ERISMATURA AUSTRALIS. 
Blue-billed Duck. 
Oxyura Australis, Gould in Proc. of Zool. Soc., Part IV. p. 85 ; and in Syn. Birds of Australia, Part II. 
Erismatura Australis, Eyton, Mon. of Anat., p. 172. 
Bood-doo, Aborigines of the lowland districts of Western Australia. 
Blue-billed Duck of the Colonists. 
This bird would appear to be so limited in its habitat, as to be confined to the colony of Western Australia ; 
at least up to this time it lias not been discovered in any other part of the country. Mr. Gilbert’s notes 
inform me that it is never seen in the rivers, either those communicating with the sea or those of the 
interior, and that it is only found on those lakes running parallel to and near the coast that are surrounded 
with high reeds and tea-trees. Its general habits resemble those of the Biziura lobata ; like that bird it 
possesses the power of remaining under water for a great length of time, and if closely hunted flaps along 
the surface without taking wing. Its voice is a peculiar inward tone, which the natives describe by saying, 
“ it has no voice, but makes a noise with its heart.” 
It breeds in September and October, constructing a nest very like that of the Biziura lobata, and laying- 
from two to nine or ten eggs which are of a large size, and of a uniform bluish white, with a very rough sur- 
face ; two inches and five-eighths long by tw r o inches hroad. 
Its food consists of insects, shelled mollusks, fish, &c. 
The sexes, as will be seen on reference to the accompanying Plate, differ very considerably in plumage. 
The male has the whole of the head, throat and neck black ; chest, breast, back and flanks rich chest- 
nut ; wings and tail brownish black ; rump brownish black freckled with brown ; belly and under tail- 
coverts brownish grey, obscurely marked transversely with dark browm ; irides very dark brown ; bill light 
blue ; front and inner side of the tarsi and toes french-grey ; outside of tarsi and webs blackish grey. 
The female is the same size as the male, and has a plumage of uniform blackish brown, transversely 
marked with indistinct zigzag lines and freckles of chestnut-brown, lighter and more greyish brown on the 
under surface ; tail-feathers black ; bill dark olive-green ; the under mandible lighter than the upper ; 
irides, legs and feet as in the male, but paler. 
The figures are of the natural size. 
