236 



M E R G U S. 



whole year for a considerable extent of latitude ; and 

 the atmospheric current which results from this, cuts 

 off the polar portion from the portion nearer the 

 tropics, and thus there is not the same interchange of 

 climate and alternation of annuals in the opposite 

 seasons in that hemisphere as there is in the north. 

 In consequence of this the birds which are met with 

 in the most southerly parts of the extensive lands, 

 whether New Holland, Africa, or America, are 

 resident birds, totally different from ours even in cor- 

 responding latitudes ; and no winter visitants similar 

 to our winter visitants arrive there. So tropical 

 indeed is the ornithology of these countries, that the 

 humming birds are found up to the very extreme 

 point of South America, and they are accompanied by 

 a vegetation which is also tropical. 



The seasonal migrations of the aquatic birds of 

 high latitudes is one of the most interesting parts of 

 their history, because they are evidences of the geo- 

 graphy of different localities, and very correct tell- 

 tales of the weather in the regions from which they 

 come ; and it is of importance to know that the general 

 knowledge which they afford us with regard to the 

 north, does not at all apply to the corresponding 

 latitudes of the south. 



The genus Mergus are all migrant, though they 

 are not all equally polar in their summer residence 

 and economy. One species, at least, lingers in a 

 straggling remnant upon some of the remote isles 

 north-westward of Scotland, and also in the extreme 

 north-west of the main land. It is true, that this is 

 but a remnant ; and, unless the winter in the high 

 latitude is exceedingly severe, the birds are not, 

 generally speaking, numerous even in the northern 

 parts of Britain, and they are comparatively rare in 

 the southern. In the western part of the continent 

 they are, perhaps, more abundant, and certainly 

 extend more to the south than any part of Britain ; 

 but the continental winter is, latitude for latitude, 

 colder than ours ; and the birds which take the range 

 of the North Sea, necessarily pass to the Netherlands 

 or the North of France before they find a resting 

 place. It is the same with all the birds which come 

 from the regions of the poles in winter, the whole of 

 them get more southerly in France than they do in 

 England. We have already mentioned that these 

 birds feed chiefly upon fish and aquatic reptiles ; and 

 their bills are not adapted for taking, or their sto- 

 machs for digesting, vegetable matter of any kind, 

 and none of them are known to feed upon the land, 

 for which they are equally ill adapted by the structure 

 of their bills, and their short and backward feet. The 

 latter are so ungainly, that they could pick up hardly 

 any land substance, not even an insect or a worm ; 

 and their pace is so slow and wriggling that they 

 could follow nothing which possessed any degree of 

 land motion. They are, therefore, entirsly cast upon 

 the waters for their subsistence, and when frozen 

 out in one place, they have no alternative but to 

 take their departure for another. 



The species of these birds were for a long time 

 very much confused by describers, and multiplied to 

 at least double the number that really exist ; and it 

 was reported by some naturalists that a species was 

 met with in tropical latitudes on the coast of Brazil, 

 but this is very unlikely, and contrary to the analogy 

 of the birds, which, when they migrate from their 

 polar localities, seek the inland lakes and rivers, or at 

 all events the estuaries rather than the open sea. The 

 cause of the multiplication of species beyond the real 



number, was the same as that which had introduced 

 confusion into many other parts of ornithology ; the 

 females are differently coloured from the males, and 

 the young are different from the mature birds of both, 

 so that in any one of the species, those who founded 

 their distinctions upon colour alone could easily divide 

 it into three. There are at least four well-authen- 

 ticated species, one of which certainly breeds in some 

 parts of the British islands, another probably does so 

 though more rarely, and the other two are rare even 

 as stragglers. The English names given to the dif- 

 ferent species vary ; the largest being called Goos- 

 ander, two of the others Merganser, and the remain- 

 ing one the Srnew, or white nun. 



The Goosander (M. Merganser). This is the 

 largest species of the genus, the male being about four 

 pounds in weight, twenty inches long, and upwards 

 of three feet in the expanse of the wings. Its summer 

 residence is in the northern parts of both continents, 

 and it is probable that a few, though a very few, may 

 linger during the summer about the extreme north of 

 Scotland. In winter it is very discursive, and more 

 so in proportion as the winter sets in more early and 

 severe. It visits many parts of the British coast, 

 according as these lie more in the line of its progress 

 southward ; and on the continent it finds its way to 

 the lakes and ponds of Germany and even of Switzer- 

 land. As it inhabits round the entire circumference 

 it is equally migrant in Asia and America as in Eu- 

 rope ; and as Finland is a country abounding in pool^ 

 and streams, many stop to breed there. 



Goosander. 



The bill is ample in the gape, but rather shorter 

 than in some of the other species. In the greater 

 part of its length it is slightly bent upwards, but the 

 tip of the upper mandible is strongly hooked down- 

 wards, and consists of a nail of harder texture than 

 the rest of the bill. The cutting edges are very 

 strongly toothed, so much so that the bird is popu- 

 larly known by the appellation of " Jack-saw." The 

 general colour of the bill is red ; but a portion round 

 the nostrils, the ridge of the upper mandible, and the 

 nail on its tip are dusky. The inside of the gape is 

 bright orange. The head and crest, the last of which 

 is most' conspicuous in the male, together with the 

 upper part of the neck, are dark green, passing into 

 black on the chin and throat. The lower part of the 

 nfick, the outer scapulars, the breast, and all the under 

 part of the body, are white with a tinge of yellowish 

 red. The back, ,and scapulars next the back, are 

 black, fading into greyish toward the rump, and the 



