The Descent of Man

wings. (39. Gould, 'Handbook to the Birds of
Australia,' vol. i. 1865, pp. 308-310. See also Mr.
T.W. Wood in the 'Student,' April 1870, p. 125.)
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, woodpeckers, etc., utter harsh
cries; and the brilliant birds of the tropics are
hardly ever songsters. (40. See remarks to this
effect in Gould's 'Introduction to the Trochilidae,'
1861, p. 22.) 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.
[Fig. 39. Tetrao cupido: male. (T.W. Wood.)]