DUCKS. 373 



DUCKS. (Anas.* Lin.) 



With the bill broader than high at the base, widening more or 

 less at the extremity, somewhat flattened, obtuse and much depressed 

 towards the point ; marginal teeth lamelliform, weak : upper man- 

 dible convex, curved, and furnished with a slender nail at the end ; 

 the lower narrower, flat, and entirely covered by the margins of the 

 upper. Nostrils basal, approaching together, oval, open, pervious, 

 and partly closed by a membrane. Tongue stout, and obtuse, fringed 

 at the sides. The neck about the length of the body. Feet nearly 

 central, but rather small and weak; tarsus about equal with the 

 middle toe, not very much compressed ; webs entire ; the hind toe 

 equal in length with a joint of the middle one, simple, touching the 

 ground at tip. Wings moderate, acute ; the primaries long ; the 1st 

 and 2d, or 2d only, longest. The tail of from 14 to IG feathers. 



The plumage of the female different from the adult male ; the 

 young more or less resemble the female. The moult takes place 

 twice in the year, in the female only partially, in the male com- 

 pletely, assuming towards the end of summer and after the close of 

 the breeding season the humble dress of the female. The plumage 

 thicker than in the Geese, but less so than in the Swans and Fuligu- 

 loB. There is a conspicuous bright colored patch, usually called the 

 speculum, on the wing in most of the species. The colors of the 

 female are generally dull and greyish. The windpipe or trachea 

 swelling out at its bifurcation into cartilaginous cavities. 



These well known birds are eminently aquatic, and migratory, 

 approaching the sea coast in flocks during autumn and winter, but 

 frequent fresh 'svater ponds, lakes and rivers, particularly those with 

 grassy and sedgy borders, preferring shallow places in which they 

 can fathom the bottom with the bill without the aid of deeply diviner^ 

 to which they only have recourse in the breeding season, or when 

 compelled by necessity to avoid their enemies ; they therefore 

 usually avoid deep waters. While swimming, which they perform 

 with singular address and facility, they stretch forward the body and 

 elevate the tail. They walk comparatively well, with the feet close 

 together, but waddle, and do not poise the body with the same ease 



* From the Greek name for the Duck vrivora, from veco to swim. 



32 



