This iuteresting specimen is not easy to determine, being in size
like D. cervinus and in colour like D. leachii. As I endeavour
to show below, these species, however, run into each other so
much that it is impossible to define the exact characters of
each.
Since I wrote my ‘ Monograph of the Kingfishers,’ our knowledge
of the great Laughing Jackasses of Australia has not been much
increased. The range of true Dacelo has been extended to Southeastern
New Guinea, w-here Dacelo intermedius of Salvadori replaces
D. cervinus of the Australian continent; but otherwise the number
of species in Australia has remained the same as it was on the completion
of th a t work.
A comparison, however, of the large series of Laughing Kingfishers
now in the British Museum raises great doubts in my mind
as to the validity of some of the species admitted by me up to 1871;
and I therefore add a few notes on the birds now before me.
The chief difference between D. cervinus and D. leachii is supposed
to consist in the smaller size, the buif-coloured breast, and the blue
outer web of the external tail-feather of the former. I t seems to me
now th at this last is a character of no v alue; for it is evident th at
the young males commence with a rufous tail like the old females,
and th at they gain their blue tails by the gradual expansion of the
blue cross bands, which unite by degrees until the whole tail becomes
uniform blue. Thus there arrives a time in the development of the
tail when the outer web of the tail-feather has not quite lost its
bars before becoming uniform, and thus the barring of the tail, considered
to be a specific difference between D. cervinus and D. leachii,
is of very little importance. As regards the other characters, we
shall see what they are w o rth ; and in order to trace the development
of the species, I add a description of a young D. cervinus :—
Nestling. General colour above dark brown, with scarcely perceptible
lighter brown edges to the feathers of the mantle and
scapulars; least wing-coverts brown like the b a c k ; median and
greater series brown, tipped with pale verditer-blue or light greenish
cobalt; hastard-wing brown, washed with blue ; primary-coverts
blackish, externally greenish blue ; quills blackish, externally deep
blue, greener on the primaries, which are white near the bases of
both webs ; the secondaries edged with white at the tips, the inner
ones brown like the back ; lower hack and rump pale silvery cobalt;
upper tail-coverts bright rufous, barred with black ; tail-feathers
bright rufous, paler at the ends, barred with dark blue, these
blue bands margined above and below with black, the hands
broader near the base and narrower towards the en d s; the blue
bands at the base of the middle feathers already coalescing into one
uniform blue base ; head nearly uniform dprk brown, the feathers
broadly centred with blackish, the edges somewhat mottled with
reddish-brown markings; the nape lighter, the crest-feathers being
whiter, with narrow dark-hrown centres ; hind neck clear fulvous,
with more or less distinct zigzag cross lines of brown ; lores tawny
buff, as also the feathers below the ej-e, the latter wnth blackish
shaft-streaks ; ear-coverts dusky brown ; cheeks clear fulvous, wnth
central streaks of light brown, breaking up into irregular cross lines
on some of the feathers ; throat and fore neck white, with irregular
zigzag cross lines of light brown; remainder of under surface of body
clear fulvous, crossed with zigzag lines of brown; under tail-coverts
uniform and deeper b u ff; axillaries like the breast and barred across
in the same manner; under wing-coverts whiter and crossed distinctly
wnth blackish bars, broader and forming a distinct patch on the
median lower coverts near the edge of the wing.
The above description is taken from a young male shot near Port
Essington.
An old bird, Avith more than half his tail-feathers blue, has his
plumage very much abraded and the crest-feathers reduced to
hair-like brown plumes. The blue ends to the wing-coverts are
almost entirely worn o ff; but on the breast he is replacing his
faded plumage by a clean moult, the new feathers being very
broadly centred with blackish ; the under surface of the body is
dirty huff, with brown zigzag cross bars, becoming less distinct on
the throat.
Compared with young birds, the old D. cervina are very much
paler buff below and less distinctly barred underneath, the collar
round the hind neck is nearly uniform, with scarcely any remains
of zigzag cross-barring, while the head and crest are white or
huffy white, streaked with brown down the centre of the feathers ;
but the whole head is distinctly streaked, instead of being uniform
brown as in the young birds. The cobalt-hlue on the shoulders is,
of course, much more brilliant and more developed than in the
young ones.
The mode in which the barring on the under surface becomes
less and the head more streaked is well shown in an immature male
bird, which has the head losing its uniformity for the streaked
stage, and yet retains the rufous upper tail-coverts of the immature
stage, while the tail is only half overshaded with blue.
The differences between the young and old specimens of Dacelo
cervinus seem to me perfectly compi’ehensible; but the relations of
D. leachii and D. occidentalis are not so clear. There is considerable
variation in length of wing throughout the whole series.
All our specimens of D. leachii have more or less remains of their
old rufous-barred tail, but they are all completing their change to
the uniform blue tail, and consequently the outer feathers are in
more or less irregularly blue-banded stages ; but every proof is furnished
th a t the outer feather will become perfectly blue, like the
corresponding stage in D. cervinus, so th a t the character of the barred
outer tail-feather will not hold.
Undoubtedly D. leachii is a larger and more powerful bird than
D. cervinus. I t is often similarly fulvous on the b re a s t; hut the
zigzag bars are coarser and are continued higher up on the throat,
as well as being strongly developed on the collar round the hind
neck. The older the bird becomes, however, it is evident that, as in
D. cervinus, the cross-markings on these parts become more and more