Contributions to the theory of natural selection. A series of essays ... By Alfred Russel Wallace ...

80 MIMICRY, AND OTHER PROTECTIVE
their under surfaces. This property places them somewhat in the position of those curious wingless birds of
oceanic islands, the dodo, the apteryx, and the moas,
which are with great reason supposed to have lost the
power of flight on account of the absence of carnivorous
quadrupeds. Our butterflies have been protected in a
different way, but quite as effectually; and the result
has been that as there has been nothing to escape from,
there has been no weeding out of slow flyers, and as
there has been nothing to hide from, there has been no
extermination of the bright-coloured varieties, and no
preservation of such as tended to assimilate with surrounding objects.
Now let us consider how this kind of protection must
act. Tropical insectivorous birds very frequently sit on
dead branches of a lofty tree, or on those which overhang
forest paths, gazing intently around, and darting off at
intervals to seize an insect at a considerable distance,
which they generally return to their station to devour.
If a bird began by capturing the slow-flying, conspicuous
Heliconid,3 and found them always so disagreeable that
it could not eat them, it would after a very few trials
leave off catching them at all; and their whole appearance, form, colouring, and mode of flight is so peculiar,
that there can be little doubt birds would soon learn to
distinguish them at a long distance, and never waste
any time in pursuit of them. Under these circumstances,
it is evident that any other butterfly of a group which
birds were accustomed to devour, would be almost
equally well protected by closely resembling a Heliconia