528 BRITISH BIRDS. 



resembling that of the female, in order that when he moults his wing- and 

 tail-feathers (which he does last of all and all at once, so that for some time 

 he is unable to fly) he can do so without bringing himself into danger by 

 the brilliancy of his colour; but he does not wear this plain moulting- 

 dress very long, at most not more than four months. Late in autumn the 

 young moult out of their first plumage into that of bii'ds of the year, 

 which, in both sexes, resembles closely that of the adult, and the adult 

 males moult out of their moulting-dress into their gay wedding-attire. 

 In neither case, however (neither in the young of both sexes nor in the 

 adult males), are the quills or tail-feathers moulted in autumn, except 

 sometimes the two centre tail-feathers, which are often gaily coloured in 

 the wedding-dress. 



There are consequently six varieties of plumage belonging to each 

 species of Duck in addition to the plumage of the young in down, namely : 

 (1) young in first plumage, in which the sexes are alike, only slightly 

 differing from females of the year ; (2, 3) males and females of the year 

 only slightly diff'ering from adults ; (4) adult male in moulting-plumage, 

 only slightly diff'ering from adult female ; (5) adult male in wedding- 

 plumage ; and (6) adult female. 



The genus Anas is almost cosmopolitan in its range. It contains about 

 sixty species, of which a third breed in the Palsearctic and Nearctic Regions, 

 a fourth in the Neotropical Region, the remaining species being nearly 

 equally divided amongst the Ethiopian, Oriental, and Australian Regions. 

 Eight species breed in Europe, all of which, ynfh one exception, breed more 

 or less commonly in the British Islands. Several American species occa- 

 sionally wander in winter as far as our shores. 



The following key will make it easy to distinguish any adult male British 

 Duck in nuptial plumage belonging to this genus : — 



A. Mantle vermiculated. 

 Gadwall. 

 Pintail Upper breast white. 



iWlGEON. 

 American Wigeon ] 



Teal J^-Greeu band on sides of neck. 



White crescent on sides of breast . Ajiehican Teal .... J 



B, Mantlo not vermiculated. 



. Gahganey. 

 Shoulders blue 



Shoa'eller 



Head and neck green. 



Mallard 



