In A Like Manner
It Might Be Fancied That A Bird Originally A Buzzard, Had Been
Induced Here To Undertake The Office Of The Carrion-Feeding
Polybori Of The American Continent.
Of waders and water-birds I was able to get only eleven
kinds, and of these only three (including a rail confined to
the damp summits of the islands) are new species.
Considering
the wandering habits of the gulls, I was surprised to
find that the species inhabiting these islands is peculiar, but
allied to one from the southern parts of South America.
The far greater peculiarity of the land-birds, namely,
twenty-five out of twenty-six, being new species, or at least
new races, compared with the waders and web-footed birds, is
in accordance with the greater range which these latter
orders have in all parts of the world. We shall hereafter
see this law of aquatic forms, whether marine or fresh-water,
being less peculiar at any given point of the earth's
surface than the terrestrial forms of the same classes,
strikingly illustrated in the shells, and in a lesser degree in
the insects of this archipelago.
Two of the waders are rather smaller than the same species
brought from other places: the swallow is also smaller,
though it is doubtful whether or not it is distinct from its
analogue. The two owls, the two tyrant-catchers (Pyrocephalus)
and the dove, are also smaller than the analogous
but distinct species, to which they are most nearly related;
on the other hand, the gull is rather larger. The two owls,
the swallow, all three species of mocking-thrush, the dove
in its separate colours though not in its whole plumage, the
Totanus, and the gull, are likewise duskier coloured than
their analogous species; and in the case of the mocking-
thrush and Totanus, than any other species of the two genera.
With the exception of a wren with a fine yellow breast,
and of a tyrant-flycatcher with a scarlet tuft and breast, none
of the birds are brilliantly coloured, as might have been
expected in an equatorial district. Hence it would appear
probable, that the same causes which here make the immigrants
of some peculiar species smaller, make most of the
peculiar Galapageian species also smaller, as well as very
generally more dusky coloured. All the plants have a
wretched, weedy appearance, and I did not see one beautiful
flower. The insects, again, are small-sized and dull-coloured,
and, as Mr. Waterhouse informs me, there is nothing in their
general appearance which would have led him to imagine
that they had come from under the equator. [1] The birds,
plants, and insects have a desert character, and are not more
brilliantly coloured than those from southern Patagonia; we
may, therefore, conclude that the usual gaudy colouring of
the intertropical productions, is not related either to the
heat or light of those zones, but to some other cause, perhaps
to the conditions of existence being generally favourable
to life.
Enter page number
PreviousNext
Page 304 of 402
Words from 156917 to 157420
of 208183
