Galapagos Islands volcanic--Number of craters--Leafless bushes
--Colony at Charles Island--James Island--Salt-lake in crater
--Character of vegetation--Ornithology, curious finches--Great
tortoises, habits of, paths to the wells--Marine lizard feeds on
sea-weed--Terrestrial species, burrowing habits, herbivorous
--Importance of reptiles in the Archipelago--Few and minute
insects--American type of organization--Species confined to certain
islands--Tameness of birds--Falkland Islands--Fear of man an
acquired instinct.
GALAPAGOS ARCHIPELAGO.
SEPTEMBER 15TH.--The Beagle arrived at the southernmost of the
Galapagos islands. This archipelago consists of ten principal
islands, of which five much exceed the others in size. They are
situated under the equatorial line, and between five and six hundred
miles to the westward of the coast of America. The constitution of
the whole is volcanic. with the exception of some ejected fragments
of granite, which have been most curiously glazed and altered by the
heat, every part consists of lava, or of sandstone resulting from the
attrition of such materials. The higher islands, (which attain an
elevation of three, and even four thousand feet) generally have one
or more principal craters towards their centre, and on their flanks
smaller orifices. I have no exact data from which to calculate, but
I do not hesitate to affirm, that there must be, in all the islands
of the archipelago, at least two thousand craters. These are of two
kinds; one, as in ordinary cases, consisting of scoriæ and lava,
the other of finely-stratified volcanic sandstone. The latter in
most instances have a form beautifully symmetrical: their origin
is due to the ejection of mud,--that is, fine volcanic ashes and
water,--without any lava.
Considering that these islands are placed directly under the equator,
the climate is far from being excessively hot; a circumstance which,
perhaps, is chiefly owing to the singularly low temperature of the
surrounding sea. Excepting during one short season, very little rain
falls, and even then it is not regular: but the clouds generally hang
low. From these circumstances the lower parts of the islands are
extremely arid, whilst the summits, at an elevation of a thousand
feet or more, possess a tolerably luxuriant vegetation. This is
especially the case on the windward side, which first receives and
condenses 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, interrupted only 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 is every where covered by astunted
brushwood, which shows little signs of life. The dry and parched
surface, having been heated by the noonday sun, gave the air a close
and sultry feeling, like that from a stove: we fancied even the
bushes smelt unpleasantly. Although I diligently tried to collect
as many plants as possible, I succeeded in getting only ten kinds;
and such wretched-looking little weeds would have better become an
arctic, than an equatorial Flora.
The thin woods, which cover the lower parts of all the islands,
excepting where the lava has recently flowed, appear from a short
distance quite leafless, like the deciduous trees of the northern
hemisphere in winter. It was some time before I discovered, that not
only almost every plant was in full leaf, but that the greater number
were now in flower. After the period of heavy rains, the islands
are said to appear for a short time partially green. The only other
country, in which I have seen a vegetation with a character at all
approaching to this, is at the volcanic island of Fernando Noronha,
placed in many respects under similar conditions.
The natural history of this archipelago is very remarkable: it
seems to be a little world within itself; the greater number of its
inhabitants, both vegetable and animal, being found nowhere else.
As I shall refer to this subject again, I will only here remark, as
forming a striking character on first landing, that the birds are
strangers to man. So tame and unsuspecting were they, that they did
not even understand what was meant by stones being thrown at them;
and quite regardless of us, they approached so close that any number
might have been killed with a stick.
The Beagle sailed round Chatham Island, and anchored in several bays.
One night I slept on shore, on a part of the island where some black
cones--the former chimneys of the subterranean heated fluids--were
extraordinarily numerous. From one small eminence, I counted sixty of
these truncated hillocks, which were all surmounted by a more or less
perfect crater. The greater number consisted merely of a ring of red
scoræ, or slags, cemented together: and their height above the plain
of lava, was not more than from fifty to a hundred feet. From their
regular form, they gave the country a _workshop_ appearance, which
strongly reminded me of those parts of Staffordshire where the great
iron-foundries are most numerous.
The age of the various beds of lava was distinctly marked by the
comparative growth, or entire absence, of vegetation. Nothing can be
imagined more rough and horrid than the surface of the more modern
streams. These have been aptly compared to the sea petrified in
its most boisterous moments: no sea, however, would present such
irregular undulations, or would be traversed by such deep chasms.
All the craters are in an extinct condition; and although the age
of the different streams of lava could be so clearly distinguished,
it is probable they have remained so for many centuries. There is
no account in any of the old voyagers of any volcano on this island
having been seen in activity; yet since the time of Dampier (1684),
there must have been some increase in the quantity of vegetation,
otherwise so accurate a person would not have expressed himself
thus:--“Four or five of the easternmost islands are rocky, barren,
and hilly, producing neither tree, herb, nor grass, but a few dildoe
(cactus) trees, except by the sea-side.”[1] This description is at
present applicable only to the western islands, where the volcanic
forces are in frequent activity.
The day, on which I visited the little craters, 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 Cyclopian
scene. In my walk I met two large tortoises, each of which must
have weighed at least two hundred pounds. One was eating a piece of
cactus, and when I approached, it looked at me, and then quietly
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, appeared to my fancy like some antediluvian animals.
SEPTEMBER 23D.--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 on it. The inhabitants are between
two and three hundred in number: they nearly all consist of people of
colour, who have been banished for political crimes from the Republic
of the Equator (Quito is the capital of this state) to which these
islands belong. The settlement is placed about four and a half miles
inland, and at an elevation probably of a thousand feet. In the first
part of the road we passed through leafless thickets, as in Chatham
Island. Higher up, the wood gradually became greener; and immediately
we had crossed the ridge of the island, our bodies were cooled by the
fine southerly trade-wind, and our senses refreshed by the sight of a
green and thriving vegetation. 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 Chile.
The inhabitants, although complaining of poverty, gain, without much
trouble, the means of subsistence from the fertile soil. In the woods
there are many wild pigs and goats, but the main article of animal
food is derived from the tortoise. Their numbers in this island have
of course been greatly reduced, but the people yet reckon on two
days’ hunting supplying food for the rest of the week. It is said
that formerly single vessels have taken away as many as seven hundred
of these animals, and that the ship’s company of a frigate some years
since brought down two hundred to the beach in one day.
We staid at this island four days, during which time I collected many
plants and birds. One morning I ascended the highest hill, which has
an altitude of nearly 1800 feet. The summit consists of a broken-down
crater, thickly clothed with coarse grass and brushwood. Even in this
one island, I counted thirty-nine hills, each of which was terminated
by a more or less perfect circular depression.
SEPTEMBER 29TH.--We doubled the south-west extremity of Albermarle
Island, and the next day were nearly becalmed between it and
Narborough Island. Both are covered with immense streams of black
naked lava; which, having either flowed over the rims of the great
caldrons, or having burst forth from the smaller orifices on the
flanks, have in their descent spread over miles of the sea-coast.
On both of these islands eruptions are known occasionally to take
place; and in Albermarle we saw a small jet of smoke curling from the
summit of one of the more lofty craters. In the evening we anchored
in Bank’s Cove, in Albermarle Island.
When morning came, we found that the harbour in which we were at
anchor was formed by a broken-down crater, composed of volcanic
sandstone. After breakfast I went out walking. To the southward of
this first crater, there was another of similar composition, and
beautifully symmetrical. It was elliptic in form; the longer axis
being less than a mile, and its depth about 500 feet. The bottom was
occupied by a shallow lake, and in its centre 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, another species was
equally common. We saw several of the latter, some clumsily running
out of our way, and others shuffling into their burrows. I shall
presently describe in more detail the habits of both these reptiles.
OCTOBER 3D.--We sailed round the northern end of Albermarle Island.
Nearly the whole of this side is covered with recent streams of
dark-coloured lavas, and is studded with craters. I should think it
would be difficult to find in any other part of the world, an island
situated within the tropics, and of such considerable size (namely 75
miles long), so sterile and incapable of supporting life.
On the 8th we reached James Island.[2] Captain FitzRoy put Mr.
Bynoe, myself, and three others on shore, leaving with us a tent and
provisions, to wait there till the vessel returned from watering.
This was an admirable plan for the collections, as we had an entire
week of hard work. We found here a party of Spaniards, who had been
sent from Charles Island to dry fish, and to salt tortoise-meat.
At the distance of about six miles, and at the height of nearly 2000
feet, the Spaniards had erected a hovel 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. In the same manner as in the other islands, the lower region
is covered by nearly leafless bushes: but here many of them grow
to the size of trees. I measured several which were two feet in
diameter, and some even two feet nine inches. The upper region being
kept damp, from the moisture of the condensed clouds, supports a
green and flourishing vegetation. So damp was the ground, that there
were large beds of a coarse carex, 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 breastplate roasted (as the
Gauchos do _carne con cuero_), with the flesh attached to it, is very
good; and the young tortoises make excellent soup; but otherwise the
meat to my taste is very indifferent.
During another 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 sandstone crater, at the bottom
of which the salt-lake is situated. The water was only three or
four inches deep, and rested on a layer of beautifully crystallized
white salt. The lake was quite circular, and fringed with a border
of brightly green succulent plants: the precipitous walls of the
crater were also clothed with wood, so that the scene was 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 week on shore, 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°; but in the open air, in the wind and sun, at only
85°. The sand was extremely hot; the thermometer placed in some of
a brown colour immediately rose to 137°, and how much higher it
would have risen, I do not know, for it was not graduated above that
number. The _black_ sand felt much hotter, so that even in thick
boots it was disagreeable, on this account, to walk over it.
I will now offer a few general observations on the natural history of
these islands. I endeavoured to make as nearly a perfect collection
in every branch as time permitted. The plants have not yet been
examined, but Professor Henslow, who has kindly undertaken the
description of them, informs me that there are probably many new
species, and perhaps even some new genera. They all have an extremely
weedy character, and it would scarcely have been supposed, that they
had grown at an inconsiderable elevation directly under the equator.
In the lower and sterile parts, the bush, which from its minute brown
leaves chiefly gives the leafless appearance to the brushwood, is
one of the Euphorbiaceæ. In the same region an acacia and a cactus
(_Opuntia Galapageia_[3]), with large oval compressed articulations,
springing from a cylindrical stem, are in some parts common. These
are the only trees which in that part afford any shade. Near the
summits of the different islands, the vegetation has a very different
character; ferns and coarse grasses are abundant; and the commonest
tree is one of the Compositæ. Tree-ferns are not present. One of the
most singular characters of the Flora, considering the position of
this archipelago, is the absence of every member of the palm family.
Cocos Island, on the other hand, which is the nearest point of land,
takes its name from the great number of cocoa-nut trees on it. From
the presence of the Opuntias and some other plants, the vegetation
partakes more of the character of that of America than of any other
country.
Of mammalia a large kind of mouse forms a well-marked species. From
its large thin ears, and other characters, it approaches in form a
section of the genus, which is confined to the sterile regions of
South America. There is also a rat which Mr. Waterhouse believes is
probably distinct from the English kind; but I cannot help suspecting
that it is only the same altered by the peculiar conditions of its
new country.
In my collections from these islands, Mr. Gould considers that there
are twenty-six different species of land-birds. With the exception
of one, all probably are undescribed kinds, which inhabit this
archipelago, and no other part of the world. Among the waders and
waterfowl it is more difficult, without detailed comparison, to say
what are new. But a water-sail which lives near the summits of the
mountains, is undescribed, as perhaps is a Totanus and a heron. The
only kind of gull which is found among these islands, is also new;
when the wandering habits of this genus are considered, this is a
very remarkable circumstance. The species most closely allied to it,
comes from the Strait of Magellan. Of the other aquatic birds, the
species appear the same with well-known American birds.
The general character of the plumage of these birds is extremely
plain, and like the Flora possesses little beauty. Although the
species are thus peculiar to the archipelago, yet nearly all in their
general structure, habits, colour of feathers, and even tone of
voice, are strictly American. The following brief list will give an
idea of their kinds. 1st. A buzzard, having many of the characters of
Polyborus or Caracara; and in its habits not to be distinguished from
that peculiar South American genus; 2d. Two owls; 3d. Three species
of tyrant-flycatchers--a form strictly American. One of these appears
identical with a common kind (_Muscicapa coronata_? Lath.), which has
a very wide range, from La Plata throughout Brazil to Mexico; 4th. A
sylvicola, an American form, and especially common in the northern
division of the continent; 5th. Three species of mocking-birds,
a genus common to both Americas; 6th. A finch, with a stiff tail
and a long claw to its hinder toe, closely allied to a North
American genus; 7th. A swallow belonging to the American division
of that genus; 8th. A dove, like, but distinct from, the Chilian
species; 9th. A group of finches, of which Mr. Gould considers
there are thirteen species; and these he has distributed into four
new sub-genera. These birds are the most singular of any in the
archipelago. They all agree in many points; namely, in a peculiar
structure of their bill, short tails, general form, and in their
plumage. The females are gray or brown, but the old cocks jet-black.
All the species, excepting two, feed in flocks on the ground, and
have very similar habits. It is very remarkable that a nearly perfect
gradation of structure in this one group can be traced in the form
of the beak, from one exceeding in dimensions that of the largest
gros-beak, to another differing but little from that of a warbler. Of
the aquatic birds I have already remarked that some are peculiar to
these islands, and some common to North and South America.
We will now turn to the order of reptiles, which forms, perhaps, the
most striking feature in the zoology of these islands. The species
are not numerous, but the number of individuals of each kind, is
extraordinarily great. There is one kind both of the turtle and
tortoise; of lizards four; and of snakes about the same number.
I will first describe the habits of the tortoise (_Testudo Indicus_)
which has been so frequently alluded to. These animals are found,
I believe, in all the islands of the Archipelago; certainly in the
greater number. They frequent in preference the high damp parts,
but likewise inhabit the lower and arid districts. I have already
mentioned[4] proofs, from the numbers which have been taken in a
single day, how very numerous they must be. Some individuals grow
to an immense size: Mr. Lawson, an Englishman, who had at the time
of our visit charge 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, chiefly feed 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, that hangs in tresses
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 elevation. The tortoises, therefore, which frequent
the lower districts, when thirsty, are obliged to travel from a
long distance. Hence broad and well-beaten paths radiate off in
every direction from the wells even 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 the well-chosen tracks. Near the
springs it was a curious spectacle to behold many of these great
monsters; 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,
it buries its head in the water above its 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 in their accounts respecting the frequency of these
visits. The animal probably regulates them according to the nature
of the food which it has consumed. It is, however, certain, that
tortoises can subsist even on those 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, the urinary bladder of these animals is 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, by killing a tortoise, and if the bladder is full,
drinking its contents. In one I saw killed, the fluid was quite
limpid, and had only a _very slightly_ bitter taste. The inhabitants,
however, always drink first the water in the pericardium, which is
described as being best.
The tortoises, when moving towards any definite point, travel by
night and day, and arrive at their journey’s end much sooner than
would be expected. The inhabitants, from observations on marked
individuals, consider that they can move a distance of about eight
miles in two or three days. One large tortoise, which I watched, I
found walked at the rate of sixty yards in ten minutes, that is 360
in the hour, or four miles a day,--allowing also 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 such times; so that when the
people hear this noise, they know 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
hollow. Mr. Bynoe found seven placed in a line in a fissure. The egg
is white and spherical; one which I measured was seven inches and
three-eighths in circumference. The young animals, as soon as they
are hatched, fall a prey in great numbers to the buzzard, with the
habits of the Caracara. The old ones seem generally to die from
accidents, as from falling down precipices. At least several of the
inhabitants told me, they had never found one dead without some such
apparent 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, upon giving a few raps on the hinder part
of the shell, 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 tortoises, it is
not sufficient to turn them like turtle, for they are often able to
regain their upright position.
It was confidently asserted, that the tortoises coming from different
islands in the archipelago were slightly different in form; and
that in certain islands they attained a larger average size than
in others. Mr. Lawson maintained that he could at once tell from
which island any one was brought. Unfortunately, the specimens which
came home in the Beagle were too small to institute any certain
comparison. This tortoise, which goes by the name of _Testudo
Indicus_, is at present found in many parts of the world. It is the
opinion of Mr. Bell, and some others who have studied reptiles,
that it is not improbable that they all originally came from this
archipelago. When it is known how long these islands have been
frequented by the bucaniers, and that they constantly took away
numbers of these animals alive, it seems very probable that they
should have distributed them in different parts of the world. If
this tortoise does not originally come from these islands, it is a
remarkable anomaly; inasmuch as nearly all the other land inhabitants
seem to have had their birthplace here.
Of lizards there are four or five species; two probably belong to
the South American genus Leiocephalus, and two to Amblyrhyncus. This
remarkable genus was characterized by Mr. Bell,[5] from a stuffed
specimen sent from Mexico, but which I conceive there can be little
doubt originally came through some whaling ship from these islands.
The two species agree pretty closely in general appearance; but one
is aquatic and the other terrestrial in its habits. Mr. Bell thus
concludes his description of _Amb. cristatus_: “On a comparison of
this animal with the true Iguanas, the most striking and important
discrepancy is in the form of the head. Instead of the long, pointed,
narrow muzzle of those species, we have here a short, obtusely
truncated head, not so long as it is broad, the mouth consequently
only capable of being opened to a very short space. These
circumstances, with the shortness and equality of the toes, and the
strength and curvature of the claws, evidently indicate some striking
peculiarity in its food and general habits, on which, however, in the
absence of all certain information, I shall abstain from offering
any conjecture.” The following account of these two lizards, will, I
think, show with what judgment Mr. Bell foresaw a variation in habit,
accompanying change in structure.
First for the aquatic kind (_Amb. cristatus_). This lizard is
extremely common on all the islands throughout the Archipelago.
It lives exclusively on the rocky sea-beaches, and is never
found, at least I never saw one, even ten yards inshore. 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: I have seen a
large one which weighed twenty pounds. On the island of Albemarle
they seem to grow to a greater size than on any other. These lizards
were occasionally seen some hundred yards from the shore swimming
about; and Captain Collnett, in his Voyage, says, “they go out to
sea in shoals to fish.” With respect to the object, I believe he
is mistaken; but the fact stated on such good authority cannot
be doubted. When in the water the animal swims with perfect ease
and quickness, by a serpentine movement of its body and flattened
tail,--the legs, during this time, 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, the lizard was quite active.
Their limbs and strong claws are admirably adapted for crawling over
the rugged and fissured masses of lava, which every where 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 stomach of several, and in each case found it largely
distended with minced sea-weed, of that kind which grows in thin
foliaceous expansions of a bright green or 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 is the
case, the object of these animals occasionally going out to sea is
explained. The stomach contained nothing but the sea-weed. Mr. Bynoe,
however, found a piece of a 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 the certain 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. From this cause, 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
tail 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. One day I carried one to a deep pool left by the
retiring tide, and threw it in several times as far as I was able.
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 margin, but still being under water,
it either 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
commenced. I asked several of the inhabitants if they knew where it
laid its eggs: they said, that although well acquainted with the eggs
of the other kind, they had not the least knowledge of the manner in
which this species is propagated;--a fact, considering how common an
animal this lizard is, not a little extraordinary.
We will now turn to the terrestrial species (_Amb. subcristatus_ of
Gray).[6] This species, differently from the last, is confined to
the central islands of the Archipelago, namely to Albemarle, James,
Barrington, and Indefatigable. To the southward, in Charles, Hood,
and Chatham islands, and to the northward, in Towers, Bindloes, and
Abington, I neither saw nor heard of any. It would appear as if this
species had been created in the centre of the Archipelago, and thence
had been dispersed only to a certain distance.
In the central islands they inhabit both the higher and damp, as well
as the lower and sterile parts; but in the latter they are much the
most numerous. 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 tent. These lizards, like their brothers the sea-kind,
are ugly animals; and from their low facial angle have a singularly
stupid appearance. In size perhaps they are a little inferior to the
latter, but several of them weighed between ten and fifteen pounds
each. The colour of their belly, front legs, and head (excepting
the crown which is nearly white), is a dirty yellowish-orange: the
back is a brownish-red, which in the younger specimens is darker. 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 with closed eyes, and
hind legs spread out on the parched soil.
They inhabit burrows; which they sometimes excavate between fragments
of lava, but more generally on level patches of the soft volcanic
sandstone. 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 excavating its burrow,
alternately works 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. This 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; and if
frightened they rush to them with a most awkward gait. Except when
running down hill, they cannot move very fast; which appears chiefly
owing to 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
the ground, down go their tails, and off they shuffle as quickly as
they can. I have frequently observed small muscivorous lizards, when
watching any thing, nod their heads in precisely the same manner; but
I do not at all know for what purpose. If this Amblyrhyncus 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 have sometimes
thrown a piece to two or three when together; and it was amusing
enough to see each trying to seize and carry it away in its mouth,
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 in request among all the
animals of the lower region), whilst a lizard was eating at the
other; 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 a species
of 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 one or a pair quietly browsing, whilst seated on a
branch several feet above the ground.
The meat of these animals when cooked is white, and by those whose
stomachs rise above all prejudices, it is relished as very good
food. Humboldt has remarked that in intertropical South America, all
lizards which inhabit _dry_ regions are esteemed delicacies for the
table. The inhabitants say, that those inhabiting the damp region
drink water, but that the others do not travel up for it from the
sterile country like the tortoises. At the time of our visit, the
females had within their bodies numerous large elongated eggs. These
they lay in their burrows, and the inhabitants seek them for food.
These two species of Amblyrhyncus agree, as I have already stated,
in general structure, and in many of their habits. Neither have that
rapid movement, so characteristic of true Lacerta and Iguana. They
are both herbivorous, although the kind of vegetation consumed in
each case 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 tempted to
suppose this is an adaptation to their herbivorous appetites. It is
very interesting thus to find a well-characterized genus, having its
aquatic and terrestrial species, belonging to so confined a portion
of the world. The former species is by far the most remarkable,
because it is the only existing Saurian, which can properly be said
to be a maritime animal. I should perhaps have mentioned earlier,
that in the whole archipelago, there is only one rill of fresh water
that reaches the coast; yet these reptiles frequent the sea-beaches,
and no other parts in all the islands. Moreover, there is no existing
lizard, as far as I am aware, excepting this Amblyrhyncus, that feeds
exclusively on aquatic productions. If, however, we refer to epochs
long past, we shall find such habits common to several gigantic
animals of the Saurian race.
To conclude with the order of reptiles. Of snakes there are several
species, but all harmless. Of toads and frogs there are none. I was
surprised at this, considering how well the temperate and damp woods
in the elevated parts appeared adapted for their habits. It recalled
to my mind the singular statement made by Bory St. Vincent,[7]
namely, that none of this family are to be found on the volcanic
islands in the great oceans. There certainly appears to be some
foundation for this observation; which is the more remarkable, when
compared with the case of lizards, which are generally among the
earliest colonists of the smallest islet. It may be asked, whether
this is not owing to the different facilities of transport through
salt-water, of the eggs of the latter protected by a calcareous coat,
and of the slimy spawn of the former?
As I at first observed, these islands are not so remarkable for
the number of species of reptiles, as for that of individuals; when
we remember the well-beaten paths made by the many hundred great
tortoises--the warrens of the terrestrial Amblyrhyncus--and the
groups of the aquatic species basking on the coast-rocks--we must
admit that there is no other quarter of the world, where this order
replaces the herbivorous mammalia in so extraordinary a manner. It
is worthy of observation by the geologist (who will probably refer
back in his mind to the secondary periods, when the Saurians were
developed with dimensions, which at the present day can be compared
only to the cetaceous mammalia), 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: I took great pains in collecting the
insects, but I was surprised to find, even in the high and damp
region, how exceedingly few they were in number. The forests of
Tierra del Fuego are certainly much more barren; but with that
exception I never collected in so poor a country. In the lower and
sterile land I took seven species of Heteromera, and a few other
insects; but in the fine thriving woods towards the centre of the
islands, although I perseveringly swept under the bushes during
all kinds of weather, I obtained only a few minute Diptera and
Hymenoptera. Owing to this scarcity of insects, nearly all the birds
live in the lower country; and the part which any one would have
thought much the most favourable for them, is frequented only by
a few of the small tyrant-flycatchers. I do not believe a single
bird, excepting the water-rail, is confined to the damp region. Mr.
Waterhouse informs me that nearly all the insects belong to European
forms, and that they do not by any means possess an equatorial
character. I did not take a single one of large size, or of bright
colours. This last observation applies equally to the birds and
flowers. It is worthy of remark, that the only land-bird with bright
colours, is that species of tyrant-flycatcher, which seems to be
a wanderer from the continent. Of shells, there are a considerable
number of land kinds, all of which, I believe are confined to this
archipelago. Even of marine species, a large proportion were not
known, before the collection made by Mr. Cuming on these islands was
brought to England.
I will not here attempt to come to any definite conclusions, as the
species have not been accurately examined; but we may infer, that,
with the exception of a few wanderers, the organic beings found on
this archipelago are peculiar to it; and yet that their general form
strongly partakes of an American character. It would be impossible
for any one accustomed to the birds of Chile and La Plata to be
placed on these islands, and not to feel convinced that he was, as
far as the organic world was concerned, on American ground. This
similarity in type, between distant islands and continents, while
the species are distinct, has scarcely been sufficiently noticed.
The circumstance would be explained, according to the views of some
authors, by saying that the creative power had acted according to the
same law over a wide area.
It has been mentioned, that the inhabitants can distinguish the
tortoises, according to the islands whence they are brought. I was
also informed that many of the islands possess trees and plants which
do not occur on the others. For instance the berry-bearing tree,
called Guyavita, which is common on James Island, certainly is not
found on Charles Island, though appearing equally well fitted for it.
Unfortunately, I was not aware of these facts till my collection was
nearly completed: it never occurred to me, that the productions of
islands only a few miles apart, and placed under the same physical
conditions, would be dissimilar. I therefore did not attempt to make
a series of specimens from the separate islands. It is the fate of
every voyager, when he has just discovered what object in any place
is more particularly worthy of his attention, to be hurried from it.
In the case of the mocking-bird, I ascertained (and have brought
home the specimens) that one species (_Orpheus trifasciatus_, Gould)
is exclusively found in Charles Island; a second (_O. parvulus_) on
Albemarle Island; and a third (_O. melanotus_) common to James and
Chatham Islands. The two last species are closely allied, but the
first would be considered by every naturalist as quite distinct. I
examined many specimens in the different islands, and in each the
respective kind was _alone_ present. These birds agree in general
plumage, structure, and habits; so that the different species replace
each other in the economy of the different islands. These species
are not characterized by the markings on the plumage alone, but
likewise by the size and form of the bill, and other differences. I
have stated, that in the thirteen species of ground-finches, a nearly
perfect gradation may be traced, from a beak extraordinarily thick,
to one so fine, that it may be compared to that of a warbler. I very
much suspect, that certain members of the series are confined to
different islands; therefore, if the collection had been made on any
_one_ island, it would not have presented so perfect a gradation. It
is clear, that if several islands have each their peculiar species
of the same genera, when these are placed together, they will have
a wide range of character. But there is not space in this work, to
enter on this curious subject.
Before concluding my account of the zoology of these islands,
I must describe more in detail the tameness of the birds. This
disposition is common to all the terrestrial species; namely, to the
mocking-birds, the finches, sylvicolæ, tyrant-flycatchers, doves, and
hawks. There is not one which will not approach sufficiently near
to be killed with a switch, and sometimes, as I have myself tried,
with a cap or hat. A gun is here almost superfluous; for with the
muzzle of one I pushed a hawk off the branch of a tree. One day a
mocking-bird alighted on the edge of a pitcher (made of the shell
of a tortoise), which I held in my hand whilst lying down. It began
very quietly to sip the water, and allowed me to lift it with the
vessel from the ground. 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[8] (in the year 1684)
says that the “Turtle-doves were so tame that they would often alight
upon 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[9] (in the same
year) also says that a man in a morning’s walk might kill six or
seven dozen of these birds. At present, although certainly very tame,
they do not alight on people’s arms; nor do they suffer themselves
to be killed in such numbers. It is surprising that the change has
not been greater; for these islands during the last hundred and fifty
years, have been frequently visited by bucaniers and whalers; and the
sailors, wandering through the woods in search of tortoises, always
take delight in knocking down the little birds.
These birds, although much persecuted, do not become wild in a short
time: 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 he had constantly been in the habit of waiting there for the
same purpose. We must conclude that the birds, not having as yet
learnt that man is a more dangerous animal than the tortoise, or the
amblyrhyncus, disregard us, in the same manner as magpies in England
do the cows and horses grazing in the fields.
The Falkland Islands offer a second instance of this disposition
among its birds. The extraordinary tameness of the dark-coloured
Furnarius has been remarked by Pernety, Lesson, and other voyagers.
It is not, however, peculiar to that bird: the Caracara, snipe,
upland and lowland goose, thrush, Emberiza, and even some true
hawks, are all more or less tame. Both hawks and foxes are present;
and as the birds are so tame, we may infer that the absence of
all rapacious animals at the Galapagos, is not the cause of their
tameness there. The geese at the Falklands, by the precaution they
take in building on the islets, show 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 the waterfowl,
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 is able to carry home;
whereas in Tierra del Fuego, it is nearly as difficult to kill one,
as it is in England of the common wild species.
In the time of Pernety[10] (1763), all the birds appear to have been
much tamer than at present. Pernety states that the Furnarius 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 quickly at the Falklands than at the latter place, and they have
had proportionate means of experience; for besides frequent visits
from vessels, the islands have been at intervals colonized during the
whole period.
Even formerly, when all the birds were so tame, by Pernety’s account
it was impossible to kill the black-necked swan. It is rather an
interesting fact, that this is a bird of passage, and therefore
brings with it the wisdom learnt in foreign countries.
I have not met with any account of the _land_ birds being so tame,
in any other quarter of the world, as at the Galapagos and Falkland
Islands. And it may be observed that of the few archipelagoes of
any size, which when discovered were uninhabited by man, these two
are among the most important. From the foregoing statements 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 on any general degree of caution arising from other sources
of danger; secondly, that it is not acquired by them 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 instincts becoming hereditary; but with those in
a state of nature, it is more rare to discover instances of such
acquired knowledge. In regard to the wildness of birds towards men,
there is no other way of accounting for it. Few young birds in
England have been injured by man, yet all are afraid of him: many
individuals, on the other hand, both at the Galapagos and at the
Falklands, have been injured, but yet have not learned that salutary
dread. 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 aborigines become adapted to the stranger’s craft or power.
FOOTNOTES:
[1] Dampier’s Voyage, vol. i., p. 101.
[2] Both Charles and James Islands take their names from the Stuarts.
See Cowley’s Voyage in 1684.
[3] Magazine of Zoology and Botany, vol. i., p. 466.
[4] Dampier says, “The land-turtles are here so numerous, that five
or six hundred men might subsist on them for several months without
any other sort of provisions. They are so extraordinarily large and
fat, and so sweet, that no pullet eats more pleasantly.”--Vol. i., p.
110.
[5] Zoological Journal, July, 1835.
[6] Briefly characterized by Mr. Gray in the Zoological Miscellany,
from a specimen badly stuffed; from which cause one of its most
important characters (the rounded tail, compared to the flattened one
of the aquatic kind) was overlooked. Captain FitzRoy has presented
some fine specimens of both species to the British Museum. I cannot
omit here returning my thanks to Mr. Gray, for the kind manner in
which he has afforded me every facility as often as I have visited
the British Museum.
[7] Voyage aux quatre Iles d’Afrique.
[8] Cowley’s Voyage, p. 10, in Dampier’s Collection of Voyages.
[9] Dampier’s Voyage, vol. i., p. 103.
[10] Pernety, Voyage aux Iles Malouines, vol. ii., p. 20.