and then proceeding to another, like a kestrel, and at other times standing stationary on the margin of water, and then dashing like
a kingfisher at a fish. In our own country the larger titmouse (Parus major) may be seen climbing branches, almost like a creeper; it often,
like a shrike, kills small birds by blows on the head; and I have many times seen and heard it hammering the seeds of the yew on a branch, and thus breaking them like a nuthatch. In North America the black bear was seen by Hearne swimming for hours with widely open mouth, thus catching, like
a whale, insects in the water. ↑1 blocks not present in 1860 1861 1866 1869 1872; present in 1859 | Even in so extreme a case as this, if the supply of insects were constant, and if better adapted competitors did not already exist in the country, I can see no difficulty in a race of bears being rendered, by natural selection, more and more aquatic in their structure and habits, with larger and larger mouths, till a creature was produced as monstrous as a whale.
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As we sometimes see individuals of a species
following habits widely
different from those both of their own
species and of
the other species of the same genus, we might expect,
on my theory,
that such individuals would occasionally have
given
rise to new species, having anomalous habits, and with their structure either slightly or considerably modified from that of their proper
type. And such instances do
occur in nature. Can a more striking instance of adaptation be given than that of a woodpecker for climbing trees and for
seizing insects in the chinks of the bark? Yet in North America there are woodpeckers which feed largely on fruit, and others with elongated wings which chase insects on the
wing. wing. 1861 1866 1869 1872 | wing; 1859 1860 |
On On 1861 1866 1869 1872 | and on 1859 1860 |
the plains of La Plata, where not
a tree grows, there is a
woodpecker woodpecker 1861 1866 1869 1872 | woodpecker, 1859 1860 |
(
Colaptes campestris
) which has two toes before and two behind, a long pointed tongue, stiff pointed tail feathers, but not so stiff as
(
Colaptes campestris
) which has two toes before and two behind, a long pointed tongue, stiff pointed tail feathers, but not so stiff as
1861 |
which in every essential part of its organisation, even in its colouring, 1859 1860 |
(
Colaptes campestris
) which has two toes before and two behind, a long pointed tongue, stiff pointed tail-feathers, but not so stiff as
1866 |
(
Colaptes campestris
) which has two toes before and two behind, a long pointed tongue, pointed tail-feathers, sufficiently stiff to support the bird in a vertical position on a post, but not so stiff as
1869 |
(Colaptes campestris) which has two toes before and two behind, a long pointed tongue, pointed tail-feathers, sufficiently stiff to support the bird in a vertical position on a post, but not so stiff as 1872 |
in the
typical woodpeckers (yet I have seen it use its tail when alighting vertically on a post), and a straight strong beak. typical woodpeckers (yet I have seen it use its tail when alighting vertically on a post), and a straight strong beak. 1861 1866 |
harsh tone of its voice, and undulatory flight, told me plainly of its close blood-relationship to our common species; yet it is a woodpecker which never climbs a tree! 1859 1860 |
typical woodpeckers, and a straight strong beak. 1869 1872 |
The beak, however, is not so straight or strong
as in the typical woodpeckers;
but it is strong enough to bore into wood;
and I may mention, as another illustration of the varied habits of the tribe, that a Mexican Colaptes has been described by De Saussure as boring holes into hard wood in order to lay up a store of acorns for its future consumption!
Hence the
Colaptes of La Plata
in all the essential parts of its organization
is a woodpecker,
and until recently was classed in the same typical genus.
Even such
trifling characters as its
colouring, the harsh tone of its
voice, and undulatory flight, all told me plainly of
its close blood-relationship to our common species; yet it is a woodpecker,
as I can assert
not only from my own observation,
but from that
of the accurate Azara, which never climbs a tree!
↑2 blocks not present in 1859 1860 1861 1866 1869; present in 1872 | In certain other districts, however, this same woodpecker, as Mr. Hudson states, frequents trees, and bores holes in the trunk for its nest.
I may mention as another illustration of the varied habits of this genus, that a Mexican Colaptes has been described by De Saussure as boring holes into hard wood in order to lay up a store of acorns.
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Petrels are the most aërial
and oceanic of birds,
but but 1861 1866 1869 1872 | yet 1859 1860 |
in the quiet Sounds
of Tierra del Fuego, the Puffinuria berardi, in its general habits, in its astonishing power of diving, its
manner of swimming,
and of flying when
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