From the examples quoted, it appears that some birds, which are stationary in one district, are migratory in ano ther. But that which chiefly merits our consideration is the circumstance of those birds, whose annual migrations are confined to our own shores, forsaking the high grounds when the purposes of incubation have been accomplished, and seeking for protection at a lower level, and in a warm er situation. When these migrations become more exten sive, they forsake the bleak moors and shores of Scotland for the warmer and more genial climate of England. Hence it happens, that some of our Scottish summer visi tants come from England, while some of the English win ter visitants come from Scotland : the summer birds of pas sage cooling from the south, and the winter passengers from the north. Do those birds, whose migrations are more extensive, obey the same laws? As the summer birds of passage are mere interesting to us, since they perform the great work of incubation in our country, than the winter birds of passage, which are the harbingers of storms and cold, and only wait the return of spring to take their leave of us, we will endeavour to find out the winter residence of the former, before we attempt to discover the summer haunts of the latter. Natural his tory, it is true, is still in too imperfect a state, to enable us to point out with certainty the retreats of those birds which visit us during summer. But enough appears to be known to enable us to ascertain the laws by which thesc migra tions are regulated in a number of birds, and as the points of resemblance in the movements of the whole arc nume rous, we can reason from analogy on safer grounds with regard to the remainder.
The swallow, about whose migrations so many idle stories have been propagated and believed, departs from Scotland about the end of September, and from England about the middle of October. In the latter month DI.
Manson observed them on the shores of Africa after their migrations from Europe. He informs us, however, that they do not build their nests in that country, but only come to spend the winter. The nightingale departs ft om England about the beginning of October, and from the other parts of Europe, about the same period. During the winter season it is found in abundance in Lower Egypt, among the thickest coverts in different parts of die Delta. The birds do not breed in that country, and to the inhabitants are merely winter birds of passage. They areive in autumn and de part in spring, and at the time of migration are plentiful in the islands of the Archipelago. The quail is another of cur summer guests, which has been traced to Africa. A few indeed brave the winters of England. and in Portugal they appear to be stationary. But in general they leave this country in autumn, and return in spring. They migrate about the same time from the eastern parts of the continent of Europe, and visit and revisit in their migrations the shores of the Mediterranean, Sicily. and the islands of the
Archipelago. When speaking of this subject, the intelli gent Willoughby adds, that when he sailed from Rhodes to Alexandria in Egypt, many quails front the north towards the south m ere taken in our ship ; whence I am verily persuaded that they shill places : for for merly also, when I sailed out of the isle of Zante to Mo•ea, or Negropont, iu the spring time, I had ob served quails flying the contrary way, from south to north, that they might abide there all summer. At which time also there were a greiit many taken in our ship." Ornitb. p. 170.
While these birds perform those extensive migrations which we have here mentioned, others are contented with shorter journies. Thus the razor-billed auk (Alca torda) and the puffin (?1ca arctica) frequent the coast of Andalusia during the winter season, and return to us in the spring.
These facts, and many others of a similar nature, which might have been stated, enable us to draw the conclusion, that our summer birds of passage come to us from south ern countries, and after all the purposes of incubation are accomplished, return again to milder regions. A few of our summer visitants may winter in Spain or Portugal ; but it appears that in general they migrate to Africa. that tin known country, possessing every variety of surface, and consequently great diversity of climate, It is true that we are unacquainted with the winter retreats of many of our summer birds of passage, particularly of many small birds; but as these arrive and depart under similar-circumstances with those whose migrations are ascertained, and as the operations which they perform during their residence with us are also similar, we have a right to conclude, that they are subject to the same laws, and execute the same move ments. What gives weight to this opinion, is the absence of all proof of a summer bird of passage retiring to the north during the winter season.
In proof of the accuracy of the preceding conclusion, we may observe, that it is a fact generally acknowledged, that the summer birds of passage visit the southern parts of the country a few days, or even weeks, before they make their appearance in the northern districts. Thus the common swallow (Hirundo rustica) appears in Sussex about the be ginning of the third week of April ; while in the neighbour hood of Edinburgh it is seldom seen before the first of May. The cuckoo appears in the same district about the last week of April ; in Edinburgh seldom before the se cond week of May. The reverse of this holds true with these summer visitants at their departure. Thus dotterels (Charadrius 7norinellus) forsake the Grampians about the beginning- of August, and Scotland by the end of that month; while they return to England in September, and remain there even until November. A differ ence of nearly a month takes place between the departure of the goat sueket (Caprimulgus Europa us) from Scotland and from the south oh England.