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Bullseye
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* Naturgesch. der Stubenvogel, 1840, s. 252.
*(2) Mr. Bold, Zoologist, 1843-44, p. 659.
That male birds should sing from emulation as well as for charming
the female, is not at all incompatible; and it might have been
expected that these two habits would have concurred, like those of
display and pugnacity. Some authors, however, argue that the song of
the male cannot serve to charm the female, because the females of some
few species, such as of the canary, robin, lark, and bullfinch,
especially when in a state of widowhood, as Bechstein remarks, pour
forth fairly melodious strains. In some of these cases the habit of
singing may be in part attributed to the females having been highly
fed and confined,* for this disturbs all the functions connected
with the reproduction of the species. Many instances have already been
given of the partial transference of secondary masculine characters to
the female, so that it is not at all surprising that the females of
some species should possess the power of song. It has also been
argued, that the song of the male cannot serve as a charm, because the
males of certain species, for instance of the robin, sing during the
autumn.*(2) But nothing is more common than for animals to take
pleasure in practising whatever instinct they follow at other times
for some real good. How often do we see birds which fly easily,
gliding and sailing through the air obviously for pleasure? The cat
plays with the captured mouse, and the cormorant with the captured
fish. The weaver-bird (Ploceus), when confined in a cage, amuses
itself by neatly weaving blades of grass between the wires of its
cage. Birds which habitually fight during the breeding-season are
generally ready to fight at all times; and the males of the
capercailzie sometimes hold their Balzen or leks at the usual place of
assemblage during the autumn.*(3) Hence it is not at all surprising
that male birds should continue singing for their own amusement
after the season for courtship is over.
* D. Barrington, Philosophical Transactions, 1773, p. 262.
Bechstein, Stubenvogel, 1840, s. 4.
*(2) This is likewise the case with the water-ouzel; see Mr. Hepburn
in the Zoologist, 1845-46, p. 1068.
*(3) L. Lloyd, Game Birds of Sweden, 1867, p. 25.
As shewn in a previous chapter, singing is to a certain extent an
art, and is much improved by practice. Birds can be taught various
tunes, and even the unmelodious sparrow has learnt to sing like a
linnet. They acquire the song of their foster parents,* and
sometimes that of their neighbours.*(2) All the common songsters
belong to the Order of Insessores, and their vocal organs are much
more complex than those of most other birds; yet it is a singular fact
that some of the Insessores, such as ravens, crows, and magpies,
possess the proper apparatus,*(3) though they never sing, and do not
naturally modulate their voices to any great extent. Hunter
asserts*(4) that with the true songsters the muscles of the larynx are
stronger in the males than in the females; but with this slight
exception there is no difference in the vocal organs of the two sexes,
although the males of most species sing so much better and more
continuously than the females.
* Barrington, ibid., p. 264, Bechstein, ibid., s. 5.
*(2) Dureau de la Malle gives a curious instance (Annales des Sc.
Nat., 3rd series, Zoolog., tom. x., p. 118) of some wild blackbirds in
his garden in Paris, which naturally learnt a republican air from a
caged bird.
*(3) Bishop, in Todd's Cyclopaedia of Anatomy and Physiology, vol.
iv., p. 1496.
*(4) As stated by Barrington in Philosophical Transactions, 1773, p.
262.
It is remarkable that only small birds properly sing. The Australian
genus Menura, however, must be excepted; for the Menura alberti, which
is about the size of a half-grown turkey, not only mocks other
birds, but "its own whistle is exceedingly beautiful and varied."
The males congregate and form "corroborying places," where they
sing, raising and spreading their tails like peacocks, and drooping
their wings.* It is also remarkable that birds which sing well are
rarely decorated with brilliant colours or other ornaments. Of our
British birds, excepting the bullfinch and goldfinch, the best
songsters are plain-coloured. The kingfisher, bee-eater, roller,
hoopoe, wood-peckers, &c., utter harsh cries; and the brilliant
birds of the tropics are hardly ever songsters.*(2) Hence bright
colours and the power of song seem to replace each other. We can
perceive that if the plumage did not vary in brightness, or if
bright colours were dangerous to the species, other means would be
employed to charm the females; and melody of voice offers one such
means.
* Gould, Handbook of the Birds of Australia, vol. i., 1865, pp.
308-310. See also Mr. T. W. Wood in the Student, April, 1870, p. 125.
*(2) See remarks to this effect in Gould's Introduction to the
Trochilidae,, 1861, p. 22.
In some birds the vocal organs differ greatly in the two sexes. In
the Tetrao cupido (see fig. 39) the male has two bare, orange-coloured
sacks, one on each side of the neck; and these are largely inflated
when the male, during the breeding-season, makes his curious hollow
sound, audible at a great distance. Audubon proved that the sound
was intimately connected with this apparatus (which reminds us of
the air-sacks on each side of the mouth of certain male frogs), for he
found that the sound was much diminished when one of the sacks of a
tame bird was pricked, and when both were pricked it was altogether
stopped. The female has "a somewhat similar, though smaller naked
space of skin on the neck; but this is not capable of inflation."* The
male of another kind of grouse (Tetrao urophasianus), whilst
courting the female, has his "bare yellow oesophagus inflated to a
prodigious size, fully half as large as the body"; and he then
utters various grating, deep, hollow tones. With his neck-feathers
erect, his wings lowered, and buzzing on the ground, and his long
pointed tail spread out like a fan, he displays a variety of grotesque
attitudes. The oesophagus of the female is not in any way
remarkable.*(2)
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