BLUE-BILLED DUCK. 
the feathers ; axillaries pale brown edged with white ; under wing-coverts greyish- 
brown tipped with white. Bill light blue ; iris very dark brown ; front and inner 
sides of tarsus and toes french grey, outside of tarsus and webs blackish-grey. 
Total length 440 mm. ; culmen 41, wing 151, tail 66, tarsus 35. 
Adult female. Entire upper-surface dark brown barred and vermiculated with white or 
buffy-white ; under-surface dusky brown with silvery white tips to the feathers. 
Bill dark ohve-green, under mandible lighter. Total length 415 mm. ; culmen 40, 
wing 150, tail 65, tarsus 35. 
Immature male. Differs in having the head and back browner with buff bars or 
vermiculations and the under-surface more silvery white. 
Nestling. Sooty brown above, darker on the crown of the head ; a spot of white on each 
wing and also on each side of the back and sides of the rump ; a pale line on each 
side of the head above the ear-coverts ; imder-surface whitish with a dusky bar 
across the fore-neck. 
Nest. “ Besembles that of B. lobata, large, with the flags bent down and interlaced, 
lined with down from the parent ” (S. A. White). 
Eggs. “ Clutch, four to five probably ; elhptically inclined in shape ; texture of shell 
coarse, surface very slightly glossy and rough ; colour, light greenish- white. 
Dimensions in inches ; 2.59-2.81 X 1.84-2.07 ” (Campbell). 
Breeding-season. “ November and December ” (S. A. White, South Austraha). 
Little is known of the economy of this rare Duck which was first described 
by Gould from West Australia. 
Captain S. A. White has communicated to me the following : “I have 
never seen this bird in any great numbers in any one place, fifteen to twenty 
is as many as I have seen together ; as the breeding-season approaches they 
disperse in pairs over the lakes and become very shy though they are a 
shy bird at any time. They seem to like the company of the Musk Duck, 
B. lobata^ and other ducks, and I have seen them playing together on the 
water. I have been trying for many years to get the eggs of this duck, but it was 
not until November, 1909, that I succeeded. Although I have often seen the 
ducks about in the swamps, hunt as much as I like, I could never strike their 
nest. Hunting about on November 19, up to the arm-pits in water amongst 
thick flags and reeds a large bird flopped into the water from a thick mass 
of broken-down flags and dived away out of sight : approaching the mass 
of dead flags and searching it well a neat opening was seen, and in a well-lined 
nest of down were the eggs, very like those of B. lobata but much smaller. 
Leaving the locality without touching the nest I returned some hours later 
with a gun : the bird left the nest in the same way as before, but showed 
herself for a moment as she came up, giving time to get a shot which proved 
her identity without a doubt. The nest was a large structure resembling a 
well-built B. lobata nest ; the flags were bent down and interlaced, and the 
inside was lined with down from the duck. I was only able to procure one 
more clutch which was found in somewhat the same way. The one taken 
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