From the returns given by the light-keepers, it would appear that birds, prior to crossing the ocean, follow closely the coast-line in their journeyings, and that during the two periods named, a continuous stream passes to and from their summer quarters, broken, it may be, by a sudden change of wind or other vicissitude of weather, and thus causing ‘throbs’ or ‘rushes,’ as they have been termed, but steady as a rule—the hereditary impulse being too powerful to admit of anything but a temporary deviation or delay on these great highways of migration.
It seems strange that while such movements are taking place, persons resident but a few miles inland may be unaware of the winged multitudes that in this way pass within a short distance of their homes. Yet a great deal of information may be gathered by close observers who are willing to visit the seacoast at daybreak about the time the birds are on the move. The present writer well remembers seeing large flights of birds of different species arriving in early spring on the shores of East Lothian for a succession of years. Among these, the swallows were conspicuous even at some distance out at sea, the main body passing northwards in undeviating flight, while numerous detachments left it and came landwards, to people the haunts in the country which they had occupied the previous year. The same was observed in the case of wheatears, redstarts, and golden-crested wrens—the last-named being particularly interesting from their tiny size. Occasionally goldcrests would come in great numbers, and immediately on alighting, would flutter in the morning sunlight among the rocks and walls near high-water mark in search of insect prey, paying no heed to the presence of any one watching their motions. Again, in the autumn months, buzzards, owls, and woodcock would arrive simultaneously, and pitch upon the rocks at low water, as if glad to touch the nearest land; and even wood-pigeons (supposed by the country folks to come from Norway), which delight only in dense woods and fertile fields, and which suddenly appear in vast numbers in severe British winters, settled in crowds upon the stony beach without any preliminary survey of the ground. Observations like these can be made on almost any part of the east of Scotland, and it is gratifying to find them verified in a remarkable degree by the returns from the light-keepers, which not only show the closeness with which birds follow the coast-line, but also indicate the points of land from which they speed seawards in their adventurous flight. Thus, it is found that arrivals and departures take place at Spurn Point and on the coast of Forfarshire—the inference being, if the theory of a former land-communication be true, that an ancient coast-line must have extended east or north-eastward probably from Holderness to Southern Scandinavia and the mouth of the Baltic. There is also reason to believe that similar points of arrival and departure exist in the north-east of Aberdeenshire, judging from the occurrence of so many rare birds, whose presence there at the migration season can hardly otherwise be accounted for.