the passage or a removal of a thing out of one place into another.
Migration of Birds.—It has been generally believed, that many different kinds of birds annually pass generally from one country to another, and spend the summer or winter where it is most agreeable to them; and that even the birds of our own island will seek the most distant southern regions of Africa, when directed by a peculiar instinct to leave their own country. It has long been an opinion pretty generally received, that swallows reside during the winter season in the warm southern regions; and Mr Adanson particularly relates his having seen them at Senegal when they were obliged to leave this country. But besides the swallow, Mr Pennant enumerates many other birds which migrate from Britain at different times of the year, and are then to be found in other countries; after which they again leave these countries, and return to Britain. The reason of these migrations he supposes to be a defect of food at certain seasons of the year, or the want of a secure asylum from the persecution of man during the time of courtship, incubation, and nutrition. The following is his list of the migrating species:
1. Crows. Of this genus, the hooded crow migrates regularly with the woodcock. It inhabits North Britain the whole year: a few are said annually to breed on Migration on Dartmoor, in Devonshire. It breeds also in Sweden and Austria; in some of the Swedish provinces it only shifts its quarters, in others it resides throughout the year. Our author is at a loss for the summer retreat of those which visit us in such numbers in winter, and quit our country in the spring; and for the reason why a bird, whose food is such that it may be found at all seasons in this country, should leave us.
2. Cuckoo. Disappears early in autumn; the retreat of this and the following bird is quite unknown to us.
3. Wryneck. Is a bird that leaves us in the winter. If its diet be ants alone, as several assert, the cause of its migration is very evident. This bird disappears before winter, and revisits us in the spring a little earlier than the cuckoo.
4. Hoopoe. Comes to England but by accident; Mr Pennant once indeed heard of a pair that attempted to make their nest in a meadow at Selborne, Hampshire, but were frightened away by the curiosity of people. It breeds in Germany.
5. Grouse. The whole tribe, except the quail, lives here all the year round; that bird either leaves us, or else retires towards the sea coasts.
6. Pigeons. Some few of the ring doves breed here; but the multitude that appears in the winter is so disproportioned to what continue here the whole year, as to make it certain that the greatest part quit the country in the spring. It is most probable they go to Sweden to breed, and return from thence in autumn; as Mr Ekmark informs us they entirely quit that country before winter. Multitudes of the common wild pigeons also make the northern retreat, and visit us in winter; not but numbers breed in the high cliffs in all parts of this island. The turtle also probably leaves us in the winter, at least changes its place, removing to the southern counties.
7. Stare. Breeds here. Possibly several remove to other countries for that purpose, since the produce of those that continue here seems unequal to the clouds of them that appear in winter. It is not unlikely that many migrate into Sweden, where Mr Berger observes they return in spring.
8. Thrushes. The fieldfare and the redwing breed and pass their summers in Norway and other cold countries; their food is berries, which abounding in our kingdoms, tempts them here in the winter. These two and the Royton crow are the only land birds that regularly and constantly migrate into England, and do not breed here. The hawfinch and crossbill come here at such uncertain times as not to deserve the name of birds of passage.
9. Chatterer. The chatterer appears annually about Edinburgh in flocks during winter; and feeds on the berries of the mountain ash. In South Britain it is an accidental visitant.
10. Grosbeaks. The grosbeak and crossbill come here but seldom; they breed in Austria. The pine grosbeak probably breeds in the forests of the Highlands of Scotland.
11. Buntings. All the genus inhabits England throughout the year; excepting the greater brambling, which is forced here from the north in very severe seasons.
12. Finches. All continue in some parts of these kingdoms, except the siskin, which is an irregular visitant, said to come from Russia. The linnets shift their quarters, breeding in one part of this island, and remove with their young to others. All finches feed on the seeds of plants.
13. Larks, fly-catchers, wagtails, and warblers. All of these feed on insects and worms; yet only part of them quit these kingdoms; though the reason of migration is the same to all. The nightingale, blackcap, fly-catcher, willow-wren, wheat-eat, and whitethroat, leave us before winter, while the small and delicate golden-crested wren braves our severest frosts. The migrants of this genus continue longest in Great Britain in the southern counties, the winter in those parts being later than in those of the north; Mr Stillingsfleet having observed several wheat-eats in the isle of Purbeck on the 18th of November. As these birds are incapable of very distant flights, Spain, or the south of France, is probably their winter asylum.
14. Swallows and goatsucker. Every species disappears at the approach of winter.
WATER-FOWL.
Of the vast variety of water-fowl that frequent Great Britain, it is amazing to reflect how few are known to breed here; the cause that principally urges them to leave this country, seems to be not merely the want of food, but the desire of a secure retreat. Our country is too populous for birds so shy and timid as the bulk of these are: when great part of our island was a mere waste, a tract of woods and fen, doubtless many species of birds (which at this time migrate) remained in security throughout the year.—Egrets, a species of heron now scarcely known in this island, were in former times in prodigious plenty; and the crane, that has totally forsaken this country, bred familiarly in our marshes: their place of incubation, as well as of all other cloven-footed water-fowl (the heron excepted), being on the ground, and exposed to every one. As rural economy increased in this country, these animals were more and more disturbed; at length, by a series of alarms, they were necessitated to seek, during the summer, some lonely safe habitation.
On the contrary, those that build or lay in the almost inaccessible rocks that impend over the British seas, breed there still in vast numbers, having little to fear from the approach of mankind: the only disturbance they meet with in general being from the desperate attempts of some few to get their eggs.
CLOVEN-FOOTED WATER-FOWL.
15. Herons. The white heron is an uncommon bird, and visits us at uncertain seasons; the common kind and the bittern never leave us.
16. Curlews. The curlew breeds sometimes on our mountains: but, considering the vast flights that appear in winter, it is probable that the greater part retire to other countries: the whimbrel breeds on the Grampian hills, in the neighbourhood of Invercauld.
17. Snipes. The woodcock breeds in the moist woods of Sweden, and other cold countries. Some snipes breed here, but the greatest part retire elsewhere: as do every other species of this genus.
18. Sandpipers. The lapwing continues here the whole year; the ruff breeds here, but retires in winter; Migration. The redshank and sandpiper breed in this country, and reside here. All the others absent themselves during summer.
19. Plovers and oyster-catcher. The long-legged plover and sandpiper visit us only in winter; the dotterel appears in spring and in autumn; yet, what is very singular, we do not find it breeds in South Britain. The oyster-catcher lives with us the whole year. The Norfolk plover and sea-lark breed in England. The green plover breeds on the mountains of the north of England, and on the Grampian hills.
We must here remark, that every species of the genera of curlews, woodcocks, sandpipers, and plovers, that forsakes us in the spring, retires to Sweden, Poland, Prussia, Norway, and Lapland, to breed; as soon as the young can fly, they return to us again, because the frosts which set in early in those countries totally deprive them of the means of subsisting; as the dryness and hardness of the ground, in general, during our summer, prevent them from penetrating the earth with their bills, in search of worms, which are the natural food of these birds. Mr Ekmark speaks thus of the retreat of the whole tribe of cloven-footed waterfowl out of his country (Sweden) at the approach of winter; and Mr Klein gives much the same account of those of Poland and Prussia.
20. Rails and gallinules. Every species of these two genera continues with us the whole year; the land-rail excepted, which is not seen here in winter. It likewise continues in Ireland only during the summer months, when they are very numerous, as Mr Smith tells us in the History of Waterford, p. 336. Great numbers appear in Anglesea the latter end of May; it is supposed that they pass over from Ireland, the passage between the two islands being but small. As we have instances of these birds lighting on ships in the Channel and the bay of Biscay, we may conjecture their winter quarters to be in Spain.
FINNED-FOOTED WATER BIRDS.
21. Phalaropes. Visit us but seldom; their breeding place is Lapland, and other arctic regions.
22. Grebes. The great crested grebe, the black and white grebe, and little grebe, breed with us, and never migrate; the others visit us accidentally, and breed in Lapland.
WEB-FOOTED BIRDS.
23. Auklet. Breed near Foalstone in Lincolnshire, but quit their quarters in winter. They are then shot in different parts of the kingdom, which they visit, not regularly, but accidentally.
24. Auks and guillemots. The great auk or pinguin sometimes breeds in St Kilda. The auk, the guillemot, and puffin, inhabit most of the maritime cliffs of Great Britain, in amazing numbers, during summer. The black guillemot breeds in the Bass island, and in St Kilda, and sometimes in Llandudno rocks. We are at a loss for the breeding place of the other species; neither can we be very certain of the winter residence of any of them, excepting of the lesser guillemot and black-billed auk, which, during winter, visit vast flocks the frith of Forth.
25. Divers. These chiefly breed in the lakes of Sweden and Lapland, and in some countries near the pole; but some of the red-throated divers, the northern Migration, and the smew, may breed in the north of Scotland and its isles.
26. Terns. Every species breeds here; but leaves us in the winter.
27. Petrels. The fulmar breeds in the Isle of St Kilda, and continues there the whole year except September and part of October; the shearwater visits the Isle of Man in April; breeds there; and, leaving it in August or the beginning of September, disperses over all parts of the Atlantic ocean. The stormfinch is seen at all distances from land on the same vast watery tract; nor is ever found near the shore except by some very rare accident, unless in the breeding season. Mr Pennant found it on some little rocky isles off the north of Skye. It also breeds in St Kilda. He also supposes that it nests on the Blasket isles off Kerry, and that it is the gourder of Mr Smith.
28. Mergansers. This whole genus is mentioned among the birds that fill the Lapland lakes during summer. Mr Pennant has seen the young of the red-breasted in the north of Scotland; a few of these, and perhaps of the goosanders, may breed there.
29. Ducks. Of the numerous species that form this genus, we know of few that breed here: The swan and goose, the shelduck, the eider duck, a few shovellers, garganies, and teals, and a very small portion of the wild ducks.
The rest contribute to form that amazing multitude of water-fowl that annually repair from most parts of Europe to the woods and lakes of Lapland and other arctic regions, there to perform the functions of incubation and nutrition in full security. They and their young quit their retreat in September, and disperse themselves over Europe. With us they make their appearance the beginning of October; circulate first round our shores; and, when compelled by severe frosts, betake themselves to our lakes and rivers. Of the web-footed fowl there are some of hardier constitutions than others: these endure the ordinary winters of the more northern countries; but when the cold reigns there with more than common rigour, they repair for shelter to these kingdoms: this regulates the appearance of some of the diver kind, as also of the wild swans, the swallow-tailed shelduck, and the different sorts of goosanders which then visit our coasts. Barentz found the barnacles with their nests in great numbers in Nova Zembla. (Collect. Voy. Dutch East-India Company, 8vo, 1703, p. 19.) Clusius, in his Exot. 368, also observes, that the Dutch discovered them on the rocks of that country and in Waygate straits. They, as well as the other species of wild geese, go very far north to breed, as appears from the histories of Greenland and Spitzbergen, by Egede and Crantz. These birds seem to make Iceland a resting place, as Horrebouw observes: few continue there to breed, but only visit that island in the spring, and after a short stay retire still further north.
30. Corvoraent. The corvoraent and flag breed on most of our high rocks: the gannet in some of the Scotch isles and on the coast of Kerry: the two first continue on our shores the whole year. The gannet disperses itself all round the seas of Great Britain, in pursuit of the herring and pilchard, and even as far as the Pagus to prey on the sardina. But of the numerous species of fowl here enumerated, it may be observed how very few intrust themselves to us in the breeding season, and what a distant flight they make to perform the first great dictate of nature.
There seems to be scarcely any but what we have traced to Lapland; a country of lakes, rivers, swamps, and alps, covered with thick and gloomy forests, that afford shelter during summer to these fowls, which in winter disperse over the greatest part of Europe. In those arctic regions, by reason of the thickness of the woods, the ground remains moist and penetrable to the woodcocks, and other slender-billed fowl; and for the web-footed birds, the waters afford larvae innumerable of the tormenting gnat. The days there are long; and the beautiful meteorous nights indulge them with every opportunity of collecting to minute a food; whilst mankind is very sparingly scattered over that vast northern waste.
Why then should Linnaeus, the great explorer of these rude deserts, be amazed at the myriads of water-fowl that migrated with him out of Lapland? which exceeded in multitude the army of Xerxes; covering, for eight whole days and nights, the surface of the river Calix! His partial observation as a botanist, would confine their food to the vegetable kingdom, almost denied to the Lapland waters; inattentive to a more plenteous table of insect food, which the all-bountiful Creator had spread for them in the wilderness. It may be remarked, that the lakes of mountainous rocky countries in general are destitute of plants: few or none are seen on those of Switzerland; and Linnaeus makes the same observation in respect to those of Lapland; having, during his whole tour, discovered only a single specimen of a lemma triflora, or "ivy-leaved duck's meat," Flora Lap. No. 472; a few of the feirus lacustris, or "bullrush," No. 18; the alopecurus geniculatus, or "flote foxtail-grass," No. 38.; and the ranunculus aquatilis, No. 234.; which are all he enumerates in his Prolegomena to that excellent performance.
We shall afterwards state the principal arguments for and against the migration of swallows; but here we shall give a short abstract of the arguments used by the Hon. Daines Barrington against the migration of birds in general, from a paper published by him in the 62d volume of the Philosophical Transactions. This gentleman denies that any well-attested instances can be produced of this supposed migration; which, he thinks, if there were any such periodical flight, could not possibly have escaped the frequent observation of seamen. It has indeed been asserted that birds of passage become invisible in their flight, because they rise too high in the air to be perceived, and because they choose the night for their passage. The author, however, expresses his doubts "whether any bird was ever seen to rise to a greater height than perhaps twice that of St Paul's cross;" and he further endeavours to show, that the extent of some of these supposed migrations (from the northern parts of Europe, for instance, to the line) is too great to be accounted for, by having recourse to the argument founded on a nocturnal passage.
The author next recites, in a chronological order, all the instances that he has been able to collect, of birds having been actually seen by mariners when they were crossing a large extent of sea; and he endeavours to show that no stress can be laid on the few casual observations of this kind that have been produced in support of the doctrine of a regular and periodical migration.
Mr Barrington afterwards proceeds to invalidate M. Adanson's celebrated observation with respect to the migration of the swallow in particular, and which has been considered by many as perfectly decisive of the present question. He endeavours to show that the four swallows which that naturalist caught, on their settling upon his ship, on the 6th of October, at about the distance of 50 leagues from the coast of Senegal, and which he supposes to have been then proceeding from Europe to pass the winter in Africa, could not be true European swallows; or, if they were, could not have been on their return from Europe to Africa. His objections are founded principally on some proofs which he produces of M. Adanson's want of accuracy on this subject, which has led him, in the present instance, to mistake two African species of the swallow tribe, described and engraved by Brisson, for European swallows, to which they bear a general resemblance; or granting even that they were European swallows, he contends that they were shifting from the Cape de Verd islands to the coast of Africa; "to which short flight, however, they were unequal, and accord. *Natural History of Selborne,* add, in opposition to the remarks of Mr Barrington, letter ix., the following observations of the Rev. Mr White * in p. 139., a letter to Mr Pennant on this subject.
"We must not (says he) deny migration in general; because migration certainly does subsist in some places, as my brother in Andalusia has fully informed me. Of the motions of these birds he has ocular demonstration, for many weeks together, both spring and fall: during which periods myriads of the swallow kind traverse the Straits from north to south, and from south to north, according to the season. And these vast migrations consist not only of hirundines, but of bee-birds, hoopoes, oro pendolos, or golden thrushes, &c. &c. and also of many of our soft-billed summer birds of passage; and moreover of birds which never leave us, such as all the various sorts of hawks and kites. Old Belon, 200 years ago, gives a curious account of the incredible armies of hawks and kites which he saw in the spring time traversing the Thracian Bosphorus from Asia to Europe. Besides the above mentioned, he remarks that the procession is swelled by whole troops of eagles and vultures.
"Now it is no wonder that birds residing in Africa should retreat before the sun as it advances, and retire to milder regions, and especially birds of prey, whose blood being heated with hot animal food, are more impatient of a sultry climate: but then I cannot help wondering why kites and hawks, and such hardy birds as are known to defy all the severity of England, and even of Sweden and all northern Europe, should want to migrate from the south of Europe, and be dissatisfied with the winters of Andalusia.
"It does not appear to me that much stress may be laid on the difficulty and hazard that birds must run in their migrations, by reason of vast oceans, crofs winds, &c.; because, if we reflect, a bird may travel from England to the equator without launching out and exposing..." Migration posing itself to boundless seas, and that by crossing the water at Dover and again at Gibraltar. And I with the more confidence advance this obvious remark, because my brother has always found that some of his birds, and particularly the swallow kind, are very sparing of their pains in crossing the Mediterranean: for when arrived at Gibraltar, they do not,
"rang'd in figure, wedge their way, and set forth
"Their airy caravan high over seas "Flying, and over lands with mutual wing "Easing their flight."
Milton.
but scat and hurry along in little detached parties of six or seven in a company; and sweeping low, just over the surface of the land and water, direct their course to the opposite continent at the narrowest passage they can find. They usually slope across the bay to the southwest, and so pass over opposite to Tangier, which it seems is the narrowest place.
"In former letters we have considered whether it was probable that woodcocks in moon-shiny nights cross the German ocean from Scandinavia. As a proof that birds of less speed may pass that sea, considerate as it is, I shall relate the following incident, which, though mentioned to have happened to many years ago, was strictly matter of fact:—As some people were shooting in the parish of Trotton, in the county of Sussex, they killed a duck in that dreadful winter 1708-9, with a silver collar about its neck (I have read a like anecdote of a swan), on which were engraved the arms of the king of Denmark. This anecdote the rector of Trotton at that time has often told to a near relation of mine; and, to the best of my remembrance, the collar was in the possession of the rector.
"At present I do not know any body near the sea side that will take the trouble to remark at what time of the moon woodcocks first come. One thing I used to observe when I was a sportsman, that there were times in which woodcocks were so sluggish and sleepy that they would drop again when flushed just before the spaniels, nay just at the muzzle of a gun that had been fired at them: whether this strange laziness was the effect of a recent fatiguing journey, I shall not presume to say.
"Nightingales not only never reach Northumberland and Scotland, but also, as I have been always told, Devonshire and Cornwall. In those two last counties we cannot attribute the failure of them to the want of warmth: the defect in the west is rather a presumptive argument that these birds come over to us from the continent at the narrowest passage, and do not stroll so far westward."
Upon the subject of the migration of the swallow there are three opinions. Some say that it migrates to a warmer climate; some, that it retires to hollow trees and caverns, where it lies in a torpid state; and others have affirmed, that it lies in the same state in the bottom of lakes and under the ice. The first opinion is supported by Maraghi, Ray, Willoughby, Catesby, Reaumur, Adanson, Buffon, &c. The first and second opinion are both adopted by Pennant and White. The third is sanctioned by Schaeffer, Hevelius, Derham, Klein, Ellis, Linnæus, Kalm; and the second and third have been strongly defended by the honourable Migration, Daines Barrington.
Though we cannot help giving a preference to that opinion which appears the most probable, yet we do not think that any one of them is established upon such evidence as so curious a subject requires, and as the advanced state of natural history would lead us to expect. We shall therefore state the arguments upon which each opinion is founded as fairly and distinctly as we can, and as often as possible in the very words of their respective advocates. By doing so, we shall place the whole subject before the eyes of our readers, who will thus have an opportunity of examining it attentively, and of making such observations and experiments as may lead to the truth.
Those who assert that the swallow migrates to a warmer country in winter, argue in this manner: That many birds migrate, is a fact fully proved by the observations of natural historians. Is it not more probable, therefore, that swallows, which disappear regularly every season, retire to some other country, than that they lie in a state of torpor in caverns or lakes? But this opinion does not rest on probability, it is founded on facts.
We often see them collected in great flocks on churches, rocks, and trees, about the time when they annually disappear. The direction of their flight has been observed to be southward. Mr White, the ingenious historian of Selborne, travelling near the coast of the British Channel one morning early, saw a flock of swallows take their departure. At the beginning of his journey he was environed with a thick fog; but on a large wild heath the mist began to break, and discovered to him numberless swallows, cluttered on the standing bushes, as if they had roosted there; as soon as the sun burst out, they were instantly on wing, and with an easy and placid flight proceeded towards the sea. After this he saw no more flocks, only now and then a straggler.
Mr Laffey of Exeter observed attentively the direction which a flock of swallows took in the autumn of 1793. On the 22d of Sept., about seven o'clock in the morning, the wind being easterly, accompanied with a cold drizzling rain, Mr Laffey's house was entirely covered with house-swallows. At intervals large flocks arrived and joined the main body, and at their arrival an unusual chirping commenced. The appearance of the whole company was so lethargic, that he found it an easy matter to catch a considerable number of them, which he kept in a room all that day. By heating the room they all revived: he opened four of them, and found their stomachs quite full. The main body occupied the house top all day, except for two hours. About half an hour after nine in the morning of the 23d, there was a great commotion, with very loud chirping, and within a few minutes after, the whole multitude took their flight, in a direct southeast direction, having ascended to a great height in the atmosphere. He let go the birds which he had caught, at certain intervals till four o'clock, and they all flew toward the same quarter.
Not only has the direction of their flight been observed, but they have also been found on their passage at a great distance from land. Mr Adamson informs us, that about 50 leagues from the coast of Senegal four swallows settled upon the ship on the 6th of October; Migration that these birds were taken; and that he knew them to be European swallows, which, he conjectures, were returning to the coast of Africa. Sir Charles Wager's authority may also be appealed to: "Returning home (says he) in the spring of the year, as I came into foundings in our channel, a great flock of swallows came and settled on all my rigging; every rope was covered, they hung on one another like a swarm of bees; the decks and carvings were filled with them. They seemed almost famished and spent, and were only feathers and bones; but, being recruited with a night's rest, took their flight in the morning." This vast fatigue proves that their journey must have been very great, considering the amazing swiftness of these birds; in all probability they had crossed the Atlantic ocean, and were returning from the shores of Senegal, or other parts of Africa; so that this account from that most able and honest seaman, confirms the later information of Mr Adanson.
Mr Kalm, who is an advocate for the opinion that swallows lie immersed in lakes during winter, acknowledges that in crossing the Atlantic from Europe a swallow lighted on the ship on the 2d September, when it had palled only two-thirds of the ocean. Since, therefore, swallows have been seen assembled in great flocks in autumn flying off in company towards southern climes, since they have been found both in their passage from Europe and returning again, can there be any doubt of their annual migration?—Mr Barrington's objections to this opinion have been noticed above in No. 5.
The second notion (says Mr Pennant) has great antiquity on its side. Aristotle and Pliny give it as their belief, that swallows do not remove very far from their summer habitation, but winter in the hollows of rocks, and during that time lose their feathers. The former part of their opinion has been adopted by several ingenious men; and of late several proofs have been brought of some species, at least, having been discovered in a torpid state. Mr Collinson favoured us with the evidence of three gentlemen, eye-witnesses to numbers of sand martins being drawn out of a cliff on the Rhine, in the month of March 1762. And the honourable Daines Barrington communicated to us the following fact, on the authority of Lord Belhaven, That numbers of swallows have been found in old dry walls and in sand-hills near his Lordship's seat in East Lothian; not once only, but from year to year; and that when they were exposed to the warmth of a fire, they revived. We have also heard of the same annual discoveries near Morpeth in Northumberland, but cannot speak of them with the same assurance as the two former: neither in the two last instances are we certain of the particular species.
Other witnesses crowd on us to prove the residence of those birds in a torpid state during the severe season. First, In the chalky cliffs of Sussex; as was seen on the fall of a great fragment some years ago. Secondly, In a decayed hollow tree that was cut down, near Dolgelli, in Merionethshire. Thirdly, In a cliff near Whitby, Yorkshire; where, on digging out a fox, whole buffalos of swallows were found in a torpid condition. And, lastly, The reverend Mr Conway of Sychton, Flintshire, was so obliging as to communicate the following fact: A few years ago, on looking down an old lead-mine in that county, he observed numbers of swallows Migration, clinging to the timbers of the shaft, seemingly asleep; and on flinging some gravel on them, they just moved, but never attempted to fly or change their place: this was between All Saints and Christmas.
There are doublets the lurking places of the later hatches, or of those young birds which are incapable of distant migrations. There they continue insensible and rigid; but like flies may sometimes be reanimated by an unseasonable hot day in the midst of winter: for very near Christmas a few appeared on the moulding of a window of Merton college, Oxford, in a remarkably warm nook, which prematurely set their blood in motion, having the same effect as laying them before a fire at the same time of year. Others have been known to make this premature appearance; but as soon as the cold natural to the season returns, they withdraw again to their former retreats.
The above are circumstances we cannot but affront to, though feebly contradictory to the common course of nature in regard to other birds. We must, therefore, divide our belief relating to these two so different opinions; and conclude, that one part of the swallow tribe migrate, and that others have their winter quarters near home. If it should be demanded, why swallows alone are found in a torpid state, and not the other many species of loft-billed birds, which likewise disappear about the same time? reasons might be assigned.
The third opinion we shall state and support in the third words of Mr Kalm. "Natural history (says he), as such, that all other histories, depends not always upon the intrinsic degree of probability, but upon facts founded on the testimony of people of noted veracity.—Swallows are seldom seen sinking down into water; swallows have not such organs as frogs or lizards, which are torpid during winter; ergo, swallows live not, and cannot live, under water.—This way of arguing, I believe, would carry us, in a great many cases too far: for though it is not clear to every one, it may however be true; and lizards and frogs are animals of a class widely different from that of birds, and must therefore of course have a different structure; hence it is they are clasped separately. The bear and marmot are in winter in a torpid state, and have, however, not such organs as lizards and frogs; and nobody doubts of their being, during some time, in the most rigid climates, in a torpid state: for the Alpine nations hunt the marmots frequently by digging their holes up; and find them so torpid, that they cut their throats, without their reviving or giving the least sign of life during the operation; but when the torpid marmot is brought into a warm room, and placed before the fire, it revives from its lethargy. The question must therefore be decided by facts; nor are these wanting here. Dr Wallerius, the celebrated Swedish chemist, informs us, That he has seen, more than once, swallows assembling on a reed, till they were all immersed and went to the bottom; this being preceded by a dirge of a quarter of an hour's length. He attests likewise, that he had seen a swallow caught during winter out of a lake with a net, drawn, as is common in northern countries, under the ice; this bird was brought into a warm room, revived, fluttered about, and soon after died.
Mr Klein applied to many farmers-general of the king Migration, king of Prussia's domains, who had great lakes in their districts, the fishery in them being a part of the revenue.
In winter the fishery thereon is the most considerable under the ice, with nets spreading more than 200 or 300 fathoms, and they are often wound by screws and engines on account of their weight. All the people that were questioned made affidavits upon oath before the magistrates. First, the mother of the countess Lebdorf said, that she had seen a bundle of swallows brought from the Frühe-Haff (a lake communicating with the Baltic at Pillau), which, when brought into a moderately warm room, revived and fluttered about. Secondly, Count Schlieben gave an information on stamped paper, importing, that by fishing on the lake belonging to his estate of Gerdaun in winter, he saw several swallows caught in the net, one of which he took up in his hand, brought it into a warm room, where it lay about an hour, when it began to stir, and half an hour after, it flew about in the room. Thirdly, Farmer-general (Amtman) Witkowski made affidavit, that, in the year 1740, three swallows were brought up with the net in the great pond at Döblitzken; in the year 1741 he got two swallows from another part of the pond, and took them home (they being all caught in his presence); after an hour's space they revived all in a warm room, fluttered about, and died in three hours after. Fourthly, Amtman Bonke says, that having had the estate of Kleefkow in farm, he had seen nine swallows brought up in the net from under the ice, all which he took into a warm room, where he distinctly observed how they gradually revived; but a few hours after they all died. Another time his people got likewise some swallows in a net, but he ordered them to be again thrown into the water. Fifthly, Andrew Rutka, a master fisherman at Oletsko, made affidavit, in 1747, that 22 years ago, two swallows were taken up by him in a net, under the ice, and, being brought into a warm room, they flew about. Sixthly, Jacob Kofilo, a master fisherman at Stradauen made affidavit, that, in 1736, he brought up in winter, in a net, from under the ice of the lake at Rafki, a seemingly dead swallow, which revived in half an hour's time in a warm room; and he saw, in a quarter of an hour after, the bird grow weaker, and soon after dying. Seventhly, I can reckon myself (says our author) among the eye-witnesses of this paradox of natural history. In the year 1735, being a little boy, I saw several swallows brought in winter by the fishermen from the river Viftula to my father's house; where two of them were brought into a warm room, revived, and flew about. I saw them several times settling on the warm stove (which the northern nations have in their rooms); and I recollect well, that the same forenoon they died, and I had them, when dead, in my hand. In the year 1754, after the death of my uncle Godefroy Wolf, captain in the Polish regiment of foot guards, being myself one of his heirs, I administered for my co-heirs several estates called the Starogly of Döschau, in Polish Prussia, which my late uncle farmed under the king. In January, the lake of Lybthaw, belonging to these estates, being covered with ice, I ordered the fishermen to fish therein, and in my presence several swallows were taken, which the fishermen threw in again; but one I took up myself, brought it home, which was five miles from thence, and it revived, but died about an hour after its reviving.
"Thele are facts attested by people of the highest quality, by some in public offices, and by others who, though of a low rank, however, made these affidavits upon oath. It is impossible to suppose indiscriminately that they were prompted, by views of interest, to assert as a fact a thing which had no truth in it. It is therefore highly probable, or rather incontestably true, that swallows retire in the northern countries, during winter, into the water, and stay there in a torpid state till the return of warmth revives them again in spring. The question therefore, I believe, ought for the future to be thus stated: The swallows in Spain, Italy, France, and perhaps some from England, remove to warmer climates; some English ones, and some in Germany and other mild countries, retire into crevices and holes in rocks, and remain there in a torpid state. In the colder northern countries the swallows immerse in the sea, in lakes, and rivers; and remain in a torpid state, under ice, during winter. There are still some objections to this latter assertion, which we must remove. It is said, Why do not rapacious fish, and aquatic quadrupeds and birds, devour these swallows? The answer is obvious, swallows choose only such places in the water for their winter retreat as are near reeds and rushes; so that sinking down there between them and their roots, they are by them secured against the rapaciousness of their enemies. But others object, Why are not these birds caught in such fresh waters as are continually harassed by nets? I believe the same answer which has been made to the first objection will serve for this likewise. Fishermen take care to keep off with their nets from places filled with reeds and rushes, for fear of entangling and tearing their net; and thus the situation of swallows under water, is the reason that they are seldom disturbed in their silent winter retreats. What confirms this opinion still more is, that swallows were never caught in Prussia according to the above-mentioned affidavits, but with those parts of the net which passed near to the reeds and rushes; and sometimes the swallows were yet fastened with their feet to a reed, when they were drawn up by the net. As to the argument taken from their being so long under water without corruption, I believe there is a real difference between animals suffocated in water and animals being torpid therein. We have examples of things being a long time under water; to which we may add the intense cold of these northern regions, which preserves them. Who would have thought that snails and polyps might be affected, and could reproduce the parts fevered from their bodies, if it was not a fact? Natural history ought to be studied as a collection of facts, not as the history of our guesses or opinions. Nature varies in an infinite manner; and Providence has diversified the instinct of animals and their economy, and adapted it to the various seasons and climates."
With Mr Kalm's concluding observations we heartily concur. Natural history ought to be studied as a collection of facts; and it was from this very notion that we have stated the above-mentioned opinions fairly, and brought together the facts which the best observers, but advocates for each opinion have judged most proper for supporting. Migration supporting them. We are sensible of the great improbability of the third opinion, and know that many arguments have been used to prove its absurdity; such as the swallow is lighter than water, and therefore cannot sink; if it moults at all, it must moult under water during its torpid state, which is very improbable; there is no instance of land animals living so long under water without respiration. Many other arguments of the same sort have been advanced, and certainly afford a short way of deciding the question; but unless they were sufficient to prove the immersion of swallows a physical impossibility, they are of no force when opposed to the evidence of testimony, if there be no cause to suspect the witnessess of inaccuracy or design. The true way to refute such an opinion is by accurate observation and experiment. We have not heard of any accurate inquiries being made by philosophers in those northern countries where swallows are said to pass the winter under water. The count de Buffon, indeed, shut up some swallows in an ice house by way of experiment, which died in a few days; but as he does not tell us what precautions he took to make the experiment succeed, it is not entitled to any attention.
Mr John Hunter made a very judicious experiment on the banks of the Thames, which is described by a correspondent in the Gentleman's Magazine, who asserts that he had it from Mr Hunter himself.
One year in the month of September, he prepared a room, with every accommodation and convenience which he could contrive, to serve as a dormitory for swallows, if they were disposed to sleep in winter. He placed in the centre a large tub of water with twigs and reeds, &c., which reached to the bottom. In the corners of the room he contrived artificial caverns and holes, into which they might retire; and he laid on the floor, or suspended in the air, different lengths of old wooden pipes, which had formerly been employed in conveying water through the streets, &c.
When the receptacle was rendered as complete as possible, he then engaged some watermen to take by night a large quantity of the swallows that hang upon the reeds in the Thames about the time of their departure. They brought him, in a hamper, a considerable number; and had so nicely hit the time of their capture, that on the very day following there were none to be seen.
He put the swallows into the room so prepared, where they continued to fly about, and occasionally perch on the twigs, &c. But not one ever retired into the water, the caverns, holes, or wooden pipes, or shewed the least disposition to grow torpid, &c. In this situation he let them remain till they all died but one. This appearing to retain some vigour, was set at liberty; when it mounted out of sight, and flew away. All the birds lay dead scattered about the room; but not one was found asleep or torpid, or had, if the correspondent remembers, so much as crept into any of the receptacles he had so provided.
This experiment was ingenious, and certainly does render the doctrine of immersion much more improbable; but it is not decisive; for it may still be urged by the advocates for that doctrine, as Mr Kalm has done, that it may only be in the colder countries where swallows retire into the water. We formerly said that none of the three opinions is supported by such evidence as to satisfy the mind completely. Opinions respecting events which happen every year ought to be confirmed by a great number of observations, and not by a few instances divested of almost all their concomitant circumstances. Can no better proofs be brought to prove the migration of swallows than those of Adanson and Sir Charles Wager, or the circumstances mentioned by Mr White and Mr Larkkey respecting their disappearance? We ought not merely to know that some swallows have taken a further flight in autumn, that some have been found at a great distance from land in the spring, or in harvest; but we ought to know to what countries they actually retire. Before we can rest satisfied, too, that it is a general fact that swallows remain in a torpid state during winter, either in caverns or in the bottom of lakes, &c., we must have more proofs; we must know what species of swallows they are said to be, in what countries this event takes place, and several other circumstances of the same kind.
We cannot help being of opinion that much remains to be done in order properly to ascertain what becomes of the swallows in Europe during winter. It would be necessary, in the first place, to know accurately what order to determine they remain visible the whole year? or, if they disappear, at what season does this happen, and when do they appear again? 3. Do they ever appear while a strong north wind blows, or do they only come in great numbers with a south wind? We will endeavour to answer some of these questions in part; but must regret, that all the information on this subject which we have been able to collect from the best writers in natural history is very scanty; and we merely give it by way of specimen, hoping that future observations will render it more complete.
There are five species which visit Britain during the summer months; the common or chimney swallow, the martin, sand martin, swift, and goat-sucker. 1. The chimney swallow frequents almost every part of the old continent; being known (says Dr Latham) from Norway to the Cape of Good Hope on the one side, and from Kamtchatka to India and Japan on the other. It is also found in all parts of North America, and in several of the West Indian islands. In Europe it disappears during the winter months. It appears generally a little after the vernal equinox; but rather earlier in the southern, and later in the northern latitudes. It adheres to the usual seasons with much regularity; for though the months of February and March should be uncommonly mild, and April and May remarkably cold, it never deviates from its ordinary time. In the cold spring of 1742 some appeared in France before the insects on which they feed had become numerous enough to support them, and great numbers died. In the mild and even warm spring of 1774 they appeared no earlier than usual. They remain in some birds, warm countries the whole year. Kolben affirms us vol vi, that this is the case at the Cape of Good Hope; but (he says) they are more numerous in winter. Some birds of this species live, during winter, even in Europe; for example, on the coast of Genoa, where they spend the night in the open country on the orange shrubs. The martins are also widely diffused through the old continent; but the countries where they reside or visit have not been marked by naturalists with much attention.
Two birds of this species were seen in Perigord in France, on the 27th December 1775, when there was a southerly wind, attended with a little rain.
The swift visits the whole continent of Europe; has also been observed at the Cape of Good Hope, and in Carolina in North America.
They are found in every country between Sweden and Africa; they are found also in India. In April the southwest wind brings them to Malta, and in autumn they repass in great numbers.
Mr Markwick of Catsfield, near Battle in Sussex, has drawn up an accurate table, expressing the day of the month on which the birds, commonly called migratory, appeared in spring, and disappeared in autumn, for 16 years, from 1768 to 1783 inclusive. The observations were made at Catsfield. From this table we shall extract the dates for five years, and add the very few observations which we have been able to collect reflecting the time when the swallow appears and disappears in other countries.
| First seen | Last seen | |------------|-----------| | 1779 | October 29 | | Chimney Swallow Martins | April 14 | | Sand Martin | May 7 | | Swift | 9 | | 1780 | November 3 | | Chimney Swallow Martins | April 29 | | Sand Martin | May 8 | | Swift | May 6 | | 1781 | October 15 | | Chimney Swallow Martins | April 8 | | Sand Martin | May 12 | | Swift | May 12 | | 1782 | September 1 | | Chimney Swallow Martins | April 22 | | Sand Martin | May 15 | | Swift | May 18 | | 1783 | November 6 | | Chimney Swallow Martins | April 13 | | Sand Martin | May 1 | | Swift | July 25 | | Chimney Swallow Martins | May 13 |
We acknowledge it to be rather a curious than an important inquiry; yet it is one which must be highly gratifying to every mind that can admire the wisdom of the Great Architect of nature. The instinct of the swallow is indeed wonderful: it appears among us just at the time when insects become numerous; and it continues with us during the hot weather, in order to prevent them from multiplying too much. It disappears when these insects are no longer troublesome. It is never found in solitude; it is the friend of man, and always takes up its residence with us, that it may protect our houses and our streets from being annoyed with swarms of flies.
Migration of Fishes. See Clupea.
Sr Miguel, one of the Azores islands, situated in W. Long. 22. 45. N. Lat. 38. 10. This island appears to be entirely volcanic. The best account we have of it hath been published in the 68th volume of the Philosophical Transactions by Mr Francis Maffon. According to him, the productions differ greatly from those of Madeira, inasmuch that none of the trees of the latter are found here, except the taya: it has a nearer affinity to Europe than Africa. The mountains are covered with the erica vulgaris, and an elegant evergreen shrub very like a phillyrea, which gives them a most beautiful appearance.
It is one of the principal and most fertile of the Azorian islands, lying nearly east and west. Its length is about 18 or 20 leagues; its breadth unequal, not exceeding five leagues, and in some places not more than two. It contains about 80,000 inhabitants.
Its capital, the city of Ponta del Guda, which contains about 12,000 inhabitants, is situated on the south side of the island, on a fine fertile plain country, pretty regularly built; the streets straight, and of a good breadth. It is supplied with good water, which is brought about the distance of three leagues from the neighbouring mountains. The churches and other religious edifices are elegant and well built for such an island. There is a large convent of Franciscan friars and one of the order of St Augustine, four convents for professed nuns, and three Ricolimentos for young women and widows who are not professed. The vessels anchor in an open road; but it is not dangerous, as no wind can prevent their going to sea in case of stormy weather.
The country round the city is plain for several miles, well cultivated, and laid out with good taste into spacious fields, which are sown with wheat, barley, Indian corn, pulse, &c., and commonly produce annually two crops; for as soon as one is taken off, another is immediately sown in its place. The soil is remarkably gentle and easy to work, being for the most part composed of pulverized pumice stone. There are in the plains a number of pleasant country seats, with orchards of orange trees, which are esteemed the best in Europe.
The second town is Ribeira Grande, situated on the north side of the island, containing about as many inhabitants as the city; a large convent of Franciscan friars, and one of nuns. It gives title to a count, called the Conde Ribeira Grande, who first instituted linen and woollen manufactures in the island.
The third town is Villa Franca, on the south side of the island, about six leagues east of Ponta del Guda. Miguel. It has a convent of Franciscan friars and one of nuns, which contains about 300. Here, about half a mile from the shore, lies a small island (Ilhao), which is hollow in the middle, and contains a fine basin with only one entrance into it, fit to hold 50 sail of vessels secure from all weather; at present it wants cleaning out, as the winter rain washes down great quantities of earth into it, which has greatly diminished its depth. But vessels frequently anchor between this island and the main.
Besides these towns are several smaller, viz. Alagao, Agoa de Pao, Brelanha, Fannes de Ajuda, and a number of hamlets, called lugares or places.
About four leagues north-east from Villa Franca, lies a place called the Furnas, being a round deep valley in the middle of the east part of the island, surrounded with high mountains, which, though steep, may be easily ascended on horseback by two roads. The valley is about five or six leagues in circuit. The face of the mountains, which are very steep, is entirely covered with beautiful evergreens, viz. myrtles, laurels, a large species of bilberry called uva de ferro &c., and numberless rivulets of the purest water run down their sides. The valley below is well cultivated, producing wheat, Indian corn, flax, &c. The fields are planted round with a beautiful sort of poplars, which grow into pyramidal forms, and by their careless irregular disposition, together with the multitude of rivulets, which run in all directions through the valley, a number of boiling fountains throwing up clouds of steam, a fine lake in the south-west part about two leagues round, compose a prospect the finest that can be imagined. In the bottom of the valley the roads are smooth and easy, there being no rocks, but a fine pulverized pumice stone that the earth is composed of.
There are numerous hot fountains in different parts of the valley, and also on the sides of the mountains; but the most remarkable is that called the chaldeira, situated in the eastern part of the valley, on a small eminence by the side of a river, on which is a basin about 30 feet diameter, where the water continually boils with prodigious fury. A few yards distant from it is a cavern in the side of the bank, in which the water boils in a dreadful manner, throwing out a thick, muddy, unctuous water, several yards from its mouth with a hideous noise. In the middle of the river are several places where the water boils up so hot, that a person cannot dip his finger into it without being scalded; also along its banks are several apertures, out of which the steam rises to a considerable height, so hot that there is no approaching it with one's hand: in other places, a person would think that 100 smiths bellows were blowing altogether, and sulphurous steams issuing out in thousands of places; so that native sulphur is found in every chink, and the ground covered with it like hoar frost; even the bushes that happen to lie near these places are covered with pure brimstone, condensing from the steam that issues out of the ground, which in many places is covered over with a substance like burnt alum. In these small caverns, from which the steam issues, the people often boil their yams.
Near these boiling fountains are several mineral springs; two in particular, whose waters have a very strong quality, of an acid taste, and bitter to the tongue.
About half a mile to the westward, and close by the river side, are several hot springs, which are used by sick people with great success. Also, on the side of a hill west of St Anne's church, are many others, with three bathing houses, which are most commonly used. These waters are very warm, although not boiling hot; but at the same place issue several streams of cold mineral water, by which they are tempered, according to every one's liking.
About a mile south of this place, and over a low ridge of hills, lies a fine lake about two leagues in circumference, and very deep, the water thick, and of a greenish colour. At the north end is a plain piece of ground, where the sulphureous steam issues out in many places, attended with a surprising blowing noise. Our author could observe strong springs in the lake, but could not determine whether they were hot or cold; this lake seems to have no visible evacuation. The other springs immediately form a considerable river, called Ribeira Quente, which runs a course about two or three leagues, through a deep rent in the mountains, on each side of which are several places where the smoke issues out. It discharges itself into the sea on the south side, near which are some places where the water boils up at some distance in the sea.
This wonderful place had been taken little notice of until very lately: so little curiosity had the gentlemen of the island, that scarcely any of them had seen it, until of late some persons, afflicted with very violent disorders, were persuaded to try its waters, and found immediate relief from them. Since that time it has become more and more frequented; several persons who had lost the use of their limbs by the gout palsy have been cured; and also others who were troubled with eruptions on their bodies.
A clergyman, who was greatly afflicted with the gout, tried the said waters, and was in a short time perfectly cured, and has had no return of it since. When Mr Masson was there, several old gentlemen, who were quite worn out with the said disorder, were using the waters, and had received incredible benefit from them; in particular, an old gentleman about 60 years of age, who had been tormented with that disorder more than 20 years, and often confined to his bed for six months together: he had used these waters for about three weeks, had quite recovered the use of his limbs, and walked about in the greatest spirits imaginable. A friar also who had been troubled with the said disorder about 12 years, and reduced to a cripple, by using them a short time was quite well, and went a-hunting every day.
There are several other hot springs in the island, particularly at Ribeira Grande; but they do not profess the same virtues, at least not in so great a degree.
The east and west part of the island rises into high mountains; but the middle is low, interspersed with round conic hills, all of which have very recent marks of fire; all the parts below the surface consisting of melted lava lying very hollow.
Most of the mountains to the westward have their tops hollowed out like a punch bowl, and contain wa- Milan. Near the west end is an immense deep valley like the Furnas, called the Sete Cidades. This valley is surrounded with very abrupt mountains, about seven or eight leagues round; in the bottom is a deep lake of water about three leagues in circuit, furnished with great numbers of water fowls. This water has no mineral quality; neither are there any hot springs in the valley. All these mountains are composed of a white crumbly pumice stone, which is so loose, that if a person thrust a stick into the banks, whole waggon loads of it will tumble down. The inhabitants of the island relate a story, that he who first discovered it observed an extraordinary high peak near the west end; but the second time he visited it, no such peak was to be seen, which he supposed must have certainly sunk; but, however improbable this story may be, at some period or other it must have certainly been the case.