Alfred Charles Smith.

The birds of Wiltshire. Comprising all the periodical and occasional visitants, as well as those which are indigenous to the county online

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Online LibraryAlfred Charles SmithThe birds of Wiltshire. Comprising all the periodical and occasional visitants, as well as those which are indigenous to the county → online text (page 4 of 53)
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their formation, whereby such persons as are either beginning
this delightful study, or are not very proficient in it, may gain
some insight into the subject. But before we examine their
general structure, let us for one moment consider the position
which birds were formed to hold in animated nature, and the
element they were fitted to people ; then, when we proceed to
consider their formation, we shall notice how admirably it is
adapted to that end, how exactly suited to that purpose. We


20 Introduction.

are told in the history of their creation that they were formed
out of the water, and that they were made ' to fly above the earth
in the open firmament of heaven.' That, then, is their own
proper sphere, that the domain allotted to them to occupy. It
is true that we find some continually remaining in the element
from which they first derived their origin, passing almost all
their time in the water ; others again there are which seldom
leave the surface of the earth, and are neither formed for swim-
ming nor for flight ; but the great majority of species are essen-
tially denizens of the air, soaring high above our heads, skimming
here and there, floating with expanded wings, 'cleaving with
rapid pinions the vast aerial expanse.' Now it is clear that to
enable them to do this, the general formation of their bodies
must be extremely different from that of the Mammalia, though
to a certain extent there are strong resemblances and analogies
between them and their respective orders. As there are carnivo-
rous quadrupeds, so there are rapacious birds, and both are
equally fierce, sullen, unsociable, and solitary in their habits,
possessed of great strength, and often of considerable courage.
As there are herbivorous quadrupeds, so there are granivorous
birds, and both of these are gentle and gregarious in their habits,
a mild and tractable race, and easily domesticated. There are
also birds as well as beasts of an amphibious nature, having
organs suited to their habits, and these live chiefly in the water,
and feed on aquatic productions; and there are many similar
resemblances. Like the quadrupeds, too, they are warm-blooded
and vertebrate; but, unlike them, they are oviparous, and,
instead of fur, are usually clothed almost entirely with feathers ;
while instead of fore-feet they are furnished with wings ; and we
shall presently see that there are many other striking points of
difference in structure between them. Unlike the heavy bodies
of the Mammalia, which are formed to live on the surface of the
earth, the bodies of the birds are light and buoyant. They each
possess externally head, neck, body, tail, legs, and feet; but
instead of the large head, the heavy neck, the deep chest, the
wide shoulder, and the sinewy legs of the quadrupeds, the ob-

Structure. 21

servant Bewick bids us note 'the pointed beak, the long and
pliant neck, the gently swelling shoulder, the expansive wings,
the tapering tail, the light and bony feet, of birds.' Every one of
these seem formed to combine, as far as possible, the least weight
with the greatest strength. There is no superfluous bulk in the
structure of a bird. Compared with its dimensions, and the
width of its expanded wings, how trifling and insignificant a
proportion does the body seem to occupy ; how every part seems
to conduce towards lightness and buoyancy. The plumage, too,
with which they are clothed is soft and delicate, and yet so close
and thick as to form an admirable protection against the intense
cold of the atmosphere through which they wing their way, and
to which their swift movements must necessarily expose them ;
the feathers which compose it are attached to the skin, somewhat
after the manner of hair, and are periodically moulted or changed,
and nothing can exceed the beauty, and often brilliancy, of their
colouring, as nothing can be conceived more adapted to combine
the two objects of extreme warmth and excessive lightness.
With such an airy framework, and clothed with a plumage in
specific gravity but little exceeding the air itself, we are at no
loss to understand the ease with which birds mount from the
earth and soar among the clouds ; but to enable them to pass
quickly through the air, to progress rapidly and without fatigue,
no instruments could be devised more excellent than the wings
with which they are provided ; so light and yet so vigorous, fur-
nished with such strong muscles, so spacious when extended in
flight, and yet so compact when closed in rest. By the help of
these oars or sails they can strike the air so forcibly, and with
such a succession of rapid and powerful strokes, as to impel for-
ward their bodies with wonderful velocity ; the greater the extent
of the wings in proportion to the size of the bird, the greater is
the facility with which it can sustain itself in the air, and the
greater the rapidity of its flight. As an example of this, compare
the stretch of wing and the proportionate speed of the common
Swift and the common Sparrow. Almost all species can fly with
exceeding swiftness ; but the progress of some is so very rapid, as

22 Introduction.

rather to rival the velocity of the arrow from the bow than the
movements of any other creature. Yet, with such amazing
power, what can be lighter than the materials of which the
wings are formed? the bones hollow and filled with air, the
muscles strong and unencumbered by flesh, the feathers large,
like sails, and of exceeding buoyancy. Then again, in like
manner, what can be more perfect than their tails ? These, too,
are only composed of feathers, but they serve as rudders, enabling
them to steer their course through the air at pleasure, with the
greatest ease and with the greatest accuracy.

Thus, when we look at the external formation of a bird, we can
but admire its symmetry and elegance, the buoyancy and light-
ness of its frame, so admirably adapted for flight ; but not less
perfect nor less calculated to excite our admiration in its internal
structure. Is a bird furnished with bones and muscles so abso-
lutely necessary to its aerial evolutions ? But mark how thin
and light are the bones, how delicate the muscles, those only
excepted which are adapted for moving the wings. Then, again,
observe the lungs. Small, indeed, they are, but so placed, and
the air so introduced into them from the windpipe, that in
passing it is conveyed into certain cells or membranous sacs
disposed for this purpose over the body. These sacs are situated
in the chest and among the muscles, and between the muscles
and the skin ; and in some birds are continued down to the
wings, and extend even to the pinions, thigh bones, and other
parts of the body. For the same purpose the feathers, and
especially the wing feathers, also contain a large quantity of air.
Now all these cavities, and others not enumerated, such as the
hollows of the bones, can be filled and distended with air at the
will of the bird. By this means the strength and bulk of the
bird is increased, without adding to its weight ; and such a
general diffusion of air throughout the body must be of infinite
service in enabling it to fly, to poise itself in the air, and to skim
far above the surface of the earth. Nor is that the only use of
this wonderful provision of nature. I again quote Bewick, who
says : ' It is likewise eminently useful in preventing its respira-

Structure. 23

tion from being stopped or interrupted by the rapidity of its
motion through a resisting medium. Were it possible for man
to move with the swiftness of the Swallow, the actual resistance
of the air, as he is not provided with internal reservoirs similar
to those of birds, would soon suffocate him.' Another very
remarkable peculiarity in the internal economy of birds is their
mode of digestion. The bill is scarcely, if ever, used for masti-
cation, but solely as an instrument of prehension ; it is the
gizzard, whose amazing strength and powers can scarcely be
overrated, that grinds down the grain and other food, and renders
it fit for digestion. Experiments have been made by which it
has been incontrovertibly proved that glass, nails, and the hardest
substances have in a few hours been filed down by the action of
the gizzard, without any injury accruing to it thereby. As a help
to this digestive power small stones are often swallowed by birds,
which are eminently useful in assisting this grinding process,
thus rendering the food more amenable to the gastric juices.

After this rapid glance at the general structure of birds, can
we conceive anything more adapted for buoyancy and for rapid
motion through the air than their external and internal forma-
tion ? We cannot but be struck with their wonderful adaptation
to the position which they were created to fill. Let us now push
our inquiries a little farther ; and still bearing in mind that they
are denizens of the air, and roam at vast distances above our
heads, and all around us, examine into the senses and faculties
with which they are endowed.


In the first place we shall find them furnished with unusual
powers of sight, hearing, and smell ; and to this end they are
supplied with three double organs of sense, viz., eyes, ears, and
nasal cavities.

The sight of some, and particularly of the rapacious birds, is
so acute and piercing as to enable them to see their prey from
an enormous height in the air, whence they dash down with
astonishing swiftness and unerring aim. The vulture sailing in

24 Introduction.

circles at an immense altitude can distinguish his prey on the
ground, without the aid of any other faculty than his eyes, as
has been clearly proved by experiment ; the lordly eagle soaring
amid the clouds seems to prefer that elevated station, whence to
seek some victim on the earth, and his wonderful power of vision
seldom fails to discover the desired object far below; the kestrel-
hawk, with which all are familiar, balances himself in the air at a
considerable height, while his piercing eyes search the ground
below for the mice which constitute his food : these are all diurnal
birds of prey, and are especially noted for the keenness of their
vision ; but not less extraordinary is the eye of the owl, which
seeks its prey by twilight, and cannot endure the full glare of
day; should any accident expose him to the light of the sun,
he either closes his eyes entirely or defends them with a curtain
or blind, which is an internal eyelid, and which he can close in
an instant. At such times he presents but a grotesque and
foolish appearance ; but see him as he emerges from his hollow
tree, or the ivy-clad ruin in the deepening twilight ; watch him
as he regularly beats the field, and quarters it like a pointer; see
him suddenly drop upon the unfortunate mouse that was hurry-
ing through the grass, and judge what acuteness of vision must
be there. In the nocturnal species the eyes are usually directed
forwards, and are brighter, larger, and clearer than those of the
diurnal birds, and thus, from their size, position, and construc-
tion, are admirably calculated for concentrating the dim rays of
twilight. In the other Orders we do not expect to find such
wonderful powers of sight, for their habits do not require it ; yet
here, too, we shall often find considerable swiftness and extent of
vision. The fly-catcher will sit perched on a twig, and suddenly
dart upon an insect passing often at a considerable distance,
which we are wholly unable to perceive. The bold and sagacious
raven and the destructive carrion-crow have been famed for their
far-seeing propensities. The rook, too, has the same property;
for which cause we may constantly see the dull- eyed starlings
attaching themselves to their society and relying on these
excellent sentinels, feeding in greater security. The swift,

Faculties Sight, Hearing. 25

careering through the air on rapid wing and dashing past like a
meteor, not only can see to steer its way clear of all obstacles,
but can discern the passing insect, which it catches in its mouth
as it rushes by. The pigeons, mounting high into the air, can
perceive the grain which they are seeking from an almost incre-
dible distance. The redstart will avoid the shot by rising on
seeing the flash from the cap ; and many of the ducks, and
especially the divers, disappear under water the moment the
trigger is pulled, seeing the flash and diving almost instan-
taneously, and so escaping the death intended for them. These
are a few instances of the extraordinary powers of vision
belonging to the feathered race. An eminent French naturalist
has calculated it to be about nine times more extensive than that
of man ; and anatomists, after dissecting the eye of the golden
eagle, or one of that family, whose sight is considered the keenest
of all, declare that nothing can be conceived more perfect than
the structure. The eye of the falcon, which feeds by day, will
differ from that of the owl, which feeds by night ; both will differ
from that of the swan, which has to procure its food under water;
but all are exactly adapted to their own peculiar spheres of
action, all are capable of very astonishing sight.

Again, the hearing of some is so subtle, that they can detect
their prey when hidden from view by this sense alone, and by
the same power are ever on the alert for the approach of an
enemy. As the eagle is the most renowned for powers of vision,
so we may without hesitation pronounce the owls to possess a
more acute sense of hearing than any other family; it seems
that this faculty is given them in common with other noc-
turnal and crepuscular animals ; as, for example, the bats, to
enable them to guide themselves in their flight on the darkest
nights, and to direct them to their prey. The organs with
which they are furnished to secure this end are of a very
remarkable construction, and developed to an extraordinary
extent ; the auditory opening, or ear-conch, is sometimes
extremely large, and is then furnished with an opercidum
or cover, which they can open and close at will ; but in those

26 Introduction.

species where the aperture is smaller, such an addition is not
provided. Another peculiarity in the nocturnal birds of prey is
that the two ears are not alike ; the one being so formed as to
hear sounds from below, the other from above. This, though an
old discovery, is not very generally known, though it is doubtless
an admirable help to catch the faintest sound proceeding from
every direction; and with such organs the owls are enabled to
detect in an instant the slightest rustling of their prey. Next to
the owl, perhaps the night-jar (or goat-sucker, as it is commonly
though erroneously called) possesses the most acute sense of
hearing; this bird is also crepuscular, and seldom hunts for
moths till the shades of evening, and, as in the owl, its ears are
of a very large size. But there are many other birds gifted
with remarkably acute powers of hearing. See the song-thrush
descend on the lawn on a damp morning ; watch how he inclines
his ear on one side, then hops forward, and again listens, till at
length he draws forth the worm which his fine ear had told him
was there, and which, alarmed at his hops and peckings, had hur-
ried to the surface, supposing they were occasioned by his dreaded
enemy, the mole. Or, visit some fine old heronry, and try to
penetrate near their chosen nursery without your presence being
detected ; these nocturnal birds are not particularly keen of
sight during the day, but long ere you can approach them, how-
ever cautiously, their keen sense of hearing has told them you
are near. Another bird remarkable for possessing this faculty
in an eminent degree is the Curlew : of all the shore birds there
is not one so difficult of approach as this ; his organs of hearing
are so sensitive that it is almost impossible to come near him.
And again, the Swedish ornithologist, Professor Nilsson, speaks
of the Black-cock as being most acute both in hearing and in
sight. Such are some of the innumerable instances one might
collect of another sense being possessed by the feathered tribes
in extraordinary perfection : that some birds hear more quickly
than others is an undisputed fact ; but we shall always find, if
we examine into it, that to those the most subtle sense of
hearing is given whose habits cause them to require it most ;

Faculties Smell. 27

while from those which would not be benefited by it, it is in a
measure withheld.

I have spoken of the powers of sight and hearing so con-
spicuous in birds ; I come now to the other sense with which
they are provided, that of smell. This, too, we shall find to be
peculiarly delicate in some families, though perhaps generally it
is but little required, and therefore but little developed ; and we
shall for the most part find that those birds whose nostrils are
the most conspicuous and open will possess this sense in the
highest degree, while those whose nostrils are concealed and
almost impervious will share in it but little. The bird which is
certainly most remarkable for this faculty, though of late years
it has been gainsaid by certain American naturalists, is the
Vulture. Blest, as I have already remarked, with a keen
sense of sight, the Vulture soaring through the air, and above
the dark forests, is also directed to his prey by the extraordinary
perfection of his organs of smell. His food is always putrid,
and the effluvium arising therefrom is necessarily most rank;
but yet when we watch their proceedings, as I have done,
in their own tropical countries, the wonderful manner in
which these birds will congregate at a putrid carcase, hidden
though it may be in a pit or a thick forest; and how, first
appearing as a speck in the distant heavens, then gradually
increasing in size as they come nearer, they arrive singly from
all quarters, whereas till then, not a single individual was to be
seen, we can form some idea of the great powers of smell which
these birds must possess. Mr. Waterton, who has seen them in
Guiana, Demerara, and other parts of Southern America ; and
Mr. Gosse, who more recently has seen them in the West Indian
islands, have published in their respective most interesting little
volumes such strong and conclusive evidence of the amazing
extent of this sense in the vulture, as to silence all dispute on
the subject. The family of the crows, also, claims our attention
as possessing very great powers of scent. It is this which so
often directs them to their food from great distances in such a
mysterious manner as to cause the wonder and incredulity of

28 Introduction.

man. Some observers, who have seen troops of ravens hurrying
along to the banquet of some fallen animal, where not a bird till
then could be seen, have attributed their discovery of the feast,
not to the true cause, their keen sense of seeing and smelling,
but to some unknown faculty, thinking it impossible that scent
could be carried so far, and having little conception of the
superior acuteness of some of the senses of birds. Again, the
rook discovers the grubs hidden in the earth by the same
wonderful sense; the carrion-crow scents the tempting morsel
from a distance; the magpie is not behind-hand in the same
perception. Some of the water-birds, too, seem to have this
faculty very highly developed. The curlew will take wing when
you are at a great distance, if you approach them down the wind ;
the hungry woodcock will discover by the smell where it will be
profitable to probe the mud with his beak. Most of the ducks
are so sensitive, that the man who works a decoy knows full
well that he has no chance of success unless he keeps to leeward
of the flock ; and, as an additional precaution, burns a piece of
turf, and holds it smoking in his hand, to prevent their scenting
him. Thus we see the faculty of scent no less conspicuous in
birds than in other animals : the well-known properties of the
pointer and the foxhound will not surpass the exquisite sense of
smell of some of the birds, and even the notorious bloodhound
will scarcely outdo the vulture in the same faculty.

But besides these three powers of seeing, hearing, and smelling,
with which we have proved them to be remarkably endowed, we
find the feathered tribe gifted with the power of feeling or handling
(if I may apply such a term to the beak), not usually allotted to
the inferior races of the animal kingdom. Their beaks serve
them for hands, as well as for lips and teeth, and wonderfully are
they adapted to a variety of purposes ; but as, in addition to their
exceeding interest and variety of form and use, the beaks are
principal characteristics whereby to distinguish the position
birds are entitled to hold, and their habits, I propose to consider
this subject separately, so for the present pass it by.

Again, they are furnished with tongues, which are not only

Facilities Smell. 29

organs of taste, but partly also of prehension. These, too, differ
exceedingly in form, according to their requirements, being some-
times short, round, and thick, sometimes long, thin, and pointed ;
and some tribes make considerable use of these members in
securing their prey, as we shall hereafter see.

Their organs of voice, too, are very various ; some most melo-
dious, charming man by their continual and often exquisite song ;
others harsh and unmusical ; notes they have of alarm, whereby
they signify to one another that danger is at hand ; notes of dis-
tress, whereby they proclaim the pain or terror they feel ; notes
of love, whereby they show their affection ; notes of communica-
tion, whereby they signify their intentions to each other and act
in concert, and so continue their migrations on the darkest nights
without danger of parting company. The notes of the different
species, too, are as various as are their forms. Some are able to
imitate those of others ; but seldom do they step beyond their
own limits, for each is content to communicate with his congeners,
in the language peculiar to its own species.

Such, then, is an outline of the faculties of birds. The subject
is one which might be pursued to an unlimited extent, until such
a knowledge of their anatomy was gained, that, like Buffon and
Cuvier, of late time, and Professor Owen, of the College of Sur-
geons, of our day, from seeing one single bone we might be able-
to describe accurately the whole bird to which it belonged, and
its habits, though of a species never hitherto seen. To such an
intimate acquaintance, however, with the structure of birds we
shall not probably aspire. Our present purpose has in view only
a general consideration of their formation and faculties ; but we
have seen enough to prove to us how admirably birds are formed
for the position they hold in the scale of Zoology. Their bodies
light and buoyant, furnished with wings enabling them to pass
rapidly through the air ; provided with air-cells, as an additional
assistance to them ; endowed with astonishing powers of sight,
hearing, and smell; possessed of organs of voice as varied as
they are remarkable ; and with many other faculties not inferior
to these, the feathered tribes claim a high position in the scale of

SO Introduction.

created beings. We see in their formation the hand of a boun-
tiful Creator ; in their endowments the wisdom and goodness of
Providence displayed. A knowledge of their structure, and an
insight into the wonderful organs with which they are supplied,
cannot but raise them in our eyes, as worthy of deeper investi-
gation and closer attention than they usually receive ; and raise
us at the same time, as should be the case after all our re-
searches into the pages of nature, * from nature's works up to

nature's God.'

' Thus the men

Whom nature's work can charm, with God himself
Hold converse : grow familiar day by day
With His conceptions ; act upon His plan,
And form to His the relish of their souls.'


I now desire to call special attention to the beaks of birds,
than which nothing in their whole structure appears to me to be
so perfect, so suitable to the end for which they were formed, so
interesting and worthy of close examination. I have cursorily
alluded to them in a former page, but I would now devote a
short space to a more close examination of these very useful
organs, which are generally the implements or tools wherewith
their owners supply themselves with their every-day food.

Every bird is furnished with a beak, composed of two parts, the
upper and lower mandible, formed of horny substances ensheath-
ing the jaws. It is analogous to the lips and teeth of quadru-

Online LibraryAlfred Charles SmithThe birds of Wiltshire. Comprising all the periodical and occasional visitants, as well as those which are indigenous to the county → online text (page 4 of 53)