GALAPAGOS ARCHIPELAGO
The whole group volcanic—Number 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 organisation—Differences in the
species or races on different islands—Tameness of the birds—Fear of man
an acquired instinct.
_September_ 15_th._—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
and scoriæ, 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.
Galapagos Archipelago
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 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, sunburnt brushwood, which
shows little signs of life. The dry and parched surface, being heated
by the noonday 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 Euphorbiaceæ: 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 scoriæ 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.
23_rd._—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_ 29_th._—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_ 8_th._—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 crystallised, 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°; 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 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 these 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°, 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 coloured, 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 above 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 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.
Finches from Galapagos Archipelago
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-flycatchers (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 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.
[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.
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?
[2] This is stated by Dr. Günther (_Zoolog. Soc._ Jan. 24th, 1859) to
be a peculiar species, not known to inhabit any other country.
[3] _Voyage aux Quatres 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.
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
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,
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 tortoises, 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.
Amblyrhynchus Cristatus
The Amblyrhynchus, a remarkable genus of lizards, is confined to this
archipelago; there are two species, resembling each other in general
form, one being terrestrial and the other aquatic. This latter species
(A. cristatus) was first characterised 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 (Ulvæ), 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. 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 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-characterised 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 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 Harpalidæ, two to the Hydrophilidæ, 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.
[4] _Ann. and Mag. of Nat. Hist.,_ vol. xvi, p. 19.
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 together 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, page 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 185 (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
Compositæ, 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 undoubted
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 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
of 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 organisation? 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 representative 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.
[5] _Voyage in the U.S. ship Essex,_ vol. i, p. 215.
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 Leguminosæ, moreover, have as
yet been only approximately worked out:—
Name Total No. of No. of No. No. of Species
of No. of Species found Species confined confined to the
Island Species in other confined to the one Galapagos
parts of to the Island Archipelago,
the world Galapagos but found on
Archipelago more than the
one Island
James Island 71 33 38 30 8
Albermarle Island 46 18 26 22 4
Chatham Island 32 16 16 12 4
Charles Island 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 Compositæ, 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
Compositæ 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 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 colonised 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 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 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 colonised 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 and 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, but 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.
[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!
[Illustration: Opuntia Galapageia]
[Illustration: Ava or kava (Macropiper Methysticum), Tahiti]