The Industries of Animals.
by Frederic Houssay.
THE INDUSTRIES OF ANIMALS.CHAPTER I.
INTRODUCTION.
THE NATURALISTS OF YESTERDAY AND THE NATURALISTS OF TO-DAY--NATURAL HISTORY AND THE NATURAL SCIENCES--THE THEORY OF EVOLUTION--THE CHIEF INDUSTRIES OF MAN--THE CHIEF INDUSTRIES OF ANIMALS--INTELLIGENCE AND INSTINCT--INSTINCTIVE ACTIONS ORIGINATE IN REFLECTIVE ACTIONS--THE PLAN OF STUDY OF THE VARIOUS INDUSTRIES.
The naturalists of yesterday and the naturalists of to-day.--The study of animals, plants, rocks, and of natural objects generally, was formerly called "natural history"; but this term is tending to disappear from our vocabulary and to give place to the term "natural sciences." What is the reason of this change, and to what does it correspond? for it is rare for a word to be modified in so short a time if the thing designated has not itself varied.
Exterior forms have certainly changed, and the naturalist of yesterday makes upon us the impression of a legendary being. I refer to the person described in George Sand"s romances, marching vigorously over hills and valleys in search of a rare insect, which he p.r.i.c.ked with delight, or of a plant difficult to reach, which he triumphantly dried and fixed on a leaf of paper bearing the date of the discovery and the name of the locality. A herbarium became a sort of journal, recalling to its fortunate possessor all the wanderings of the happy chase, all the delightful sounds and sights of the country. Every naturalist concealed within him a lover of idylls or eclogues. a.s.suredly all the preliminary studies which resulted from these excursions were necessary; we owe grat.i.tude to our predecessors, and we profit from their labours, sometimes regretting the loss of the picturesque fashion in which their researches were carried out.
The naturalist of to-day usually lives more in the laboratory than in the country.
Occasional expeditions to the coast or dredgings are the only links that attach him to nature; the scalpel and the microtome have replaced the collector"s pins, and the magnifying gla.s.s gives place to the microscope. When the observer begins to pursue his studies in the laboratory he no longer cares to pa.s.s the threshold. He has still so much to learn concerning the most common creatures that it seems useless to him to waste his time in seeking those that are rarer, unless he takes into account the unquestionable pleasure of rambling throughwoods or along coasts;--but such a consideration does not belong to the scientific domain.
A change of conditions of this nature does not suffice to create a science. To take away from a study all that rendered it pleasant and easy, and to make it the property of a small coterie, when it was formerly accessible to all, is not sufficient to render it scientific. It is a fatality rather than a triumph to have undergone such a change. The change is an effect rather than a cause.
When little or nothing was known it was necessary to begin by examining the phenomena which first met the eyes of the observer, such as the customs of animals and the characters which distinguished them from each other. Their differences and resemblances were studied; they were formed into groups, cla.s.sed and arranged in an order recalling as much as possible their natural relations. In cla.s.sifying it is impossible to consider all the facts or the result would be chaos; it is necessary to choose the characters and to give preponderance to certain of them. This sorting of characters has been executed with the sagacity of genius by the ill.u.s.trious naturalists of the last century and the beginning of the present. But the frames which they have traced are fixed and rigid; nature with her infinite plasticity escapes from them. We render a great homage to the cla.s.sifiers when we say that they have confined the facts as closely as it is possible to do. The catalogues which they have prepared are of a utility which is unquestionable, although their role is to be useful only; we cannot pretend to make them the expression, the symbol, the formula in which all natural phenomena are to be enclosed. To confound cla.s.sification with science is to confound the lever with the effect which we expect from it.
Curiosity, moreover, always impels towards that which is least known. External appearances having been studied, the form and function of internal organs were investigated. Physiology and comparative anatomy were born and developed; researches abounded and observers abandoned the field for the laboratory.
The difference in methods of research and the pushing of precision to its extreme limits--an inevitable result of the different nature of the observations to be made--did not however yet render legitimate the claim for natural studies to be called "science."
Natural history and the natural sciences.--A more important event has taken place. The ancient naturalists, like their contemporaries, had firm beliefs whichthey used as unquestionable principles for the comprehension of all facts. The explanation of an observation was ready in advance. The study of facts invariably brought to the pen of the writer the same enthusiastic admiration of the marvellous part played by Providence in nature.[1] The phenomena in which this action was not strikingly apparent were merely described without any attempt to relate them with each other, or with the other facts. A hypothesis which left a great number of facts without explanation was necessarily insufficient. The descriptions, in spite of all their individual interest, did not const.i.tute a h.o.m.ogeneous whole, a science. They were merely a collection of more or less natural histories.
[1] See, for example, Reaumur, Memoires pour l"histoire des Insectes, t. i., pp.
23-25.
Science only begins on the day when we have found the simple theory which binds together all the facts at that time known, without of course prejudicing the future. As the number of acquired facts increases, if the theory in question continues to explain the new as it explained the old, the science becomes more firmly established. If we can imagine a time arriving when all the possible phenomena are known, and the existing hypothesis still explains them, nothing henceforth can overturn it, the science is completed. That is the simple case in which a theory has been victorious; but if it is contradicted by a single well-authenticated fact it must fall or become modified. The more things a theory explains in the present the more chance it has of success in the future. It is still only a matter of chances, for the theory is always at the mercy of unforeseen observation, which may rudely overthrow it.
There is no theory which must not be modified constantly, at least in its details.
To render it more and more general by successive improvements is the aim to be pursued. A collection of studies const.i.tutes a science when a hypothesis has arisen already sufficiently strong to oblige us to refer to it all new acquisitions, and to compel us to see if they fortify or oppose it.
It would indeed be a narrow conception if we were to consider as scientific the partisans of the theory alone; more than anywhere else discussion is fruitful in the natural sciences; and if it is necessary to be constantly preoccupied with the general ideas of the day, it is not at all necessary to adhere to them servilely. The naturalists of to-day are in possession of a formula with which we must always preoccupy ourselves; in other words, there are natural sciences.The theory of Evolution.--This hypothesis which comes before all others is the theory of evolution. This is not the place to expound it, to go over the proofs which have been ama.s.sed to build it up, nor the criticisms which have been directed against it. It has to-day come out of the struggle victoriously. A prodigious quant.i.ty of facts, of comparative anatomy and of embryology, inexplicable without it, emerge from the chaos and const.i.tute a whole, truly and marvellously h.o.m.ogeneous. Issued from the natural sciences, the doctrine of evolution now overflows them and tends to embrace everything that concerns man: history, sociology, political economy, psychology. The moralists seek, and will surely find, compromises permitting ethical laws to endure the rule of this overwhelming hypothesis.
Without going too far back into history, let us look towards the end of the last century and the beginning of this. Cuvier, Lamarck,[2] and Geoffroy Saint-Hilaire,[3] all preoccupied with general ideas, were each trying to build up a doctrine. The theory of evolution was born beneath the pen of Lamarck, but immediately fell under the attacks of Cuvier.[4] It is to Darwin that the honour belongs of having rescued it from oblivion and of having initiated the movement which to-day rules the natural sciences. Studies in embryology and anatomy are rising without number beneath this impulse; and perhaps it may be said that these new sciences, so fruitful in results, absorb a little too much attention and leave in the shade subjects longer known, but which, however, gain new interest by the way they fit into present scientific theories.
[2] Philosophie zoologique, 2e edition, Paris, 1830; Histoire des Animaux sans Vertebres, Introduction, 1835.
[3] Philosophie anatomique, 1818; Zoologie generale, 1841.
[4] Le Regne Animal, 1829; Lecons d"Anatomie comparee, 2e edition, 1835-46.
I wish to speak of the manners of animals; the facts regarding them are of sufficient interest if we consider them one by one, and they become much more interesting when we attempt to show the close way in which they are bound together. Volumes would not suffice to exhaust the subject; but if the entire task is too considerable, I may at least hope to accomplish a part of it by treating of those facts which may be brought together under the common t.i.tle of Animal Industries. Taken separately, they may be reproached with a certain anecdotal character, but we cannot fail to agree that taken altogether they const.i.tute animportant chapter in the sciences of life.
The chief industries of Man.--Let us first throw a rapid glance at the various stages which the civilisation and industry of Man have gone through before arriving at their present condition. To make clear these phases we might either follow the state of civilisation in any given country by tracing back the course of centuries, or else at a given epoch find out in different parts of the earth all the stages of human evolution. The savage men of to-day are not further advanced in their evolution than our own ancestors who have now gone to fossil. However it may be, Man, at first frugivorous, as his dent.i.tion shows as well as his zoological affinities, in consequence of a famine of fruit or from whatever other cause, gradually began to nourish himself with the flesh of other animals. To search for this fleeing prey developed in him the art of hunting and fishing. His intelligence, still feeble, was entirely concentrated on this one point: to seize on an animal and to feed on it, although neither his nails nor his teeth nor his muscles make it natural to him. To hunt, to fish, to defend his territory against the wild beasts who attacked it and himself, to drive back tribes of his fellows who would diminish his provisions, these were the first rudiments of the industry of Man. Having become more skilful, he obtained in an expedition more game than he could consume at once; he then kept near him living beasts in order to sacrifice them when hunger came. His reserve of animals increased; they became accustomed to live near him; and he took care of his larder. A flock was gradually const.i.tuted, and the owner learnt to profit from all the resources which it offered him, from milk to wool. Henceforth he became economical with his beasts, and moved about in order to procure for them abundance of gra.s.s and water. He was still always hunting and fighting; but there were now accessory industries, and he was especially occupied in the domestication of animals. Then it happened that he acquired a taste for a graminaceous grain--corn. To seek the blades one by one is not a very fruitful labour, and decidedly troublesome. Man collected a supply of them, cultivated them, possessed fields which he sowed and harvested. He was henceforth obliged to renounce his herds, which had become immense; for he could not leave the soil where his corn was ripening, if he wished to gather it himself, and his cattle were lacking pasture. The number of beasts diminished; bread had killed milk. Man only kept near him a small flock capable of feeding on a moderate territory. He abandoned his temporary shelters, tents of skin or of woven wool, and since he must henceforth live on the same piece of land, he constructed there a fixed dwelling. Such is, taken altogether, the genesis of the industry of the dwelling connected with the culture of the soil; to earlier periods corresponded the natural or hollowed cave and the woven tent.The chief industries of Animals.--In a more or less perfect degree we find the same industries among animals generally. In order to make just comparisons, we ought especially to consider the methods of those who are not endowed with specially appropriated organs, for in this case their task is rendered too simple.
To take an example. The Lion is certainly an incomparable hunter; but his whole organisation tends to facilitate the capture of living prey. His agility and the strength of his muscles enable him to seize it at the first leap before it can escape. With his sharp claws he holds it; his teeth are so keen and his jaw so strong that he kills it immediately; with such natural advantages what need has he of ingenuity? But in the case of the Wolf or the Fox it is quite another matter; they hunt with a veritable art which Man himself has not disdained, since he has taken as his a.s.sociate their relative, the Dog. It is the same with the Eagle and the Crow. The latter, in order to seize the prey which he desires, needs much more varied resources than the great bird of rapine for whom nature has done everything.
We find among animals not only hunting and fishing but the art of storing in barns, of domesticating various species, of harvesting and reaping--the rudiments of the chief human industries. Certain animals in order to shelter themselves take advantage of natural caverns in the same way as many races of primitive men.
Others, like the Fox and the Rodents, dig out dwellings in the earth; even to-day there are regions where Man does not act otherwise, preparing himself a lodging by excavations in the chalk or the tufa. Woven dwellings, constructed with materials entangled in one another, like the nests of birds, proceed from the same method of manufacture as the woollen stuffs of which nomad tribes make their tents. The Termites who construct vast dwellings of clay, the Beavers who build huts of wood and of mud, have in this industry reached the same point as Man. They do not build so well, no doubt, nor in so complex a fashion as modern architects and engineers, but they work in the same way. All these ingenious artisans operate without organs specially adapted to accomplish the effect which they reach. It is with such genuine industries that we have to deal, for the most part neglecting other productions, more marvellous in certain ways, which are formed by particular organs, or are elaborated within the organism, and are not the result of the intelligent effort of the individual. To this category belong the threads which the Spider stretches, and the coc.o.o.n with which the Caterpillar surrounds himself to shelter his metamorphosis.
Intelligence and instinct.--By attentive observation it is possible to find in animals all the intermediate stages between a deliberate reflective action and an act thathas become instinctive and so inveterate to the species that it has re-acted on its body, and thus profoundly modified it so as to produce a new organ in such a way that the phenomena are accomplished as a simple function of vegetative life, in the same way as respiration or digestion.
If an individual is led to reproduce often the same series of actions it contracts a habit; the repet.i.tion may be so frequent that the animal comes to accomplish it without knowing it; the brain no longer intervenes; the spinal cord or the chain of ganglia alone govern this order of acts, to which has been given the name of reflex actions. A reflex may be so powerful as to be transmitted by heredity to the descendants; it then becomes an instinct.
Thus by its nature instinct does not differ from intelligence, but is intimately connected with it by a chain of which all the links may be counted. The most intelligent of beings, Man, performs actions that are purely mechanical; many indeed can with justice be called instinctive; and, on the other hand, an animal for whom an innate hereditary instinct is sufficient in ordinary life will give proof of intelligence and reflection if circ.u.mstances in which his instinct is generally efficacious become modified so that he can no longer profit by them. Among other ingenious experiments to show the supposed difference between instinctive and reflective acts, Fabre brings forward the following[5]:--The Chalicodoma, a hymenopterous relative of the Bees, constructs nests composed of cells formed of mud agglutinated with saliva. The cell once constructed, the insect begins to fill it with honey before laying an egg there. He returns with his booty and wishes to disburse himself in the nest, finds the cellule which he has to fill, and proceeds always in the same order: first, he plunges his head in the cell and disgorges the honey which fills his crop; secondly, he emerges from the cell, turns round, and lets fall the pollen which remains attached to his legs. Suppose that an insect has just disgorged his honey, the observer touches his belly with a straw; the little animal, disturbed in his operation, returns to it having only the second act to perform. But he re-commences the whole of his operations though having nothing more to disgorge; he again plunges his head into the cell and goes through a pretence of disgorging, then turns round and frees himself from the pollen.
Although touched twice, thrice, or more frequently, he always repeats the first action before executing the second. It is, says Fabre, almost like the movement of a machine of which the wheelwork will not act until one has begun to turn the wheel which directs it.
[5] J. H. Fabre, Souvenirs entomologiques, Paris, 1879, pp. 275 et seq.It is incontestable; but I would add, as this conscientious observer does not, that that does not prove that the intelligence of the insect differs essentially from ours; it is a simple question of degree. Look at a boy who is going to jump over a ditch: he begins by spitting into his hands and rubbing them one against the other before taking his spring. In what has this served him? It is not more intelligent than the gesture of the bee who first plunges his head in the cell before freeing his claws, although the first gesture is useless.[6]
[6] It should perhaps be added that while the boy"s action is not consciously intelligent, it is by no means purposeless, and is therefore not quite parallel with the insect"s. By vigorously irritating the sensory nerves of the hand the boy imparts a stimulus to his muscular system. His act belongs to a large group which has been especially studied by Fere. See his Sensation et Mouvement (1887), and Pathologie des Emotions (1892).
And, from another side, if nothing is more instinctive than the manner in which domestic Bees construct their cells of wax with geometric regularity, there are other circ.u.mstances in which these same insects give proof of remarkable reflection, sagacity, and intelligence in co-ordinating their actions in the presence of an event to which they are not accustomed, and in attaining an end which has presented itself by accident. Such are, for example, the arrangements which they make to defend their honey against the attacks of a great nocturnal Moth, the Death"s Head. I shall have to revert to these facts.
We must not then regard instinct, as has often been done, as a rudiment of intelligence, susceptible or not of development; but much rather as a series of intelligent acts at first reasoned, then by their frequent repet.i.tion become habitual, reflex, and at last, by heredity, instinctive.
What the individual loses in individuality and in personal initiative, heredity restores to him in the form of instinct which is, as it were, the condensed and acc.u.mulated intelligence of his ancestors. He himself no longer needs to take thought either to preserve his life or to a.s.sure the perpetuation of his race. The qualities which he received at birth render reflection less necessary; thus species endowed with some powerful instinct seem not to be intelligent when they live sheltered from unforeseen events.
From one point of view instinct appears to be a degradation rather than a perfecting of intelligence, because the acts which proceed from it are neither sospontaneous nor so personal; but from another point of view they are much better executed, with less hesitation, with a slighter expenditure of cerebral force and a minimum of muscular effort. A habitual act costs us much less to execute than a deliberate and reflective act. It is thus that the constructions of bees are more perfect than those of ants; the former act by instinct, the latter reason their acts at each step.
Instinctive actions originate in reflective actions.--No doubt it may be said: It is a pure hypothesis thus to consider instinct as derived from intelligence; why not admit as well that instinctive acts have been such from the beginning--in other words, that species have been created such as we see them to-day? The preceding explanation, however, has the advantage of being in harmony with the general theory of evolution, which, whether true or not, so well explains the most complicated facts that for the present it must be accepted. For the rest, if it is not possible to appraise the psychic faculties possessed by the ancestors of existing animals we may at least observe certain facts which put us on the road of explanation.
An interesting member of the Hymenoptera, the Sphex, a.s.sures food for the early days of the life of its larvae in a curious way.[7] Before laying its eggs it seizes a cricket, paralyses it with two strokes of its sting--one at the articulation of the head and the neck, the other at the articulation of the first ring of the thorax with the second--each stab traversing and poisoning a nervous ganglion. The cricket is paralysed without being killed; its flesh does not putrefy, and yet it makes no movement. The Sphex places an egg on this motionless prey, and the larva which emerges from it devours the cricket. Here a.s.suredly is a marvellous and certain instinct. One cannot even object that the strokes of the sting are inevitably directed to these points because the chitinous envelope of the victim offers too much resistance in other spots for the dart to penetrate, because here is the Ammophila, a near relative of the Sphex, which chooses for its prey a caterpillar.
It is free to introduce its sting into any part of the body, and yet with extreme certainty it strikes the two ganglions already mentioned.[8]
[7] "etude sur l"Instinct et les Metamorphoses des Sphegiens," Ann. Sc. Nat., iv.
Serie, t. 6, 1856.
[8] P. Marchal, "Observations sur l"Ammophila affinis," Arch. de Zool. exper. et gener., ii. Serie, t. 10, 1892.We cannot suppose that the insect has anatomical and physiological knowledge to inform it of what it is doing. The act is distinctly instinctive, and seems imprinted by a fatality involving no possible connection with intelligence. But let us suppose that the ancestors of these Hymenoptera have thus attacked crickets and killed (not paralysed) them with one or more wounds at any point. By chance some of these insects, either in consequence of their manner of attacking the prey or from any other cause, happen to deliver their blows at the points in question. Their larvae on this account are placed in more favourable conditions than those of their relatives whom chance has less well served; they will prosper and develop sooner. They inherit this habit, which gradually becomes through the ages that which we know. It is possible; but why, it may be asked, this hypothesis, apparently gratuitous, of strokes of the sting given at random? Are there any facts which render this explanation plausible? a.s.suredly. Thus the Bembex, which especially attacks Diptera to make them the prey of its larvae, throws itself suddenly on them and kills them with one blow in any part of the body. It is unable in this way to ama.s.s in advance sufficient provision for its larvae; the corpses would putrefy. It is obliged to return from time to time bearing new pasture.[9] Again, M. Paul Marchal, taking up the study of instinct in the Cerceris ornata,[10] has shown that in this species at least of Sphegidae the stings have not so considerable an effect. This insect attacks a wild bee, the Halictus. He strikes his victim with two or three strokes of the sting beneath the thorax, but the paralysis is not definite, perhaps on account of the nature of the venom, which is not identical in all species. The tortured creature may regain life at the end of some hours. Thus the Cerceris is obliged to destroy the upper part of the neck by repeated malaxation of that part for several minutes at a time. The effect of this second act, by injuring the cerebroid ganglia, is to render impossible the return of action; moreover, it permits the aggressor to satisfy personal gluttony, and to feed on the liquids of the organism of the vanquished, which is easy, because the dorsal blood-vessel pa.s.ses at this level. It can thus satisfy a personal need while thinking of the future of the race.
[9] J. H. Fabre, Souvenirs entomologiques, pp. 225 et seq.
[10] "etude sur l"Instinct du Cerceris ornata," Archives de Zoologie experimentale, ii. Serie, t. 5, 1887.
It has been said in this connection that in such cases the sure instinct with which these species were originally endowed has been distorted, but that is to admit some degree of variation; the hypothesis of degeneration is as gratuitous as theother, and if we go so far as to risk a hypothesis, it would be better to use it to explain facts and not to entangle them.
Plan of study of the various industries.--The different industries carried on by animals may be divided into a certain number of groups. In the case of each of these categories I propose to arrange the facts in such a way as to bring forward first those animals which, having no special organs, are obliged to exercise the greatest ingenuity, and then to indicate the facts which show how variations have arisen which enable other species to accomplish these acts with marvellous ease.
We will first examine the simplest industries: hunting and fishing, those industries of which the object is the immediate search for prey; and to these may be added those which are related to them as re-action is to action--that is to say, the industries of which the effect is to provide for the immediate safety of the individual.
Then in an exposition parallel to the march of progress followed by human civilisations, we shall study among animals the art of collecting provisions, of domesticating and exploiting flocks, of reducing their fellows to slavery.
Finally, we shall investigate the series of modifications which the dwelling undergoes, and we shall see how certain species, after having constructed admirably-arranged houses, know how to make them healthy, and how to defend them against attacks from without.CHAPTER II.
HUNTING--FISHING--WARS AND EXPEDITIONS.
THE CARNIVORA MORE SKILFUL HUNTERS THAN THE HERBIVORA--DIFFERENT METHODS OF HUNTING--HUNTING IN AMBUSH--THE BAITED AMBUSH--HUNTING IN THE DWELLING OR IN THE BURROW--COURSING--STRUGGLES THAT TERMINATE THE HUNT--HUNTING WITH PROJECTILES--PARTICULAR CIRc.u.mSTANCES PUT TO PROFIT--METHODS FOR UTILISING THE CAPTURED GAME--WAR AND BRIGANDAGE--EXPEDITIONS TO ACQUIRE SLAVES--WARS OF THE ANTS.
The Carnivora more skilful hunters than the Herbivora.--The search for food has necessarily been the cause of the earliest industries among animals. It is easy to understand that the herbivora need little ingenuity in seeking nourishment; they are so superior to their prey that they can obtain it and feed on it by the sole fact of an organisation adapted to its a.s.similation. They are, it is true, at the mercy of circ.u.mstances over which they have no control, and which lead to famine. The carnivora also may have to suffer from the absence of prey, but even in the most favourable seasons, and in the regions where the animals on which they live abound, it is necessary to them to develop a special activity to obtain possession of beings who are suspicious, prompt in flight, and as fleet as themselves. Thus it is among these that we expect to find the art of hunting most cultivated; especially if we put aside the more grossly carnivorous of them, whose whole organisation is adapted for rapid and effective results.
Different methods of hunting.--Like Man, some animals hunt in ambush or by coursing; others know how to overturn the desired victim by throwing some object at it. These profit by all the exterior circ.u.mstances which are capable of frightening the game, of stunning it, and of rendering capture easy. But it is by studying each separate feature that we shall best be able to observe the close way in which these industries are related to our own. It is impossible to bring forward all the facts relating to the search for prey among animals; we can only take a few as signposts which mark the road.
Hunting in ambush.--The most rudimentary method of hunting in ambush is simply to take advantage of some favourable external circ.u.mstance to obtain concealment, and then to await the approach of the prey. Some animals placethemselves behind a tuft of gra.s.s, others thrust themselves into a thicket, or hang on to the branch of a tree in order to fall suddenly on the victim who innocently approaches the perfidious ambush. The Crocodile, as described by Sir Samuel Baker, conceals himself by his skill in plunging noiselessly. On the bank a group of birds have alighted. They search the mud for insects or worms, or simply to approach the stream to drink or bathe. In spite of his great size and robust appet.i.te the Crocodile does not disdain this slight dish; but the least noise, the least wrinkle on the surface of the water would cause the future repast to vanish.
The reptile plunges, the birds continue without suspicion to come and go.
Suddenly there emerges before them the huge open jaw armed with formidable teeth. In the moment of stupor and immobility which this unforeseen apparition produces a few imprudent birds have disappeared within the reptile"s mouth, while the others fly away. In the same sly and brutal manner he snaps up dogs, horses, oxen, and even men who come to the river to drink.
One of the most dangerous ambushes which can be met on the road by animals who resort to a spring is that prepared by the Python. This gigantic snake hangs by his tail to the branch of a tree and lets himself droop down like a long creeper.
The victim who comes within his reach is seized, enrolled, pounded in the knots which the snake forms around him. It is not necessary to multiply examples of this simple and widespread method of hunting.
Not content with utilising the natural arrangements they meet with, there are animals which construct genuine ambushes, acting thus like Man, who builds in the middle or on the edge of ponds, cabins in which to await wild ducks, or who digs in the path of a lion a hole covered with trunks of trees, at the bottom of which he may kill the beast without danger. Certain insects practise this method of hunting. The Fox, for instance, so skilful a hunter in many respects, constructs an ambush when hunting hares.[11]
[11] C. St. John, Wild Sports, etc., chap. xx.
The larva of the Tiger Beetle (Cicindela campestris) constructs a hole about the size of a feather quill, disposed vertically, and of a depth, enormous for its size, of forty centimetres. It maintains itself in this tube by arching its supple body along the walls at a height sufficient for the top of its head to be level with the surface of the soil, and to close the opening of the hole. (Fig. 1.) A little insect--an ant, a young beetle, or something similar--pa.s.ses. As soon as it begins to walk on the head of the larva, the latter letting go its hold of the wall allows itself to fall to thebottom of the trap, dragging its victim with it. In this narrow prison it is easily able to obtain the mastery over its prey, and to suck out the liquid parts.[12]
[12] Lamarck, Histoire des Animaux sans Vertebres, 2e edition, 1835, p. 676.
[Ill.u.s.tration: FIG. 1.]
The Staphilinus Caesareus acts with still greater shrewdness; not only is his pit more perfect, but he takes care to remove all traces of preceding repasts which might render the place obviously one of carnage. He chooses a stone, beneath which he hollows a cylindro-conical hole with extremely smooth walls. This hole is not to serve as a trap, that is to say that the proprietor has no intention of causing any pedestrian to roll to the bottom. It is simply a place of concealment in which he awaits the propitious moment. No creature is more patient than this insect, and no delay discourages him. As soon as some small animal approaches his hiding-place he throws himself on it impetuously, kills it, and devours it. Near his ditch he has hollowed a second of a much coa.r.s.er character, the walls of which have not been smoothed with the same care. One here sees elytra and claws piled up; they are the hard and h.o.r.n.y parts which he has not been able to eat.
The heap in this ditch is not then an alimentary store. It is the oubliette in which the Staphilinus buries the remains of his victims. If he allowed them to acc.u.mulate around his hole all pedestrians would come to fear this spot and to avoid it. It would be like the dwelling of a Polypus, which is marked by the numerous carapaces of crabs and sh.e.l.ls which strew the neighbourhood.
The ambuscade of the Ant-lion is cla.s.sic; it does not differ greatly from the others. He excavates a conical pitfall, in which he conceals himself, and seizes the unfortunate ants and other insects whom ill-chance causes to roll into it.[13]
[13] See e.g. Tennent, Ceylon, vol. i. p. 252. Also Reaumur, Memoires pour d"histoire des Insectes, t. i. p. 14, and t. vi. p. 333.
The baited ambush.--A variety of ambush which brings this method of hunting to considerable perfection lies in inciting the prey to approach the hiding-place instead of trusting to chance to bring it there. In such circ.u.mstances Man places some allurement in the neighbourhood--that is to say, one of the foods preferred by the desired victim, or at least some object which recalls the form of that food, as, for example, an artificial fly to obtain possession of certain fishes.It is curious to find that fish themselves utilise this system; it is the method adopted by the Angler and the Uranoscopus.[14] The Uranoscopus scaber lives in the Mediterranean. At the end of his lower jaw there is developed a mobile and supple filament which he is able to use with the greatest dexterity. Concealed in the mud, without moving and only allowing the end of his head to emerge, he agitates and vibrates his filament. The little fishes who prowl in the neighbourhood, delighted with the sight of this apparent worm, regarding it as a destined prey, throw themselves on to it, but before they are able to bite and recognise their error they have disappeared in the mouth of the proprietor of the bait.
[14] Lacepede, Histoire des Poissons, 1798-1803.
The Angler (Lophius piscatorius) has not usurped his rather paradoxical name.
He retires to the midst of the sea-weed and algae. On his body and all round his head he bears fringed appendages which, by their resemblance to the leaves of marine plants, aid the animal to conceal himself. The colour of his body also does not contrast with neighbouring objects. From his head arise three movable filaments formed by three spines detached from the upper fin. He makes use of the anterior one, which is the longest and most supple. Working in the same way as the Uranoscopus, the Angler agitates his three filaments, giving them as much as possible the appearance of worms, and thus attracting the little fish on which he feeds.
In these two examples we see a special organ utilised for a particular function; it is one of the intermediate cases, already referred to, between the true industries involving ingenuity and the simple phenomena due to adaptations and modifications of the body.
Hunting in the dwelling or in the burrow.--All these methods of hunting or of fishing by surprise are for the most part practised by the less agile species which cannot obtain their prey by superior fleetness. Midway between these two methods may be placed that which consists in surprising game when some circ.u.mstance has rendered it motionless. Sometimes it is sleep which places it at the mercy of the hunter, whose art in this case consists in seeking out its dwelling. Sometimes he profits by the youth of the victim, like all bird-nesters, whose aim is to eat the eggs or to devour the young while still incapable of flying.
The animals who eat birds" eggs are numerous both among mammals and reptiles, as well as among birds themselves.The Alligator of Florida and of Louisiana delights in this chase. He seeks in particular the Great Boat-Tail (Quiscalus major) which nests in the reeds at the edge of marshes and ponds. When the young have come out and are expecting from their parents the food which the chances of the hunt may delay, they do not cease chirping and calling by their cries. But the parents are not alone in hearing these appeals. They may also strike the ears of the alligator, who furtively approaches the imprudent singers. With a sudden stroke of his tail he strikes the reeds and throws into the water one or more of the hungry young ones, who are then at his mercy. (Audubon.) The animals who feed on species living in societies either seize on their prey when isolated or when all the members of the colony are united in their city. A search for the nest is necessary in the case of creatures who are very small in comparison with the hunter, as in the case of ants and the Ant-eater. But the ant-eater possesses a very long and sticky tongue, which renders the capture of these insects extremely easy; when he finds a frequented pa.s.sage it is enough to stretch out his tongue; all the ants come of their own accord and place themselves on it, and when it is sufficiently charged he withdraws it and devours them. The African Orycteropus (Fig. 2), who is also a great eater of ants and especially of termites, is equally aided by a very developed tongue; but he has less patience than the ant-eater, and he adds to this resource other proceedings which render the hunt more fruitful and enable him to obtain a very large number of insects at one time. Thanks to his keenness of scent he soon discovers an ant-path bearing the special and characteristic odour which these Hymenoptera leave behind them, and he follows the track which leads to their nest. On arriving there, without troubling himself about the scattered insects that prowl in the neighbourhood, he sets himself to penetrate into the midst of the dwelling, and with his strong claws hollows out a pa.s.sage which enables him to gain access.
On the way he pierces walls, breaks down floors, gathering here and there some fugitives, and arrives at last at the centre, in which millions of animals swarm. He then swallows them in large mouthfuls and retires, leaving behind him a desert and a ruin in the spot before occupied by a veritable palace, full of prodigious activity.
[Ill.u.s.tration: FIG. 2.]
The colonies are not only exposed to the devastations of those who feed on their members; they have other enemies in the animals who covet their stores of food.
The most inveterate robber of bees is the nocturnal Death"s Head Moth. When hehas succeeded in penetrating the hive the stings of the proprietors who throw themselves on him do not trouble him, thanks to his thick fleece of long hairs which the sting cannot penetrate; he makes his way to the cells, rips them open, gorges himself with honey, and causes such havoc that in Switzerland, in certain years when these b.u.t.terflies were abundant, numbers of hives have been found absolutely empty.[15] Many other marauders and of larger size, such as the Bear, also spread terror among these laborious insects and empty their barns. No animal is more crafty than the Raven, and the fabulist who wished to make him a dupe was obliged to oppose to him the very cunning Fox in order to render the tale fairly life-like. A great number of stories are told concerning the Raven"s cleverness, and many of them are undoubtedly true. There is no bolder robber of nests. He swallows the eggs and eats the little ones of the species who cannot defend themselves against him; he even seeks the eggs of Sea-gulls on the coast; but in this case he must use cunning, for if he is discovered it means a serious battle. On the coast also the Raven seeks to obtain possession of the Hermit-crab. This Crustacean dwells in the empty sh.e.l.ls of Gasteropods. At the least alarm he retires within this sh.e.l.l and becomes invisible, but the bird advances with so much precaution that he is often able to seize the crab before he has time to hide himself. If the raven fails he turns the sh.e.l.l over and over until the impatient crustacean allows a claw to emerge; he is then seized and immediately devoured.
[15] Huber, Nouvelles Observations sur les Abeilles, t. ii. p. 291.
If there is a question of hunting larger game like a Hare, the Raven prefers to take an ally. They start him at his burrow and pursue him flying. In spite of his proverbial rapidity the hare is scarcely able to flee more than two hundred yards.
He succ.u.mbs beneath vigorous blows on his skull from the beaks of his a.s.sailants. During winter, in the high regions of the Alps, when the soil is covered with snow, this chase is particularly fruitful for ravens. The story is told of that unfortunate hare who had hollowed out in the snow a burrow with two entrances.
Two of these birds having recognised his presence, one entered one hole in order to dislodge the hare, the other awaited him at the other opening to batter his head with blows from his beak and kill him before he had time to gain presence of mind.[16]
[16] F. von Tschudi, Les Alpes, Berne and Paris, 1859.Rooks sometimes hunt in burrows by ingeniously-concerted operations. Mr.
Bernard[17] has described the interesting way in which the Rook hunts voles or field-mice in Thuringia. His curiosity was excited by the way in which numerous rooks stood about a field cawing loudly. In a few days this was explained: the field was covered with rooks; the original a.s.semblage had been calling together a mouse-hunt, which could only be successfully carried out by a large number of birds acting in conjunction. By diligently probing the ground and blocking up the network of runs, the voles, one or more at a time, were gradually driven into a corner. The hunt was very successful, and no more voles were seen in that field during the winter.
[17] Zoologist, October 1892.
Coursing.--Other animals are not easily discouraged by the swiftness of their prey; they count on their own resistance in order to tire the game; some of them also manage their pursuit in the most intelligent way, so as to preserve their own strength while the tracked animal"s strength goes on diminishing until exhaustion and fatigue place him at their mercy.
Mammals especially, such as Dogs, Wolves, and Foxes, exercise this kind of chase; it is, exactly, the coursing which Man has merely had to direct for his own benefit. Wild dogs pursue their prey united in immense packs. They excite each other by barking while they frighten the game and half paralyse his efforts. No animal is agile and strong enough to be sure of escaping. They surround him and cut off his retreat in a most skilful manner; Gazelles and Antelopes, in spite of their extreme nimbleness and speed, are caught at last; Boars are rapidly driven into a corner; their vigorous defence may cost the life of some of the a.s.sailants, but they nevertheless become the prey of the band who rush on to the quarry. In Asia wild dogs do not fear even to attack the tiger. Many no doubt are crushed by a blow of the animal"s paw or strangled in his jaws, but the death of comrades does not destroy either the courage or the greediness of the surviving aggressors. Their number also is such that the great beast, covered by agile enemies who cling to him and wound him in every part, must at last succ.u.mb.
Wolves hunt also in considerable bands. Their audacity, especially when pressed by hunger in the bad season, is well known. In time of war they follow armies, to attack stragglers and to devour the dead. In Siberia they pursue sledges on the snow with terrible perseverance, and the pack is not delayed by the ma.s.sacre of those who are shot. A few stop to devour at once their fallen comrades, while theothers continue the pursuit.
Besides these brutal chases wolves seem able to exercise a genuine feint.
Sometimes it is a couple who hunt in concert. If they meet a flock, as they are well aware that the dog will bravely defend the animals entrusted to him, that he is vigilant, and that his keen scent will bring him on them much sooner than the shepherd, it is with him that they first occupy themselves. The two wolves approach secretly; then suddenly one of them unmasks and attracts the attention of the dog, who rushes after him with such ardour that he fails to perceive that in the meantime the second thief has seized the sheep and dragged it into the wood. The dog finally renounces his pursuit of the fugitive and returns to his flock.
Then the two confederates join each other and share the prey. In other circ.u.mstances it is a wolf who hunts with his female. When they wish to obtain possession of a deer, whose robust flight may last a long time, one of the couple, the male for example, pursues him and directs his chase in such a way that the game must pa.s.s by a place where the female wolf is concealed. She then takes up the chase while the male reposes. It is an organised system of relays. The strength of the deer becomes necessarily exhausted; he cannot resist the animation shown by his active foe, and is seized and killed. Then the other wolf calmly approaches the place of the feast to share his part of the booty.
The small but bold Hawk called the Merlin also courses in relays in exactly the same manner. These birds pursue a Lark or a Swallow in the most systematic manner. First one Merlin chases the bird for a short time, while his companion hovers quietly at hand; then the latter relieves his fellow-hunter, who rests in his turn. The victim is soon tired out and caught in mid-air by one of the Merlins, who flies away with him, leaving his companion to hunt alone, while he feeds the young brood.[18]
[18] C. St. John, Wild Sports and Natural History of the Highlands, chap. xi.