Chapter V: THE BIOLOGICAL TYPE. In some ways the most important scientific (9)

Quite different from such wanderings are the expeditions made by mammals to secure a temporary betterment. These are probably undertaken, if not by all species, at least by representatives of every family in the class; they vary in duration and distance, and may even have the character of true migrations, but they always come to an end after a certain time, and the wanderer ultimately returns to his original place of abode. The intention or hope of reaching better grazing or hunting grounds, the desire to profit by some casual opportunity for making life more comfortable, may be said to be the chief motive of such expeditions. They take place all the year round, in every latitude and longitude, even in districts where the conditions of life do not vary materially at different times. The mammal begins and ends them either alone or in bands, companies or herds, according as it is wont to live with its fellows; it follows the same routes with more or less regularity, and appears at certain places at approximately the same time, yet it is always guided by chance circumstances.

When the fruits of the sacred fig and other trees surrounding the temples of the Hindoos are beginning to ripen, the Brahmins who tend temple and trees await with unctuous devotion the arrival of their four-footed gods. And not in vain, for the two divinities, Hulman and Bunder, two species of monkey, unfailingly appear to strip the luscious fruits from the trees piously planted and tended for their benefit, and also to rob and plunder in the neighbouring fields and gardens as long as it is worth while. Then they disappear again, to the sorrow of their worshippers and the joy of the other inhabitants of India, whose possessions they have ravaged, as they gathered in their spoils in their usual ruthless fashion. In Central Africa, when the chief cereal of that country, the dhurra or Kaffir-millet, comes to maturity, a dignified and inventive baboon, tried and experienced in all the critical situations of life, leads down the flock of which, as leader, he is justifiably proud, to see whether Cousin Man has been good enough to sow the nutritive grain for him this year also. Or, about the same time, a band of long-tailed monkeys, under not less excellent leadership, approaches the edge of the forest in order not to miss the right moment for a profitable, and, as far as possible, undisturbed ravaging of the fields. When the golden orange glows among the dark foliage in South American plantations, the capuchin monkeys make their appearance, often from a great distance, to share the fruit with the owner. Other plant-eaters too are led by the hope of gaining an easier livelihood into regions and districts which they usually avoid; insectivores periodically follow the insects when they are for the time abundant at this place or that, and large beasts of prey keep in the wake of herbivorous mammals, especially of the herds belonging to man. The lion journeys from place to place, following the wandering herdsmen on the steppes of Africa; Russian wolves followed close on the retreat of Napoleon’s defeated army, pursuing the unfortunate fugitives as far as the middle of Germany. Otters undertake land journeys to get from one river-basin to another; lynxes and wolves in winter often traverse very wide stretches of country. Such journeys bring about a change of residence, but they do not constitute a migration in the true sense of the word. It is only exceptionally, too, that they are undertaken from real necessity, which we must look upon as the cause of all true migrations; in most cases they are undertaken simply to gratify a passing desire.

Quite otherwise is it with those mammals which, every year about the same time, leave their habitat for some other region often far distant, from which at a definite time they will return to their former abode. These migrate; for they do not seize a chance opportunity, but obey, consciously or unconsciously, a compelling necessity.

The fundamental cause of all true migration among mammals, is some very distinct and decided seasonal change. In countries of everlasting spring true migrations do not take place, for want is never imminent. Summer must contrast with winter, whether the latter bring frost and snow, or heat and drought; scarcity must alternate with superfluity before the sluggish mammal makes up its mind to migrate.

To a slight extent migrations take place among all mountain animals. The chamois, the steinbock, the Alpine hare, the marmot all migrate when the snow begins to melt, or a little later; they clamber over hillsides and glaciers to the heights above, where the pasturage, now laid bare, promises rich and abundant nourishment, and they return to the lower slopes of the mountain before winter sets in. The bear, by nature omnivorous, by habit a thief, undertakes a similar migration at the same season, and completes it before winter sets in,--at least so it is in the mountains of Siberia; the various wild cats and dogs which live among the mountains do the same. Such changes of residence occur also on the mountains of southern countries, even of those lying within the tropics. In India and Africa certain species of monkey ascend and descend the mountains at regular intervals; elephants seek the high grounds on the approach of summer, the low grounds in winter; on the Andes in South America the guanacos flee before the snow into the valleys, and before the summer-heat to the shoulders of the mountains. All these migrations are confined by the mountains within comparatively narrow limits. They only involve a change of altitude of from three to nine thousand feet, or a journey which may be accomplished in a few hours, or, at most, in a few days. They have, however, the regularity characteristic of true migrations, especially in the precise periodicity of their occurrence, and not less in the constant choice of the same routes.

Highlands and plain, sea and air, offer a much wider field than the mountains, and therefore the migrations of the animals inhabiting, or temporarily traversing these can be more easily observed, and they are more appropriately termed migratory animals than the dwellers among the mountains. In the tundras of Russia and Siberia, the reindeer, which, in Scandinavia, never leaves the mountains, migrates to a great distance every autumn and returns the following spring to his former summer haunts.[57] About the same time it leaves Greenland, and, crossing the sea on a bridge of ice, reaches the continent of America, where it spends the whole winter, only returning to the hills of its native peninsula the following April. In both cases, dread of the approaching winter does not seem to be the sole cause of migration; there is at the same time a further incentive supplied by a plague much feared in the far north. For the short summer on these expanses calls to life an insect-world poor in species, but endlessly rich in individuals, particularly an indescribable number of mosquitoes and bot-flies, which make life a burden to the reindeer, as well as to man. To escape these the reindeer forsakes the marshy tundra, over which dense clouds of mosquitoes hover during summer, and hies to where the scourge is less severely felt--to the Alpine heights, which, in the summer season afford their most fragrant pasturage. From inherited habit, the reindeer migrate not only at the same time, but along the same paths, thus forming tracks which may be distinctly traced, traversing the tundra for many miles, and crossing streams and rivers at definite places. At the beginning of the journey, the cows with their calves arrange themselves in herds of from ten to a hundred, and precede the young stags and hinds, which are followed again by the old stags. One troop follows directly behind another, and the observer can count thousands as they pass. All hurry incessantly on, turning aside neither for the mountains nor the broad streams which cross their path, and resting only when they have reached their winter-quarters. Packs of wolves, bears, and gluttons follow close on their heels and often pursue them no small part of the way. In spring, on the return journey, the animals keep to the same order, but the herds are much smaller, and they travel in a much more leisurely fashion, and keep less strictly to the paths by which they went.

Journeys still longer than those of the reindeer are taken by the American bison, the “buffalo” of the prairies.[58] What distance individual animals travel cannot be stated with certainty, but herds in course of migrating have been met from Canada to Mexico, from the Missouri to the Rocky Mountains, and it may be assumed that a single herd traverses a considerable part of the country lying between these limits. The bisons have been seen in summer scattered over the boundless prairie, and in winter in the same places, but assembled in many thousands; their migrations have been observed, for they have been followed for hundreds of miles along the tracks--the so-called “buffalo-paths”, trodden out straight across plains and over mountains. We learn from eye-witnesses that a stream a mile wide is to them no barrier, scarcely even a hindrance, for they throw themselves into it like an irresistible avalanche, so that the water is covered with the dark, moving throng; that the animals associate and separate again, the herds increase and diminish; that old, surly, tyrannous, malevolent bulls avoid the other bisons, having perhaps been expelled from the herd, and compelled, probably only after protracted struggles, to live in hermit-fashion until the following summer; and that, during heavy snowfalls, the herds take shelter in the forests or on the slopes of the mountains. From July onwards they begin their migrations from the north towards the south. Small companies, which, till then, have been leading a comfortable summer life, combine with others and set out on the journey with them; other troops join the band, which grows as it presses on, until there is, at length, formed one of those extraordinary herds which, united till the next spring, moves and acts as if animated by one soul. When the winter is safely past, the army gradually breaks up, probably in exactly reverse order, into herds, and these divide more and more until at length only small companies are left. This breaking-up takes place during the course of the return journey. Both in going and returning, one herd follows another at some distance, but more or less along the same paths. Specially favourable places, such as low grounds covered with rich grass, cause a temporary damming up of the living stream. In such places incalculable herds assemble together, spend days in the same spot, and break up only again when all the grass has been eaten, and hunger urges them to continue their journey. As they march the wolves and bears follow their track, while eagles and vultures, birds of ill omen, circle over their heads.

Scarcity of water, as well as of food, is often a cause of regular migrations. When winter approaches in the south-east of Siberia, more particularly in the high Gobi steppe, all the non-hibernating mammals are compelled, by the peculiar circumstances of these highlands, to seek refuge in lower-lying regions. The winter in these high grounds of Central Asia is not more severe than in districts lying further to the north or north-east, but it is usually almost snowless, and such pools of water as have been formed by the extremely slight fall of rain or snow, are covered with a thick sheet of ice. As soon as this sheet becomes so strong that the animals inhabiting the Gobi are unable to break it, they are obliged to change their quarters, and they travel not only to southern but to northern lands, whose only advantage is that they are covered with snow, for this affords ready refreshment to the parched tongues of the wanderers, and offers less resistance to their weak feet than the hard, unbreakable, and less easily melted ice. This is the explanation of the fact that the antelope, of which great numbers are found in the Gobi, forsakes a land which, save for the lack of snow and therefore of available water, is exactly the same as that which it chooses for its winter quarters. Not hunger, but thirst, drives it from its home. At the beginning of winter, the antelopes, at all times gregarious, assemble in herds of many thousands, spreading over all the low grounds around their native plateau; they often travel at the rate of fifty or sixty miles in a single night, and extend their wanderings many hundreds of miles beyond the boundaries of their proper habitat. The observer who follows them can detect their tracks everywhere, and in such numbers that it seems as though vast herds of sheep, far exceeding in number any ordinary flock, had just passed by.

Before the Chinese antelope begins its migration, restlessness seizes the kulan or dziggetai, probably the ancestor of our horse, and certainly the most beautiful and the proudest of all wild horses. The foals of the summer are by autumn strong enough to be able to endure a long journey with quick marches, and to bid defiance to all the accidents and dangers of a wandering life. The young stallions attain their full strength at the end of their fourth year, and towards the end of September they leave the parent-herd and press forward. Finally, the impulse to mate begins to animate the older stallions and mares, and with it comes unrest and the desire to wander. Thus the fleet, enterprising animals begin their annual migration long before winter has set in, before even its approach has become at all apparent; and on this account their migrations at first lack steadiness and regularity, and have something of the character of journeys in search of adventure. With the intention of shaking off the burdensome yoke of the leader and absolute lord of the herd, and of becoming independent and in their turn equally despotic, the young stallions forsake the herd, and thenceforward traverse the sandy steppes singly. All the younger mares who are mature, and even many of the older ones, seem to be animated by the same feeling as the young stallions, and they attempt to escape from the rule of their tyrant and join his young rival, to fall immediately under his dominion. But not without a struggle does the new candidate for leadership gain his troop of mares; the old leader does not readily relinquish his rights. For hours together the stallion stands on the top of a hill or on the shoulder of a ridge, keenly scanning the country around. His eye wanders over the desert, his dilated nostrils are turned towards the wind, his ears are directed forwards on the alert. Eager for battle, he rushes at full gallop towards every herd which approaches, every adversary who shows himself; and a furious struggle takes place for the possession of the mares, who always attach themselves to the victor. Such combats and strife set the herd in motion, detach it from the place where the summer has been spent, and lead on to migrations which become gradually regular, prolonged, persistent, and almost uninterrupted. In the course of these, if not before the end of the combats just described, the kulan troops assemble in ever-growing numbers, until at length herds of more than a thousand head set out together for fields which give promise of pasturage. They do not break up while in their winter quarters, and they are thus compelled to be continually on the move in order to find sufficient nourishment. The combined tread of the army, as they gallop on in their usual furious fashion, rings dully out, and more than once, in Russia, the sound has called the Cossacks of the military cordon to arms. No wolf ventures to attack such a herd, for the courageous wild horses know so well how to use their hoofs against him that he soon gives up any attempt; it is only the sick and exhausted horses which become his prey, as he follows the wandering herd. Even man can do them no great damage, for their caution and shyness render them difficult of approach. But winter, especially if much snow falls, brings them much suffering. The pasture, at all times scanty, is exhausted the more quickly the more numerous the herd which feeds on it. Then the animals devour indiscriminately all the vegetable substances they can find. For months together they have to maintain life on leafless shoots. Their bodies cease to be fat and plump, till at length they are like wandering skeletons. The mother, herself starving, is no longer able to nourish her foal, for the milk-yielding udder dries up in times of such need. Many a one whose tender youth is unable to endure the hard fare dies of starvation. Even the old horses suffer from the poverty and treachery of the winter. Snow-storms blowing over their feeding-ground for days at a time depress their usually cheerful courage, and increase the boldness of the wolves, which, even if they do not fall upon the already exhausted horses, persecute and annoy to the utmost those who are not yet worn out. But as soon as circumstances begin to improve, the wiry, weather-hardened, enduring creatures recover their high spirits, and, when the snow begins to melt, they set out on the return journey, reaching their summer home in about a month’s time. There they break up into single herds, recuperate among the luxuriantly sprouting, fragrant pasture, and, in a surprisingly short time, become fat and plump again. Soon the want and misery of the winter are forgotten.

Great as are the distances often traversed by all the mammals already mentioned, they can scarcely be compared with those covered by seals and whales. The water favours all the movements of animals adapted to aquatic life, and offers everywhere the same general conditions of life and the same amenities. Thus it renders the migrations of its inhabitants easier, less toilsome and hazardous than those of any other wanderers. Nevertheless it is somewhat surprising to learn that many sea-mammals, and particularly the whales, are among the most nomadic of all creatures; in fact that many, if not most of them, pass their whole life in travelling. Strictly speaking, no whale has a permanent place of sojourn for the whole year, but passes singly, in pairs, with its young, or in more or less numerous companies--the so-called schools--from one part of the ocean to another, visiting certain favourite haunts in regular order, and choosing different haunts in summer and in winter. The seas inhabited by the same species of whale in winter and in summer often lie farther apart than people seem to suppose, for some whales travel, twice a year, more than a quarter of the earth’s circumference; they are to be found in summer among the ice-floes of the Arctic Ocean, and in winter on the other side of the Equator. The female whales, who are in the highest degree sociable, and attached to their young with the tenderest, most devoted love, assemble together in surprising numbers, and under the guidance of a few males, traverse the ocean by definite routes and at definite times, some keeping to the open sea, others making their way along the coasts. Storms may force them to change their route, or delay in the appearance of the animals on which they feed, whose occurrence and disappearance is obviously the chief cause of their migration, may to some extent influence their course and the time of their visiting certain spots; but, as a general rule, their migrations are so systematic that on northern and southern coasts people look for the arrival of the whale on a particular day, and place watches so that they may be able to begin the long-desired chase without loss of time. Whales, which are recognized by the dwellers on the coast by some mark, such as mutilated fins, and which have been several times pursued in vain, have been known to appear several years in succession at the same time and at the same place; and the chase after these most valuable and therefore increasingly persecuted animals takes place with the same regularity as do hare-hunts on land, though at any other time of the year it would be vain to look for them. “After Twelfth Day,” says old Pontoppidan, “the Norwegians watch from all the hills for the whale, whose arrival is announced by the herring.” First appears the killer, then, three or four days, or at the most a fortnight later, the rorqual, though, apparently, one comes from Davis Straits and the other from Greenland. On the south coasts of the Faroë Islands, and especially in the Qualbenfjord, from three to six bottle-nose whales still appear every year about Michaelmas, as they did a hundred and ninety years ago. In a Scottish bay there appeared twenty years in succession a rorqual, which was generally known by the name of “Hollie Pyke”, and was pursued every year and finally captured. On the coast of Iceland single whales choose the same bays for a temporary sojourn every year in the same months, and even weeks, so that the inhabitants have got to know them individually, and have given them special names. Certain well-known mother-whales visit the same bays every year to bring forth their young, and they themselves are spared, but they have to purchase their own lives, dearly enough, at the cost of that of their young ones, which are regularly taken captive. It is very unusual for the migrating whales to keep neither to time nor to route; in general, their journeys are as regular as if they were arranged according to the position of the stars, and as if they took place along laid-out paths bounded on both sides. No other mammal migrates more regularly; indeed, their wanderings may be compared with the migrations of birds.

The seals, like the whales, migrate every year, on the whole with great regularity, though not to such a distance. Those species which inhabit inland seas cannot, of course, leave these, but they traverse them every year in regular order, or at certain times ascend the rivers flowing into them; all the ocean species, on the other hand, set out every autumn and spring, by definite routes, to certain regions or localities. All the seals in the far north, as well as those in the seas about the South Pole, are forced to migrate by the extension of the ice in winter, and may travel with it towards temperate zones, returning towards the poles again as the ice melts. But they, like all other members of their order, are impelled to travel for another not less weighty reason; they require the mainland, or at least large, spreading, fixed masses of ice, on which to bring forth and nurture their young, until these are able to follow them into the water, there to shift for themselves. Thus every year thousands and hundreds of thousands of seals appear on certain islands and ice-banks, covering some of these birth-places of their race in such crowds that every available spot must be utilized in order to secure space for all to bring forth their young. They pass weeks, even months, on land or on the ice without hunting, descending into the sea, or taking food; they suckle their young, then mate, and by degrees break up their great assemblage, distributing themselves over the wide ocean to resume their former manner of life, or setting out with their young, who still require training, on more or less extensive foraging expeditions.[59]

As is well known, there are many mammals which have the habit of hibernating, which pass the severe part of the year well protected in deep and carefully closed burrows, and are thus spared the necessity of leaving their haunts. Even among these, however, at least among those living in the temperate zones, there are some which migrate during their waking time, namely, the bats. Defective as the wing of a bat must appear when compared with that of a bird, it is nevertheless of such assistance in flight, that it makes journeys possible which seem out of all proportion to the size of the animal. Another fact makes travelling easier to the restless bat; it is not tied down by its offspring to any particular spot, for the young one attaches itself directly after birth to the breast of the mother, and is borne by her through the air till it is capable of independent life. The bat is thus one of the best-adapted of migratory mammals, and, under some circumstances, it makes full use of its advantages. As a general rule, the wanderings of the different species of bat are to be regarded simply as excursions made with a view to taking advantage of any district which is, for the time being, particularly rich in food; but they do sometimes become really long journeys, which lead some species to far distant lands, and they are then not without the regularity characteristic of all true migrations. The largest bats, the flying foxes, fly long distances every evening in search of the fruits on which they chiefly subsist; they do not hesitate to cross an arm of the sea fifty or sixty miles in breadth, and they must even have traversed the distance between Southern Asia and the East of Africa, as certain species occur in both these regions. The bats proper accomplish at least as much. Following the reappearance of the insects, which occurs at different times in regions of different altitude, they ascend from the plains to the mountain heights, and descend in autumn to the low grounds again; they pursue the numerous flies which congregate about the wandering cattle-herds of Central Africa, and they migrate also from the south towards the north and return southwards again, or in reverse order. The boreal bat appears at the beginning of the bright nights in the north of Scandinavia and Russia, and leaves these districts, which may be considered its head-quarters, towards the end of summer, to spend the winter among the mountains of Central Germany and the Alps. The pond-bat is regularly seen on the plains of North Germany during summer, but only exceptionally at that period among the mountains of Central Germany, in whose caverns it spends the winter. That other species of bat occurring in Germany change their place of abode in a similar manner can scarcely be doubted.

In the cases cited, which have been selected from a mass of available material, I have given examples of those migrations of mammals which we may call voluntary, because of their regularity; but in so doing I have by no means completed my task. Hunger and thirst, the poverty and temporary inhospitableness of a particular region, sometimes press so severely on certain mammals that they endeavour, as if despairing, to save themselves by flight. Abundant nourishment and good weather favour the increase of all animals, and affect that of a few plant-eating mammals to such an extraordinary degree, that, even under propitious conditions, their habitat must be extended. But if one or more rich years--in some cases a few favourable months--be followed by a sudden reverse, the famine soon passes all bounds, and robs the creatures not only of the possibility of subsistence, but also of all hope, or at least of all presence of mind.

It is under circumstances such as these that the field-voles of our own country, and the Siberian voles, assemble in enormous multitudes, leave their native haunts and migrate to other districts, turning back for no obstacles, avoiding the water as little as the forbidding mountains or the gloomy forest, fighting to the last against hunger and misery, but perishing hopelessly from diseases and epidemics which rage among them like plagues, reducing armies of millions to a few hundreds. Thus, too, the squirrels of Siberia, which, in ordinary years, undertake, at the most, only short excursions, assemble in vast armies, hurry in troops or companies from tree to tree, in compact masses from forest to forest, swim across rivers and streams, throng into towns and villages, lose their lives by thousands; but suffer no obstacle or hindrance--not even the most obvious dangers--to delay them or divert them from their path. The soles of their feet become worn and cracked, their nails ground down, the hairs of their usually smooth fur rough and matted. Through the forest lynxes and sables, in the open fields gluttons, foxes and wolves, eagles, falcons, owls and ravens follow them closely; pestilence claims more victims from their ranks than the teeth and claws of beast of prey or the guns and cudgels of men, yet they press on and on, apparently without hope of return. A Siberian sportsman of my acquaintance gave me a verbal account of the appearance of such an army of squirrels, in August 1869, in the town of Tapilsk, among the Ural Mountains. It was only one wing of a migrating army, of which the main body travelled through the forest about five miles farther north. Sometimes in single file, sometimes in companies of varying strength, but in unbroken succession, the animals pressed on, crowding as densely through the town as through the neighbouring forest; used the streets, as well as the hedges, and the roofs of buildings as paths; filled every court-yard, thronged through windows and doors into the houses, and created quite an uproar among the inhabitants--much more among the dogs, which killed thousands of them, evincing an unbridled bloodthirstiness till then unsuspected. The squirrels, however, did not seem to concern themselves in the least about the innumerable victims falling in their midst; in fact, they took no notice of anything, and allowed nothing to divert them from their route. The procession lasted for three whole days, from early morning till late in the evening, and only after nightfall each day was there a break in the continuity of the stream. All travelled in exactly the same direction, from south to north, and those that came last took the same paths as their predecessors. The rushing Tchussoveia proved no obstacle, for all that reached the bank of that rapid mountain-river plunged without hesitation into its whirling and seething waters, and swam, deeply sunk and with their tails laid across their backs, to the opposite bank. My informant, who had been watching the procession with growing attention and sympathy, rowed out into the midst of the throng. The tired swimmers, to whom he stretched out an oar, climbed up by it into the boat, where, apparently exhausted, they sat quietly and confidingly, until it came alongside a larger vessel, when they climbed into that, and remained on it for some time as indifferent as before. As soon as the boat touched the bank they sprang ashore, and proceeded on their journey as unconcernedly as if it had suffered no interruption.

It must be similar circumstances which compel the lemmings to the migrations which have been known for centuries. For many successive years the heights in the tundras of Scandinavia, North Russia, and the North of Siberia afford them comfortable quarters and abundant nourishment; for the broad ridges of the fjelds and the extensive plains between them, the highlands and the low grounds, offer room and maintenance for millions of them. But not every year do they enjoy the accustomed abundance for the whole summer. If a winter in which much snow falls, and which is therefore favourable to them, as they live safely below the snow, be followed by an early, warm, and agreeable spring, their extraordinary fertility and power of increase seem to have almost no bounds, and the tundra literally teems with lemmings. A fine warm summer increases their numbers past computing, but it also accelerates the life-course of all the plants on which they feed, and before it is over these are partly withered, partly devoured by the greedy teeth of the insatiable rodents. Scarcity of food begins to be felt, and their comfortable life comes to an end in panic. Their fearless, bold demeanour gives place to a general uneasiness, and soon a mad anxiety for the future takes possession of them. Then they assemble together and begin to migrate. The same impulse animates many simultaneously, and from them it spreads to others; the swarms become armies; they arrange themselves in ranks, and a living stream flows like running water from the heights to the low grounds. All hurry onwards in a definite direction, but this often changes according to locality and circumstances. Gradually long trains are formed in which lemming follows lemming so closely that the head of one seems to rest on the back of the one in front of it; and the continuous tread of the light, little creatures hollows out paths deep enough to be visible from a long distance in the mossy carpet of the tundra. The longer the march lasts, the greater becomes the haste of the wandering lemmings. Eagerly they fall upon the plants on and about their path and devour whatever is edible; but their numbers impoverish even a fresh district within a few hours, and though a few in front may pick up a little food, nothing is left for those behind; the hunger increases every minute, and the speed of the march quickens in proportion; every obstacle seems surmountable, every danger trifling, and thousands rush on to death. If men come in their way they run between their legs; they face ravens and other powerful birds of prey defiantly; they gnaw through hay-stacks, climb over mountains and rocks, swim across rivers, and even across broad lakes, arms of the sea, and fjords. A hostile company, like that behind the migrating squirrels, follows in their wake: wolves and foxes, gluttons, martens and weasels, the ravenous dogs of the Lapps and Samoyedes, eagles, buzzards, and snowy owls, ravens and hooded crows fatten on the innumerable victims which they seize without trouble from the moving army; gulls and fishes feast on those which cross the water. Diseases and epidemics, too, are not awanting, and probably destroy more than all their enemies together. Thousands of carcasses lie rotting on the wayside, thousands are carried away by the waves; whether indeed any are left, and whether these return later to their native Alpine heights, or whether all, without exception, perish in the course of their journey, no one can say with certainty; but so much I know, that I have traversed great tracts of the tundra of Lapland where the paths and other traces of a great migrating army were to be seen almost everywhere, while not a single lemming could be discovered. Such tracts, I have been told, remain thus for several successive years, and only after long periods become gradually repeopled with the busy little rodents.[60]

What hunger causes in the North is brought about by the tortures of thirst in the richer South. As the brackish pools which have afforded water to the zebras, quaggas, antelopes, buffaloes, ostriches, and other animals of the steppes, dry up more and more under the burning heat of a South African winter, all the animals whose necessities have hitherto been supplied by the steppes assemble about the pools which still contain a little water, and these become scenes of stirring, active life. But when these, too, evaporate, the animals which have congregated around them are compelled to migrate, and it may happen that despair takes possession of them, as it did of the little rodents already described, and that, collecting in herds like the wild horses and Chinese antelopes (dzieren) of the steppes of Central Asia, or the bisons of the North American prairies, they rush straight on for hundreds of miles, to escape the hardships of winter.

In the South, too, the wild horses are the first to turn their backs on the inhospitable country. Till the drought sets in, these beautifully-marked, strong, swift, self-confident children of the Karroo, the zebra, quagga, and dauw, wander careless and free through their vast domain, each herd going its own way under the guidance of an old, experienced, and battle-tried stallion. Then the cares of the winter season begin to make themselves felt. One water-pool after another disappears, and the herds which gather about those which remain become more and more numerous. The general distress makes even the combative stallions forget to quarrel and fight. Instead of small companies, herds of more than a hundred head are formed, and these move and act collectively, and finally forsake the wintry region altogether before want has enfeebled their powers or broken their stubborn wills. Travellers describe with enthusiasm the spectacle presented by such a herd of wild horses on the march. Far into the distance stretches the sandy plain, its shimmering red ground-colour interrupted here and there by patches of sunburnt grass, its scanty shade supplied by a few feathery-leaved mimosas, and, as far away as the eye can reach, the horizon is bounded by the sharp lines of mountains quivering in a bluish haze. In the midst of this landscape appears a cloud of dust which, disturbed by no breath of air, ascends to the blue heavens like a pillar of smoke. Nearer and nearer the cloud approaches, until at length the eye can distinguish living creatures moving within it. Soon the brightly-coloured and strangely-marked animals present themselves clearly to the spectator’s gaze; in densely thronged ranks, with heads and tails raised, neck and neck with the quaintly-shaped gnus and ostriches which have joined their company, they rush by on their way to a new, and possibly far-distant feeding-ground, and ere the onlooker has recovered himself, the wild army has passed by and is lost from view in the immeasurable steppe.

The antelopes, which are also driven out by winter, do not always follow the same paths, but usually travel in the same direction. None is more numerous or more frequently seen than the springbok, one of the most graceful and beautiful gazelles with which we are acquainted. Its unusual beauty and agility strike everyone who sees it in its wild state, now walking with elastic step, now standing still to feed, now springing about in playful leaps, and thus disclosing its greatest ornament, a mane-like snow-white tuft of hair, which at a quieter pace is hidden in a longitudinal groove of the back. None of the other antelopes, when forced to migrate, assemble in such numerous herds as this one. Even the most vivid description cannot convey to one who has not seen a herd of springboks on their journey any adequate idea of the wonderful spectacle. After having congregated for weeks, perhaps waiting for the first shower of rain, the springboks at last resolve to migrate. Hundreds of the species join other hundreds, thousands other thousands, and the more threatening the scarcity, the more torturing the thirst, the longer the distances which they cover; the flocks become herds, the herds armies, and these resemble the swarms of locusts which darken the sun. In the plains they cover square miles; in the passes between the mountains they throng together in a compact mass which no other creature can resist; over the low grounds they pour, like a stream which has overflowed its banks and carries all before it. Bewildering, intoxicating, and stupefying even the calmest of men, the throng surges past for hours, perhaps days together.[61] Like the greedy locusts, the famishing animals fall upon grass and leaves, grain, and other fruits of the field; where they have passed, not a blade is left. The man who comes in contact with them is at once thrown to the ground, and so sorely wounded by the tread of their hoofs, light indeed, but a thousand times repeated, that he may be glad if he escapes with his life; a herd of sheep feeding in the way is surrounded and carried off, never to be seen again; a lion, who thought to gain an easy prey, finds himself forced to relinquish his victim, and to travel with the stream. Unceasingly those behind press forward, and those in front yield slowly to the pressure; those cooped up in the middle strive continually to reach the wings, and their efforts are strenuously resisted. Above the clouds of dust raised by the rushing army the vultures circle; flanks and rear are attended by a funeral procession of various beasts of prey; in the passes lurk sportsmen, who send shot after shot into the throng. So the tortured animals travel for many miles, till at length spring sets in and their armies are broken up.

Shall I go on to consider other compulsory migrations, such as those of the arctic foxes and polar bears when an ice-floe on which they were hunting is loosened and floated off by the waves till, under favourable circumstances, it touches some island? I think not, for journeys such as these are not migrations, they are simply passive driftings.

LOVE AND COURTSHIP AMONG BIRDS.

An irresistible instinct, an all-compelling law of nature, moves every living creature to seek a mate of its own species but of opposite sex, to unite a second existence with its own, to awaken responsive emotions through complete self-surrender, and thus to form the closest bond which links being to being, life to life. No power is strong enough to set aside this law, no command authoritative enough to influence it. Yielding to no hindrance this instinct overcomes every obstacle, and presses victorious to its goal.

The almighty power through which this law works we call Love, when we speak of its influence on man; we describe it as Instinct when we discuss its operation on the lower animals. But this is a mere play upon words, nothing more; unless by the former word we intend to imply that every natural instinct in man should by man himself be ennobled and moralized. If it be not so, it will be difficult to distinguish between the two. Man and beast are subject to the same law, but the beast yields it a more absolute obedience. The animal does not weigh or reflect, but gives itself up without resistance to the sway of love, which man often fondly imagines he can withstand or escape.

Of course, he who ventures at the outset to dispute man’s belonging to the animal world at all, sees in an animal nothing more than a machine which is moved and guided, stimulated to action, incited to sue for the favour of the opposite sex, impelled to songs of rejoicing, provoked to combat with rivals, by forces outside of itself; and, naturally enough, he denies to such a machine all freedom and discretion, all conflict between opposing motives, all emotional and intellectual life. Without raising himself by thus claiming a monopoly of intelligent action, or at least of intellectual freedom, he degrades the lower animals to false creations of his own hollow vanity, suggesting that they lead a seeming rather than a real life, and that they are without any of the joys of existence.[62]

An exactly contrary position would be undoubtedly more just, as it certainly is more accurate. Indeed, it is scarcely too much to say that he who refuses to credit the lower animals with intelligence raises anxiety on the score of his own, and that he who denies them all emotional life has himself no experience of what emotional life is. Whoever observes without prejudice is sooner or later forced to admit that the mental activity of all animal beings, diverse as its expression may be, is based upon the same laws, and that every animal, within its own allotted life-circle and under the same circumstances, thinks, feels, and acts like any other, and is not, in contrast to man, impelled to quite definite actions by so-called higher laws. The causes of the actions of animals may perhaps be termed laws, but, if so, we must not forget that man is subject to the same. His intellect may enable him to make some of these laws of nature subservient to his purposes, to modify others, sometimes even to evade them, but never to break or annul them.

Let me attempt to prove the correctness of these opinions by giving examples to show how essentially the expressions of life in man and in the lower animals may resemble each other, how both are alike all-powerfully influenced by the most important of the laws of nature, that which has for its aim, or its consequence, the continuance of the species. Man and bird: how wide the gulf which separates them and their lives! how vast the differences between their habits and behaviour! Is there a power which can bridge over this gulf? Are conditions conceivable which can incite them to essentially similar expressions of life? We shall see.

The birds are more unreservedly dependent on the rotation of the seasons than man is. “They sow not, neither do they reap, nor gather into barns”, and they must perforce adapt themselves to the seasons if they are to find sufficient food, if they are to live at all. Therefore they blossom in spring, bring forth their fruits in summer, conceal these and themselves in autumn, and rest in winter like the motherly earth. The chapters of their life-history are closely bound up with the seasonal progress of the year.

In this respect they are indeed governed by an iron law which, within a certain limit, renders anything like freedom and caprice impossible. But whither should spontaneity tend save to want and misery, to the imperilling of their own lives and those of their young? So they bow submissively to nature’s law, and enjoy, in consequence, a freedom which we men might envy them, and should envy them, were we not more capable of withdrawing ourselves from the influence of the seasons than they. But do not we also blossom in spring, and rest in winter? And must not we, too, bow before iron necessity?

If the birds are in bondage in certain respects, they preserve their freedom and power of choice in others, and they exercise both more joyously and unrestrainedly than man himself.

No bird voluntarily renounces the joys of love; very few evade the bonds of marriage; but everyone seeks to attain to and enjoy love as early as possible. Before it has laid aside its youthful dress the young bird has learnt to recognize and respect the distinctions of sex; much earlier than that, the young male fights with his fellows as if in boyish wantonness; as soon as he is full-grown he woos ardently and persistently some female of his own species. No male bird condemns himself to bachelorhood, no female bird hardens her heart against a deserving suitor. For lack of a mate, the male wanders restlessly and aimlessly over land and sea; for a worthy mate the female forgets pain and oppressive grief, however deep these may have been; for the wooer who seems to her most worthy she breaks even her conjugal bonds.

Every female bird attains to the possession of a husband, but not every male readily succeeds in gaining a wife. Even among birds so great a good must be sought after and striven for. On an average, there are more males than females, and many males are obliged to suffer the severest misfortune which can befall them, and to live, at least temporarily, unmated. For the great majority of birds, celibacy is a state of torment from which they strive with all their strength to escape. So they traverse wide tracts in search of a mate, seeking diligently, and when they imagine they have found one, wooing with equal ardour, whether she be maid, wife, or widow. If these wanderings were usually fruitless, they would not take place so regularly as they do.

In wooing their mates, the males exhaust all the charms with which nature has endowed them. According to his species and capacity each brings his best gifts into play, each seeks to show his best side, to reveal all his amiability, to surpass in brilliance others of his kind. This desire increases with the hope of fulfilment; his love intoxicates him, throws him into ecstasies. The older he is the more remarkably does he conduct himself, the more self-confident does he appear, the more impetuously does he strive for the reward of love. The proverb, “There are no fools like old fools”, does not apply in his case, for it is but rarely that age condemns him to weakness and incapacity; on the contrary, it strengthens all his capabilities and increases his energy by mature experience. Little wonder then that at least the younger females prefer the older males, and that these woo, if not more ardently, at least more confidently than their younger rivals.

The means by which a male bird declares his love and conducts his courtship are very various, but, naturally, they always accord with his most prominent gifts. One woos with his song, another with his wings, this one with his bill, and that with his foot; one displays all the magnificence of his plumage, another some special decoration, and a third some otherwise unused accomplishment. Serious birds indulge in play and joke and dignified pranks; silent ones chatter, quiet ones become restless, gentle ones combative, timid ones bold, cautious ones careless: in short, all show themselves in an unwonted light. Their whole nature appears changed, for all their movements are more active, more excited than usual, and their conduct differs from their ordinary behaviour in every respect; they are possessed by an intoxication which increases the elasticity of their nature to such a degree that no flagging is ever perceptible. They deprive themselves of sleep, or reduce it to a minimum without weariness, and while awake they exert all their powers to the utmost without fatigue.

All birds with a voice utter clear, articulate notes in their courtship, and their song is nothing more than a supplication or exultation of love. Our poet’s words:

“Hushed is the nightingale’s lay,
Which gladdened our hearts in spring;
’Tis only in love’s heyday
That we hear its minstrels sing”,