424 



NATATORES. BIRDS. COLYMBID.-E. 



the water, swimming and diving with astonishing ease 

 and rapidity in pursuit of the fishes and other animals 

 which constitute their food. 



The Goosander, which is one of the largest species 

 of tliis peculiar form, is a common bird in the northern 



Head of Goosander. 



regions of both hemispheres; in this country it is 

 usually seen only in the winter, although some indivi- 

 duals remain to breed in the northern parts of Scot- 

 land. It frequents indifferently the fresh and salt 

 waters, but in severe winters is usually driven to take 

 up its abode in deep bays, where its great power of 

 diving enables it to procure a supply of food. 



THE RED-BREASTED MERGANSER (Mergus ser- 

 rator) is another species which may be regarded as, 

 to a certain extent, permanently resident in Britain, 

 although chiefly a winter visitor ; and the HOODED 

 MERGANSER (AT, cucullatus), distinguished by its 

 broad crest, with a large white patch on each side of 

 it, is a native of North America, of which, however, 

 specimens have found their way to oimshores. 



FAMILY II. COLYMBID^E. 



The birds known as Divers and Grebes, which con- 

 stitute this family, are readily distinguished from those 

 just described, by the absence of the lamellae along the 

 edges of the bill, which is rather elongated, of a coni- 

 cal form, and acutely pointed. The nostrils are small 

 and very narrow, forming mere slits in the sides of the 

 upper mandible ; the wings are short, and the legs are 

 placed so far back, and attached to the body in such a 

 manner, that the birds are compelled to sit upright, rest- 

 ing upon the whole length of the tarsus when on dry 

 ground. The feet are large, and the toes sometimes 

 fully webbed, sometimes bordered by ample but dis- 

 tinct membranes ; the posterior toe is always present, 

 although small. 



These birds, which are essentially aquatic in their 

 habits, never venturing to move far from the water's 

 edge, are found principally in the northern hemisphere. 



Some of them frequent fresh waters, others prefer the 

 sea-coast ; they fly with considerable rapidity, but only 

 for short distances. They swim and dive with the 

 greatest ease, and progress under water with the most 

 astonishing rapidity, then- movements when submerged 

 being greatly aided by the action of the wings. Then- 

 food consists of fishes, mollusca, insects, and Crustacea. 



THE GREAT NORTHERN DIVER (Coli/mlus fjluci- 

 alts), the largest species of this group, measuring 

 nearly three feet in length, is met with chiefly in 

 the arctic regions of both hemispheres, but advances 

 further south at the approach of winter, when it 

 occurs in great abundance about the shores of the 

 northern parts of Scotland. At this period it lives 

 principally on the sea, capturing herrings, sprats, and 

 other small fish by diving ; but in the summer these 

 birds frequent the numerous fresh-water lakes of the 

 extreme north, on the margins of which they make 

 their large flat nests of dry herbage. On laud the 

 Diver is very awkward, as it is compelled to rest upon 

 its lower surface, and push itself on with its feet ; but in 

 the water it moves with surprising rapidity, its speed 

 equalling that of a four-oared boat ; and even under 

 water it moves with undiminished swiftness, coming 

 up at intervals for the sake of air, but often remaining 

 below the surface for six or seven minutes at a time. 

 Two . other species, the BLACK-THROATED DIVER 

 (C. arcticus) and the RED-THROATED DIVER (C. sep- 

 tentrionalis), which correspond with the Great Northern 

 Diver hi their distribution and habits, are sufficiently 

 distinguished by the peculiarities indicated in their 

 names. They are both met with on the British coasts, 

 the latter abundantly, the former more rarely. 



THE GREAT CRESTED GREBE (Podiceps cristatus). 

 The Grebes are distinguished from the Divers by the 

 peculiar structure of their feet, in which the mem- 

 branes, instead of uniting the toes, are cleft nearly to 

 the base of the latter, forming broad membranous 

 margins. In other respects, the two forms are very 

 similar, as also in their habits, although the Grebes 

 frequent lakes and other pieces of fresh water in pre- 

 ference to the sea. The Great Crested Grebe, one 

 of the largest -pecies, measures from twenty-one to 

 twenty-two inches in length, and has the plumage of 

 the upper surface dark brown, and that of the lower 

 parts white ; the wings exhibit a white patch formed 

 by the secondary quills ; the top of the head is dark 

 brown, and is adorned at the back with a double crest 

 of the same colour; the cheeks are white, and below 

 the head there is a sort of tippet, hanging down all 

 round the neck, of a pale chestnut colour, deep chest- 

 nut at the lower margin. 



This bird is an inhabitant of most of the northern 

 parts of both hemispheres. In this country it is a 

 constant resident, frequenting the lakes and other 

 extensive pieces of water. It feeds upon acuiatic 

 animals of all kinds, which its great natatorial powers 

 enable it to capture with ease. 



THE HORNED GREBE (Pocliceps cornutus), also 

 known as the SCLAVONIAN GREBE, is a much smaller 

 species than the preceding one, which it resembles in 

 its general habits and distribution, but is a rare bird 

 in this country in summer. The male is distinguished 



