.
But there are other birds whose feet, as some one has said, are good
feet, but poor hands--that is, they are not intended for prehensile
purposes, only for walking and wading. Therefore, in these birds the
hind toe is small, and more or less elevated above the plane of the
other digits, or, as has already been said, is wholly wanting. The
feet of some of these birds are partly webbed, so that, if necessary,
they can change their mode of locomotion from running and wading to
swimming. Birds whose feet are partly webbed are said to be
semipalmated.
This introduces us to that interesting group of birds whose toes are
connected throughout their entire length by a thin, membranous web.
Their feet are said to be palmated. We can readily understand why they
are thus formed, for their webbed feet answer the purpose of oars to
propel them over the water. Most of the swimmers have feet of this
kind. Watch them glide like feathered craft over the smooth surface of
the stream or lake.
When a swimmer thrusts his foot forward, the toes naturally drop
together and partly close, presenting only a narrow front--almost an
edge--of resistance to the water; then, when he makes a backward
stroke, the toes spread far apart and, with the connecting membranes,
are converted into a broad, propelling oar. Is it not a wonderfully
wise contrivance?
Most swimming birds have only the front toes webbed, but in a few
species, like the pelicans, even the hind toe is connected with its
fellows by means of such a membrane. Nor must we forget those water
fowls which, instead of palmated feet, have what is called the lobate
foot, which means that the digits have broad lobes or flaps on their
sides. While in such cases the toes are all distinct, the expanded
lobes serve almost, if not quite, as good a purpose for propulsion in
the water as do the webs. The coot swims almost as well as the duck or
the goose, and at the same time his feet, with their disconnected toes,
are better adapted for paddling about amid the watergrass and dense
weeds than if they were webbed.
The birds of prey, such as hawks, owls, and eagles, have large, strong,
and sharply curved talons and powerful digits, and a sad use they make
of them in clutching small birds and animals. The claws of the
woodpeckers and other climbing birds are stout and extremely acute,
just as they should be for clinging to the bark of trees. In short,
the structure of a bird's foot,
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