Sterninæ, Terns.—Inner Farne L.H., April 20th, Sandwich Tern, Sterna cantiaca, Gmel., heard calling for first time. Longstone L.H., May 3rd, first Sandwich Tern seen on island. Inner Farne L.H., May 2nd, Arctic Tern, Sterna macrura, Naum., seen first time; 4th, both together, flying round their breeding-stations. Inner Farne, Aug. 28th, most of Arctic and Sandwich Terns left their breeding-quarters. Longstone and Inner Farne, Sept. 6th and 7th, both species finally left island.

Larinæ, Gulls.—Heligoland, Jan. 17th, Greater Black-backed Gull, Larus marinus, Linn., hundreds, all old birds; and on 31st, the same, nearly without exception old birds; Kittiwake, Rissa tridactyla (Linn.), same. Whitby, Feb. 12th, Herring Gulls came to the cliffs to breed, in 1881; it was on the 14th. Longstone, March 15th, Gulls coming to nesting-quarters. Whitby, July 16th, young first seen on wing; Sept. 7th, old and young left. Great Cotes, Sept. 28th, Humber-flats covered with various Gulls. Whitby, Oct. 14th, large numbers seen at sea, going S. Spurn, in December, Iceland Gull, L. leucopterus, Faber, mature and immature, obtained.

Stercorariinæ, Skuas.—Farne Inner, Sept. 26th, Skuas seen in attendance on Black-headed Gulls. Teesmouth (Redcar), Oct. 20th, five Skuas to E. Nov. 1st, Longstone, one. Have been remarkably scarce on the coast.

Procellariidæ, Petrels.—Coquet L.H., Oct. 14th, 7 p.m., one Stormy Petrel caught against glass and set at liberty again. Languard, 11th, one, 6.15 p.m. Spurn, 29th, one at edge of water.

Alcidæ, Auks.—Common Guillemot, Lomvia troile, (Linn.), Longstone L.H., Jan. 3rd, 1883, Guillemots flying in from sea to island; March 15th, 1882, assembling for breeding on islands; May 15th, Puffins assembling on islands; Aug. 25th, Guillemots and Puffins have left their nesting-quarters on rocks; Oct. 22nd, Little Auk, Mergulus alba, Linn., one seen; Nov. 1st, two young Puffins seen. Inner Farne, April 1st, multitudes of Guillemots flying up to their nesting-quarters; Nov. 18th, several Puffins and Guillemots off islands. Flamborough, Guillemots great many last week in January, towards headland; Feb. 5th, great numbers going N. all morning; Dec. 27th, first seen off coast, are passing and repassing daily in great numbers.

Colymbidæ, Divers.—Inner Farne, Sept. 6th, Great Northern Diver, C. glacialis, Linn., three to N.; Dec, first week, Red-throated Diver, C. septentrionalis, Linn., Black-throated Diver, C. arcticus, Linn., and Great Northern Diver, all three about the islands this week; on 5th, fourteen Great Northern Divers to W. Longstone, Nov. 14th, two young Great Northern Divers off island fishing. Teesmouth, Oct. 31st, flock of Great Northern Divers passed at noon.

Podicipitidæ, Grebes.—October, Sclavonian Grebe, Podiceps auritus, Linn., adult in winter plumage shot in a timber pond at Hull; Red-necked Grebe, P. griseigena (Bodd.), and Sclavonian Grebe, on Humber in October and November.

The Committee are indebted to Professor Chr. Fr. Lütken, of the Universitetets Zoologiske Museum, Copenhagen, for a list of the birds killed against the lantern of the lighthouse of Stevns, on the projecting part of Zealand, marking the limit between the Baltic and the Grönsund Belt, in the autumn of 1882. Professor Lütken, in forwarding the list, remarked that his late lamented predecessor. Professor Reinhardt, made arrangements with a physician, Mr. Antander, residing at the small town of Storeheddinge, seven Danish miles south of Copenhagen, in the neighbourhood of Stevns Klint and the lighthouse of Stevns, for forwarding any birds found killed to the museum, with the following result:—

Stevns Fyr, Zealand, Denmark, 1882.

* Is often seen swarming around the lighthouse at the time of its migration—six or seven on this night flew against the panes without being killed, and two others were caught alive. About forty Redbreasts and Wheatears were caught on the same night, but set at liberty again in the morning. On clear moonlight nights nothing at all is caught or found.

† According to Mr. Antander were not sent to museum.

Mr. Gätke sends the following notes of an extraordinary migration of the Silver Gamma Moth, Plusia gamma, across Heligoland in August, 1882:—

On Aug. 13th, at 1 a.m. till 4, thousands on thousands passed the Heligoland lighthouse, travelling E. to W. From 11 p.m. on the 15th, till 3 a.m. on 16th, millions, like a snow-storm, all belonging to the same species, passed forward in the same direction. Again, on the 18th, from 11 p.m. till 3 a.m. on the 19th, thousands on thousands were observed under the same circumstances. Some scores caught for identification were all in most perfect plumage; no fading or abrasion.

General Remarks.

The observations taken along the E. coast of England in the spring and autumn of 1882 have been such as to confirm the conclusions arrived at in previous reports.

As in 1880 and 1881, the line of autumn migration has been a broad stream from E. to W., or from points S. of E. to N. of W., covering the whole of the E. coast. In 1880 a considerable proportion of the immigrants crossed at the more southern stations; in 1881 they covered the whole of the E. coast in tolerably equal proportions; but in 1882 the stations N. of the Humber show a marked preponderance of arrivals.

Although migration has extended over an unusually long period, commencing in July and continued with but slight intermission throughout the autumn and into the following year to the end of January, yet the great mass of immigrants arrived on our E. coast in October, and a large proportion of these during the first fortnight in the month. From Oct. 6th to 8th, inclusive, and again from the 12th to the 15th there was, night and day, an enormous rush, under circumstances of wind and weather, which observation has shown are most opposed to a favourable passage. During these periods birds arrived in an exhausted condition, and we have reasons for supposing, from the number reported as alighting on fishing-boats and vessels in the North Sea, that the loss must have been very considerable; large flights also are recorded as having appeared round the lanterns of lighthouses and light-vessels during the night migration. From the 6th to the 9th, inclusive, strong E. winds blew over the North Sea, with fog and drizzling rain, and from the night of the 12 to 17th very similar weather prevailed. Mr. W. Littlewood, of the Galloper L.V., moored on the bank of that name forty miles S.E. of Orfordness, reports that on the night of Oct. 6th, Larks, Starlings, Mountain Sparrows, Titmice, Common Wrens, Redbreasts, Chaffinches and Plover were picked up on the deck, and that it is calculated five to six hundred struck the rigging and fell overboard; a large proportion of these were Larks. Thousands of birds were flying round the lantern from 11.30 p.m. to 4.45 a.m., their white breasts, as they dashed to and fro in the circle of light, having the appearance of a heavy fall of snow. This was repeated on the 8th and 12th, and on the night of the 13th 160 were picked up on deck, including Larks, Starlings, Thrushes and two Redbreasts; it was thought one thousand struck and went overboard into the sea. It is only on dark rainy nights, snow or fog, that these casualties occur; when the nights are light, or any stars visible, the birds appear to give the lanterns a wide berth.

Unquestionably the principal feature of the autumn migrations has been the enormous arrival of the little Gold-crested Wren. The migrations appear to have covered not only the E. coast of England, but to have extended southward to the Channel Islands and northward to the Faroes (see Report East Coast of Scotland, Harvie Brown). On the E. coast of England they are recorded at no less than twenty-one stations, from the Farne Islands to the Hanois L.H., Guernsey. The earliest notice is Aug. 6th, the latest Nov. 5th, or ninety-two days; during the same period enormous numbers crossed Heligoland, more especially in October, and quite up to the end of the month. On the night from the 28th to 29th Mr. Gätke remarks, "We have had a perfect storm of Goldcrests, poor little souls, perching on the ledges of the window-panes of the lighthouse, preening their feathers in the glare of the lamps. On the 29th all the island swarmed with them, filling the gardens and over all the cliff,—hundreds of thousands; by 9 a.m. most of them had passed on again."

Not less remarkable was the great flight of the Common Jay past and over that island early in October, on the 6th, 7th, and 8th; thousands on thousands without interruption passing on overhead like Crows, N. and S. of the island too, multitudes like a continual stream, all going E. to W. in a strong south-easterly gale. It would have been an interesting fact if we had been able to correlate this migration of Jays with any visible arrival on our English coast, but in none of our returns is any mention made of the Jay. Mr. Matthew Bailey, of Flamborough, told me that on one evening early in October (the exact date he was not able to give) he had observed at dusk large flights of birds, about the size of Jackdaws, coming to land, and was struck with the good headway they seemed to make against a strong wind. It was too dark, however, to make out what they were. Subsequently I have received numerous notices speaking of the extraordinary number of Jays seen during the winter in our English woodlands. This seems especially to have been the case south of a line drawn from Flamborough Head to Portland Bill, in Dorset.[9]

Extraordinary numbers of the Common Hedge Sparrow (Accentor modularis)—"the dunnock" of the English schoolboy, the "blue Janet" of Scotland—passed over Heligoland in October, more especially on the 6th, 7th, and 8th; and it is curious that on the 8th of the same month they swarmed in astonishing numbers, both at Spurn and in N.E. Lincolnshire.

The Woodcock arrived on the east coast on the night of Oct. 12th, or early morning of the 13th; wind E., strong, fog, and drizzling rain. On the morning of the 13th they are recorded from nine stations, covering 250 miles of coast-line, from the Farne Islands to Orfordness.[10] It is fair to suppose that this, the "great flight" of the season, did not start from the same locality, but from various parts of the opposite coast of Europe,—places widely apart. Both previous and subsequent to their passage the weather had been much of the same character over the North Sea. Why they should start simultaneously on this special evening, and how they managed to "keep touch," to use a military term, during a passage of several hundred miles across a stormy sea, in fog and drizzling rain, so as to arrive about the same time at their Tel-el-Kebir on our English sand-hills, is one of those points in the phenomena of migration which will probably take some time and more extended observations, especially on the opposite coast-line, to clear up.

An interesting entry in one of the returned schedules, that from the Inner Dowsing L.V., placed seventeen miles E. of Sutton, on the Lincolnshire coast, is that of two Hawfinches, which came on board on the evening of Oct. 20th, a strong S.S.W. wind blowing, and remaining all night, left again at daybreak, their course being from S.E. to N.W., the course followed by a large proportion of our immigrants. As far as we are aware this is the first notice of Hawfinches having been seen at sea. At Heligoland, Mr. Gätke says the species is a well-known customer, never in any numbers, but every spring and fall some, betraying itself forthwith by its peculiar call-note, so out of all proportion with its colossal beak.

There are some birds occurring on our east coast year by year with tolerable regularity, which, during the autumn of 1882, have been remarkable for their scarcity. This has been the case with all the large raptorial birds, and especially with the Short-eared Owl, and Common Linnet and Twite. Their absence on migration has also been remarked upon in Heligoland. The Short-eared Owl also appears to have been specially scarce on the east coast of Scotland. (See East Coast of Scotland Report.)

Our returns show very clearly that the spring lines of migration, followed by birds leaving our shores, are identically the same as those followed in the autumn, but of course in the reverse direction from W. and N.W. to E. and S.E.

As this is the fourth report issued by the Committee, we may, perhaps, with the mass of facts at our disposal, be expected to draw deductions, which, if they do not explain, will serve at least to throw some light on the causes influencing the migration of birds. We might reasonably reply that the work undertaken by us was not to theorise, or attempt explanations, but simply to collect facts and tabulate them. This we have endeavoured to do in the shortest and simplest manner consistent with accuracy of detail. There is, however, one circumstance which can scarcely fail to present itself to those who have gone carefully into the reports issued by the Committee, namely, the marvellous persistency with which, year by year, birds follow the same lines of migration when approaching or leaving our shores: the constancy of these periodical phenomena is suggestive of some settled principle or law governing the movement. It is clearly evident, from the facts already at our disposal, that there are two distinct migrations going forward at the same time; one, the ordinary flow in the spring and ebb in the autumn, across the whole of the western Palæarctic regions, which of course includes the British Isles, of a great migratory wave moving to and from the nesting-quarters of the birds in the coldest part of their range, N.E. in the spring and S.W. in the autumn. Quite independent of this there is a continual stream of immigrants, week by week and month by month, to the eastern shores of these islands, coming directly across Europe from E. to W., or more commonly from points S. of E. to others N. of W., and the reverse in the spring. These are mainly composed of those common and well-known species which annually make these islands their winter resort, and take the place of our summer birds: they come in one broad stream, cutting the line of ordinary migration at nearly right angles; one flank brushes the Orkneys and Shetlands, pouring through the Pentland Firth, even touching the distant Faroes; the southern wing crosses the Channel Islands, shaping its course in a north-westerly direction to the English coast. In our explanation of the causes which first induced, and perhaps still influences, this E. to W. migration, we must probably go back a long way in the history of the world, when the distribution of the land and water of continental Europe was very different to what it now is; when there was no North Sea, and the western coast-line of Europe was represented by what is now known as the hundred-fathom line off' the West of Ireland, a coast which on the one side touched Scandinavia, and on the other was linked with the Spanish peninsula. Great as is now the contrast between the winters of Central Russia and those of these islands, the difference would then be much more marked,—arctic cold on one hand, and semi-tropical warmth on the other.[11] It requires then no stretch of imagination to believe that great flights of birds would on the approach of winter be driven before the intense cold of Eastern and Central Europe to seek refuge and find food in the warm regions of the west, regions which then would feel the full effects of the warm equatorial currents, and enjoy an almost perpetual summer. This movement once begun would, by the very necessities of existence, and in time by an hereditary instinct, be continued. Gradually the land now occupied by the North Sea has been withdrawn from beneath the migrating flocks; year after year the middle passage became wider and more difficult; yet the habit once formed would be continued, and hereditary instinct, or whatever other name we choose to give it, supply the rest.

Mr. Wallace has told us how, in the Eastern Archipelago, comparatively narrow, and probably very ancient, straits of water divide and wholly separate distinct races of birds; and we have instances of this in Europe, where species, common on the opposite coast of the Continent, rarely or never occur in the British Islands.

Small birds, like the Goldcrest, do not cross great breadths of water from choice; they doubtless would prefer a migration over land, from field to field, or hedge to hedge; or at the most closely following some old established coast-line. Why, except on some such hypothesis as stated, should they attempt the North Sea, not alone at the narrowest part, the straits of Dover, or from Ostend to the coast of Kent, but in the very widest parts also, from the Elbe to the Humber, or Danish coast to the Pentland Firth and Scotch islands? What impels our autumn visitants, the young weeks in advance of their parents, to launch westward across what, for anything they can possibly know to the contrary, may prove an Atlantic, an ocean without a further shore?

There are doubtless several causes, working separately or together, which influence migration, and we must not look for an explanation of the phenomena attending these great periodical movements to one cause only, for by doing this we lose sight perhaps of other equally powerful incentives. I have spoken in previous reports of the probability of birds following ancient coast-lines once linking now distant lands, impelled by what we call, for want of a better term, hereditary instinct, that is, an instinct derived through ancestors. It is, perhaps, an open question whether the young, which undoubtedly arrive in the autumn weeks in advance of the great mass of old birds, depend entirely on this, or whether they are in any way dependent on guidance and direction. It is a curious fact, which we have frequently remarked, that the very earliest of their kind are frequently a few old birds,—flocks of young, too, often contain a sprinkling of old female birds,—such as may be supposed have made the journey before; but it must be also borne in mind that on dark or even starlight nights, when these movements mostly take place, any guidance, even that of call-note, would be futile at any but a very limited range.