domestic architecture of the human race. Man, as a reasonable animal, it
is said, continually alters and improves his dwelling. This I entirely
deny. As a rule, he neither alters nor improves, any more than the birds
do. What have the houses of most savage tribes improved from, each as
invariable as the nest of a species of bird? The tents of the Arab are
the same now as they were two or three thousand years ago, and the mud
villages of Egypt can scarcely have improved since the time of the
Pharaohs. The palm-leaf huts and hovels of the various tribes of South
America and the Malay Archipelago, what have they improved from since
those regions were first inhabited? The Patagonian's rude shelter of
leaves, the hollowed bank of the South African Earthmen, we cannot even
conceive to have been ever inferior to what they now are. Even nearer
home, the Irish turf cabin and the Highland stone shelty can hardly have
advanced much during the last two thousand years. Now, no one imputes
this stationary condition of domestic architecture among these savage
tribes to instinct, but to simple imitation from one generation to
another, and the absence of any sufficiently powerful stimulus to
change or improvement. No one imagines that if an infant Arab could be
transferred to Patagonia, or to the Highlands, it would, when it grew
up, astonish its foster-parents by constructing a tent of skins. On the
other hand, it is quite clear that physical conditions, combined with
the degree of civilization arrived at, almost necessitate certain types
of structure. The turf, or stones, or snow--the palm-leaves, bamboo, or
branches, which are the materials of houses in various countries, are
used because nothing else is so readily to be obtained. The Egyptian
peasant has none of these, not even wood. What, then, can he use but
mud? In tropical forest-countries, the bamboo and the broad palm-leaves
are the natural material for houses, and the form and mode of structure
will be decided in part by the nature of the country, whether hot or
cool, whether swampy or dry, whether rocky or plain, whether frequented
by wild beasts, or whether subject to the attacks of enemies. When once
a particular mode of building has been adopted, and has become confirmed
by habit and by hereditary custom, it will be long retained, even when
its utility has been lost through changed conditions, or through
migration into a very different region. As a general rule, throughout
the whole continent of America, native houses are built directly upon
the ground--strength and security being given by thickening the low
walls and the roof. In almost the whole of the Malay Islands, on the
contrary, the houses are raised on posts, often to a great height, with
an open bamboo floor; and the whole structure is exceedingly slight and
thin. Now, what can be the reason of this remarkable difference between
countries, many parts of which are strikingly similar in physical
conditions, natural productions, and the state of civilization of their
inhabitants? We appear to have some clue to it in the supposed origin
and migrations of their respective populations. The indigenes of
tropical America are believed to have immigrated from the north--from a
country where the winters are severe, and raised houses with open floors
would be hardly habitable. They moved southwards by land along the
mountain ranges and uplands, and in an altered climate continued the
mode of construction of their forefathers, modified only by the new
materials they met with. By minute observations of the Indians of the
Amazon Valley, Mr. Bates arrived at the conclusion that they were
comparatively recent immigrants from a colder climate. He says:--"No one
could live long among the Indians of the Upper Amazon without being
struck with their constitutional dislike to the heat ... Their skin is
hot to the touch, and they perspire little ... They are restless and
discontented in hot, dry weather, but cheerful on cool days, when the
rain is pouring down their naked backs." And, after giving many other
details, he concludes, "How different all this is with the Negro, the
true child of tropical climes! The impression gradually forced itself on
my mind that the Red Indian lives as an immigrant or stranger in these
hot regions, and that his constitution was not originally adapted, and
has not since become perfectly adapted, to the climate."
The Malay races, on the other hand, are no doubt very ancient
inhabitants of the hottest regions, and are particularly addicted to
forming their first settlements at the mouths of rivers or creeks, or in
land-locked bays and inlets. They are a pre-eminently maritime or
semi-aquatic people, to whom a canoe is a necessary of life, and who
will never travel by land if they can do so by water. In accordance with
these tastes, they have built their houses on posts in the water, after
the manner of the lake-dwellers of ancient Europe; and this mode of
construction has become so confirmed, that even those tribes who have
spread far into the interior, on dry plains and rocky mountains,
continue to build in exactly the same manner, and find safety in the
height to which they elevate their dwellings above the ground.
_Why does each Bird build a peculiar kind of Nest?_
These general characteristics of the abode of savage man will be found
to be exactly paralleled by the nests of birds. Each species uses the
materials it can most readily obtain, and builds in situations most
congenial to its habits. The wren, for example, frequenting hedgerows
and low thickets, builds its nest generally of _moss_, a material always
found where it lives, and among which it probably obtains much of its
insect food; but it varies sometimes, using hay or feathers when these
are at hand. Rooks dig in pastures and ploughed fields for grubs, and
in doing so must continually encounter _roots_ and _fibres_. These are
used to line its nest. What more natural! The crow feeding on carrion,
dead rabbits, and lambs, and frequenting sheep-walks and warrens,
chooses _fur_ and _wool_ to line its nest. The lark frequents cultivated
fields, and makes its nest, on the ground, of grass lined with
_horsehair_--materials the most easy to meet with, and the best adapted
to its needs. The kingfisher makes its nest of the _bones_ of the fish
which it has eaten. Swallows use clay and mud from the margins of the
ponds and rivers over which they find their insect food. The materials
of birds' nests, like those used by savage man for his house, are, then,
those which come first to hand; and it certainly requires no more
special instinct to select them in one case than in the other.
But, it will be said, it is not so much the materials as the form and
structure of nests, that vary so much, and are so wonderfully adapted to
the wants and habits of each species; how are these to be accounted for
except by instinct? I reply, they may be in a great measure explained by
the general habits of the species, the nature of the tools they have to
work with, and the materials they can most easily obtain, with the very
simplest adaptations of means to an end, quite within the mental
capacities of birds. The delicacy and perfection of the nest will bear a
direct relation to the size of the bird, its structure and habits. That
of the wren or the humming-bird is perhaps not finer or more beautiful
in proportion than that of the blackbird, the magpie, or the crow. The
wren, having a slender beak, long legs, and great activity, is able with
great ease to form a well-woven nest of the finest materials, and places
it in thickets and hedgerows which it frequents in its search for food.
The titmouse, haunting fruit-trees and walls, and searching in cracks
and crannies for insects, is naturally led to build in holes where it
has shelter and security; while its great activity, and the perfection
of its tools (bill and feet), enable it readily to form a beautiful
receptacle for its eggs and young. Pigeons having heavy bodies and weak
feet and bills (imperfect tools for forming a delicate structure) build
rude, flat nests of sticks, laid across strong branches which will bear
their weight and that of their bulky young. They can do no better. The
Caprimulgidae have the most imperfect tools of all, feet that will not
support them except on a flat surface (for they cannot truly perch) and
a bill excessively broad, short, and weak, and almost hidden by feathers
and bristles. They cannot build a nest of twigs or fibres, hair or moss,
like other birds, and they therefore generally dispense with one
altogether, laying their eggs on the bare ground, or on the stump or
flat limb of a tree. The clumsy hooked bills, short necks and feet, and
heavy bodies of Parrots, render them quite incapable of building a nest
like most other birds. They cannot climb up a branch without using both
bill and feet; they cannot even turn round on a perch without holding on
with their bill. How, then, could they inlay, or weave, or twist the
materials of a nest? Consequently, they all lay in holes of trees, the
tops of rotten stumps, or in deserted ants' nests, the soft materials of
which they can easily hollow out.
Many terns and sandpipers lay their eggs on the bare sand of the
sea-shore, and no doubt the Duke of Argyll is correct when he says, that
the cause of this habit is not that they are unable to form a nest, but
that, in such situations, any nest would be conspicuous and lead to the
discovery of the eggs. The choice of _place_ is, however, evidently
determined by the habits of the birds, who, in their daily search for
food, are continually roaming over extensive tide-washed flats. Gulls
vary considerably in their mode of nesting, but it is always in
accordance with their structure and habits. The situation is either on a
bare rock or on ledges of sea-cliffs, in marshes or on weedy shores. The
materials are sea-weed, tufts of grass or rushes, or the _debris_ of the
shore, heaped together with as little order and constructive art as
might be expected from the webbed feet and clumsy bill of these birds,
the latter better adapted for seizing fish than for forming a delicate
nest. The long-legged, broad-billed flamingo, who is continually
stalking over muddy flats in search of food, heaps up the mud into a
conical stool, on the top of which it lays its eggs. The bird can thus
sit upon them conveniently, and they are kept dry, out of reach of the
tides.
Now I believe that throughout the whole class of birds the same general
principles will be found to hold good, sometimes distinctly, sometimes
more obscurely apparent, according as the habits of the species are more
marked, or their structure more peculiar. It is true that, among birds
differing but little in structure or habits, we see considerable
diversity in the mode of nesting, but we are now so well assured that
important changes of climate and of surface have occurred within the
period of existing species, that it is by no means difficult to see how
such differences have arisen. Simple habits are known to be hereditary,
and as the area now occupied by each species is different from that of
every other, we may be sure that such changes would act differently upon
each, and would often bring together species which had acquired their
peculiar habits in distinct regions and under different conditions.
_How do Young Birds learn to Build their First Nest?_
But it is objected, birds do not _learn_ to make their nest as man does
to build, for all birds will make exactly the same nest as the rest of
their species, even if they have never seen one, and it is instinct
alone that can enable them to do this. No doubt this would be instinct
if it were true, and I simply ask for proof of the fact. This point,
although so important to the question at issue, is always assumed
without proof, and even against proof, for what facts there are, are
opposed to it. Birds brought up from the egg in cages do not make the
characteristic nest of their species, even though the proper materials
are supplied them, and often make no nest at all, but rudely heap
together a quantity of materials; and the experiment has never been
fairly tried, of turning out a pair of birds so brought up, into an
enclosure covered with netting, and watching the result of their
untaught attempts at nest-making. With regard to the songs of birds,
however, which is thought to be equally instinctive, the experiment has
been tried, and it is found that young birds never have the song
peculiar to their species if they have not heard it, whereas they
acquire very easily the song of almost any other bird with which they
are associated.
_Do Birds sing by Instinct or by Imitation?_
The Hon. Daines Barrington was of opinion that "notes in birds are no
more innate than language is in man, and depend entirely on the master
under which they are bred, _as far as their organs will enable them to
imitate_ the sounds which they have frequent opportunities of hearing."
He has given an account of his experiments in the "Philosophical
Transactions" for 1773 (Vol. 63); he says: "I have educated nestling
linnets under the three best singing larks--the skylark, woodlark, and
titlark, every one of which, instead of the linnet's song, adhered
entirely to that of their respective instructors. When the note of the
titlark linnet was thoroughly fixed, I hung the bird in a room with two
common linnets for a quarter of a year, which were full in song; the
titlark linnet, however, did not borrow any passage from the linnet's
song, but adhered stedfastly to that of the titlark." He then goes on
to say that birds taken from the nest at two or three weeks old have
already learnt the call-note of their species. To prevent this the birds
must be taken from the nest when a day or two old, and he gives an
account of a goldfinch which he saw at Knighton in Radnorshire, and
which sang exactly like a wren, without any portion of the proper note
of its species. This bird had been taken from the nest at two or three
days old, and had been hung at a window opposite a small garden, where
it had undoubtedly acquired the notes of the wren without having any
opportunity of learning even the call of the goldfinch.
He also saw a linnet, which had been taken from the nest when only two
or three days old, and which, not having any other sounds to imitate,
had learnt almost to articulate, and could repeat the words "Pretty
Boy," and some other short sentences.
Another linnet was educated by himself under a _vengolina_ (a small
African finch, which he says sings better than any foreign bird but the
American mocking bird), and it imitated its African master so exactly
that it was impossible to distinguish the one from the other.
Still more extraordinary was the case of a common house sparrow, which
only chirps in a wild state, but which learnt the song of the linnet and
goldfinch by being brought up near those birds.
The Rev. W. H. Herbert made similar observations, and states that the
young whinchat and wheatear, which have naturally little variety of
song, are ready in confinement to learn from other species, and become
much better songsters. The bullfinch, whose natural notes are weak,
harsh, and insignificant, has nevertheless a wonderful musical faculty,
since it can be taught to whistle complete tunes. The nightingale, on
the other hand, whose natural song is so beautiful, is exceedingly apt
in confinement to learn that of other birds instead. Bechstein gives an
account of a redstart which had built under the eaves of his house,
which imitated the song of a caged chaffinch in a window underneath,
while another in his neighbour's garden repeated some of the notes of a
blackcap, which had a nest close by.
These facts, and many others which might be quoted, render it certain
that the peculiar notes of birds are acquired by imitation, as surely as
a child learns English or French, not by instinct, but by hearing the
language spoken by its parents.
It is especially worthy of remark that, for young birds to acquire a new
song correctly, they must be taken out of hearing of their parents very
soon, for in the first three or four days they have already acquired
some knowledge of the parent notes, which they will afterwards imitate.
This shows that very young birds can both hear and remember, and it
would be very extraordinary if, after they could see, they could neither
observe nor recollect, and could live for days and weeks in a nest and
know nothing of its materials and the manner of its construction.
During the time they are learning to fly and return often to the nest,
they must be able to examine it inside and out in every detail, and as
we have seen that their daily search for food invariably leads them
among the materials of which it is constructed, and among places similar
to that in which it is placed, is it so very wonderful that when they
want one themselves they should make one like it? How else, in fact,
should they make it? Would it not be much more remarkable if they went
out of their way to get materials quite different from those used in the
parent nest, if they arranged them in a way they had seen no example of,
and formed the whole structure differently from that in which they
themselves were reared, and which we may fairly presume is that which
their whole organization is best adapted to put together with celerity
and ease? It has, however, been objected that observation, imitation, or
memory, can have nothing to do with a bird's architectural powers,
because the young birds, which in England are born in May or June, will
proceed in the following April or May to build a nest as perfect and as
beautiful as that in which it was hatched, although it could never have
seen one built. But surely the young birds _before_ they left the nest
had ample opportunities of observing its _form_, its _size_, its
_position_, the _materials_ of which it was constructed, and the manner
in which those materials were arranged. Memory would retain these
observations till the following spring, when the materials would come in
their way during their daily search for food, and it seems highly
probable that the older birds would begin building first, and that those
born the preceding summer would follow their example, learning from them
how the foundations of the nest are laid and the materials put
together.[H]
+--------------------------------------------------------------+
| [H] It has been very pertinently remarked by a friend, that, |
| if young birds did observe the nest they were reared in, |
| they would consider it to be a natural production like the |
| leaves and branches and matted twigs that surrounded it, and |
| could not possibly conclude that their parents had |
| constructed the one and not the other. This may be a valid |
| objection, and, if so, we shall have to depend on the mode |
| of instruction described in the succeeding paragraphs, but |
| the question can only be finally decided by a careful set of |
| experiments. |
+--------------------------------------------------------------+
Again, we have no right to assume that young birds generally pair
together. It seems probable that in each pair there is most frequently
only one bird born the preceding summer, who would be guided, to some
extent, by its partner.
My friend, Mr. Richard Spruce, the well-known traveller and botanist,
thinks this is the case, and has kindly allowed me to publish the
following observations, which he sent me after reading my book.
_How young Birds may learn to build Nests._
"Among the Indians of Peru and Ecuador, many of whose customs are relics
of the semi-civilisation that prevailed before the Spanish conquest, it
is usual for the young men to marry old women, and the young women old
men. A young man, they say, accustomed to be tended by his mother, would
fare ill if he had only an ignorant young girl to take care of him; and
the girl herself would be better off with a man of mature years, capable
of supplying the place of a father to her.
"Something like this custom prevails among many animals. A stout old
buck can generally fight his way to the doe of his choice, and indeed of
as many does as he can manage; but a young buck 'of his first horns,'
must either content himself with celibacy, or with some dame
well-stricken in years.
"Compare the nearly parallel case of the domestic cock and of many other
birds. Then consider the consequences amongst birds that pair, if an old
cock sorts with a young hen and an old hen with a young cock, as I think
is certainly the case with blackbirds and others that are known to fight
for the youngest and handsomest females. One of each pair being already
an 'old bird,' will be competent to instruct its younger partner (not
only in the futility of 'chaff,' but) in the selection of a site for a
nest and how to build it; then, how eggs are hatched and young birds
reared.
"Such, in brief, is my idea of how a bird on its first espousals may be
taught the Whole Duty of the married state."
On this difficult point I have sought for information from some of our
best field ornithologists, but without success, as it is in most cases
impossible to distinguish old from young birds after the first year. I
am informed, however, that the males of blackbirds, sparrows, and many
other kinds fight furiously, and the conqueror of course has the choice
of a mate. Mr. Spruce's view is at least as probable as the contrary one
(that young birds, _as a rule_, pair together), and it is to some extent
supported by the celebrated American observer, Wilson, who strongly
insists on the variety in the nests of birds of the same species, some
being so much better finished than others; and he believes _that the
less perfect nests are built by the younger, the more perfect by the
older, birds_.
At all events, till the crucial experiment is made, and a pair of birds
raised from the egg without ever seeing a nest are shown to be capable
of making one exactly of the parental type, I do not think we are
justified in calling in the aid of an unknown and mysterious faculty to
do that which is so strictly analogous to the house-building of savage
man.
Again, we always assume that because a nest appears to us delicately and
artfully built, that it therefore requires much special knowledge and
acquired skill (or their substitute, instinct) in the bird who builds
it. We forget that it is formed twig by twig and fibre by fibre, rudely
enough at first, but crevices and irregularities, which must seem huge
gaps and chasms in the eyes of the little builders, are filled up by
twigs and stalks pushed in by slender beak and active foot, and that the
wool, feathers, or horsehair are laid thread by thread, so that the
result seems a marvel of ingenuity to us, just as would the rudest
Iinand hut to a native of Brobdignag. Levaillant has given an account
of the process of nest-building by a little African warbler, which
sufficiently shows that a very beautiful structure may be produced with
very little art. The foundation was laid of moss and flax interwoven
with grass and tufts of cotton, and presented a rude mass, five or six
inches in diameter, and four inches thick. This was pressed and trampled
down repeatedly, so as at last to make it into a kind of felt. The birds
pressed it with their bodies, turning round upon them in every
direction, so as to get it quite firm and smooth before raising the
sides. These were added bit by bit, trimmed and beaten with the wings
and feet, so as to felt the whole together, projecting fibres being now
and then worked in with the bill. By these simple and apparently
inefficient means, the inner surface of the nest was rendered almost as
smooth and compact as a piece of cloth.
_Man's Works mainly Imitative._
But look at civilised man! it is said; look at Grecian, and Egyptian,
and Roman, and Gothic, and modern Architecture! What advance! what
improvement! what refinements! This is what reason leads to, whereas
birds remain for ever stationary. If, however, such advances as these
are required, to prove the effects of reason as contrasted with
instinct, then all savage and many half-civilized tribes have no reason,
but build instinctively quite as much as birds do.
Man ranges over the whole earth, and exists under the most varied
conditions, leading necessarily to equally varied habits. He
migrates--he makes wars and conquests--one race mingles with
another--different customs are brought into contact--the habits of a
migrating or conquering race are modified by the different circumstances
of a new country. The civilized race which conquered Egypt must have
developed its mode of building in a forest country where timber was
abundant, for it is not probable, that the idea of cylindrical columns
originated in a country destitute of trees. The pyramids might have been
built by an indigenous race, but not the temples of El Uksor and Karnak.
In Grecian architecture, almost every characteristic feature can be
traced to an origin in wooden buildings. The columns, the architrave,
the frieze, the fillets, the cantelevers, the form of the roof, all
point to an origin in some southern forest-clad country, and strikingly
corroborate the view derived from philology, that Greece was colonised
from north-western India. But to erect columns and span them with huge
blocks of stone, or marble, is not an act of reason, but one of pure
unreasoning imitation. The arch is the only true and reasonable mode of
covering over wide spaces with stone, and therefore, Grecian
architecture, however exquisitely beautiful, is false in principle, and
is by no means a good example of the application of reason to the art of
building. And what do most of us do at the present day but imitate the
buildings of those that have gone before us? We have not even been able
to discover or develope any definite style of building best suited for
us. We have no characteristic national style of architecture, and to
that extent are even below the birds, who have each their characteristic
form of nest, exactly adapted to their wants and habits.
_Birds do Alter and Improve their Nests when altered Conditions require
it._