292 NATATORES. TADOBNA. SHIELDKAKE. 



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 

 Food. 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. 



PLATE 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. 



General Head and upper part of the neck blackish-green, shewing 

 tktti" 1 *" glossy reflections as opposed to the light. Lower part 



Adult. f 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 ahvavs 

 much less. 

 Young. The young, previous to the first moult, differ considerably 



