But spots or stripes would
at once betray the crouching lion among the bare rocks or desert sands;
and therefore the lion is approximately sand-coloured. Seen in a cage at
the Zoo, the British lion is a very conspicuous animal indeed; but
spread at full length on a sandy patch or among bare yellow rocks under
the Saharan sun, you may walk into his mouth before you are even aware
of his august existence.
The three other great desert beasts of Asia or Africa--the ostrich, the
giraffe, and the camel--are less protectively coloured, for various
reasons. Giraffes and ostriches go in herds; they trust for safety
mainly to their swiftness of foot, and, when driven to bay, like most
gregarious animals, they make common cause against the ill-advised
intruder. In such cases it is often well, for the sake of stragglers,
that the herd should be readily distinguished at a distance; and it is
to insure this advantage, I believe, that giraffes have acquired their
strongly marked spots, as zebras have acquired their distinctive
stripes, and hyaenas their similarly banded or dappled coats. One must
always remember that disguise may be carried a trifle too far, and that
recognisability in the parents often gives the young and giddy a point
in their favour. For example, it seems certain that the general
grey-brown tint of European rabbits serves to render them
indistinguishable in a field of bracken, stubble, or dry grass. How hard
it is, either for man or hawk, to pick out rabbits so long as they sit
still, in an English meadow! But as soon as they begin to run towards
their burrows the white patch by their tails inevitably betrays them;
and this betrayal seems at first sight like a failure of adaptation.
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