MALLARD OR WILD DUCK 283 



authorities. Exclusive of this, there appear to be only a dozen 

 authenticated records of the occurrence of this species in Great Britain 

 up to the year 1 900, two of these dating from the eighteenth century. 

 In two of these instances a couple of birds were recorded. The species 

 is easily recognised by its black upper-parts and the bright chestnut 

 of the lower part of the throat and the sides and fore part of the neck. 



Most specimens of the Canada goose {Bj-anta cmiadcnsis inclusive 

 of the nearly allied B. JmtcJiinsi) met with in this country have in all 

 probability escaped from captivity, but an example recorded from the 

 Outer Hebrides in 1903 may perhaps have been a truly wild bird. 



As to the Egyptian goose {CJienalopex cegyptiaccx) and the spur- 

 winged goose {Plectrop terns ganibensis), which is also African, there can 

 be little hesitation in refusing to admit either to a place in the list of 

 occasional stragglers to the British Islands. 



Mallard or Wild ^^i^h the mallard (a name properly applicable only 



Duck (Anas boseas) ^° ^^^^ drake of the species), or wild duck, we reach 



the typical representative not only of the entire 



order, but likewise of the sub-family Antinae, which is here taken to 



include the pochards as well as the more typical ducks. 



The members of the Anatinae, as distinct from the geese on the 

 one hand and from the mergansers on the other, are best distinguished 

 by the circumstance that in the drakes the lower end of the windpipe 

 is usually expanded so as to form a large bladder-like bony chamber, 

 while the legs, which are set relatively far back, are adapted for swim- 

 ming rather than for walking, and the plumage of the two sexes is 

 in most cases markedly dissimilar for the greater part of the year. 

 An unimportant character not unfrequently found in the members of 

 the group is the presence of a lobe of membrane of variable width on the 

 under side of the hind-toe. Again, in the majority of species the exposed 

 portions of the secondary quill-feathers of the wing, together with their 

 larger coverts, form a brightly coloured patch often showing metallic 

 tints, known as the " speculum." In all cases the beak is depressed 

 and much expanded at the tip. Most ducks are much smaller birds 

 than geese. 



Among those species, like the mallard, in which the drake assumes 

 a special breeding-plumage, there are two annual moults, sometimes 

 (as in the present species) following one another after a very short 

 interval. In the case of the mallard the dull-coloured plumage 

 is worn only for a few months in summer, and thus appears 

 to correspond with the summer or breeding dress of other birds. 



