black, the lower surface being partly fawn-coloured, and there is much
red about the head; in the female the upper surface is reddish-brown
banded with black, and the lower surface white with black markings. It
is an interesting fact, as shewing how the same peculiar style of
sexual colouring often characterises allied forms, that in three
species of Dacelo the male differs from the female only in the tail
being dull-blue banded with black, whilst that of the female is brown
with blackish bars; so that here the tail differs in colour in the two
sexes in exactly the same manner as the whole upper surface in the two
sexes of Carcineutes.
With parrots, which likewise build in holes, we find analogous cases:
in most of the species, both sexes are brilliantly coloured and
indistinguishable, but in not a few species the males are coloured
rather more vividly than the females, or even very differently from
them. Thus, besides other strongly-marked differences, the whole under
surface of the male King Lory (Aprosmictus scapulatus) is scarlet,
whilst the throat and chest of the female is green tinged with red: in
the Euphema splendida there is a similar difference, the face and wing
coverts moreover of the female being of a paler blue than in the male.
(23. Every gradation of difference between the sexes may be followed in
the parrots of Australia. See Gould s Handbook, etc., vol. ii. pp.
14-102.) In the family of the tits (Parinae), which build concealed
nests, the female of our common blue tomtit (Parus caeruleus), is much
less brightly coloured than the male: and in the magnificent Sultan
yellow tit of India the difference is greater. (24. Macgillivray s
British Birds, vol. ii. p. 433. Jerdon, Birds of India, vol. ii. p.
282.)
Again, in the great group of the woodpeckers (25. All the following
facts are taken from M. Malherbe s magnificent Monographie des
Picidees, 1861.), the sexes are generally nearly alike, but in the
Megapicus validus all those parts of the head, neck, and breast, which
are crimson in the male are pale brown in the female. As in several
woodpeckers the head of the male is bright crimson, whilst that of the
female is plain, it occurred to me that this colour might possibly make
the female dangerously conspicuous, whenever she put her head out of
the hole containing her nest, and consequently that this colour, in
accordance with Mr. Wallace s belief, had been eliminated. This view is
strengthened by what Malherbe states with respect to Indopicus
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