DUCKS. 63 



regularly in England, but is now only a straggler to our shores. Like 

 its allies, it almost always breeds in colonies ; the nest, a mass of twigs, 

 flags, or sticks, is sometimes placed in reed-beds or on low bushes, 

 but more usually in a tree. Four or five rough white eggs with red- 

 brown spots are the full complement for a sitting. 



Order XVI. ANSERI FORMES. DUCK-TRIBE. 

 Family ANATID^E. MERGANSERS, DUCKS, GEESE & SWANS. 



The cosmopolitan family Anatidcs, which alone comprises this Order, [Cases 



includes the Mergansers. Ducks, Geese and Swans. They are all easily 3 ^7^ 



. J J & Central 



recognised by their external characters, such as the flattened or partially Case.] 



flattened bill, short legs and fully webbed toes, which distinguish them 

 from the Screamers and Flamingoes. The majority of the species find 

 their food under the water, which is drained away between the lamellfe 

 with which the edges of the soft-skinned bill are provided, and which 

 act like a sieve in retaining the substances or animalcules fit for food. 

 In the Geese these lamellae are harder and adapted for cutting grass, 

 while in the Mergansers they are recurved to prevent the captured fish 

 from escaping. 



A curious feature about many of the Duck's, apparently peculiar to 

 all those species in which the male is more brightly coloured than the 

 female, is that after the young are hatched the male moults his bright 

 plumage and assumes a dull- coloured dress similar to that of the female. 

 This change is no doubt protective, for during the moult the male, 

 having cast all his flight-feathers, is practically helpless. The " eclipse " 

 plumage lasts for several weeks till the quills have been renewed, and is 

 then replaced by new feathers of the normal bright livery. 



On the lower shelves of this Case the visitor will find various species [Case 37.1 

 of " Saw- bills/' as the genus Merganser and its allies are commonly 

 called. The Red-breasted Merganser (M. serrator) (684), the Goosander 

 (M. castor] (685), and the beautiful Smew (Mergus albellus) (686) are 

 all three British species, the first two breeding in the north of Scotland. 

 The Merganser is much the commonest and is particularly hated 

 by fishermen on account of the enormous numbers of fish it catches, 

 including small trout and salmon-fry. A remarkably handsome species 

 is the North-American Hooded Merganser (Lophodytes cucullatus) (687), 

 which has occasionally been obtained in Great Britain and Ireland 

 during severe winter-weather. The Red- breasted Merganser hides its 

 nest among thick heather or coarse grass, but the other species men- 

 tioned almost always select a hollow tree. 



The genus Merganetta, represented by the Chilian Merganser or 



