Procellariidæ.—At Coquet L.H., July 22nd, 11 p.m., misty, one Petrel caught against glass of lantern, examined and set at liberty. At Redcar, Oct. 28th, two Stormy and one Fulmar Petrels picked up during great gale. At Flamborough, first week in October, Stormy Petrel. At Spurn, Oct. 28th, Stormy Petrels after great gale. At Galloper L.V., Nov. 6th, 2 to 4 p.m., twelve Stormy Petrels about ship. At Gull L.V., Oct. 9th, 2 a.m., N., several struck glass, none killed.
Independent of these very numerous notes on known species, the schedules contain many notices of birds the species of which were either not known or not recognised. At the Hasborough L.H., Oct. 26th, 10 p.m., E., o.m., a great many various small birds; eight killed were Larks and Thrushes. At Swin Middle L.V., Sept. 9th and 12th, flocks of small birds passed all night to N.W. At Hanois L.H., Sept. 8th and 27th, fog and rain, evening to 9 p.m., great rush of small birds of many sorts.
General Remarks.
The report for 1880 compared with that of the previous year shows very similar results, as in 1879 a considerable proportion of the immigrants crossed at the more southern stations, or at the narrowest portion of the North Sea. If we divide the east coast into three divisions, one north-easterly from the Farne Islands to the Humber, mid-east from the Humber to Yarmouth, and south-eastern forward to the South Foreland, we find that in 1879 the main body of migrants passed in the south-eastern division; in 1880 they have been tolerably equally distributed over the mid and south-eastern. During the principal month of migration, October, the wind blew persistently day by day and week by week from northerly and easterly quarters, and to this cause we may fairly attribute the deflection of migrants to the south. In support of this I may quote the letter of Mr. Thos. O. Hall of the Longstone Lighthouse, who, writing under date Feb. 15th, 1881, says:—"The chief flight undoubtedly took place on the 15th and 16th of October, at which time I was on shore. I have been resident on the Farne Islands thirteen years, and during that time never remember seeing so few birds as we have had this autumn. I have remarked that when the flight takes place with the wind at E. or N.E., the body of birds is to the south of us about Whitby and southward."
Notwithstanding the enormous number of immigrants arriving, as shown in our returned schedules from each station, we may be quite certain these returns only represent an almost inappreciable percentage of the actual number on passage. On days of uncertain light or on clear fine starlight nights, when migration is carried on at a considerable height, immense numbers of birds might pass any station for hours without a chance of observation; and it is quite possible that, if the whole three hundred miles of coast were studded with floating posts of observation at the distance of half a mile, equal average results would have been obtained, our present stations on the light-vessels affording no more especial line of advantage than any other imaginary line drawn across the North Sea. Incredible although it may appear, we believe that the vast majority of the immigrants coming to us in the autumn in one broad front from east to west are such as cross with the intention of remaining the winter in some part or other of the British Islands, and naturally take the place of our own resident summer species which have left, or are about leaving us, for the south.
As in 1879 the main line of migration has been a broad stream from east to west, and covering the whole of the English east coast, this is the line mainly followed by the Passeres. Taking this line as a basis, we find birds also occasionally coming from points north of east; but in the vast majority of instances the migration has had a decidedly southerly trend, coming from points south of east, and even direct from the southward. Again, there is in the autumn always a steady stream of migrants which closely follows the coast-line from N. to S., composed of birds either moving from more northerly districts of our islands, or of such immigrants coming from the east as strike the coast in more northern latitudes and then follow it to the south. The great wide E. to W. stream of migration is composed of some few well-known species which regularly come to us in the autumn, the great body undoubtedly remaining to winter; placed in order of rotation according to their numerical superiority or otherwise, we find Alauda arvensis, Sturnus vulgaris, Corvus cornix and frugilegus, the Turdidæ, including two native and two northern species, with sparrows, linnets, and chaffinches compose the bulk of the immigrants. Others, as Ruticilla phœnicurus, the Saxicolæ, and other soft-billed insect-eaters, although coming from the eastward, persistently follow the coast-line to the south. All the Limicolæ and other shore birds, as well as the Geese, Ducks, Divers, Gulls, and sea-fowl generally, move from north to south as a general rule, the sea-fowl at some distance at sea, the waders along the coast. Although so far we have no stations, excepting Heligoland, on the European coast of the North Sea, we may, I think, fairly presume that there is similarly another stream of birds passing down the coast-line of Europe. Migration as observed on that island for many years points to the undoubted fact that the line followed by birds is, as a rule, from E. to W., and doubtless some portion of these Heligoland birds keep moving westward or south-westward, till eventually they strike our east coast. There are, however, many species which make Heligoland the western boundary of their autumn wanderings, and crossing, as they do, that island in enormous numbers, must eventually follow the coast-line to the south, for the simple reason that they never occur on our own coast, except as very rare or occasional wanderers; such are Motacilla alba and flava, Ruticilla suecica, Emberiza hortulana, Plectrophanes lapponicus, Anthus Richardi, and, in a less degree, Muscicapa luctuosa and Otocorys alpestris. These all, then, must pass southward along the European coast, as do doubtless an immense majority of those countless Sparrowhawks, Siskins, and more familiar birds which cross the island in the autumn migration; and just as occasionally some species, whose line of migration lies farther to the eastward still, turn up as wanderers to the old rock from the regular track, so do occasionally now one and now another of the regular Heligoland immigrants get blown across to one side.
The observations taken at some of our southern stations both in 1879 and 1880 show that, in the autumn, there is what may be called a double stream of birds crossing each other near the entrance of the English Channel, that is, from the Essex and Kent coast towards the S.E. on to the French and Belgian coast, and again in the opposite direction from the Belgian land to the coast of Kent. During the severe weather in the early part of 1881, as well as in December, flocks of birds came to us direct from the French coast, or from the south to the north. These must be considered purely local migrations, caused by outbursts of severe weather.
It is a curious fact that in nearly every case of birds passing the Casquets L.H. in the past autumn, they were travelling in a N.W. direction, or from the French to the English coast, a line of migration which does not seem to be in proper accord with what we should imagine migrating birds would or rather ought to take. On reference to the chart of the Channel it is apparent that any flocks leaving the French coast at or near Cape de la Hague, and crossing. Alderney, when once off the Casquets might as readily and easily steer for the Start Point on the English side as across the wide break in the French coast for Port Sillon, each being about equal distances from the Casquets.
As in 1879 birds have crossed in all hours of the day and night, and in all winds and weathers, the returns also show, as did the preceding, that they seldom fly dead to windward, except with light breezes, and that strong head winds are prejudicial to their passage. The line of flight mostly adopted is within three or four points of the wind; they will go on well, even with a beam wind or some points short of beam, if not too strong. Small birds have often much difficulty in making head against a strongly-opposing wind. Mr. John Cutting, writing from the light-vessel on the Galloper Bank, says, that out of the number of small birds passing that station in October and November against strong adverse winds, he could not think they would ever reach land, they made such very slow progress, the wind being too strong and the distance from land so great. Even such strong-winged birds as the Grey Crow do not always cross in safety; I have been told by an old fen farmer that, many years ago, when a great gale swept the Lincolnshire coast, at the time the Hooded Crow crossed, the coast was subsequently strewed with their bodies cast up by the sea.
Birds are noticed at the stations as sometimes flying high, sometimes low; often it will be observed with northerly and easterly winds they will fly high, and with winds in opposite quarters, low. The state of weather at the time of migration has more, we think, to do with the height at which birds travel than the direction of the wind. On clear light nights they travel high, as a rule, but in fog, and thick murky weather, rain or snow, not far above the waves. On thick nights, indeed, lost birds will wheel for hours round a lightship, but with the first break in the clouds or streak of early dawn are on their course again. At the Casquets, which is a revolving light, the larger birds follow the rays, but do not often strike the glass.