76 RUDOLF SÖDERBERG, STUDIES OF THE BIRDS IN NORTH WEST AUSTRALIA. 
Moulting. — As has been mentioned above, the birds (”/12, !"/12, ”/1) show a strong 
watering in cobalt blue, caused by the edges of old feathers. The new feathers are 
green without blue edges, except (on the crown of the head and) in the black spot 
on the throat. Two birds at least are old, with old tail-feathers, and yet they have 
blue edges. It looks, therefore, as if the blue were caused by a mere bleaching- 
phenomenon in the originally green plumage. Specimen from ”h is in typical 
moulting. The middle tail-feathers are growing out. The others are finished. There 
are pins in the central part of the back, in the black spot, etc. 
A male adult of the llth of Febr. has finished moulting the tail-feathers and 
almost all the plumage, only one secondary, the first in each wing, is about to grow 
out. With this one may be compared a female from '!/s. This female has one pri- 
mary and one secondary of each wing growing out. The tail is completely moulted, 
and the rest of the plumage is moulting, though rather full-feathered (2 ad.). 
With regard to the two birds of the 6th of March we have to note the following: 
The plumage entirely new, two feathers of each wing about to grow out. The tail 
(almost) finished. But the black spot on the throat is, curiously enough, in strong 
moulting and mixed with white parts. From this it looks as these were juvenals 
that had already obtained the adult plumage in the main, and whose last stage of 
moulting was marked by the acquisition of the black patch on the throat. 
The origin of the black is interesting. Al the black feathers have in the be- 
ginning bright cobalt blue edges. This is also the case in the adults that are changing 
the feathers of this part of body. In the fully-developed plumage the blue edges 
are gone, and a deep, entirely black, spot remains. The blue may, however, remain 
a very long time. Whether a moulting of the edges or a change of colour has taken 
place perhaps by wearing away of the outher scales of the feathers, I cannot settle. 
(Especially in the case of the younger specimen of March the spot has been blue at first.) 
In contradistinction to these specimens the juvenals of the 9th and 27th of 
Dec., and the 4th of Jan. seem still to have the plumage of the nest. In the spe- . 
cimen of the 4th of Jan. the central part of the back is, however, in moulting, and 
green feathers are being developed. 
Moulting-season. — I have in the cases above been able to follow the 
moulting process rather carefully. The moulting-season appears to begin in the first 
part of Dec., and go on as far as March (for younger birds). Evidently it takes 
place during the whole summer. 
(A specimen of the 1l0th of Dec., a male adult, is just about to moult; the 
specimen of the 1l6th of Oct., a female with »brooding»-spot, is not moulting, but has 
a very worn dress.) 
Ecological. — During the winter a great number of the birds of Kimberley 
are scattered far and wide, and at this time (March, April, etc.) one might therefore 
find the ornithological conditions different from what they usually are at other seasons. 
This scattering plays a very remarkable part in the birdlife of these districts and is 
to be compared with the straggling of the birds in, for instance, the cold regions of 
