vertebrates. Consequently, when I find a frog, I have no hesitation in placing my hands upon it, and the cold sensation it gives one is the worse result I fear. It came to pass, however, that I once encountered a frog that was not like other frogs, for it possessed an instinct and weapons of offence which greatly astonished me. I was out snipe shooting one day when, peering into an old disused burrow, two or three feet deep, I perceived a burly-looking frog sitting it. It was larger and stouter-looking than
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our common Rana, though like it in colour, and I at once dropped on to my knees and set about its capture. Though it watched me attentively, the frog remained perfectly motionless, and this greatly surprised me. Before I was sufficiently near to make a grab, it sprang straight at my hand, and, catching two of my fingers round with its fore legs, administered a hug so sudden and violent as to cause an acute sensation of pain; then, at the very instant I experienced this feeling, which made me start back quickly, it released its hold and bounded out and away. I flew after it, and barely managed to overtake it before it could gain the water. Holding it firmly pressed behind the shoulders, it was powerless to attack me, and I then noticed the enormous development of the muscles of the fore legs, usually small in frogs, bulging out in this individual, like a second pair of thighs, and giving-it a strangely bold and formidable appearance. On holding my gun within its reach, it clasped the barrel with such energy as to bruise the skin of its breast and legs. After allowing it to partially exhaust itself in these fruitless huggings, I experimented by letting it seize my hand again, and I noticed that invariably after each squeeze it made a quick, violent attempt to free itself. Believing that I had discovered a frog differing in structure from all known species, and possessing a strange unique instinct of self-preservation, I carried my captive home, intending to show it to Dr. Burmeister, the director of the National Museum at Buenos Ayres-Unfortunately, after I had kept it some days, it effected its escape by pushing up the glass cover of
Some curious Animal Weapons.77
its box, and I have never since met with another individual like it. That this singular frog has it in its power to seriously injure an opponent is, of course, out of the question; but its unexpected attack must be of great advantage. The effect of the sudden opening of an umbrella in the face of an angry bull gives, I think, only a faint idea of
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Wrestler Frog.
the astonishment and confusion it must cause an adversary by its leap, quick as lightning, and the violent hug it administers; and in the confusion it finds time to escape. I cannot for a moment believe that an instinct so admirable, correlated as it is with the structure of the fore legs, can be merely an individual variation; and I confidently expect
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that all I have said about my lost frog will some day be confirmed by others. Rana luctator would be a good name for this species.
The toad is a slow-moving creature that puts itself in the way of persecution; yet, strange to say, the acrid juice it exudes when irritated is a surer protection to it than venomous fangs are to the deadliest snake. Toads are, in fact, with a very few exceptions, only attacked and devoured by snakes, by lizards, and by their own venomous relative, Ceratophrys ornata. Possibly the cold sluggish natures of all these creatures protects them against the toad's secretion, which would be poison to most warm-blooded animals, but I am not so sure that all fish enjoy a like immunity. I one day noticed a good-sized fish (bagras) floating, belly upmost, on the water. It had apparently just died, and had such a glossy, well-nourished look about it, and appeared so full, I was curious to know the cause of its death. On opening it I found its stomach quite filled with a very large toad it had swallowed. The toad looked perfectly fresh, not even a faint discoloration of the skin showing that the gastric juices had begun to take effect; the fish, in fact, must have died immediately after swallowing the toad. The country people in South America believe that the milky secretion exuded by the toad possesses wonderful curative properties; it is their invariable specific for shingles--a painful, dangerous malady common amongst them, and to cure it living toads are applied to the inflamed parb. I dare say learned physicians would laugh at this cure, but then, if I mistake not, the learned have in past
Some curious Animal Weapons.79
times laughed at other specifics used by the vulgar, but which now have honourable places in the pharmacopoeia--pepsine, for example. More than two centuries ago (very ancient times for South America) the gauchos were accustomed to take the lining of the rhea's stomach, dried and powdered, for ailments caused by impaired digestion; and the remedy is popular still. Science has gone over to them, and the ostrich-hunter now makes a double profit, one from the feathers, and the other from the dried stomachs which he supplies to the chemists of Buenos Ayres. Yet he was formerly told that to take the stomach of the ostrich to improve his digestion was as wild an idea as it would be to swallow birds' feathers in order to fly.
I just now called Ceratophrys ornata venomous, though its teeth are not formed to inject poison into the veins, like serpents' teeth. It is a singular creature, known asescuerzoin the vernacular, and though beautiful in colour, is in form hideous beyond description. The skin is of a rich brilliant green, with chocolate-coloured patches, oval in form, and symmetrically disposed. The lips are bright yellow, the cavernous mouth pale flesh colour, the throat and under-surface dull white. The body is lumpy, and about the size of a large man's fist. The eyes, placed on the summit of a disproportionately large head, are embedded in horn-like protuberances, capable of being elevated or depressed at pleasure. When the creature is undisturbed, the eyes, which are of a pale gold colour, look outasfrom a couple of watch towers, but when touched on the head or menaced, the prominences sink down
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to a level with the head, closing the eyes completely, and giving the creature the appearance of being eyeless. The upper jaw is armed with minute teeth, and there are two teeth in the centre of the lower jaw, the remaining portions of the jaw being armed with two exceedingly sharp-edged bony plates. In place of a tongue, it has a round
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Ceratophrys ornata.
muscular process with a rough flat disc the size of a halfpenny.
It is common all over the pampas, ranging as far south as the Rio Colorado in Patagonia. In the breeding season it congregates in pools, and one is then struck by their extraordinary vocal powers, which they exercise by night. The performance in no way resembles the series of percussive sounds uttered by most batrachians. The notes it utters
Some curious Animal Weapons.Si
are long, as of a wind instrument, not unmelodious, and so powerful as to make themselves heard distinctly a mile off on still evenings. After the amorous period these toads retire to moist places and sit inactive, buried just deep enough to leave the broad green back on a level with the surface, and it is then very difficult to detect them. In this position they wait for their prey--frogs, toads, birds, and small mammals. Often they capture and attempt to swallow things too large for them, a mistake often made by snakes. In very wet springs they sometimes come about houses and lie in wait for chickens and ducklings. In disposition they are most truculent, savagely biting at anything that comes near them; and when they bite they hang on with the tenacity of a bulldog, poisoning the blood with their glandular secretions. When teased, the creature swells itself out to such an extent one almost expects to see him burst; he follows his tormentors about with slow awkward leaps, his vast mouth wide open, and uttering an incessant harsh croaking sound. A gaucho I knew was once bitten by one. He sat down on the grass, and, dropping his hand at his side, had it seized, and only freed himself by using his hunting knife to force the creature's mouth open. He washed and bandaged the wound, and no bad result followed; but when the toad cannot be shaken off, then the result is different. One summer two horses were found dead on the plain near my home. One, while lying down, had been seized by a fold in the skin near the belly; the other had been grasped by the nose while cropping grass. In both instances the
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vicious toad was found dead, with jaws tightly closed, still
hanging to the dead horse. Perhaps they are sometimes
incapable of letting go at will, and like honey bees, destroy themselves in these savage attacks.
CHAPTER V.
FEAR IN BIRDS.
THE statement that birds instinctively fear man is frequently met with in zoological works written since theOrigin of Speciesappeared; but almost the only reason--absolutely the only plausible reason, all the rest being mere supposition--given in support of such a notion is that birds in desert islands show at first no fear of man, but afterwards, finding him a dangerous neighbour, they become wild; and their young also grow up wild. It is thus assumed that the habit acquired by the former has become hereditary in the latter--or, at all events, that in time it becomes hereditary. Instincts, which are few in number in any species, and practically endure for ever, are not, presumably, acquired with such extraordinary facility.
Birds become shy where persecuted, and the young, even when not disturbed, learn a shy habit from the parents, and from other adults they associate with. I have found small birds shyer in desert places, where the human form was altogether strange to them, than in thickly-settled districts. Large birds are actually shyer than the small ones, although, to the civilized or shooting man they seem astonishingly tame where they have never been
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fired at. I have frequently walked quite openly to within twenty-five or thirty yards of a flock of flamingoes without alarming them. This, however, was when they were in the water, or on the opposite side of a stream. Having no experience of guns, they fancied themselves secure as long as a strip of water separated them from the approaching object. When standing on dry land they would not allow so near an approach. Sparrows in England aro very much tamer than the sparrows I have observed in desert places, where they seldom see a human being. Nevertheless young sparrows in England are very much tamer than old birds, as anyone may see for himself. During the past summer, while living near Kew Gardens, I watched the sparrows a great deal, and fed forty or fifty of them every day from a back window. The bread and seed was thrown on to a low roof just outside the window, and I noticed that the young birds when first able to fly were always brought by the parents to this feeding place, and that after two or three visits they would begin to come of their own accord. At such times they would venture quite close to me, showing as little suspicion as young chickens. The adults, however, although so much less shy than birds of other species, were extremely suspicious, snatching up the bread and flying away; or, if they remained, hopping about in a startled manner, craning their necks to view me, and making so many gestures and motions, and little chirps of alarm, that presently the young would become infected with fear. The lesson was taught them in a surprisingly short time; their suspicion was seen to increase day by
Fear in Birds.85
day, and about a week later they were scarcely to be distinguished, in behaviour from the adults. It is plain that, with these little birds, fear of man is an associate feeling, and that, unless it had been taught them, his presence would trouble them as little as does that of horse, sheep, or cow. But how about the larger species, used as food, and which have had a longer and sadder experience of man's destructive power?
The rhea, or South American ostrich, philosophers tell us, is a very ancient bird on the earth; and from its great size and inability to escape by flight, and its excellence as food, especially to savages, who prefer fat rank-flavoured flesh, it must have been systematically persecuted by man as long as, or longer than, any bird now existing on the globe. If fear of man ever becomes hereditary in birds, we ought certainly to find some trace of such an instinct in this species. I have been unable to detect any, though I have observed scores of young rheas in captivity, taken before the parent bird had taught them what to fear. I also once kept a brood myself, captured just after they had hatched out. With regard to food they were almost, or perhaps quite, independent, spending most of the time catching flies, grasshoppers, and other insects with surprising dexterity; but of the dangers encompassing the young rhea they knew absolutely frothing. They would follow me about as if they took me for their parent; and, whenever I imitated the loud snorting or rasping warning-call emitted the old bird in moments of danger, they would to me in the greatest terror, though no animal
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was in sight, and, squatting at my feet, endeavour to conceal themselves by thrusting their heads and long necks up my trousers. If I had caused a person to dress in white or yellow clothes for several consecutive days, and had then uttered the warning cry each time he showed himself to the birds, I have no doubt that they would soon have acquired a habit of running in terror from him, even without the warning cry, and that the fear of a person in white or yellow would have continued all their lives. Up to within about twenty years ago, rheas were seldom or never shot in La Plata and Patagonia, but were always hunted on horseback and caught with the bolas. The sight of a mounted man would set them off at once, while a person on foot could walk quite openly to within easy shooting distance of them; yet their fear of a horseman dates only two hundred years back--a very short time, when we consider that, before the Indian borrowed the horse from the invader, he must have systematically pursued the rhea on foot for centuries. The rhea changed its habits when the hunter changed his, and now, if anestancieroputs down ostrich hunting on his estate, in a very few years the birds, although wild birds still, become as fearless and familiar as domestic animals. I have known old and ill-tempered males to become a perfect nuisance on some estancias, running after and attacking every person, whether on foot or on horseback, that ventured near them. An old instinct of a whole race could not be thus readily lost here and there on isolated estates wherever a proprietor chose to protect his birds for half a dozen years.
Fear in Birds,87
I suppose the Talegallus--the best-known brush-turkey--must be looked on as an exception to all other birds with regard to the point I am considering; for this abnormal form buries its eggs in the huge mound made by the male, and troubles herself no more about them. When the young is fully developed it simply kicks the coffin to pieces in which its mother interred it, and, burrowing its way up to the sunshine, enters on the pleasures and pains of an independent existence from earliest infancy--that is, if a species born into the world in full possession of all the wisdom of the ancients, can be said ever to know infancy. At all events, from Mr. Bartlett's observations on the young hatched in the Zoological Gardens, it appears that they took no notice of the old birds, but lived quite independently from the moment they came out of the ground, even flying up into a tree and roosting separately at night. I am not sure, however, that these observations are quite conclusive; for it is certain that captivity plays strange pranks with the instincts of some species, and it is just possible that in a state of nature the old birds exercise at first some slight parental supervision, and, like all other species, have a peculiar cry to warn the young of the dangers to be avoided. If this is not so, then the young Talegallus must fly or hide with instinctive tear from every living thing that approaches it. I, at any rate, find it hard to believe that it has a knowledge, independent of experience, of the different habits of man and kangaroo, and dis-criminates at first sight between animals that are dangerous to it and those that are not. This
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interesting point will probably never be determined, as, most unhappily, the Australians are just now zealously engaged in exterminating their most wonderful bird for the sake of its miserable flesh; and with less excuse than the Maories could plead with regard to the moa, since they cannot deny that they have mutton and rabbit enough to satisfy hunger.
Whether birds fear or have instinctive knowledge of any of their enemies is a much larger question. Species that run freely on the ground from the time of quitting the shell know their proper food, and avoid whatever is injurious. Have all young birds a similarly discriminating instinct with regard to their enemies? Darwin says, "Fear of any particular enemy is certainly an instinctive quality, as may be seen in nestling birds." Here, even man seems to be included among the enemies feared instinctively; and in another passage he says, "Young chickens have lost, wholly from habit, that fear of the dog and cat which, no doubt, was originally instinctive in them." My own observations point to a contrary conclusion; and I may say that I have had unrivalled opportunities for studying the habits of young birds.
Animals of all classes, old and young, shrink with instinctive fear from any strange object approaching them. A piece of newspaper carried accidentally by the wind is as great an object of terror to an inexperienced young bird as a buzzard sweeping down with death in its talons. Among birds not yet able to fly there are, however, some curious exceptions; thus the young of most owls and
Fear in Birds.89
pigeons are excited to anger rather than fear, and, puffing themselves up, snap and strike at an intruder with their beaks. Other fledglings simply shrink down in the nest or squat close on the ground, their fear, apparently, being in proportion to the suddenness with which the strange animal or object comes on them; but, if the deadliest enemy approaches with slow caution, as snakes do--and snakes must be very ancient enemies to birds--there is no fear or suspicion shown, even when the enemy is in full view and about to strike. This, it will be understood, is when no warning-cry is uttered by the parent bird. This shrinking, and, in some cases, hiding from an object corning swiftly towards them, is the "wildness"of young birds, which, Darwin says again, is greater in wild than in domestic species. Of the extreme tameness of the young rhea I have already spoken; I have also observed young tinamous, plovers, coots, &c., hatched by fowls, and found them as incapable of distinguishing friend from foe as the young of domestic birds. The only difference between the young of wild and tame is that the former are, as a rule, much more sprightly and active. But there are many exceptions; and if this greater alertness and activity is what is meant by "wildness," then the young of some wild birds--rhea, crested screamer, &c.--are actually much tamer than our newly-hatched chickens and ducklings.
To return to what may be seen in nestling birds, n very young, and before their education has begun, if quietly approached and touched, they open their bills and take food as readily from a man
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as from the parent bird. But if while being thus fed the parent returns and emits the warning note, they instantly cease their hunger-cries, close their gaping mouths, and crouch down frightened in the nest. This fear caused by the parent bird's warning note begins to manifest itself even before the young are hatched--and my observations on this point refer to several species in three widely separated orders. When the little prisoner is hammering at its shell, and uttering its feeblepeep,as if begging to be let out, if the warning note is uttered, even at a considerable distance, the strokes and complaining instantly cease, and the chick will then remain quiescent in the shell for a long time, or until the parent, by a changed note, conveys to it an intimation that the danger is over. Another proof that the nestling has absolutely no instinctive knowledge of particular enemies, but is taught to fear them by the parents, is to be found in the striking contrast between the habits of parasitical and genuine young in the nest, and after they have left it, while still unable to find their own food. I have had no opportunities of observing the habits of the young cuckoo in England with regard to this point, and do not know whether other observers have paid any attention to the matter or not, but I am very familiar with the manners of the parasitical starling or cow-bird of South America. The warning cries of the foster parent have no effect on the young cow-bird at any time. Until they are able to fly they will readily devour worms from the hand of a man, even when the old birds are hovering close by and screaming their danger notes, and
Fear in Birds'.91
while their own young, if the parasite has allowed any to survive in the nest, are crouching down in the greatest fear. After the cow-bird has left the nest it is still stupidly tame, and more than once I have seen one carried off from its elevated perch by a milvago hawk, when, if it had understood the warning cry of the foster parent, it would have dropped down into the bush or grass and escaped. But as soon as the young cow-birds are able to shift for themselves, and begin to associate with their own kind, their habits change, and they become suspicious and wild like other birds.
On this point--the later period at which the parasitical young bird acquires fear of man--and also bearing on the whole subject under discussion, I shall add here some observations I once made on a dove hatched and reared by a pigeon at my home on the pampas. A very large ombú tree grew not far from the dove-cote, and some of the pigeons used to make their nests on the lower horizontal branches. One summer a dove of the most common species, Zenaida maculata, in size a third less than the domestic pigeon, chanced to drop an egg in one of these nests, and a young dove was hatched and reared; and, in due time, when able to fly, it was brought to the dove-cote. I watched it a great deal, and it was evident that this foster-young, though' with the pigeons, was not nor ever would be of them, for it could not take kiudly to their flippant flirty ways. Whenever a male approached it, and with guttural noises and strange gestures made a pompous declaration of amorous feelings, the dove would strike vigorously at its undesirable lover,
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and drive him off, big as he was; and, as a rule, it would sit apart, afoot or so, from the others. The dove was also a male; but its male companions, with instinct tainted by domestication, were ignorant alike of its sex and different species. Now, it chanced that my pigeons, never being fed and always finding their own living on the plain like wild birds, were, although still domestic, not nearly so tame as pigeons usually are in England. They would not allow a person to approach within two or three yards of them without flying, and if grain was thrown to them they would come to it very suspiciously, or not at all. And, of course, the young pigeons always acquired the exact degree of suspicion shown by the adults as soon as they were able to fly and consort with the others. But the foundling Zenaida did not know what their startled gestures and notes of fear meant when a person approached too near, and as he saw none of his own kind, he did not acquire their suspicious habit. On the contrary, he was perfectly tame, although by parentage a wild bird, and showed no more fear of a man than of a horse. Throughout the winter it remained with the pigeons, going afield every day with them, and returning to the dove-cote; but as spring approached the slight tie which united him to them began to be loosened; their company grew less and less congenial, and he began to lead a solitary life. But he did not go to the trees yet. He came to the house, and his favourite perch was on the low overhanging roof of a vine-covered porch, just over the main entrance. Here he would pass several hours every day, taking no notice of the
Fear in Birds.93
people passing in and out at all times; and when the weather grew warm he would swell out his breast and coo mournfully by the hour for our pleasure.
We can, no doubt, learn best by observing the behaviour of nestlings and young birds; nevertheless, I find much even in the confirmed habits of adults to strengthen me in the belief that fear of particular enemies is in nearly all cases--for I will not say all--the result of experience and tradition.
Hawks are the most open, violent, and persistent enemies birds have; and it is really wonderful to see how well the persecuted kinds appear to know the power for mischief possessed by different raptorial species, and how exactly the amount of alarm exhibited is in proportion to the extent of the danger to be apprehended. Some raptors never attack birds, others only occasionally; still others prey only on the young and feeble; and, speaking of La Plata district, where I have observed hawks, from the milvago chimango--chiefly a carrion-eater--to the destructive peregrine falcon, there is a very great variety of predatory habits, and all degrees of courage to be found; yet all these raptors are treated differently by species liable to be preyed on, and have just as much respect paid them as their strength and daring entitles them to, and no more, So much discrimination must seem almost incredible to those who are not very familiar with the manners of wild birds; I do not think it could exist if the fear shown resulted from instinct or inherited habit. There would be no end to the blunders of
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such an instinct as that; and in regions where hawks are extremely abundant most of the birds would be in a constant state of trepidation. On the pampas the appearance of the comparatively harmless chimango excites not the least alarm among small birds, yet at a distance it closely resembles a henharrier, and it also readily attacks young, sick, and wounded birds; all others know how little they have to fear from it. When it appears unexpectedly, sweeping over a hedge or grove with a rapid flight, it is sometimes mistaken for a more dangerous species; there is then a little flutter of alarm, some birds springing into the air, but in two or three seconds of time they discover their mistake, and settle down quietly again, taking no further notice of the despised carrion-eater. On the other hand, I have frequently mistaken a harrier (Circus cinereus, in the brown state of plumage) for a chimango, and have only discovered my mistake by seeing the commotion among the small birds. The harrier I have mentioned, also the C. macropterus, feed partly on small birds, which they flush from the ground and strike down with their claws. When the harrier appears moving along with a loitering flight near the surface, it is everywhere attended by a little whirlwind of alarm, small birds screaming or chirping excitedly and diving into the grass or bushes; but the alarm does not spread far, and subsides as soon as the hawk has passed on its way. Buzzards (Buteo and Urubitinga) are much more feared, and create a more widespread alarm, and they ars certainly more destructive to birds than harriers. Another curious instance is that of the sociable
Fear in Birds.95
hawk (Rostrhanrus sociabilis). This bird spends the summer and breeds in marshes in La Plata, and birds pay no attention to it, for it feeds exclusively on water-snails (Ampullaria). But when it visits woods and plantations to roost, during migration, its appearance creates as much alarm as that of a true buzzard, which it closely resembles. Wood-birds, unaccustomed to see it, do not know its peculiar preying habits, and how little they need fear its presence. I may also mention that the birds of La Plata seem to fear the kite-like Elanus less than other hawks, and I believe that its singular resemblance to the common gull of the district in its size, snowy-white plumage and manner of flight, has a deceptive effect on most species, and makes them so little suspicious of it.
The wide-ranging peregrine falcon is a common species in La Plata, although, oddly enough, not included in any notice of the avifauna of that region before 1888. The consternation caused among birds by its appearance is vastly greater than that produced by any of the raptors I have mentioned: and it is unquestionably very much more destructive to birds, since it preys exclusively on them, and, as a rule, merely picks the flesh from the head and neck, and leaves the untouched body to its jackal, the carrion-hawk. When the peregrine appears speeding through the air in a straight line at a great height, the feathered world, as far as one able to see, is thrown into the greatest commo-tion, all birds, from the smallest up to species large as duck, ibis, and curlew, rushing about in the air as if distracted. When the falcon has disappeared
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in the sky, and the wave of terror attending its progress subsides behind it, the birds still continue wild and excited for some time, showing how deeply they have been moved; for, as a rule, fear is exceedingly transitory in its effects on animals.
I must, before concluding this part of my subject, mention another raptor, also a true falcon, but differing from the peregrine in being exclusively a marsh-hawk. In size it is nearly a third less than the male peregrine, which it resembles in its sharp wings and manner of flight, but its flight is much more rapid. The whole plumage, is uniformly of a dark grey colour. Unfortunately, though I have observed it not fewer than a hundred times, I have never been able to procure a specimen, nor do I find that it is like any American falcon already described; so that for the present it must remain nameless. Judging solely from the effect produced by the appearance of this hawk, it must be even more daring and destructive than its larger relation, the peregrine. It flies at a great height, and sometimes descends vertically and with extraordinary velocity, the wings producing a sound like a deep-toned horn. The sound is doubtless produced at will, and is certainly less advantageous to the hawk than to the birds it pursues. No doubt it can afford to despise the wing-power of its quarry; and I have sometimes thought that it takes a tyrannous delight in witnessing the consternation caused by its hollow trumpeting sound. This may be only a fancy, but some hawks do certainly take pleasure in pursuing and striking birds when not seeking prey. The
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peregrine has been observed, Baird says, capturing birds, only to kill and drop them. Many of the Felidae, we know, evince a similar habit; only these prolong their pleasure by practising a more refined and deliberate cruelty.
The sudden appearance overhead of this hawk produces an effect wonderful to witness. I have frequently seen all the inhabitants of a marsh struck with panic, acting as if demented, and suddenly grown careless to all other dangers; and on such occasions I have looked up confident of seeing the sharp-winged death, suspended above them in the sky. All birds that happen to be on the wing drop down as if shot into the reeds or water; ducks away from the margin stretch out their necks horizontally and drag their bodies, as if wounded, into closer cover; not one bird is found bold enough to rise up and wheel about the marauder--a usual proceeding in the case of other hawks; while, at every sudden stoop the falcon makes, threatening to dash down on his prey, a low cry of terror rises from the birds beneath; a sound expressive of an emotion so contagious that it quickly runs like a murmur all over the marsh, as if a gust of wind had swept moaning through, the rushes. As long as the falcon hangs overhead, always at a height of about forty yards, threatening at intervals to dash down, this murmuring sound, made up of many hundreds of individual cries, is heard swelling and dying away, and occasionally, when he drops lower than usual, rising to a sharp scream of terror.
Sometimes when I have been riding over marshy
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ground, one of these hawks has placed himself directly over my head, within fifteen or twenty yards of me; and it has perhaps acquired the habit of following a horseman in this way in order to strike at any birds driven up. On one occasion my horse almost trod on a couple of snipe squatting terrified in the short grass. The instant they rose the hawk struck at one, the end of his wing violently smiting my cheek as he stooped, and striking at the snipe on a level with the knees of my horse. The snipe escaped by diving under the bridle, and immediately dropped down on the other side of me, and the hawk, rising up, flew away.
To return. I think I am justified in believing that fear of hawks, like fear of men, is, in very nearly all cases, the result of experience and tradition. Nevertheless, I think it probable that in some species which have always lived in the open, continually exposed to attack, and which are preferred as food by raptors, such as duck, snipe, and plover, the fear of the falcon may be an inherited habit. Among passerine birds I am also inclined to think that swallows show inherited fear of hawks. Swallows and humming-birds have least to fear from raptors; yet, while humming-birds readily pursue and tease hawks, thinking as little of them as of pigeons or herons, swallows everywhere manifest the greatest terror at the approach of a true falcon; and they also fear other birds of prey, though in a much less degree. It has been said that the European hobby occasionally catches swal-lows on the wing, but this seems a rare and exceptional habit, and in South America I have
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never seen any bird of prey attempt the pursuit of a swallow. The question then arises, how did this unnecessary fear, so universal in swallows, originate? Can it be a survival of a far past--a time when some wide-ranging small falcon, aerial in habits as the swallow itself, preyed by preference on hirundines only?
[NOTE.-Herbert Spencer, who accepts Darwin's inference, explains how the fear of man, acquired by experience, becomes instinctive in birds, in the following passage: "It is well known that in newly-discovered lands not inhabited by man, birds are so devoid offear as to allow themselves to be knocked over with sticks; but that, in the course of generations, they acquire such a dread ofman as to fly on his approach: and that this dread is manifested by young as well as by old. Now unless this change be
ascribed to the killing-off of the least fearful, and the preservation and multiplication of the most fearful which, considering the comparatively small number killed by man, is an inadequate cause, it must be ascribed to accumulated experience; and each experience must be held to have a share in producing it. We
must conclude that in each bird that escapes with injuries inflicted by man, or is alarmed by the outcries of other members of the flock (gregarious creatures of any intelligence being necessarily more or less sympathetic), there is established an association of ideas between the human aspect and the pains, direct and in-direct, suffered from human agency. And we must further con-clude, that the state of consciousness which compels the bird to take flight, is at first nothing more than an ideal reproduction of
those painful impressions which before followed man's approach; that such ideal reproduction becomes more vivid and more massive as the painful experiences, direct or sympathetic, increase;and that thus the emotion, in its incipient state, is nothing else than
an aggregation of the revived pains before experience.
"As, in the course of generations, the young birds of this race begin to display a fear of man before yet they have been injured by him, it is an unavoidable inference that the nervous system of the race has been organically modified by these experiences, we have no choice but to conclude, that when a young bird is led
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to fly, it is because the impression produced in its senses by the approaching man entails, through an incipiently reflex action, a partial excitement of all those nerves which in its ancestors had been excited under the like conditions; that this partial excitement has its accompanying painful consciousness, and that the vague painful consciousness thus arising constitutes emotion proper--emotion undecomposable into specific experiences, and, therefore, seemingly homogeneous"(Essays, vol. i. p. 320.)
It is comforting to know that the "unavoidable inference" is, after all, erroneous, and that the nervous system in birds has not yet been organically altered as a result of man's persecution; for in that case it would take long to undo the mischief, and we should be indeed far from that "better friendship" with the children of the air which many of us would like to see.
CHAPTER VI.
PARENTAL AND EARLY INSTINCTS.
UNDER this heading I have put together several notes from my journals on subjects which have no connection with each other, except that they relate chiefly to the parental instincts of some animals I have observed, and to the instincts of the young at a very early period of life.
While taking bats one day in December, I captured a female of our common Buenos Ayrean species (Molossus bonariensis), with her two young attached to her, so large that it seemed incredible she should be able to fly and take insects with such a weight to drag her down. The young were about a third less in size than the mother, so that she had to carry a weight greatly exceeding that of her own body. They were fastened to her breast and belly, one on each side, as when first born; and, possibly, the young bat does not change its position, or move, like the young developed opossum, to other parts of the body, until mature enough to begin an independent life. On forcibly separating them from their parent, I found that they were not yet able to fly, but when set free fluttered feebly to the ground. This bat certainly appeared more burdened with its young
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than any animal I had ever observed. I have seen an old female opossum (Didelphys azarae) with eleven young, large as old rats--the mother being less than a cat in size--all clinging to various parts of her body; yet able to climb swiftly and with the greatest agility in the higher branches of a tree. The actual weight was in this case rela-