Food. 
General 
descrip- 
tion. 
Adult. 
Young. 
292 NATATORES. TADORNA. SHIELDRAKE. 
themselves, and uttering a shrill whistling note, repeated 
with great quickness, and attended with a frequent movement 
of the head; they are also very jealous and irascible at the 
approach of any other bird to their mates.—The food of the 
Shieldrake, in its wild state, consists of marine vegetables, 
molluscous shell-fish, insects, &c.; but when domesticated, it 
thrives well upon grain, and indeed upon the usual fare of 
poultry. The trachea of the male bird is furnished, at the 
divarication, with a curious labyrinth, composed of two thin 
membranous bladders, of which the one on the right side is 
the largest ; the surfaces of both are uneven, and their tex- 
ture so delicate, as to be indented or broken by a very slight 
pressure. In the young drakes, previous to the acquisition 
of the mature plumage, it is very small, but after that period 
soon attains its full development. 
Piate 48. Represents the adult male of the natural size, 
taken in spring, when the fleshy tubercle at the base of 
the bill becomes much enlarged. 
Head and upper part of the neck blackish-green, shewing 
glossy reflections as opposed to the light. Lower part 
of the neck, sides of the body, wing-coverts, lower part 
of the back, upper tail-coverts, and basal part of the 
tail, pure white. A broad pectoral band of fine orange- 
brown extends upwards, and forms a mantle of the 
same colour. Scapulars, mesial abdominal list, greater 
quills, and end of the tail, black. Secondaries, with 
their outer webs, rich bronzed-green, and forming a 
speculum ; and the three tertials next to them, with part 
of their outer webs, rich orange-brown. Under tail- 
coverts sienna-yellow. Bill bright venous blood-red. 
Legs and toes crimson-red. 
The female is similar to the male bird in markings, but 
the colours are not so deep and bright, and she is always 
much less. 
The young, previous to the first moult, differ considerably 
