26o 
Allen’s naturalist's library. 
the bill does not appear till the bird is at least two years old, 
and commences to breed for the first time. The knob in- 
creases in size with age. 
Nestling:.— Brown above, white beneath, with a slight 
yellowish tinge; forehead and sides of face white; in the 
middle of the back a white patch ; a white patch on each 
side of the lower back, and a white streak along each side of 
the rump. 
Characters.— The striking contrast of colours in this beautiful 
species, to say nothing of its red bill and frontal knob, render 
it easy of identification, and there is no other species of 
British Duck with which it can possibly be confounded. 
Hybrids.— The Common Sheld-Duck has been known to 
interbreed with the South African Sheld-Duck \Casarca cana) 
and with the Wild Duck (^Anas boscas). Cf. Salvador!, Cat. B. 
Brit. Mus. xxvii. p. 173. 
Range in Great Britain — The present species occurs in suit- 
able localities on most parts of the British coasts, and is found 
breeding in those portions which afford it suitable nestino-- 
places. Mr. Ussher states that it breeds in small numbers on 
the coasts of Donegal, Londonderry, Antrim, Down, Dublin, 
Vy exford, Waterford, K.erry, Clare, and Mayo. In winter con- 
siderable numbers visit us from the north of Europe, and the 
bird IS then killed in many parts of Great Britain, in which it is 
not seen in the summer. 
Range outside the British Islands. — The Sheld-Duck is a Balm- 
arctic bird, and breeds on the coast of Norway up to 70° N. 
lat., being only occasionally met with in the Fseroes. It nests 
in Sweden, Denmark, the Baltic provinces, and Holland, as well 
as on the shores of France and Spain, but in other parts of 
Europe and^ the Mediterranean countries it is only known as 
a winter visitor. It is, however, again resident on the shores 
of the Black and Caspian Seas, and its range extends in locali- 
ties suited to its habits, through Central Asia and Southern 
Siberia to Mongolia and Japan. 
Habits. — From its habit of nesting in rabbit-holes in many 
parts of the country the Sheld-Duck is known as the “ Burrow 
Duck,” and the nest is often constructed at the end of a 
