KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 52. N:o |17. 61 
a tinge of red. It is easy to see the yellow changes into red, particularly in the tail- 
feathers. 
Moulting. — Specimen 9 ad. "/12: This specimen is in strong moult. About half of 
the dress is old, the rest new. The new and the old feathers alternate. At almost all 
places where the old plumage remains, the yellow seems to have disappeared as a 
pigment, and spots and stripes are indicated by a light part extending over the 
same parts as the yellow did. The bluish black is dark-brown. We see this meta- 
morphosis partly in the tail-feathers. Only the innermost (uppermost) ones are new, 
the rest of them old. 
Specimen 2 ad. !?/2: Closely resembles the former. Red in the tail-feathers. Breast 
and belly no waterings, which is partly due to moult, but some of the new feathers 
also appear to have no stripes. The tail-feathers are all new. 
A detailed account of the moulting and the change of plumage is as follows: 
First of all a noteworthy difference seems to exist in the way the feathers 
degenerate in the females and in the males. This in due to the differences of colours. 
The male has no trace of the yellow spots and stripes of the female. And those 
yellow parts are affected first. 'The spots especially show an abrasion phenomenon, 
which cannot be found at all in the adult male. 
As the time for moulting approaches, the feathers generally begin more and 
more to lose the glossiness and intensity of colour that they possess when just un- 
folded from the sheaths. 
The bluish black vanishes and is dicoloured to dull dark-brown, at the same 
time as the feather seems to be worn away at the edges. It is the same with both 
sexes. Then the pigment of the female's yellow-coloured parts is destroyed until only 
a light muddy brown place, which almost seems unpigmented, is found instead of 
those yellow spots. Finally the web itself is affected, and barbs are broken. Espe- 
cially in spotted feathers the tops desappear, this part accurately following the limits 
for the yellow spots. In this way they get an empty part corresponding to the size 
of the spot and the lost barbs above it. The feather gets a peculiar, jagged appear- 
ance. (Plate 2, fig. 11 a and 11 b and page 22, fig. 6.) 
The specimen above has the yellow spots very reduced and no yellow stripes 
at all on the lower part of the body. It has the above-mentioned red part on 
the tail-feather and the bill darker than is usually the case. The specimen is in 
moulting, it is true, but new feathers without any apparent stripes seem to show, 
that we have here a plumage very different from the ordinary of one of the female, 
which on account of its resemblance to that of the male may indicate, that the specimen 
is a sterile female (without generative power). Another female has also some of 
these peculiarities. Other females in moulting have, of course, their plumage bleached, 
but the feathers are striped or mottled. In new feathers the yellow colour is fresh 
and distinct. In some males the red on the tail has some yellow at the top of the 
outer part of the inner plumes. 
Moulting-season. — The collection has 8 specimens in moulting. These are all 
from the upper part of the Fitzroy river and were shot between "”/1 and '”/2. Later 
