KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 52. N:o |7. 91 
'The change of colours in the feathers. (Plate 1, fig. 4b, 4c, 4d.) 
The change of colours in the juvenals, when the adult male plumage is acquired, 
is obtained in another way than in the case of Malwrus. This case is to be compared 
with the corresponding moulting in Ephthianura (cf. this species). Some instances of the 
observations that I made at the place may be mentioned here. 
One juvenal of the lst of Dec. 1910 was beginning to get black sprinkles of 
the male plumage in the crown of the head and the back (the same also in wings 
and tail, the latter, however, with the middlemost feathers still kept). 
The pins showed different developments of the black in the grey or pale brown 
feathers, from small spots up to entirely black feathers. The black colour was thus 
formed to some extent through partial colouring of certain feathers, and to some 
extent by total colouring of other ones; it remains to be added that even black edgings 
on grey feathers are found. 
By this the juvenal gets in the first moulting the mixed dress described above 
and consequently developed: 
1”) partly from new black feathers coming out of sheaths, 
2?) partly fom feathers with black parts mixed in, growing out of other sheaths, 
and finally 
3”) from feathers with the juvenal-character also coming out of sheaths now. 
For further details with regard to the change of colours see Ephthianura tricolor 
assimilis. 
Ecological. — At Mowla Downs, Fitzroy river, Derby etc., this bird was one 
of the most common in the bush. At Sunday Island it was absent. In the summer 
it sang very frequently, especially in the mornings. It then swung from tree to tree, but 
also sang sitting in the tops of the trees. The first part of the singing, often heard 
from the flying bird, is clear and assonant, the second part of it is a twittering 
refrain. Being one of the few real singers of these regions it conduces in a high 
degree to animate the bush and for a little time to break the oppressive tediousness 
there. vi 
A juvenal in the transition plumage (cf. above) that I shot on the lst of Dec. 
was singing eagerly but did not yet know more than the first part of the warble of 
the adults. Although it was not wearing full male plumage, I have reason, never- 
theless, to think that it was breeding. 
The 30th of Nov. I found in Mowla Downs a nest with 3 eggs; the nest was 
shaped like a plate and had very low, thin but solid walls (cf. fig. 18). It lay quite 
exposed on a thick branch and was fastened there by a cobweb. Because of its 
small height it was exceedingly hard to discover. I also observed that the green- 
and brown-spotted eggs, which even reached a little over the edges of the nest, were 
not easily seen because of their ornamentation. 
As is seen above, the species was met with in the winter in Kimberley and 
Beagle Bay. Already in March the singing of the bird was heard no more. 
