KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 52. N:o |7. 89 
Juvenals. — Four juvenals of different ages. Of those two are in moulting 
(the specimen from Oct. and Dec.), not the others (from July). These passed the winter 
in Dampier land. As a rule the species is a migratory bird, leaving the country in 
Jan., Febr. and returning in Sept. Three of these juvenals — all young males — 
have a plumage that forms a transition from juvenal to adult, with black strongly 
mixed in the brown on the back. 
Moulting. 
All the birds shot during the season when the species lives in the country 
(during the breeding season, the summer), are in moulting. The two shot when passing 
the winter in Beagle bay are not in moulting (both of them young males, one of them 
partly in adult plumage). 
To take them in order: 
Specimen no. 1, an old male, shot ”!/10, is moulting (back part), but the moult 
seems not to be fully developed yet. 
Specimen no. 2, a young male (Derby, Oct.), is moulting very strongly both 
on the back and in the tail and partly in the wings. 
Specimen no. 3 (S ad., Oct.) is also moulting to some extent. Then follows 
the long series from Nooncanbah, including the specimens of Dec.—Jan., which 
are more or less moulting. One of them (specimen g3S ad., "/1i2, Nooncanbah) has 
sepia-brown wing-feathers (old, faded ones) and has finished the moulting on the 
back and for the most part in the tail. Only the wing-feathers are not dropped yet. 
The young male ”/12 has the dress of the adult bird, which is almost complete 
on the back. The tail, too, is very nearly ready, but not the wing-feathers, which 
are also old and brown in this bird. Similarly the young male, ”/10, which has the 
tail partly ready and is in moulting on the back but not in the wings (brown 
feathers). The other adults have very nearly finished moulting. 
The juvenals are very interesting. BSpecimen '/r is a real juvenal (35), brown 
on the back and not moulting. Specimen ”/r has partly the male's dress but is not in 
moulting. Some black pins are, however, to be seen on the back. Both have 
black feathers in the wing. If we compare specimen ”'/12, with the specimen 
”/7 we shall find some interesting details. The latter is in a considerably more ad- 
vanced stage, though it is a July specimen, that is not now in real moulting; this 
seems to indicate that the juvenal wears a partial male plumage during a shorter 
or longer period of the year, before it gets its full plumage. The juvenal ”!'/10 (in 
moulting) was then just about to get a partial dress from such a stage as is repre- 
sented by the specimen '”/r- Beside the intermixture of black, it acquires the white 
on the wing-coverts. It has, anyhow, not yet dropped either the wing-feathers or 
the wing-coverts, though the tail is growing out. 
We must also note that the wing is the part that passes through the moulting 
last of all; many of the smaller white wing-coverts have in the beginning a black 
streak, which is absent in the old males. 
E. Sv. Vet. Akad. Handl. Band 52. N:o 17. 12 
