Kitabı oku: «A Year with the Birds», sayfa 3
We are now close to our old winter-station on the bridge over the mill-stream, and leaning over it once more on the upper side, we shall hear, if not see, both the remaining species of the warblers that Oxford has to show us. They are the only species of River-warblers that are known to visit England regularly every year; these two, the Sedge-warbler and the Reed-warbler, never fail, and the Sedge-warbler comes in very large numbers, but only a few specimens of other River-warblers have been found out in their venturesomeness. Still, every young bird-hunter should acquaint himself with the characteristics of the rarer visitors, in order to qualify himself for helping to throw light on what is still rather a dark corner of English ornithology. These same species which we so seldom see are swarming in the flat lands of Holland, close by us, and why should they not come over to the island which birds seem to love so dearly?
But there is no doubt that birds have ways, and reasons for them, which man is very unlikely ever to be able to understand. Why, as Mr. Harting asks,17 should the Reed-warbler be so much less “generally distributed” than the Sedge-warbler? That it is so, we can show well enough even from Oxford alone. You will find Sedge-warblers all along the Cherwell and the Isis, wherever there is a bit of cover, and very often they will turn up where least expected; in a corn-field, for example, where I have seen them running up and down the corn-stalks as if they were their native reeds. But you must either know where to find the Reed-warbler, or learn by slow degrees. Parsons’ Pleasure is almost the only place known to me where
There is, however, in this case, at least a plausible answer to Mr. Harting’s question. Owing to the prime necessity of reeds for the building of this deep-sheltered nest, which is swung between several of them, kept firm by their centrifugal tendency, yielding lovingly yet proudly to every blast of wind or current of water – owing to this necessity, the Reed-Warbler declines to take up his abode in any place where the reeds are not thick enough and tall enough to give a real protection to himself and his brood. Now in the whole length of Isis between Kennington19 and Godstow, and of Cherwell between its mouth and Parsons’ Pleasure, there is no reed-bed which answers all the requirements of this little bird. Now and then, it is true, they will leave the reeds for some other nesting-place; one of them sang away all the Summer Term of 1884 in the bushes behind the Museum, nearly half a mile from the river, and probably built a nest among the lilac-bushes which there abound. But that year they seemed to be more abundant than usual; and this, perhaps, was one for whom there was no room in the limited space of the reeds at Parsons’ Pleasure. Thick bushes, where many lithe saplings spring from a common root, would suit him better than a scanty reed-bed.20
There is no great difficulty in distinguishing Sedge- and Reed-warblers, if you have an eye for the character of birds. The two are very different in temperament, though both are of the same quiet brown, with whitish breast. The Sedge-bird is a restless, noisy, impudent little creature, not at all modest or retiring, and much given to mocking the voices of other birds. This is done as a rule in the middle of one of his long and continuous outpourings of chatter; but I one day heard a much more ridiculous display of impertinence. I was standing at the bottom of the Parks, looking at a pair or two of Sedge-warblers on a bush, and wondering whether they were going to build a nest there, when a Blackbird emerged from the thicket behind me, and seeing a human being, set up that absurd cackle that we all know so well. Instantly, out of the bush I was looking at, there came an echo of this cackle, uttered by a small voice in such ludicrous tones of mockery, as fairly to upset my gravity. It seemed to say, “You awkward idiot of a bird, I can make that noise as well as you: only listen!” —
The Reed-warbler, on the other hand, is quieter and gentler, and utters, by way of song, a long crooning soliloquy, in accents not sweet, but much less harsh and declamatory than those of his cousin. I have listened to him for half-an-hour together among the bushes that border the reed-bed, and have fancied that his warble suits well with the gentle flow of the water, and the low hum of the insects around me. He will sit for a long time singing on the same twig, while his partner is on her nest in the reeds below; but the Sedge-warbler, in this and other respects like a fidgety and ill-trained child, is never in one place, or in the same vein of song, for more than a minute at a time.
It is amusing to stand and listen to the two voices going on at the same time; the Sedge-bird rattling along in a state of the intensest excitement, pitching up his voice into a series of loud squeaks, and then dropping it into a long-drawn grating noise, like the winding-up of an old-fashioned watch, while the Reed-warbler, unaffected by all this volubility, takes his own line in a continued prattle of gentle content and self-sufficiency.
These eight birds, then, are the warblers which at present visit Oxford. Longer walks and careful observation may no doubt bring us across at least two others, the Wood-warbler and the Grasshopper-warbler: the nest of the Wood-warbler has been found within three miles. Another bird, too, which is often called a warbler, has of late become very common both in and about Oxford – the Redstart. Four or five years ago they were getting quite rare; but this year (1885) the flicker of the red tail is to be seen all along the Cherwell, in the Broad Walk, where they build in holes of the elms, in Port Meadow, where I have heard the gentle warbling song from the telegraph wires, and doubtless in most gardens. The Redstart is so extremely beautiful in summer, his song so tender and sweet, and all his ways so gentle and trustful, that if he were as common, and stayed with us all the year, he would certainly put our Robin’s popularity to the proof. Nesting in our garden, or even on the very wall of our house, and making his presence there obvious by his brilliant colouring and his fearless domesticity, he might become, like his plainer cousin of the continent, the favourite of the peasant, who looks to his arrival in spring as the sign of a better time approaching. “I hardly hoped,” writes my old Oberland guide to me, after an illness in the winter, “to see the flowers again, or hear the little Röthel (Black Redstart) under my eaves.”
The Oxford Redstarts find convenient holes for their nests in the pollard willows which line the banks of the Cherwell and the many arms of the Isis. The same unvaried and unnatural form of tree, which looks so dreary and ghastly in the waste of winter flood, is full of comfort and adaptability for the bird in summer. The works of man, though not always beautiful, are almost always turned to account by the birds, and by many kinds preferred to the solitude of wilder haunts. Whether he builds houses, or constructs railways, or digs ditches, or forces trees into an unnatural shape, they are ready to take advantage of every chance he gives them. Only when the air is poisoned by smoke and drainage, and vegetation retreats before the approach of slums, do they leave their natural friends to live without the charm of their voices – all but that strange parasite of mankind, the Sparrow. He, growing sootier every year, and doing his useful dirty work with untiring diligence and appetite, lives on his noisy and quarrelsome life even in the very heart of London.
Whether the surroundings of the Oxford Sparrows have given them a sense of higher things, I cannot say; but they have ways which have suggested to me that the Sparrow must at some period of his existence have fallen from a higher state, of which some individuals have a Platonic ἀνάμνησις which prompts them to purer walks of life. No sooner does the summer begin to bring out the flies among our pollard willows, than they become alive with Sparrows. There you may see them, as you repose on one of the comfortable seats on the brink of the Cherwell in the Parks, catching flies in the air with a vigour and address which in the course of a few hundred years might almost develop into elegance. Again and again I have had to turn my glass upon a bird to see if it could really be a Sparrow that was fluttering in the air over the water with an activity apparently meant to rival that of the little Fly-catcher, who sits on a bough at hand, and occasionally performs the same feat with native lightness and deftness. But these are for the most part young Sparrows of the year, who have been brought here perhaps by their parents to be out of the way of cats, and for the benefit of country air and an easily-digested insect diet. How long they stay here I do not know; but before our Autumn Term begins they must have migrated back to the city, for I seldom or never see them in the willows except in the Summer Term.
These seats by the Cherwell are excellent stations for observation. Swallows, Martins, and Sand-martins flit over the water; Swifts scream overhead towards evening; Greenfinches trill gently in the trees, or utter that curious lengthened sound which is something between the bleat of a lamb and the snore of a light sleeper; the Yellow Wagtail, lately arrived, walks before you on the path, looking for materials for a nest near the water’s edge; the Fly-catcher, latest arrival of all, is perched in silence on the railing, darting now and then into the air for flies; the Corn-crake sounds from his security beyond the Cherwell, and a solitary Nightingale, soon to be driven away by dogs and boats and bathers, may startle you with a burst of song from the neighbouring thicket.
Of the birds just mentioned, the Swifts, Swallows, and Martins build, I need hardly say, in human habitations, the Sand-martins in some sand- or gravel-pit, occasionally far away from the river. The largest colony of these little brown birds, so characteristic of our Oxford summer, is in a large sand-pit on Foxcombe Hill: there, last July, I chanced to see the fledgelings peeping out of their holes into the wide world, like children gazing from a nursery window. The destruction all these species cause among the flies which swarm round Oxford must be enormous. One day a Martin dropped a cargo of flies out of its mouth on to my hat, just as it was about to be distributed to the nestlings; a magnifying glass revealed a countless mass of tiny insects, some still alive and struggling. One little wasp-like creature disengaged himself from the rest, and crawled down my hand, escaping literally from the very jaws of death.
Before I leave these birds of summer, let me record the fact that last June (1886) a pair of swallows built their nest on the circular spring of a bell just over a doorway behind the University Museum; the bell was constantly being rung, and the nest was not unfrequently examined, but they brought up their young successfully. This should be reassuring to those who believe that the Museum and its authorities are a terror to living animals.
CHAPTER III.
THE ALPS IN JUNE
When the University year is over, usually about mid-June, responsibilities cease almost entirely for a few weeks; and it is sometimes possible to leave the lowlands of England and their familiar birds without delay, and to seek new hunting-grounds on the Continent before the freshness of early summer has faded, and before the world of tourists has begun to swarm into every picturesque hole and corner of Europe. An old-standing love for the Alpine region usually draws me there, sooner or later, wherever I may chance to turn my steps immediately after leaving England. He who has once seen the mountain pastures in June will find their spell too strong to be resisted.
At that early time the herdsmen have not yet reached the higher pastures, and cows and goats have not cropped away the flowers which scent the pure cool breeze. The birds are undisturbed and trustful, and still busy with their young. The excellent mountain-inns are comparatively empty, the Marmots whistle near at hand, and the snow lies often so deep upon footpaths where a few weeks later even the feeblest mountaineer would be at home, that a fox, a badger, or even a little troop of chamois, may occasionally be seen without much climbing. If bad weather assails us on the heights, which are liable even in June to sudden snow-storms and bitter cold, we can descend rapidly into the valleys, to find warmth and a new stratum of bird-life awaiting us. And if persistent wet or cold drives us for a day or two to one of the larger towns, Bern, or Zürich, or Geneva, we can spend many pleasant hours in the museums with which they are provided, studying specimens at leisure, and verifying or correcting the notes we have made in the mountains.
It is a singular fact that I do not remember to have ever seen an Englishman in these museums, nor have I met with one in my mountain walks who had a special interest in the birds of the Alps. Something is done in the way of butterfly-hunting; botanists, or at least botanical tins, are not uncommon. The guide-books have something to say of the geology and the botany of the mountains, but little or nothing of their fauna. I have searched in vain through all the volumes of the Jahrbuch of the Swiss Alpine Club for a single article or paragraph on the birds, and the oracles of the English Alpine Club are no less dumb.
Not that ornithologists are entirely wanting for this tempting region; Switzerland has many, both amateur and scientific. A journal of Swiss ornithology is published periodically. Professor Fatio, of Geneva, one of the most distinguished of European naturalists, has given much time and pains to the birds of the Alpine world, and published many valuable papers on the subject, the results of which have been embodied in Mr. Dresser’s Birds of Europe. But what with the all-engrossing passion for climbing, and the natural indisposition of the young Englishman to loiter in that exhilarating air, it has come to pass that the Anglo-Saxon race has for long past invaded and occupied these mountains for three months in each year, without discovering how remarkable the region is in the movements and characteristics of its animal life.
I myself have been fortunate in having as a companion an old friend, a native of the Oberland, who has all his life been attentive to the plants and animals of his beloved mountains. Johann Anderegg will be frequently mentioned in this chapter, and I will at once explain who he is. A peasant of the lower Hasli-thal, in the canton of Bern, born before the present excellent system of education had penetrated into the mountains, was not likely to have much chance of developing his native intelligence; but I have never yet found his equal among the younger generation of guides, either in variety of knowledge, or in brightness of mental faculty. He taught himself to read and write, and picked up knowledge wherever he found a chance. When his term of military service was over, he took to the congenial life of a guide and “jäger,” in close fellowship with his first cousin and namesake, the famous Melchior, the prince of guides. But a long illness, which sent him for many months to the waters of Leukerbad, incapacitated him for severe climbing, and at the same time gave him leisure for thinking and observing: Melchior outstripped him as a guide, and their companionship, always congenial to both as men possessed of lively minds as well as muscular bodies, has long been limited to an occasional chat over a pipe in winter-time.
But he remained an ardent hunter, and has always been an excellent shot: and it was in this capacity, I believe, that he first became useful to the Professor Fatio whom I mentioned just now. He did much collecting for him, and in the course of their expeditions together, contrived to learn a great deal about plants, insects, and birds, most of which he retains in his old age. There is nothing scientific in his knowledge, unless it be a smattering of Latin names, which he brings out with great relish if with some inaccuracy; but it is of a very useful kind, and is aided by a power of eyesight which is even now astonishing in its keenness. I first made his acquaintance in 1868, and for several years he accompanied my brother and myself in glacier-expeditions in all parts of the Alps; but it has been of late years, since we have been less inclined for strenuous exertion, that I have found his knowledge of natural history more especially useful to me. He is now between sixty and seventy, but on a bracing alp, with a gun on his shoulder, his step is as firm and his enjoyment as intense, as on the day when he took us for our first walk on a glacier, eighteen years ago.
The mention of his gun reminds me, that though my old friend’s eyes and my own field-glasses were of the greatest help to me, I could not always satisfy myself as to the identity of a species; and two years ago I was forced to sacrifice the lives of some six or seven individuals. This, it is worth knowing, is illegal in all parts of Switzerland, and illegal at all times of the year; and I had to obtain a license from the Cantonal Government at Bern, kindly procured for me by another old acquaintance, Herr Immer of Meiringen and the Engstlen-alp, to shoot birds ‘in the cause of science.’ This delighted Anderegg; but at my earnest request he suppressed his sporting instincts, or only gave them rein in fruitless scrambles over rock and snow in search of Ptarmigan and Marmots.
I propose to occupy the latter part of this chapter in taking my readers a short expedition, in company with Anderegg, in search of Alpine birds; but let me first say something of the general conditions and characteristics of bird-life in Switzerland.
And first of the number of species, and abundance of individuals. People sometimes tell me that they never see any birds in the Alps. An elderly German, whose bodily exertions were limited, and whose faculties seemed to turn inwards on himself instead of radiating outwards, could not understand why I should go to Switzerland to study birds – for he could see none. And it is indeed true that they do not swarm there, as with us; in this respect Switzerland is like the rest of the Continent. It is a curious fact, that though we have only lately begun to preserve our small birds by law in the breeding-season, they are far more abundant here than they are in any part of the Continent known to me: and this is the case even with the little delicate migrants, many of which seem to have a preference for England in spite of the risk of the sea-crossing. I remember taking up a position one afternoon by the side of a rushing stream, dividing beautiful hay-meadows, and edged with dwarf willows; and during the half-hour I sat there, I neither saw nor heard a single bird. In such a spot in England there would have been plenty. But this is an exception: the rule is, that you may read wherever you run, if you will keep your eyes and ears open, and learn by experience where chiefly to be on the look-out. Variety is more interesting than numbers; the birds are more obvious from their comparative rarity; and their voices are not lost, as is sometimes the case with us, in a general and unceasing chorus. As regards the number of species in the country, I have never seen an accurate computation of it. But looking over Mr. Dresser’s very useful catalogue of the Birds of Europe, I calculate roughly that it would amount to about three hundred in all; i. e. less by some seventy or eighty than the avi-fauna of the British Islands. This is, however, a remarkably large number for a country that possesses no sea-board and very few of those sea-birds which form so large a contingent in our wonderful British list; and it suggests a few remarks on the causes which bring some birds to the Alps periodically, and have tempted others to make them their permanent home.
The greatest attractions for birds, and therefore the chief agents – as far as our present knowledge reaches – in inducing birds to move from place to place are food and variety of temperature. Now in the Alps we find these conditions of bird-life everywhere present, except, of course, in the very highest levels of snow and ice. The seed-eating birds find sufficient food in the rich hay, thick and sweet with flowers, which covers the whole of the Alpine pastures from May to July, and abundance of corn, flax, and fruit in the valleys: in the steep pine-woods that usually separate these valleys from the pastures, the larger seed-eaters enjoy an endless supply of fir-cones. The insect-eating birds are still more fortunate. Nothing is more striking in the Alps than the extraordinary abundance in the summer of insects of all kinds, as we know to our cost in the sun-baked valleys; and on the mountains it is equally wonderful though less annoying. There it is that the beetles have their paradise. In loose heaps of stone, often collected to clear a stony pasture; in the wooden palings used to separate alp from alp; in the decaying lumber of the pine-forests, beetles both small and great are absolutely swarming. A clergyman, pastor of a valley near Meiringen, who collected them, found more than eight hundred different species in his parish alone. All the birds shot for me at the Engstlen-alp had been living on a diet of minute beetles as their principal food. It is indeed wonderful to notice the strange disproportion between the abundance of food provided and the numbers of the birds who avail themselves of the repast: there is so much more to eat than can ever possibly be eaten.
But we must remember that this is the case only during the warm months. During the greater part of the year the snow is on the ground in the regions of which I am speaking, and hardly any birds are to be found there. A great and general migration takes place, either to the valleys below, or out of the mountain region altogether, southward, or in a very few cases, northward. Switzerland is, in fact, an admirable centre for the study of migration; migration, that is, on a large scale, where the birds leave the country entirely, and also on that limited scale which we call in England ‘partial’ migration. I believe that the Alps will some day win the attention of the ornithologists as being one of the best of all positions as a centre of observation. We will pause for a moment to glance at it in this light.
We need hardly look at the map to see that the huge mass of the Alps lies directly in the path of the great yearly migration of birds from south and east to northern Europe. The question arises at once, does this immense mountain-range, with its icy peaks and wind-swept passes, act as an obstacle to the travelling birds, or do they rise to it and cross it, without going round, into the plains of North Switzerland and Germany? I confess that I should like to be able to answer this question with greater certainty; but I believe the right answer, in the rough, to be as follows. In the first place, a large number of species never attempt to cross the mountains, but remain in the great basin of the Po, and in southern France, the whole summer, thus making the avi-fauna of Lombardy distinct in many points from that of Switzerland. If we look through the works of Dresser, Gould, or Bree, on European birds, with the object of learning something on this point, we find that bird after bird, especially among the tenderer kinds of warblers, gets no further than North Italy and the southern slopes of the Alps, seldom straggling into Switzerland proper. On the other hand, some migrating birds, such as the Black Redstart, the Citril Finch, and some of the hardier warblers, seem to desire a cool climate to breed in, and doubtless come across the passes to inhabit the Alpine pastures during the whole of the summer. How far this is also the case with the vast number of more delicate birds, such as the various Reed- and Willow-warblers, who live by the rivers and lakes during the summer, I cannot undertake to say; and it is a mere guess on my part if I hazard an opinion that many of these must come into Switzerland by way of France and Austria. Anderegg sent me word last autumn that he had noticed the Swallows leaving Meiringen, not southwards over the Grimsel pass towards Italy, but westwards, as if they were seeking to turn the vast mountain barrier. Yet it is a known fact that on some of the passes birds are watched and killed in their passage.
But I have still to speak of partial or internal migration in Switzerland; and this is what, if I am not mistaken, will prove a very fertile source of ornithological knowledge when thoroughly understood. As I said before, the agents which chiefly cause birds to move from one place to another (so far as we know), are food-supply and temperature. Now we have only to look at a raised map of Switzerland to see at once how subject the birds must be to such incitements towards change of place. Any one who has been to Switzerland will have noticed that the scenery falls into three great divisions – that of the lakes and valleys, that of the Alpine pastures and forests, and lastly, that of the regions on the border-line of perpetual snow, running upwards to the higher snow-fields. The professional mountaineer pays little attention to any but the last of these; the botanist and ornithologist have, fortunately, much reason to pause and reap a harvest in the lower levels, which are incomparably more beautiful. For convenience’ sake I will call the lowest, No. 1; the second – that of the Alpine pastures, No. 2; and the highest, No. 3. The distribution of birds in these three regions is continually changing. No. 3, in the winter, is entirely devoid of life and food. The Eagles and the great bearded Vultures, now very rare, can find not even a marmot to prey upon, for they are all asleep in their burrows. The Snow-finches and the Ptarmigan, which in the summer delight in the cool air of an altitude of 8000 to 10,000 feet, have descended to No. 2, or even lower, compelled by want of food and water: and so too the red-winged Rock-creeper, the Alpine-pipit and others, which may be seen in summer close to the great glaciers. In the same way the birds which haunt No. 2 in the summer – I am speaking of those which do not leave the country altogether – descend in the autumn to No. 1, and there remain till the following spring: among these are the Ring-ousel and Blackbird, the Nutcrackers, the Titmice, the Alpine Choughs, the Alpine Accentor, and others. Then in the spring the reverse process takes place. As the spring advances up the mountain-slopes, which it gains slowly, not reaching the highest region of vegetation till June or even July, the birds follow it. Region No. 1, now peopled by the immigrations from Africa and the Mediterranean, sends on large numbers of its winter birds to region No. 2, where, like the cows and the herdsmen who ascend about the same time, they enjoy cool air and abundance of food in the well-watered pastures. Meanwhile the Snow-finches, the Ptarmigan, and the birds of prey, who have been living during the winter in the lower slopes and woods of region No. 2, retire upwards to breed in the rocks and snowy crevices of No. 3. We can hardly help believing that with all these wonderful provisions of nature for their change of scene and temperature, these partial migrants of Switzerland must lead a life supremely happy. Man himself and his cattle are partial migrants in the Alps; and no day is so welcome to the herdsman as that on which the authorities of his commune fix for the first movement of the cows upwards. Bitter indeed has been the disappointment of my old guide, now the happy possessor of two cows, when he has not been able to follow them in their annual migration to the cooler pastures. He could realize the feelings of a caged bird, unable to follow its fellows in seeking the southern lands for which its heart yearns.
Before leaving this subject I should, perhaps, note that these three regions are not divided from each other by any definite line; and in respect of their bird-life I need hardly say they slide insensibly into each other. But I think it will be found that the division is a fair one for our purposes, and is a useful one to bear in mind in all dealings with the natural history of the country.
I will now ask my readers to follow me mentally in an expedition which will bring us into actual contact with many of the birds I have noticed in Switzerland. We will choose a route which from its great beauty, comparative quiet, and good inns, has always been a favourite of mine, and will carry us over parts of all the three regions I have just described, enabling us to compare their avi-fauna with that of our own country. Starting from the village of Stanz-stadt, famous in Swiss history, which stands on that arm of the lake of Lucerne which lies immediately beneath Mount Pilatus, we will pass up the luxuriant valley of the Aa, in canton Unter-walden, to Engelberg, where most of the land and forest is owned by the monks of a great monastery, whose care for their possessions has doubtless helped to make them a pleasant home for the birds; then we will mount to the pastures of the Gerstni-alp, in region No. 2, and so upwards to the Joch-pass, which in early summer is covered with snow, and introduces us to region No. 3. Descending for an hour to the Engstlen-alp, loveliest of Swiss pastures, we find ourselves here, at the excellent inn, again in No. 2, but still within very easy reach of No. 3; and then we can pass downwards through the Gentelthal, or along the pastures that look down on it from the north – for there are three different ways, all of them of the rarest beauty – to the deep valley of the Aar, or Hasli-thal, where we arrive once more in region No. 1.
