GALAPAGOS ARCHIPELAGO
The whole Group Volcanic--Numbers of Craters--Leafless Bushes Colony at
Charles Island--James Island--Salt-lake in Crater--Natural History of
the Group--Ornithology, curious Finches--Reptiles--Great Tortoises,
habits of--Marine Lizard, feeds on Sea-weed--Terrestrial Lizard,
burrowing habits, herbivorous--Importance of Reptiles in the
Archipelago--Fish, Shells, Insects--Botany--American Type of
Organization--Differences in the Species or Races on different
Islands--Tameness of the Birds--Fear of Man, an acquired Instinct.
SEPTEMBER 15th.--This archipelago consists of ten principal islands, of
which five exceed the others in size. They are situated under the
Equator, and between five and six hundred miles westward of the coast
of America. They are all formed of volcanic rocks; a few fragments of
granite curiously glazed and altered by the heat, can hardly be
considered as an exception. Some of the craters, surmounting the
larger islands, are of immense size, and they rise to a height of
between three and four thousand feet. Their flanks are studded by
innumerable smaller orifices. I scarcely hesitate to affirm, that
there must be in the whole archipelago at least two thousand craters.
These consist either of lava or scoriae, or of finely-stratified,
sandstone-like tuff. Most of the latter are beautifully symmetrical;
they owe their origin to eruptions of volcanic mud without any lava: it
is a remarkable circumstance that every one of the twenty-eight
tuff-craters which were examined, had their southern sides either much
lower than the other sides, or quite broken down and removed. As all
these craters apparently have been formed when standing in the sea, and
as the waves from the trade wind and the swell from the open Pacific
here unite their forces on the southern coasts of all the islands, this
singular uniformity in the broken state of the craters, composed of the
soft and yielding tuff, is easily explained.
Considering that these islands are placed directly under the equator,
the climate is far from being excessively hot; this seems chiefly
caused by the singularly low temperature of the surrounding water,
brought here by the great southern
[map]
Polar current. Excepting during one short season, very little rain
falls, and even then it is irregular; but the clouds generally hang
low. Hence, whilst the lower parts of the islands are very sterile,
the upper parts, at a height of a thousand feet and upwards, possess a
damp climate and a tolerably luxuriant vegetation. This is especially
the case on the windward sides of the islands, which first receive and
condense the moisture from the atmosphere.
In the morning (17th) we landed on Chatham Island, which, like the
others, rises with a tame and rounded outline, broken here and there by
scattered hillocks, the remains of former craters. Nothing could be
less inviting than the first appearance. A broken field of black
basaltic lava, thrown into the most rugged waves, and crossed by great
fissures, is everywhere covered by stunted, sun-burnt brushwood, which
shows little signs of life. The dry and parched surface, being heated
by the noon-day sun, gave to the air a close and sultry feeling, like
that from a stove: we fancied even that the bushes smelt unpleasantly.
Although I diligently tried to collect as many plants as possible, I
succeeded in getting very few; and such wretched-looking little weeds
would have better become an arctic than an equatorial Flora. The
brushwood appears, from a short distance, as leafless as our trees
during winter; and it was some time before I discovered that not only
almost every plant was now in full leaf, but that the greater number
were in flower. The commonest bush is one of the Euphorbiaceae: an
acacia and a great odd-looking cactus are the only trees which afford
any shade. After the season of heavy rains, the islands are said to
appear for a short time partially green. The volcanic island of
Fernando Noronha, placed in many respects under nearly similar
conditions, is the only other country where I have seen a vegetation at
all like this of the Galapagos Islands.
The Beagle sailed round Chatham Island, and anchored in several bays.
One night I slept on shore on a part of the island, where black
truncated cones were extraordinarily numerous: from one small eminence
I counted sixty of them, all surmounted by craters more or less
perfect. The greater number consisted merely of a ring of red scoriae
or slags, cemented together: and their height above the plain of lava
was not more than from fifty to a hundred feet; none had been very
lately active. The entire surface of this part of the island seems to
have been permeated, like a sieve, by the subterranean vapours: here
and there the lava, whilst soft, has been blown into great bubbles; and
in other parts, the tops of caverns similarly formed have fallen in,
leaving circular pits with steep sides. From the regular form of the
many craters, they gave to the country an artificial appearance, which
vividly reminded me of those parts of Staffordshire, where the great
iron-foundries are most numerous. The day was glowing hot, and the
scrambling over the rough surface and through the intricate thickets,
was very fatiguing; but I was well repaid by the strange Cyclopean
scene. As I was walking along I met two large tortoises, each of which
must have weighed at least two hundred pounds: one was eating a piece
of cactus, and as I approached, it stared at me and slowly walked away;
the other gave a deep hiss, and drew in its head. These huge reptiles,
surrounded by the black lava, the leafless shrubs, and large cacti,
seemed to my fancy like some antediluvian animals. The few
dull-coloured birds cared no more for me than they did for the great
tortoises.
23rd.--The Beagle proceeded to Charles Island. This archipelago has
long been frequented, first by the bucaniers, and latterly by whalers,
but it is only within the last six years, that a small colony has been
established here. The inhabitants are between two and three hundred in
number; they are nearly all people of colour, who have been banished
for political crimes from the Republic of the Equator, of which Quito
is the capital. The settlement is placed about four and a half miles
inland, and at a height probably of a thousand feet. In the first part
of the road we passed through leafless thickets, as in Chatham Island.
Higher up, the woods gradually became greener; and as soon as we
crossed the ridge of the island, we were cooled by a fine southerly
breeze, and our sight refreshed by a green and thriving vegetation. In
this upper region coarse grasses and ferns abound; but there are no
tree-ferns: I saw nowhere any member of the palm family, which is the
more singular, as 360 miles northward, Cocos Island takes its name from
the number of cocoa-nuts. The houses are irregularly scattered over a
flat space of ground, which is cultivated with sweet potatoes and
bananas. It will not easily be imagined how pleasant the sight of
black mud was to us, after having been so long, accustomed to the
parched soil of Peru and northern Chile. The inhabitants, although
complaining of poverty, obtain, without much trouble, the means of
subsistence. In the woods there are many wild pigs and goats; but the
staple article of animal food is supplied by the tortoises. Their
numbers have of course been greatly reduced in this island, but the
people yet count on two days' hunting giving them food for the rest of
the week. It is said that formerly single vessels have taken away as
many as seven hundred, and that the ship's company of a frigate some
years since brought down in one day two hundred tortoises to the beach.
September 29th.--We doubled the south-west extremity of Albemarle
Island, and the next day were nearly becalmed between it and Narborough
Island. Both are covered with immense deluges of black naked lava,
which have flowed either over the rims of the great caldrons, like
pitch over the rim of a pot in which it has been boiled, or have burst
forth from smaller orifices on the flanks; in their descent they have
spread over miles of the sea-coast. On both of these islands,
eruptions are known to have taken place; and in Albemarle, we saw a
small jet of smoke curling from the summit of one of the great craters.
In the evening we anchored in Bank's Cove, in Albemarle Island. The
next morning I went out walking. To the south of the broken
tuff-crater, in which the Beagle was anchored, there was another
beautifully symmetrical one of an elliptic form; its longer axis was a
little less than a mile, and its depth about 500 feet. At its bottom
there was a shallow lake, in the middle of which a tiny crater formed
an islet. The day was overpoweringly hot, and the lake looked clear
and blue: I hurried down the cindery slope, and, choked with dust,
eagerly tasted the water--but, to my sorrow, I found it salt as brine.
The rocks on the coast abounded with great black lizards, between three
and four feet long; and on the hills, an ugly yellowish-brown species
was equally common. We saw many of this latter kind, some clumsily
running out of the way, and others shuffling into their burrows. I
shall presently describe in more detail the habits of both these
reptiles. The whole of this northern part of Albemarle Island is
miserably sterile.
October 8th.--We arrived at James Island: this island, as well as
Charles Island, were long since thus named after our kings of the
Stuart line. Mr. Bynoe, myself, and our servants were left here for a
week, with provisions and a tent, whilst the Beagle went for water. We
found here a party of Spaniards, who had been sent from Charles Island
to dry fish, and to salt tortoise-meat. About six miles inland, and at
the height of nearly 2000 feet, a hovel had been built in which two men
lived, who were employed in catching tortoises, whilst the others were
fishing on the coast. I paid this party two visits, and slept there
one night. As in the other islands, the lower region was covered by
nearly leafless bushes, but the trees were here of a larger growth than
elsewhere, several being two feet and some even two feet nine inches in
diameter. The upper region being kept damp by the clouds, supports a
green and flourishing vegetation. So damp was the ground, that there
were large beds of a coarse cyperus, in which great numbers of a very
small water-rail lived and bred. While staying in this upper region,
we lived entirely upon tortoise-meat: the breast-plate roasted (as the
Gauchos do _carne con cuero_), with the flesh on it, is very good; and
the young tortoises make excellent soup; but otherwise the meat to my
taste is indifferent.
One day we accompanied a party of the Spaniards in their whale-boat to
a salina, or lake from which salt is procured. After landing, we had a
very rough walk over a rugged field of recent lava, which has almost
surrounded a tuff-crater, at the bottom of which the salt-lake lies.
The water is only three or four inches deep, and rests on a layer of
beautifully crystallized, white salt. The lake is quite circular, and
is fringed with a border of bright green succulent plants; the almost
precipitous walls of the crater are clothed with wood, so that the
scene was altogether both picturesque and curious. A few years since,
the sailors belonging to a sealing-vessel murdered their captain in
this quiet spot; and we saw his skull lying among the bushes.
During the greater part of our stay of a week, the sky was cloudless,
and if the trade-wind failed for an hour, the heat became very
oppressive. On two days, the thermometer within the tent stood for
some hours at 93 degs.; but in the open air, in the wind and sun, at
only 85 degs. The sand was extremely hot; the thermometer placed in
some of a brown colour immediately rose to 137 degs., and how much
above that it would have risen, I do not know, for it was not graduated
any higher. The black sand felt much hotter, so that even in thick
boots it was quite disagreeable to walk over it.
The natural history of these islands is eminently curious, and well
deserves attention. Most of the organic productions are aboriginal
creations, found nowhere else; there is even a difference between the
inhabitants of the different islands; yet all show a marked
relationship with those of America, though separated from that
continent by an open space of ocean, between 500 and 600 miles in
width. The archipelago is a little world within itself, or rather a
satellite attached to America, whence it has derived a few stray
colonists, and has received the general character of its indigenous
productions. Considering the small size of the islands, we feel the
more astonished at the number of their aboriginal beings, and at their
confined range. Seeing every height crowned with its crater, and the
boundaries of most of the lava-streams still distinct, we are led to
believe that within a period geologically recent the unbroken ocean was
here spread out. Hence, both in space and time, we seem to be brought
somewhat near to that great fact--that mystery of mysteries--the first
appearance of new beings on this earth.
Of terrestrial mammals, there is only one which must be considered as
indigenous, namely, a mouse (Mus Galapagoensis), and this is confined,
as far as I could ascertain, to Chatham Island, the most easterly
island of the group. It belongs, as I am informed by Mr. Waterhouse,
to a division of the family of mice characteristic of America. At
James Island, there is a rat sufficiently distinct from the common kind
to have been named and described by Mr. Waterhouse; but as it belongs
to the old-world division of the family, and as this island has been
frequented by ships for the last hundred and fifty years, I can hardly
doubt that this rat is merely a variety produced by the new and
peculiar climate, food, and soil, to which it has been subjected.
Although no one has a right to speculate without distinct facts, yet
even with respect to the Chatham Island mouse, it should be borne in
mind, that it may possibly be an American species imported here; for I
have seen, in a most unfrequented part of the Pampas, a native mouse
living in the roof of a newly built hovel, and therefore its
transportation in a vessel is not improbable: analogous facts have been
observed by Dr. Richardson in North America.
Of land-birds I obtained twenty-six kinds, all peculiar to the group
and found nowhere else, with the exception of one lark-like finch from
North America (Dolichonyx oryzivorus), which ranges on that continent
as far north as 54 degs., and generally frequents marshes. The other
twenty-five birds consist, firstly, of a hawk, curiously intermediate
in structure between a buzzard and the American group of
carrion-feeding Polybori; and with these latter birds it agrees most
closely in every habit and even tone of voice. Secondly, there are two
owls, representing the short-eared and white barn-owls of Europe.
Thirdly, a wren, three tyrant-flycatchers (two of them species of
Pyrocephalus, one or both of which would be ranked by some
ornithologists as only varieties), and a dove--all analogous to, but
distinct from, American species. Fourthly, a swallow, which though
differing from the Progne purpurea of both Americas, only in being
rather duller colored, smaller, and slenderer, is considered by Mr.
Gould as specifically distinct. Fifthly, there are three species of
mocking thrush--a form highly characteristic of America. The remaining
land-birds form a most singular group of finches, related to each other
in the structure of their beaks, short tails, form of body and plumage:
there are thirteen species, which Mr. Gould has divided into four
sub-groups. All these species are peculiar to this archipelago; and so
is the whole group, with the exception of one species of the sub-group
Cactornis, lately brought from Bow Island, in the Low Archipelago. Of
Cactornis, the two species may be often seen climbing about the flowers
of the great cactus-trees; but all the other species of this group of
finches, mingled together in flocks, feed on the dry and sterile ground
of the lower districts. The males of all, or certainly of the greater
number, are jet black; and the females (with perhaps one or two
exceptions) are brown. The most curious fact is the perfect gradation
in the size of the beaks in the different species of Geospiza, from one
as large as that of a hawfinch to that of a chaffinch, and (if Mr.
Gould is right in including his sub-group, Certhidea, in the main
group) even to that of a warbler. The largest beak in the genus
Geospiza is shown in Fig. 1, and the smallest in Fig. 3; but instead of
there being only one intermediate species, with a beak of the size
shown in Fig. 2, there are no less than six species with insensibly
graduated beaks. The beak of the sub-group Certhidea, is shown in Fig.
4. The beak of Cactornis is
[picture]
1. Geospiza magnirostris. 2. Geospiza fortis. 3. Geospiza parvula.
4. Certhidea olivasea.
somewhat like that of a starling, and that of the fourth sub-group,
Camarhynchus, is slightly parrot-shaped. Seeing this gradation and
diversity of structure in one small, intimately related group of birds,
one might really fancy that from an original paucity of birds in this
archipelago, one species had been taken and modified for different
ends. 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.
We will now turn to the order of reptiles, which gives the most
striking character to the zoology of these islands. The species are not
numerous, but the numbers of individuals of each species are
extraordinarily great. There is one small lizard belonging to a South
American genus, and two species (and probably more) of the
Amblyrhynchus--a genus confined to the Galapagos Islands. There is one
snake which is numerous; it is identical, as I am informed by M.
Bibron, with the Psammophis Temminckii from Chile. [2] Of sea-turtle I
believe there are more than one species, and of tortoises there are, as
we shall presently show, two or three species or races. Of toads and
frogs there are none: I was surprised at this, considering how well
suited for them the temperate and damp upper woods appeared to be. It
recalled to my mind the remark made by Bory St. Vincent, [3] namely,
that none of this family are found on any of the volcanic islands in
the great oceans. As far as I can ascertain from various works, this
seems to hold good throughout the Pacific, and even in the large
islands of the Sandwich archipelago. Mauritius offers an apparent
exception, where I saw the Rana Mascariensis in abundance: this frog is
said now to inhabit the Seychelles, Madagascar, and Bourbon; but on the
other hand, Du Bois, in his voyage in 1669, states that there were no
reptiles in Bourbon except tortoises; and the Officier du Roi asserts
that before 1768 it had been attempted, without success, to introduce
frogs into Mauritius--I presume for the purpose of eating: hence it may
be well doubted whether this frog is an aboriginal of these islands.
The absence of the frog family in the oceanic islands is the more
remarkable, when contrasted with the case of lizards, which swarm on
most of the smallest islands. May this difference not be caused, by
the greater facility with which the eggs of lizards, protected by
calcareous shells might be transported through salt-water, than could
the slimy spawn of frogs?
I will first describe the habits of the tortoise (Testudo nigra,
formerly called Indica), which has been so frequently alluded to. These
animals are found, I believe, on all the islands of the archipelago;
certainly on the greater number. They frequent in preference the high
damp parts, but they likewise live in the lower and arid districts. I
have already shown, from the numbers which have been caught in a single
day, how very numerous they must be. Some grow to an immense size: Mr.
Lawson, an Englishman, and vice-governor of the colony, told us that he
had seen several so large, that it required six or eight men to lift
them from the ground; and that some had afforded as much as two hundred
pounds of meat. The old males are the largest, the females rarely
growing to so great a size: the male can readily be distinguished from
the female by the greater length of its tail. The tortoises which live
on those islands where there is no water, or in the lower and arid
parts of the others, feed chiefly on the succulent cactus. Those which
frequent the higher and damp regions, eat the leaves of various trees,
a kind of berry (called guayavita) which is acid and austere, and
likewise a pale green filamentous lichen (Usnera plicata), that hangs
from the boughs of the trees.
The tortoise is very fond of water, drinking large quantities, and
wallowing in the mud. The larger islands alone possess springs, and
these are always situated towards the central parts, and at a
considerable height. The tortoises, therefore, which frequent the
lower districts, when thirsty, are obliged to travel from a long
distance. Hence broad and well-beaten paths branch off in every
direction from the wells down to the sea-coast; and the Spaniards by
following them up, first discovered the watering-places. When I landed
at Chatham Island, I could not imagine what animal travelled so
methodically along well-chosen tracks. Near the springs it was a
curious spectacle to behold many of these huge creatures, one set
eagerly travelling onwards with outstretched necks, and another set
returning, after having drunk their fill. When the tortoise arrives at
the spring, quite regardless of any spectator, he buries his head in
the water above his eyes, and greedily swallows great mouthfuls, at the
rate of about ten in a minute. The inhabitants say each animal stays
three or four days in the neighbourhood of the water, and then returns
to the lower country; but they differed respecting the frequency of
these visits. The animal probably regulates them according to the
nature of the food on which it has lived. It is, however, certain,
that tortoises can subsist even on these islands where there is no
other water than what falls during a few rainy days in the year.
I believe it is well ascertained, that the bladder of the frog acts as
a reservoir for the moisture necessary to its existence: such seems to
be the case with the tortoise. For some time after a visit to the
springs, their urinary bladders are distended with fluid, which is said
gradually to decrease in volume, and to become less pure. The
inhabitants, when walking in the lower district, and overcome with
thirst, often take advantage of this circumstance, and drink the
contents of the bladder if full: in one I saw killed, the fluid was
quite limpid, and had only a very slightly bitter taste. The
inhabitants, however, always first drink the water in the pericardium,
which is described as being best.
The tortoises, when purposely moving towards any point, travel by night
and day, and arrive at their journey's end much sooner than would be
expected. The inhabitants, from observing marked individuals, consider
that they travel a distance of about eight miles in two or three days.
One large tortoise, which I watched, walked at the rate of sixty yards
in ten minutes, that is 360 yards in the hour, or four miles a
day,--allowing a little time for it to eat on the road. During the
breeding season, when the male and female are together, the male utters
a hoarse roar or bellowing, which, it is said, can be heard at the
distance of more than a hundred yards. The female never uses her voice,
and the male only at these times; so that when the people hear this
noise, they know that the two are together. They were at this time
(October) laying their eggs. The female, where the soil is sandy,
deposits them together, and covers them up with sand; but where the
ground is rocky she drops them indiscriminately in any hole: Mr. Bynoe
found seven placed in a fissure. The egg is white and spherical; one
which I measured was seven inches and three-eighths in circumference,
and therefore larger than a hen's egg. The young tortoises, as soon as
they are hatched, fall a prey in great numbers to the carrion-feeding
buzzard. The old ones seem generally to die from accidents, as from
falling down precipices: at least, several of the inhabitants told me,
that they never found one dead without some evident cause.
The inhabitants believe that these animals are absolutely deaf;
certainly they do not overhear a person walking close behind them. I
was always amused when overtaking one of these great monsters, as it
was quietly pacing along, to see how suddenly, the instant I passed, it
would draw in its head and legs, and uttering a deep hiss fall to the
ground with a heavy sound, as if struck dead. I frequently got on
their backs, and then giving a few raps on the hinder part of their
shells, they would rise up and walk away;--but I found it very
difficult to keep my balance. The flesh of this animal is largely
employed, both fresh and salted; and a beautifully clear oil is
prepared from the fat. When a tortoise is caught, the man makes a slit
in the skin near its tail, so as to see inside its body, whether the
fat under the dorsal plate is thick. If it is not, the animal is
liberated and it is said to recover soon from this strange operation.
In order to secure the tortoise, it is not sufficient to turn them like
turtle, for they are often able to get on their legs again.
There can be little doubt that this tortoise is an aboriginal
inhabitant of the Galapagos; for it is found on all, or nearly all, the
islands, even on some of the smaller ones where there is no water; had
it been an imported species, this would hardly have been the case in a
group which has been so little frequented. Moreover, the old Bucaniers
found this tortoise in greater numbers even than at present: Wood and
Rogers also, in 1708, say that it is the opinion of the Spaniards, that
it is found nowhere else in this quarter of the world. It is now
widely distributed; but it may be questioned whether it is in any other
place an aboriginal. The bones of a tortoise at Mauritius, associated
with those of the extinct Dodo, have generally been considered as
belonging to this tortoise; if this had been so, undoubtedly it must
have been there indigenous; but M. Bibron informs me that he believes
that it was distinct, as the species now living there certainly is.
The Amblyrhynchus, a remarkable genus of lizards, is confined to this
archipelago; there are two species, resembling
[picture]
each other in general form, one being terrestrial and the other
aquatic. This latter species (A. cristatus) was first characterized by
Mr. Bell, who well foresaw, from its short, broad head, and strong
claws of equal length, that its habits of life would turn out very
peculiar, and different from those of its nearest ally, the Iguana. It
is extremely common on all the islands throughout the group, and lives
exclusively on the rocky sea-beaches, being never found, at least I
never saw one, even ten yards in-shore. It is a hideous-looking
creature, of a dirty black colour, stupid, and sluggish in its
movements. The usual length of a full-grown one is about a yard, but
there are some even four feet long; a large one weighed twenty pounds:
on the island of Albemarle they seem to grow to a greater size than
elsewhere. Their tails are flattened sideways, and all four feet
partially webbed. They are occasionally seen some hundred yards from
the shore, swimming about; and Captain Collnett, in his Voyage says,
"They go to sea in herds a-fishing, and sun themselves on the rocks;
and may be called alligators in miniature." It must not, however, be
supposed that they live on fish. When in the water this lizard swims
with perfect ease and quickness, by a serpentine movement of its body
and flattened tail--the legs being motionless and closely collapsed on
its sides. A seaman on board sank one, with a heavy weight attached to
it, thinking thus to kill it directly; but when, an hour afterwards, he
drew up the line, it was quite active. Their limbs and strong claws
are admirably adapted for crawling over the rugged and fissured masses
of lava, which everywhere form the coast. In such situations, a group
of six or seven of these hideous reptiles may oftentimes be seen on the
black rocks, a few feet above the surf, basking in the sun with
outstretched legs.
I opened the stomachs of several, and found them largely distended with
minced sea-weed (Ulvae), which grows in thin foliaceous expansions of a
bright green or a dull red colour. I do not recollect having observed
this sea-weed in any quantity on the tidal rocks; and I have reason to
believe it grows at the bottom of the sea, at some little distance from
the coast. If such be the case, the object of these animals
occasionally going out to sea is explained. The stomach contained
nothing but the sea-weed. Mr. Baynoe, however, found a piece of crab
in one; but this might have got in accidentally, in the same manner as
I have seen a caterpillar, in the midst of some lichen, in the paunch
of a tortoise. The intestines were large, as in other herbivorous
animals. The nature of this lizard's food, as well as the structure of
its tail and feet, and the fact of its having been seen voluntarily
swimming out at sea, absolutely prove its aquatic habits; yet there is
in this respect one strange anomaly, namely, that when frightened it
will not enter the water. Hence it is easy to drive these lizards down
to any little point overhanging the sea, where they will sooner allow a
person to catch hold of their tails than jump into the water. They do
not seem to have any notion of biting; but when much frightened they
squirt a drop of fluid from each nostril. I threw one several times as
far as I could, into a deep pool left by the retiring tide; but it
invariably returned in a direct line to the spot where I stood. It
swam near the bottom, with a very graceful and rapid movement, and
occasionally aided itself over the uneven ground with its feet. As
soon as it arrived near the edge, but still being under water, it tried
to conceal itself in the tufts of sea-weed, or it entered some crevice.
As soon as it thought the danger was past, it crawled out on the dry
rocks, and shuffled away as quickly as it could. I several times
caught this same lizard, by driving it down to a point, and though
possessed of such perfect powers of diving and swimming, nothing would
induce it to enter the water; and as often as I threw it in, it
returned in the manner above described. Perhaps this singular piece of
apparent stupidity may be accounted for by the circumstance, that this
reptile has no enemy whatever on shore, whereas at sea it must often
fall a prey to the numerous sharks. Hence, probably, urged by a fixed
and hereditary instinct that the shore is its place of safety, whatever
the emergency may be, it there takes refuge.
During our visit (in October), I saw extremely few small individuals of
this species, and none I should think under a year old. From this
circumstance it seems probable that the breeding season had not then
commenced. I asked several of the inhabitants if they knew where it
laid its eggs: they said that they knew nothing of its propagation,
although well acquainted with the eggs of the land kind--a fact,
considering how very common this lizard is, not a little extraordinary.
We will now turn to the terrestrial species (A. Demarlii), with a round
tail, and toes without webs. This lizard, instead of being found like
the other on all the islands, is confined to the central part of the
archipelago, namely to Albemarle, James, Barrington, and Indefatigable
islands. To the southward, in Charles, Hood, and Chatham islands, and
to the northward, in Towers, Bindloes, and Abingdon, I neither saw nor
heard of any. It would appear as if it had been created in the centre
of the archipelago, and thence had been dispersed only to a certain
distance. Some of these lizards inhabit the high and damp parts of the
islands, but they are much more numerous in the lower and sterile
districts near the coast. I cannot give a more forcible proof of their
numbers, than by stating that when we were left at James Island, we
could not for some time find a spot free from their burrows on which to
pitch our single tent. Like their brothers the sea-kind, they are ugly
animals, of a yellowish orange beneath, and of a brownish red colour
above: from their low facial angle they have a singularly stupid
appearance. They are, perhaps, of a rather less size than the marine
species; but several of them weighed between ten and fifteen pounds. In
their movements they are lazy and half torpid. When not frightened,
they slowly crawl along with their tails and bellies dragging on the
ground. They often stop, and doze for a minute or two, with closed
eyes and hind legs spread out on the parched soil.
They inhabit burrows, which they sometimes make between fragments of
lava, but more generally on level patches of the soft sandstone-like
tuff. The holes do not appear to be very deep, and they enter the
ground at a small angle; so that when walking over these
lizard-warrens, the soil is constantly giving way, much to the
annoyance of the tired walker. This animal, when making its burrow,
works alternately the opposite sides of its body. One front leg for a
short time scratches up the soil, and throws it towards the hind foot,
which is well placed so as to heave it beyond the mouth of the hole.
That side of the body being tired, the other takes up the task, and so
on alternately. I watched one for a long time, till half its body was
buried; I then walked up and pulled it by the tail, at this it was
greatly astonished, and soon shuffled up to see what was the matter;
and then stared me in the face, as much as to say, "What made you pull
my tail?"
They feed by day, and do not wander far from their burrows; if
frightened, they rush to them with a most awkward gait. Except when
running down hill, they cannot move very fast, apparently from the
lateral position of their legs. They are not at all timorous: when
attentively watching any one, they curl their tails, and, raising
themselves on their front legs, nod their heads vertically, with a
quick movement, and try to look very fierce; but in reality they are
not at all so: if one just stamps on the ground, down go their tails,
and off they shuffle as quickly as they can. I have frequently
observed small fly-eating lizards, when watching anything, nod their
heads in precisely the same manner; but I do not at all know for what
purpose. If this Amblyrhynchus is held and plagued with a stick, it
will bite it very severely; but I caught many by the tail, and they
never tried to bite me. If two are placed on the ground and held
together, they will fight, and bite each other till blood is drawn.
The individuals, and they are the greater number, which inhabit the
lower country, can scarcely taste a drop of water throughout the year;
but they consume much of the succulent cactus, the branches of which
are occasionally broken off by the wind. I several times threw a piece
to two or three of them when together; and it was amusing enough to see
them trying to seize and carry it away in their mouths, like so many
hungry dogs with a bone. They eat very deliberately, but do not chew
their food. The little birds are aware how harmless these creatures
are: I have seen one of the thick-billed finches picking at one end of
a piece of cactus (which is much relished by all the animals of the
lower region), whilst a lizard was eating at the other end; and
afterwards the little bird with the utmost indifference hopped on the
back of the reptile.
I opened the stomachs of several, and found them full of vegetable
fibres and leaves of different trees, especially of an acacia. In the
upper region they live chiefly on the acid and astringent berries of
the guayavita, under which trees I have seen these lizards and the huge
tortoises feeding together. To obtain the acacia-leaves they crawl up
the low stunted trees; and it is not uncommon to see a pair quietly
browsing, whilst seated on a branch several feet above the ground.
These lizards, when cooked, yield a white meat, which is liked by those
whose stomachs soar above all prejudices.
Humboldt has remarked that in intertropical South America, all lizards
which inhabit dry regions are esteemed delicacies for the table. The
inhabitants state that those which inhabit the upper damp parts drink
water, but that the others do not, like the tortoises, travel up for it
from the lower sterile country. At the time of our visit, the females
had within their bodies numerous, large, elongated eggs, which they lay
in their burrows: the inhabitants seek them for food.
These two species of Amblyrhynchus agree, as I have already stated, in
their general structure, and in many of their habits. Neither have
that rapid movement, so characteristic of the genera Lacerta and
Iguana. They are both herbivorous, although the kind of vegetation on
which they feed is so very different. Mr. Bell has given the name to
the genus from the shortness of the snout: indeed, the form of the
mouth may almost be compared to that of the tortoise: one is led to
suppose that this is an adaptation to their herbivorous appetites. It
is very interesting thus to find a well-characterized genus, having its
marine and terrestrial species, belonging to so confined a portion of
the world. The aquatic species is by far the most remarkable, because
it is the only existing lizard which lives on marine vegetable
productions. As I at first observed, these islands are not so
remarkable for the number of the species of reptiles, as for that of
the individuals, when we remember the well-beaten paths made by the
thousands of huge tortoises--the many turtles--the great warrens of the
terrestrial Amblyrhynchus--and the groups of the marine species basking
on the coast-rocks of every island--we must admit that there is no
other quarter of the world where this Order replaces the herbivorous
mammalia in so extraordinary a manner. The geologist on hearing this
will probably refer back in his mind to the Secondary epochs, when
lizards, some herbivorous, some carnivorous, and of dimensions
comparable only with our existing whales, swarmed on the land and in
the sea. It is, therefore, worthy of his observation, that this
archipelago, instead of possessing a humid climate and rank vegetation,
cannot be considered otherwise than extremely arid, and, for an
equatorial region, remarkably temperate.
To finish with the zoology: the fifteen kinds of sea-fish which I
procured here are all new species; they belong to twelve genera, all
widely distributed, with the exception of Prionotus, of which the four
previously known species live on the eastern side of America. Of
land-shells I collected sixteen kinds (and two marked varieties), of
which, with the exception of one Helix found at Tahiti, all are
peculiar to this archipelago: a single fresh-water shell (Paludina) is
common to Tahiti and Van Diemen's Land. Mr. Cuming, before our voyage
procured here ninety species of sea-shells, and this does not include
several species not yet specifically examined, of Trochus, Turbo,
Monodonta, and Nassa. He has been kind enough to give me the following
interesting results: Of the ninety shells, no less than forty-seven are
unknown elsewhere--a wonderful fact, considering how widely distributed
sea-shells generally are. Of the forty-three shells found in other
parts of the world, twenty-five inhabit the western coast of America,
and of these eight are distinguishable as varieties; the remaining
eighteen (including one variety) were found by Mr. Cuming in the Low
Archipelago, and some of them also at the Philippines. This fact of
shells from islands in the central parts of the Pacific occurring here,
deserves notice, for not one single sea-shell is known to be common to
the islands of that ocean and to the west coast of America. The space
of open sea running north and south off the west coast, separates two
quite distinct conchological provinces; but at the Galapagos
Archipelago we have a halting-place, where many new forms have been
created, and whither these two great conchological provinces have each
sent up several colonists. The American province has also sent here
representative species; for there is a Galapageian species of
Monoceros, a genus only found on the west coast of America; and there
are Galapageian species of Fissurella and Cancellaria, genera common on
the west coast, but not found (as I am informed by Mr. Cuming) in the
central islands of the Pacific. On the other hand, there are
Galapageian species of Oniscia and Stylifer, genera common to the West
Indies and to the Chinese and Indian seas, but not found either on the
west coast of America or in the central Pacific. I may here add, that
after the comparison by Messrs. Cuming and Hinds of about 2000 shells
from the eastern and western coasts of America, only one single shell
was found in common, namely, the Purpura patula, which inhabits the
West Indies, the coast of Panama, and the Galapagos. We have,
therefore, in this quarter of the world, three great conchological
sea-provinces, quite distinct, though surprisingly near each other,
being separated by long north and south spaces either of land or of
open sea.
I took great pains in collecting the insects, but excepting Tierra del
Fuego, I never saw in this respect so poor a country. Even in the upper
and damp region I procured very few, excepting some minute Diptera and
Hymenoptera, mostly of common mundane forms. As before remarked, the
insects, for a tropical region, are of very small size and dull
colours. Of beetles I collected twenty-five species (excluding a
Dermestes and Corynetes imported, wherever a ship touches); of these,
two belong to the Harpalidae, two to the Hydrophilidae, nine to three
families of the Heteromera, and the remaining twelve to as many
different families. This circumstance of insects (and I may add
plants), where few in number, belonging to many different families, is,
I believe, very general. Mr. Waterhouse, who has published [4] an
account of the insects of this archipelago, and to whom I am indebted
for the above details, informs me that there are several new genera:
and that of the genera not new, one or two are American, and the rest
of mundane distribution. With the exception of a wood-feeding Apate,
and of one or probably two water-beetles from the American continent,
all the species appear to be new.
The botany of this group is fully as interesting as the zoology. Dr.
J. Hooker will soon publish in the "Linnean Transactions" a full
account of the Flora, and I am much indebted to him for the following
details. Of flowering plants there are, as far as at present is known,
185 species, and 40 cryptogamic species, making altogether 225; of this
number I was fortunate enough to bring home 193. Of the flowering
plants, 100 are new species, and are probably confined to this
archipelago. Dr. Hooker conceives that, of the plants not so confined,
at least 10 species found near the cultivated ground at Charles Island,
have been imported. It is, I think, surprising that more American
species have not been introduced naturally, considering that the
distance is only between 500 and 600 miles from the continent, and that
(according to Collnet, p. 58) drift-wood, bamboos, canes, and the nuts
of a palm, are often washed on the south-eastern shores. The
proportion of 100 flowering plants out of 183 (or 175 excluding the
imported weeds) being new, is sufficient, I conceive, to make the
Galapagos Archipelago a distinct botanical province; but this Flora is
not nearly so peculiar as that of St. Helena, nor, as I am informed by
Dr. Hooker, of Juan Fernandez. The peculiarity of the Galapageian
Flora is best shown in certain families;--thus there are 21 species of
Compositae, of which 20 are peculiar to this archipelago; these belong
to twelve genera, and of these genera no less than ten are confined to
the archipelago! Dr. Hooker informs me that the Flora has an
undoubtedly Western American character; nor can he detect in it any
affinity with that of the Pacific. If, therefore, we except the
eighteen marine, the one fresh-water, and one land-shell, which have
apparently come here as colonists from the central islands of the
Pacific, and likewise the one distinct Pacific species of the
Galapageian group of finches, we see that this archipelago, though
standing in the Pacific Ocean, is zoologically part of America.
If this character were owing merely to immigrants from America, there
would be little remarkable in it; but we see that a vast majority of
all the land animals, and that more than half of the flowering plants,
are aboriginal productions. It was most striking to be surrounded by new
birds, new reptiles, new shells, new insects, new plants, and yet by
innumerable trifling details of structure, and even by the tones of
voice and plumage of the birds, to have the temperate plains of
Patagonia, or rather the hot dry deserts of Northern Chile, vividly
brought before my eyes. Why, on these small points of land, which
within a late geological period must have been covered by the ocean,
which are formed by basaltic lava, and therefore differ in geological
character from the American continent, and which are placed under a
peculiar climate,--why were their aboriginal inhabitants, associated, I
may add, in different proportions both in kind and number from those on
the continent, and therefore acting on each other in a different
manner--why were they created on American types of organization? It is
probable that the islands of the Cape de Verd group resemble, in all
their physical conditions, far more closely the Galapagos Islands, than
these latter physically resemble the coast of America, yet the
aboriginal inhabitants of the two groups are totally unlike; those of
the Cape de Verd Islands bearing the impress of Africa, as the
inhabitants of the Galapagos Archipelago are stamped with that of
America.
I have not as yet noticed by far the most remarkable feature in the
natural history of this archipelago; it is, that the different islands
to a considerable extent are inhabited by a different set of beings. My
attention was first called to this fact by the Vice-Governor, Mr.
Lawson, declaring that the tortoises differed from the different
islands, and that he could with certainty tell from which island any
one was brought. I did not for some time pay sufficient attention to
this statement, and I had already partially mingled together the
collections from two of the islands. I never dreamed that islands,
about 50 or 60 miles apart, and most of them in sight of each other,
formed of precisely the same rocks, placed under a quite similar
climate, rising to a nearly equal height, would have been differently
tenanted; but we shall soon see that this is the case. It is the fate
of most voyagers, no sooner to discover what is most interesting in any
locality, than they are hurried from it; but I ought, perhaps, to be
thankful that I obtained sufficient materials to establish this most
remarkable fact in the distribution of organic beings.
The inhabitants, as I have said, state that they can distinguish the
tortoises from the different islands; and that they differ not only in
size, but in other characters. Captain Porter has described [5] those
from Charles and from the nearest island to it, namely, Hood Island, as
having their shells in front thick and turned up like a Spanish saddle,
whilst the tortoises from James Island are rounder, blacker, and have a
better taste when cooked. M. Bibron, moreover, informs me that he has
seen what he considers two distinct species of tortoise from the
Galapagos, but he does not know from which islands. The specimens that
I brought from three islands were young ones: and probably owing to
this cause neither Mr. Gray nor myself could find in them any specific
differences. I have remarked that the marine Amblyrhynchus was larger
at Albemarle Island than elsewhere; and M. Bibron informs me that he
has seen two distinct aquatic species of this genus; so that the
different islands probably have their representative species or races
of the Amblyrhynchus, as well as of the tortoise. My attention was
first thoroughly aroused, by comparing together the numerous specimens,
shot by myself and several other parties on board, of the
mocking-thrushes, when, to my astonishment, I discovered that all those
from Charles Island belonged to one species (Mimus trifasciatus) all
from Albemarle Island to M. parvulus; and all from James and Chatham
Islands (between which two other islands are situated, as connecting
links) belonged to M. melanotis. These two latter species are closely
allied, and would by some ornithologists be considered as only
well-marked races or varieties; but the Mimus trifasciatus is very
distinct. Unfortunately most of the specimens of the finch tribe were
mingled together; but I have strong reasons to suspect that some of the
species of the sub-group Geospiza are confined to separate islands. If
the different islands have their representatives of Geospiza, it may
help to explain the singularly large number of the species of this
sub-group in this one small archipelago, and as a probable consequence
of their numbers, the perfectly graduated series in the size of their
beaks. Two species of the sub-group Cactornis, and two of the
Camarhynchus, were procured in the archipelago; and of the numerous
specimens of these two sub-groups shot by four collectors at James
Island, all were found to belong to one species of each; whereas the
numerous specimens shot either on Chatham or Charles Island (for the
two sets were mingled together) all belonged to the two other species:
hence we may feel almost sure that these islands possess their
respective species of these two sub-groups. In land-shells this law of
distribution does not appear to hold good. In my very small collection
of insects, Mr. Waterhouse remarks, that of those which were ticketed
with their locality, not one was common to any two of the islands.
If we now turn to the Flora, we shall find the aboriginal plants of the
different islands wonderfully different. I give all the following
results on the high authority of my friend Dr. J. Hooker. I may
premise that I indiscriminately collected everything in flower on the
different islands, and fortunately kept my collections separate. Too
much confidence, however, must not be placed in the proportional
results, as the small collections brought home by some other
naturalists though in some respects confirming the results, plainly
show that much remains to be done in the botany of this group: the
Leguminosae, moreover, has as yet been only approximately worked out:--
----------------------------------------------------------------
Number of
Species
confined
to the
Number of Number of Galapagos
species species Number Archipelago
Total found in confined confined but found
Name Number other to the to the on more
of of parts of Galapagos one than the
Island Species the world Archipelago island one island
----------------------------------------------------------------
James 71 33 38 30 8
Albemarle 46 18 26 22 4
Chatham 32 16 16 12 4
Charles 68 39 29 21 8
(or 29, if
the probably
imported
plants be
subtracted.)
----------------------------------------------------------------
Hence we have the truly wonderful fact, that in James Island, of the
thirty-eight Galapageian plants, or those found in no other part of the
world, thirty are exclusively confined to this one island; and in
Albemarle Island, of the twenty-six aboriginal Galapageian plants,
twenty-two are confined to this one island, that is, only four are at
present known to grow in the other islands of the archipelago; and so
on, as shown in the above table, with the plants from Chatham and
Charles Islands. This fact will, perhaps, be rendered even more
striking, by giving a few illustrations:--thus, Scalesia, a remarkable
arborescent genus of the Compositae, is confined to the archipelago: it
has six species: one from Chatham, one from Albemarle, one from Charles
Island, two from James Island, and the sixth from one of the three
latter islands, but it is not known from which: not one of these six
species grows on any two islands. Again, Euphorbia, a mundane or
widely distributed genus, has here eight species, of which seven are
confined to the archipelago, and not one found on any two islands:
Acalypha and Borreria, both mundane genera, have respectively six and
seven species, none of which have the same species on two islands, with
the exception of one Borreria, which does occur on two islands. The
species of the Compositae are particularly local; and Dr. Hooker has
furnished me with several other most striking illustrations of the
difference of the species on the different islands. He remarks that
this law of distribution holds good both with those genera confined to
the archipelago, and those distributed in other quarters of the world:
in like manner we have seen that the different islands have their
proper species of the mundane genus of tortoise, and of the widely
distributed American genus of the mocking-thrush, as well as of two of
the Galapageian sub-groups of finches, and almost certainly of the
Galapageian genus Amblyrhynchus.
The distribution of the tenants of this archipelago would not be nearly
so wonderful, if, for instance, one island had a mocking-thrush, and a
second island some other quite distinct genus,--if one island had its
genus of lizard, and a second island another distinct genus, or none
whatever;--or if the different islands were inhabited, not by
representative species of the same genera of plants, but by totally
different genera, as does to a certain extent hold good: for, to give
one instance, a large berry-bearing tree at James Island has no
representative species in Charles Island. But it is the circumstance,
that several of the islands possess their own species of the tortoise,
mocking-thrush, finches, and numerous plants, these species having the
same general habits, occupying analogous situations, and obviously
filling the same place in the natural economy of this archipelago, that
strikes me with wonder. It may be suspected that some of these
representative species, at least in the case of the tortoise and of
some of the birds, may hereafter prove to be only well-marked races;
but this would be of equally great interest to the philosophical
naturalist. I have said that most of the islands are in sight of each
other: I may specify that Charles Island is fifty miles from the
nearest part of Chatham Island, and thirty-three miles from the nearest
part of Albemarle Island. Chatham Island is sixty miles from the
nearest part of James Island, but there are two intermediate islands
between them which were not visited by me. James Island is only ten
miles from the nearest part of Albemarle Island, but the two points
where the collections were made are thirty-two miles apart. I must
repeat, that neither the nature of the soil, nor height of the land,
nor the climate, nor the general character of the associated beings,
and therefore their action one on another, can differ much in the
different islands. If there be any sensible difference in their
climates, it must be between the Windward group (namely, Charles and
Chatham Islands), and that to leeward; but there seems to be no
corresponding difference in the productions of these two halves of the
archipelago.
The only light which I can throw on this remarkable difference in the
inhabitants of the different islands, is, that very strong currents of
the sea running in a westerly and W.N.W. direction must separate, as
far as transportal by the sea is concerned, the southern islands from
the northern ones; and between these northern islands a strong N.W.
current was observed, which must effectually separate James and
Albemarle Islands. As the archipelago is free to a most remarkable
degree from gales of wind, neither the birds, insects, nor lighter
seeds, would be blown from island to island. And lastly, the profound
depth of the ocean between the islands, and their apparently recent (in
a geological sense) volcanic origin, render it highly unlikely that
they were ever united; and this, probably, is a far more important
consideration than any other, with respect to the geographical
distribution of their inhabitants. Reviewing the facts here given, one
is astonished at the amount of creative force, if such an expression
may be used, displayed on these small, barren, and rocky islands; and
still more so, at its diverse yet analogous action on points so near
each other. I have said that the Galapagos Archipelago might be called
a satellite attached to America, but it should rather be called a group
of satellites, physically similar, organically distinct, yet intimately
related to each other, and all related in a marked, though much lesser
degree, to the great American continent.
I will conclude my description of the natural history of these islands,
by giving an account of the extreme tameness of the birds.
This disposition is common to all the terrestrial species; namely, to
the mocking-thrushes, the finches, wrens, tyrant-flycatchers, the dove,
and carrion-buzzard. All of them are often approached sufficiently
near to be killed with a switch, and sometimes, as I myself tried, with
a cap or hat. A gun is here almost superfluous; for with the muzzle I
pushed a hawk off the branch of a tree. One day, whilst lying down, a
mocking-thrush alighted on the edge of a pitcher, made of the shell of
a tortoise, which I held in my hand, and began very quietly to sip the
water; it allowed me to lift it from the ground whilst seated on the
vessel: I often tried, and very nearly succeeded, in catching these
birds by their legs. Formerly the birds appear to have been even tamer
than at present. Cowley (in the year 1684) says that the "Turtledoves
were so tame, that they would often alight on our hats and arms, so as
that we could take them alive, they not fearing man, until such time as
some of our company did fire at them, whereby they were rendered more
shy." Dampier also, in the same year, says that a man in a morning's
walk might kill six or seven dozen of these doves. At present,
although certainly very tame, they do not alight on people's arms, nor
do they suffer themselves to be killed in such large numbers. It is
surprising that they have not become wilder; for these islands during
the last hundred and fifty years have been frequently visited by
bucaniers and whalers; and the sailors, wandering through the wood in
search of tortoises, always take cruel delight in knocking down the
little birds. These birds, although now still more persecuted, do not
readily become wild. In Charles Island, which had then been colonized
about six years, I saw a boy sitting by a well with a switch in his
hand, with which he killed the doves and finches as they came to drink.
He had already procured a little heap of them for his dinner, and he
said that he had constantly been in the habit of waiting by this well
for the same purpose. It would appear that the birds of this
archipelago, not having as yet learnt that man is a more dangerous
animal than the tortoise or the Amblyrhynchus, disregard him, in the
same manner as in England shy birds, such as magpies, disregard the
cows and horses grazing in our fields.
The Falkland Islands offer a second instance of birds with a similar
disposition. The extraordinary tameness of the little Opetiorhynchus
has been remarked by Pernety, Lesson, and other voyagers. It is not,
however, peculiar to that bird: the Polyborus, snipe, upland and
lowland goose, thrush, bunting, and even some true hawks, are all more
or less tame. As the birds are so tame there, where foxes, hawks, and
owls occur, we may infer that the absence of all rapacious animals at
the Galapagos, is not the cause of their tameness here. The upland
geese at the Falklands show, by the precaution they take in building on
the islets, that they are aware of their danger from the foxes; but
they are not by this rendered wild towards man. This tameness of the
birds, especially of the water-fowl, is strongly contrasted with the
habits of the same species in Tierra del Fuego, where for ages past
they have been persecuted by the wild inhabitants. In the Falklands,
the sportsman may sometimes kill more of the upland geese in one day
than he can carry home; whereas in Tierra del Fuego it is nearly as
difficult to kill one, as it is in England to shoot the common wild
goose.
In the time of Pernety (1763), all the birds there appear to have been
much tamer than at present; he states that the Opetiorhynchus would
almost perch on his finger; and that with a wand he killed ten in half
an hour. At that period the birds must have been about as tame as they
now are at the Galapagos. They appear to have learnt caution more
slowly at these latter islands than at the Falklands, where they have
had proportionate means of experience; for besides frequent visits from
vessels, those islands have been at intervals colonized during the
entire period. Even formerly, when all the birds were so tame, it was
impossible by Pernety's account to kill the black-necked swan--a bird
of passage, which probably brought with it the wisdom learnt in foreign
countries.
I may add that, according to Du Bois, all the birds at Bourbon in
1571-72, with the exception of the flamingoes and geese, were so
extremely tame, that they could be caught by the hand, or killed in any
number with a stick. Again, at Tristan d'Acunha in the Atlantic,
Carmichael [6] states that the only two land-birds, a thrush and a
bunting, were "so tame as to suffer themselves to be caught with a
hand-net." From these several facts we may, I think, conclude, first,
that the wildness of birds with regard to man, is a particular instinct
directed against _him_, and not dependent upon any general degree of
caution arising from other sources of danger; secondly, that it is not
acquired by individual birds in a short time, even when much
persecuted; but that in the course of successive generations it becomes
hereditary. With domesticated animals we are accustomed to see new
mental habits or instincts acquired or rendered hereditary; but with
animals in a state of nature, it must always be most difficult to
discover instances of acquired hereditary knowledge. In regard to the
wildness of birds towards man, there is no way of accounting for it,
except as an inherited habit: comparatively few young birds, in any one
year, have been injured by man in England, yet almost all, even
nestlings, are afraid of him; many individuals, on the other hand, both
at the Galapagos and at the Falklands, have been pursued and injured by
man, yet have not learned a salutary dread of him. We may infer from
these facts, what havoc the introduction of any new beast of prey must
cause in a country, before the instincts of the indigenous inhabitants
have become adapted to the stranger's craft or power.
[1] The progress of research has shown that some of these birds, which
were then thought to be confined to the islands, occur on the American
continent. The eminent ornithologist, Mr. Sclater, informs me that
this is the case with the Strix punctatissima and Pyrocephalus nanus;
and probably with the Otus Galapagoensis and Zenaida Galapagoensis: so
that the number of endemic birds is reduced to twenty-three, or
probably to twenty-one. Mr. Sclater thinks that one or two of these
endemic forms should be ranked rather as varieties than species, which
always seemed to me probable.
[2] This is stated by Dr. Gunther (Zoolog. Soc. Jan 24th, 1859) to be a
peculiar species, not known to inhabit any other country.
[3] Voyage aux Quatre Iles d'Afrique. With respect to the Sandwich
Islands, see Tyerman and Bennett's Journal, vol. i. p. 434. For
Mauritius, see Voyage par un Officier, etc., part i. p. 170. There are
no frogs in the Canary Islands (Webb et Berthelot, Hist. Nat. des Iles
Canaries). I saw none at St. Jago in the Cape de Verds. There are
none at St. Helena.
[4] Ann. and Mag. of Nat. Hist., vol. xvi. p. 19.
[5] Voyage in the U. S. ship Essex, vol. i. p. 215.
[6] Linn. Trans., vol. xii. p. 496. The most anomalous fact on this
subject which I have met with is the wildness of the small birds in the
Arctic parts of North America (as described by Richardson, Fauna Bor.,
vol. ii. p. 332), where they are said never to be persecuted. This
case is the more strange, because it is asserted that some of the same
species in their winter-quarters in the United States are tame. There
is much, as Dr. Richardson well remarks, utterly inexplicable connected
with the different degrees of shyness and care with which birds conceal
their nests. How strange it is that the English wood-pigeon, generally
so wild a bird, should very frequently rear its young in shrubberies
close to houses!