Having thus ascertained the winter haunts of our summer birds of passage, let us now endeavour to find out the summer retreat of our winter visitants. The con clusions which we have already established dispose us to look for these birds in countries situated to the north ward. And as we ate much better acquainted with the ornithology of those countries than of Africa, it will be in our power to prosecute our researches with greater cer tainty of success.
The snow bunting, (Embcriza nivalis), which is among the smallest of our winter guests, retires to the hoary mountains of Spitzbergen, Greenland, and Lapland, and there performs the purposes of incubation, making its nest in the fissures of the rocks. In these countries it is therefore a summer visitant, as it retires southwards in au tumn, to spend the winter in more temperate regions. To the sea coasts of the same regions the little auk (.41ca and the black-billed auk (Aka pica), repair for similar pur poses as the snow-flake. The woodcock winters with us, hut retires in the spring to Sweden, Norway, and Lapland. Eckmark says of this bird, as a Swedish summer bird of passage, (4 Pollis in sylvis nostris exclusis, mare transmi grans. in Angliam avolat ; ut ex Austria in Italiam. Vere autem novo, duo blatire incipit Tetrao tetrix, illinct desce dunt, matrimonio junctx ad nos revertentes." The field fare and the redwing resemble the woodcock in their mi grations, depart at the same season, and retire for similar purposes to the same countries.
These instances may suffice to support the conclusion, that all our winter birds of passage come from northern countries, and that the winter visitants of the south of Eu rope become the Summer visitants of its northern regions. This is evidently an arrangement depending on the same law by which the African winter birds of passage are sum mer birds of passage in Europe.
In support of this conclusion it may be mentioned, that, in their progress southward, the winter birds of passage appear first in the northern and eastern parts of the island, and gradually proceed to the southward and westward. Thus the snow-bunting arrives in the Orkney islands about the end of August, and often proves destructive to the corn fields. It then passes into the mainland of Scotland, and is seldom seen in the Lothians, even in the high grounds, before November. In like manner, the woodcock, which crosses the German Ocean, is first observed on the eastern side of the island, and then by degrees disperses towards the west.
Having now ascertained the period arid the direction of these migrations, let us next attend to the act of migration itself, and the circumstances attending the flight.
Migrating birds, before they take their departure, in general collect together in flocks. This is very obviously the case with the swallow, and is even still better known with woodcocks. These last arrive in this country in great flocks about the same time; and should adverse winds occur at the period of their departure, they accu mulate in such numbers on the eastern shot-es, as to fur nish the fowler with excellent sport. Geese too, during their migratory flights, always keep in company ; and the 'picture which the poet draws of the movements of the crane is equally just when applied to them, only we do not vouch for the truth of their geometrical precision, and their knowledge of the power of the wedge.
Bnt there are many migrating birds which have never been observed to congregate previous to their departure. Thus the cuckoo, seldom seen in company with his mate even during the breeding season, is to all appearance equally solitary at the period of migration. These birds are supposed by naturalists to go off in succession. .
It is certainly a vet y curious, and perhaps unexpected occurrence, that the males of many species of migrating birds appear to perform their migrations a few days before the females. This is remarkably the case with the night ingale. The bird catchers in the neighbourhood of Lon don obtain only males on the first arrival of this bird. The females do not make their appearance for a week or ten days after. Similar observations have been made with re spect to the wheatear (Matacilla enanthe.) Those birds which feed during the night, may be ex pected to perform their migrations during the same inter val, it being the season of their activity ; while those birds which feed during the day, may be expected to migrate with the help of light. The migrations of the woodcock and quail confirm this conjecture. The woodcocks arrive in this Country during the night, and hence they are some times found in the morning, after their art ival, in a neigh bouring ditch, in too weak a state to enable them to pro ceed. Poachers are aware that they migrate during the night, and sometimes kindle fires on the coast, to which the woodcocks, attracted by the light, bend their course, and in this manner great numbers are destroyed. Quails, on the other hand, perform their migrations during the day, so that the sportsman in the islands of the Medi terranean can use his dog and gun.