BIOGRAPHY OF THE VIZCACHA.
_(Lagostomus Trichodactylus.)_
The vizcacha is perhaps the most characteristic of the South American
Rodentia, [Footnote: "According to Mr. Waterhouse, of all rodents the
vizcacha is most nearly related to marsupials; but in the points in
which it approaches this order its relations are general, that is, not
to any one marsupial species more than to another. As these points of
affinity are believed to be real and not merely adaptive, they must be
due in accordance with our view to inheritance from a common progenitor.
Therefore wo must suppose either that all rodents, including the
vizcacha, branched off from some ancient marsupial, which will naturally
have been more or less intermediate in character with respect to all
existing marsupials; or, that both lodents and marsupials branched off
from a common progenitor. ... On either view we must suppose that the
vizcacha has retained, by inheritance, more of the characters of its
ancient progenitor than have other rodents."--DARWIN; _Origin of
Species._] while its habits, in some respects, are more interesting than
those of any other rodent known: it is, moreover, the most common mammal
we have on the pampas; and all these considerations have induced me to
write a very full account of its customs. It is necessary to add that
since the following pages were written at my home on the pampas a great
war of extermination has been waged against this animal by the
landowners, which has been more fortunate in its results--or unfortunate
if one's sympathies are with the vizcacha--than the war of the
Australians against their imported rodent--the smaller and more prolific
rabbit.
The vizcachas on the pampas of Buenos Ayres live in societies, usually
numbering twenty or thirty members. The village, which is called
Vizcachera, is composed of a dozen or fifteen burrows or mouths; for one
entrance often serves for two or more distinct holes. Often, where the
ground is soft, there are twenty or thirty or more burrows in an old
vizcachera; but on stony, or "tosca" soil even an old one may have no
more than four or five burrows. They are deep wide-mouthed holes, placed
very close together, the entire village covering an area of from one
hundred to two hundred square feet of ground.
The burrows vary greatly in extent; and usually in a vizcachera there
are several that, at a distance of from four to six feet from the
entrance, open into large circular chambers. From these chambers other
burrows diverge in all directions, some running horizontally, others
obliquely downwards to a maximum depth of six feet from the surface:
some of these burrows or galleries communicate with those of other
burrows. A vast amount of loose earth is thus brought up, and forms a
very irregular mound, fifteen to thirty inches above the surrounding
level.
It will afford some conception of the numbers of these vizcacheras on
the settled pampas when I say that, in some directions, a person might
ride five hundred miles and never advance half a mile without seeing one
or more of them. In districts where, as far as the eye can see, the
plains are as level and smooth as a bowling-green, especially in winter
when the grass is close-cropped, and where the rough giant-thistle has
not sprung up, these mounds appear like brown or dark spots on a green
surface. They are the only irregularities that occur to catch the eye,
and consequently form an important feature in the scenery. In some
places they are so near together that a person on horseback may count a
hundred of them from one point of view.
The sites of which the vizcacha invariably makes choice to work on, as
well as his manner of burrow-ing, adapt him peculiarly to live and
thrive on the open pampas. Other burrowing species seem always to fix
upon some spot where there is a bank or a sudden depression in the soil,
or where there is rank herbage, or a bush or tree, about the roots of
which to begin their kennel. They are averse to commence digging on a
clear level surface, either because it is not easy for them where they
have nothing to rest their foreheads against while scratching, or
because they possess a wary instinct that impels them to place the body
in concealment whilst working on the surface, thus securing the
concealment of the burrow after it is made. Certain it is that where
large hedges have been planted on the pampas, multitudes of opossums,
weasels, skunks, armadillos, &c., come and make their burrows beneath
them; and where there are no hedges or trees, all these species make
their kennels under bushes of the perennial thistle, or where there is a
shelter of some kind. The vizcacha, on the contrary, chooses an open
level spot, the cleanest he can find to burrow on. The first thing that
strikes the observer when viewing the vizcachera closely is the enormous
size of the entrance of the burrows, or, at least, of several of the
central ones in the mound; for there are usually several smaller outside
burrows. The pit-like opening to some of these principal burrows is
often four to six feet across the mouth, and sometimes deep enough for a
tall man to stand up waist-deep in. How these large entrances can be
made on a level surface may be seen when the first burrow or burrows of
an incipient vizcachera are formed. It is not possible to tell what
induces a vizcacha to be the founder of a new community; for they
increase very slowly, and furthermore are extremely fond of each other's
society; and it is invariably one individual that leaves his native
village to found a new and independent one. If it were to have better
pasture at hand, then he would certainly remove to a considerable
distance; but he merely goes from forty to fifty or sixty yards off to
begin his work. Thus it is that in desert places, where these animals
are rare, a solitary vizcachera is never seen; but there are always
several close together, though there may be no others on the surrounding
plain for leagues. When the vizcacha has made his habitation, it is but
a single burrow, with only himself for an inhabitant, perhaps for many
months. Sooner or later, however, others join him: and these will be the
parents of innumerable generations; for they construct no temporary
lodging-place, as do the armadillos and other species, but their
posterity continues in the quiet possession of the habitations
bequeathed to it; how long, it is impossible to say. Old men who have
lived all their lives in one district remember that many of the
vizcacheras around them existed when they were children. It is
invariably a male that begins a new village, and makes his burrow in the
following manner, though he does not always observe the same method. He
works very straight into the earth, digging a hole twelve or fourteen
inches wide, but not so deep, at an angle of about 25 degrees with the
surface. But after he has progressed inwards a few feet, the vizcacha is
no longer satisfied with merely scattering away the loose earth he
fetches up, but cleans it away so far in a straight line from the
entrance, and scratches so much on this line (apparently to make the
slope gentler), that he soon forms a trench a foot or more in depth, and
often three or four feet in length. Its use is, as I have inferred, to
facilitate the conveying of the loose earth as far as possible from the
entrance of the burrow. But after a while the animal is unwilling that
it should accumulate even at the end of this long passage; he therefore
proceeds to make two additional trenches, that form an acute, sometimes
a right angle, converging into the first, so that when the whole is
completed it takes the form of a capital Y.
These trenches are continually deepened and lengthened as the burrow
progresses, the angular segment of earth between them, scratched away,
until by degrees it has been entirely conveyed off, and in its place is
the one deep great unsymmetrical mouth I have already described. There
are soils that will not admit of the animals working in this manner.
Where there are large cakes of "tosca" near the surface, as in many
localities on the southern pampas, the vizcacha makes its burrow as best
he can, and without the regular trenches. In earths that crumble much,
sand or gravel, he also works under great disadvantages.
The burrows are made best in the black and red moulds of the pampas; but
even in such soils the entrances of many burrows are made differently.
In some the central trench is wanting, or is so short that there appear
but two passages converging directly into the burrow; or these two
trenches may be so curved inwards as to form the segment of a circle.
Many other forms may also be noticed, but usually they appear to be only
modifications of the most common Y-shaped system.
As I have remarked that its manner of burrowing has peculiarly adapted
the vizcacha to the pampas, it may be asked what particular advantage a
species that makes a wide-mouthed burrow possesses over those that
excavate in the usual way. On a declivity, or at the base of rocks or
trees, there would be none; but on the perfectly level and shelterless
pampas, the durability of the burrow, a circumstance favourable to the
animal's preservation, is owing altogether to its being made in this
way, and to several barrows being made together. The two outer trenches
diverge so widely from the mouth that half the earth brought out is cast
behind instead of before it, thus creating a mound of equal height about
the entrance, by which it is secured from water during great rainfalls,
while the cattle avoid treading over the great pit-like entrances. But
the burrows of the dolichotis, armadillo, and other species, when made
on perfectly level ground, are soon trod on and broken in by cattle; in
summer they are choked up with dust and rubbish; and, the loose earth
having all been thrown up together in a heap on one side, there is no
barrier to the water which in every great rainfall flows in and
obliterates the kennel, drowning or driving out the tenant.
I have been minute in describing the habitations of the vizcacha, as I
esteem the subject of prime importance in considering the zoology of
this portion of America. The vizcacha does not benefit himself alone by
his perhaps unique style of burrowing; but this habit has proved
advantageous to several other species, and has been so favourable to two
of our birds that they are among the most common species found here,
whereas without these burrows they would have been exceedingly rare,
since the natural banks in which they breed are scarcely found anywhere
on the pampas. I refer to the Minera (Geositta cunicularia), which makes
its breeding-holes in the bank-like sides of the vizcacha's burrow, and
to the little swallow (Atticora cyanoleuca) which breeds in these
excavations when forsaken by the Minera. Few old vizcacheras are seen
without some of these little parasitical burrows in them.
Birds are not the only beings in this way related to the vizcachas: the
fox and the weasel of the pampas live almost altogether in them. Several
insects also frequent these burrows that are seldom found anywhere else.
Of these the most interesting are:--a large predacious nocturnal bug,
shining black, with red wings; a nocturnal Cicindela, a beautiful
insect, with dark green striated wing-cases and pale red legs; also
several diminutive wingless wasps. Of the last I have counted six
species, most of them marked with strongly contrasted colours, black,
red, and white. There are also other wasps that prey on the spiders
found on the vizcachera. All these and others are so numerous on the
mounds that dozens of them might there be collected any summer day; but
if sought for in other situations they are exceedingly rare. If the dry
mound of soft earth which the vizcacha elevates amidst a waste of humid,
close-growing grass is not absolutely necessary to the existence of all
these species, it supplies them with at least one favourable condition,
and without doubt thereby greatly increases their numbers: they, too,
whether predacious or preyed on, have so many relations with other
outside species, and these again with still others, that it would be no
mere fancy to say that probably hundreds of species are either directly
or indirectly affected in their struggle for existence by the
vizcacheras so abundantly sprinkled over the pampas.
In winter the vizcachas seldom leave their burrows till dark, but in
summer come out before sunset; and the vizcachera is then a truly
interesting spectacle. Usually one of the old males first appears, and
sits on some prominent place on the mound, apparently in no haste to
begin his evening meal. When approached from the front he stirs not, but
eyes the intruder with a bold indifferent stare. If the person passes to
one side, he deigns not to turn his head.
Other vizcachas soon begin to appear, each one quietly taking up his
station at his burrow's mouth, the females, known by their greatly
inferior size and lighter grey colour, sitting upright on their
haunches, as if to command a better view, and indicating by divers
sounds and gestures that fear and curiosity struggles in them for
mastery; for they are always wilder and sprightlier in their motions
than the males. With eyes fixed on the intruder, at intervals they dodge
the head, emitting at the same time an internal note with great
vehemence; and suddenly, as the danger comes nearer, they plunge
simultaneously, with a startled cry, into their burrows. But in some
curiosity is the strongest emotion; for, in spite of their fellow's
contagious example, and already half down the entrance, again they start
up to scrutinize the stranger, and will then often permit him to walk
within five or six paces of them.
Standing on the mound there is frequently a pair of burrowing owls
(Pholeoptynx cunicularia). These birds generally make their own burrows
to breed in, or sometimes take possession of one of the lesser outside
burrows of the village; but their favourite residence, when not engaged
in tending their eggs or young, is on the vizcachera. Here a pair will
sit all day; and I have often remarked a couple close together on the
edge of the burrow; and when the vizcacha came out in the evening,
though but a hand's breadth from them, they did not stir, nor did he
notice them, so accustomed are these creatures to each other. Usually a
couple of the little burrowing Geositta are also present. They are
lively creatures, running with great rapidity about the mound and bare
space that surrounds it, suddenly stopping and jerking their tails in a
slow deliberate manner, and occasionally uttering their cry, a trill, or
series of quick short clear notes, resembling somewhat the shrill
excessive laughter of a child. Among the grave, stationary vizcachas, of
which they take no heed, perhaps half a dozen or more little swallows
(Atticora cyanoleuca) are seen, now clinging altogether to the bank-like
entrance of a burrow, now hovering over it in a moth-like manner, as if
uncertain where to alight, and anon sweeping about in circles, but never
ceasing their low and sorrowful notes.
The vizcachera with all its incongruous inhabitants thus collected upon
it is to a stranger one of the most novel sights the pampas afford.
The vizcacha appears to be a rather common species over all the
extensive Argentine territory; but they are so exceedingly abundant on
the pampas inhabited by man, and comparatively so rare in the desert
places I have been in, that I was at first much surprised at finding
them so unequally distributed. I have also mentioned that the vizcacha
is a tame familiar creature. This is in the pastoral districts, where
they are never disturbed; but in wild regions, where he is scarce, he is
exceedingly wary, coming forth long after dark, and plunging into his
burrow on the slightest alarm, so that it is a rare thing to get a sight
of him. The reason is evident enough; in desert regions the vizcacha has
several deadly enemies in the larger rapacious mammals. Of these the
puma or lion (Felis concolor) is the most numerous, as it is also the
swiftest, most subtle, and most voracious; for, as regards these traits,
the jaguar (F. onca) is an inferior animal. To the insatiable bloody
appetite of this creature nothing comes amiss; he takes the male ostrich
by surprise, and slays that wariest of wild things on his nest; He
captures little birds with the dexterity of a cat, and hunts for diurnal
armadillos; he comes unawares upon the deer and huanaco, and, springing
like lightning on them, dislocates their necks before their bodies touch
the earth. Often after he has thus slain them, he leaves their bodies
untouched for the Polyborus and vulture to feast on, so great a delight
does he take in destroying life. The vizcacha falls an easy victim to
this subtle creature; and it is not to be wondered at that it becomes
wild to excess, and rare in regions hunted over by such an enemy, even
when all other conditions are favourable to its increase. But as soon
as these wild regions are settled by man the pumas are exterminated, and
the sole remaining foe of the vizcacha is the fox, comparatively an
insignificant one.
The fox takes up his residence in a vizcachera, and succeeds, after
some quarrelling (manifested in snarls, growls, and other subterranean
warlike sounds), in ejecting the rightful owners of one of the burrows,
which forthwith becomes his. Certainly the vizcachas are not much
injured by being compelled to relinquish the use of one of their kennels
for a season or permanently; for, if the locality suits him, the fox
remains with them always. Soon they grow accustomed to the unwelcome
stranger; he is quiet and unassuming in demeanour, and often in the
evening sits on the mound in their company, until they regard him with
the same indifference they do the burrowing owl. But in spring, when the
young vizcachas are large enough to leave their cells, then the fox
makes them his prey; and if it is a bitch fox, with a family of eight or
nine young to provide for, she will grow so bold as to hunt her helpless
quarry from hole to hole, and do battle with the old ones, and carry off
the young in spite of them, so that all the young animals in the village
are eventually destroyed. Often when the young foxes are large enough to
follow their mother, the whole family takes leave of the vizcachera
where such cruel havoc has been made to settle in another, there to
continue their depredations. But the fox has ever a relentless foe in
man, and meets with no end of bitter persecutions; it is consequently
much more abundant in desert or thinly settled districts than in such as
are populous, so that in these the check the vizcachas receive from the
foxes is not appreciable.
The abundance of cattle on the pampas has made it unnecessary to use the
vizcacha as an article of food. His skin is of no value; therefore man,
the destroyer of his enemies, has hitherto been the greatest benefactor
of his species. Thus they have been permitted to multiply and spread
themselves to an amazing extent, so that the half-domestic cattle on the
pampas are not nearly so familiar with man, or so fearless of his
presence as are the vizcachas. It is not that they do him no injury, but
because they do it indirectly, that they have so long enjoyed immunity
from persecution. It is amusing to see the sheep-farmer, the greatest
sufferer from the vizcachas, regarding them with such indifference as to
permit them to swarm on his "run," and burrow within a stone's throw of
his dwelling with impunity, and yet going a distance from home to
persecute with unreasonable animosity a fox, skunk, or opossum on
account of the small annual loss it inflicts on the poultry-yard. That
the vizcacha has comparatively no adverse conditions to war with
wherever man is settled is evident when we consider its very slow rate
of increase, and yet see them in such incalculable numbers. The female
has but one litter in the year of two young, sometimes of three. She
becomes pregnant late in April, and brings forth in September; the
period of gestation is, I think, rather less than five months.
The vizcacha is about two years growing. A full-sized male measures to
the root of the tail twenty-two inches, and weighs from fourteen to
fifteen pounds; the female is nineteen inches in length, and her
greatest weight nine pounds. Probably it is a long-lived, and certainly
it is a very hardy animal. Where it has any green substance to eat it
never drinks water; but after a long summer drought, when for months it
has subsisted on bits of dried thistle-stalks and old withered grass, if
a shower falls it will come out of its burrows even at noonday and drink
eagerly from the pools. It has been erroneously stated that vizcachas
subsist on roots. Their food is grass and seeds; but they may also
sometimes eat roots, as the ground is occasionally seen scratched up
about the burrows. In March, when the stalks of the perennial cardoon or
Castile thistle (Cynara cardunculus) are dry, the vizcachas fell them by
gnawing about their roots, and afterwards tear to pieces the great dry
flower-heads to get the seeds imbedded deeply in them, of which they
seem very fond. Large patches of thistle are often found served thus,
the ground about them literally white with the silvery bristles they
have scattered. This cutting down tall plants to get the seeds at the
top seems very like an act of pure intelligence; but the fact is, the
vizcachas cut down every tall plant they can. I have seen whole acres of
maize destroyed by them, yet the plants cut down were left untouched. If
posts be put into the ground within range of their nightly rambles they
will gnaw till they have felled them, unless of a wood hard enough to
resist their chisel-like incisors.
The strongest instinct of this animal is to clear the ground thoroughly
about its burrows; and it is this destructive habit that makes it
necessary for cultivators of the soil to destroy all the vizcachas in or
near their fields. On the uninhabited pampas, where the long grasses
grow, I have often admired the vizcachera; for it is there the centre of
a clean space, often of half an acre in extent, on which there is an
even close-shaven turf: this clearing is surrounded by the usual rough
growth of herbs and giant grasses. In such situations this habit of
clearing the ground is eminently advantageous to them, as it affords
them a comparatively safe spot to feed and disport themselves on, and
over which they can fly to their burrows without meeting any
obstruction, on the slightest alarm.
Of course the instinct continues to operate where it is no longer of any
advantage. In summer, when the thistles are green, even when growing
near the burrows, and the giant thistle (Carduus mariana) springs up
most luxuriantly right on the mound, the vizcachas will not touch them,
either disliking the strong astringent sap, or repelled by the thorns
with which they are armed. As soon as they dry, and the thorns become
brittle, they are levelled; afterwards, when the animal begins to drag
them about and cut them up, as his custom is, he accidentally discovers
and feasts on the seed: for vizcachas are fond of exercising their teeth
on hard substances, such as sticks and bones, just as cats are of
"sharpening their claws" on trees.
Another remarkable habit of the vizcacha, that of dragging to and
heaping about the mouth of his burrow every stalk he cuts down, and
every portable object that by dint of great strength he can carry, has
been mentioned by Azara, Darwin, and others. On the level plains it is a
useful habit; for as the vizcachas are continually deepening and
widening their burrows, the earth thrown out soon covers up these
materials, and so assists in raising the mound. On the Buenos-Ayrean
pampas numbers of vizcacheras would annually be destroyed by water in
the great sudden rainfalls were the mounds loss high. But this is only
an advantage when the animals inhabit a perfectly level country subject
to flooding rains; for where the surface is unequal they invariably
prefer high to low ground to burrow on, and are thus secured from
destruction by water; yet the instinct is as strong in such situations
as on the level plains. The most that can be said of a habit apparently
so obscure in its origin and uses is, that it appears to be part of the
instinct of clearing the ground about the village. Every tall stalk the
vizcacha cuts down, every portable object he finds, must be removed to
make the surface clean and smooth; but while encumbered with it he does
not proceed further from his burrows, but invariably re-tires towards
them, and so deposits it upon the mound. So well known is this habit,
that whatever article is lost by night--whip, pistol, or knife--the
loser next morning visits the vizcacheras in the vicinity, quite sure of
finding it there. People also visit the vizcacheras to pick up sticks
for firewood.
The vizcachas are cleanly in their habits; and the fur, though it has a
strong earthy smell, is kept exceedingly neat. The hind leg and foot
afford a very beautiful instance of adaptation. Propped by the hard
curved tail, they sit up erect, and as firmly on the long horny disks on
the undersides of the hind legs as a man stands on his feet. Most to be
admired, on the middle toe the skin thickens into a round cushion, in
which the curved teeth-like bristles are set; nicely graduated in
length, so that "each particular hair" may come into contact with the
skin when the animal scratches or combs itself. As to the uses of this
appendage there can be no difference of opinion, as there is about the
serrated claw in birds. It is quite obvious that the animal cannot
scratch himself with his hind paw (as all mammals do) without making use
of this natural comb. Then the entire foot is modified, so that this
comb shall be well protected, and yet not be hindered from performing
its office: thus the inner toe is pressed close to the middle one, and
so depressed that it comes under the cushion of skin, and cannot
possibly get before the bristles, or interfere their coming against the
skin in scratching, as certainly be the case if this toe were free as
outer one.
Again, the vizcachas appear to form the deep trenches before the burrows
by scratching the earth violently backwards with the hind claws. Now
these straight, sharp, dagger-shaped claws, and especially the middle
one, are so long that the vizcacha is able to perform all this rough
work without the bristles coming into contact with the ground, and so
getting worn by the friction. The Tehuelcho Indians in Patagonia comb
their hair with a brush-comb very much like that on the vizcacha's toe,
but in their case it does not properly fulfil its office, or else the
savages make little use of it. Vizcachas have a remarkable way of
dusting themselves: the animal suddenly throws himself on his back, and,
bringing over his hind legs towards his head, depresses them till his
feet touch the ground. In this strange posture he scratches up the earth
with great rapidity, raising a little cloud of dust, then rights himself
with a jerk, and, after an interval, repeats the dusting. Usually they
scratch a hole in the ground to deposit their excrements in. Whilst
opening one of the outside burrows that had no communication with the
others, I once discovered a vast deposit of their dung (so great that it
must have been accumulating for years) at the extremity. To ascertain
whether this be a constant, or only a casual habit, it would be
necessary to open up entirely a vast number of vizcacheras. When a
vizcacha dies in his burrow the carcass is, after some days, dragged out
and left upon the mound.
The language of the vizcacha is wonderful for its variety. When the male
is feeding he frequently pauses to utter a succession of loud,
percussive, and somewhat jarring cries; these he utters in a leisurely
manner, and immediately after goes on feeding. Often he utters this cry
in a low grunting tone. One of his commonest expressions sounds like the
violent hawking of a man clearing his throat. At other times he bursts
into piercing tones that may be heard a mile off, beginning like the
excited and quick-repeated squeals of a young pig, and growing longer,
more attenuated, and quavering towards the end. After retiring alarmed
into the burrows, he repeats at intervals a deep internal moan. All
these, and many other indescribable guttural, sighing, shrill, and deep
tones, are varied a thousand ways in strength and intonation, according
to the age, sex, or emotions of the individual; and I doubt if there is
in the world any other four-footed thing so loquacious, or with a
dialect so extensive. I take great pleasure in going to some spot where
they are abundant, and sitting quietly to listen to them; for they are
holding a perpetual discussion, all night long, which the presence of a
human being will not interrupt.
At night, when the vizcachas are all out feeding, in places where they
are very abundant (and in some districts they literally swarm) any very
loud and sudden sound, as the report of a gun, or a clap of unexpected
thunder, will produce a most extraordinary effect. No sooner has the
report broken on the stillness of night than a perfect storm of cries
bursts forth over the surrounding country. After eight or nine seconds
there is in the storm a momentary hill or pause; and then it breaks
forth again, apparently louder than before. There is so much difference
in the tones of different animals that the cries of individuals close at
hand may be distinguished amidst the roar of blended voices coming from
a distance. It sounds as if thousands and tens of thousands of them
were striving to express every emotion at the highest pitch of their
voices; so that the effect is indescribable, and fills a stranger with
astonishment. Should a gun be fired off several times, their cries
become less each time; and after the third or fourth time it produces no
effect. They have a peculiar, sharp, sudden, "far-darting" alarm-note
when a dog is spied, that is repeated by all that hear it, and produces
an instantaneous panic, sending every vizcacha flying to his burrow.
But though they manifest such a terror of dogs when out feeding at night
(for the slowest dog can overtake them), in the evening, when sitting
upon their mounds, they treat them with tantalizing contempt. If the dog
is a novice, the instant he spies the animal he rushes violently at it;
the vizcacha waits the charge with imperturbable calmness till his enemy
is within one or two yards, and then disappears into the burrow. After
having been foiled in this way many times, the dog resorts to stratagem:
he crouches down as if transformed for the nonce into a Felis, and
steals on with wonderfully slow and cautious steps, his hair bristling,
tail hanging, and eyes intent on his motionless intended victim; when
within seven or eight yards he makes a sudden rush, but invariably with
the same dis-appointing result. The persistence with which the dogs go
on hoping against hope in this unprofitable game, in which they always
act the stupid part, is highly amusing, and is very interesting to the
naturalist; for it shows that the native dogs on the pampas have
developed a very remarkable instinct, and one that might be perfected by
artificial selection; but dogs with the hunting habits of the cat would,
I think, be of little use to man. When it is required to train dogs to
hunt the nocturnal armadillo (Dasypus villosus), then this deep-rooted
(and, it might be added, hereditary) passion for vizcachas is
excessively annoying, and it is often necessary to administer hundreds
of blows and rebukes before a dog is induced to track an armadillo
without leaving the scent every few moments to make futile grabs at his
old enemies.
The following instance will show how little suspicion of man the
vizcachas have. A few years ago I went out shooting them on three
consecutive evenings. I worked in a circle, constantly revisiting the
same burrows, never going a greater distance from home than could be
walked in four or five minutes. During the three evenings I shot sixty
vizcachas dead; and probably as many more escaped badly wounded into
their burrows; for they are hard to kill, and however badly wounded, if
sitting near the burrow when struck, are almost certain to escape into
it. But on the third evening I found them no wilder, and killed about as
many as on the first. After this I gave up shooting them in disgust; it
was dull sport, and to exterminate or frighten them away with a gun
seemed an impossibility.
It is a very unusual thing to eat the vizcacha, most people, and
especially the gauchos, having a silly unaccountable prejudice against
their flesh. I have found it very good, and while engaged writing this
chapter have dined on it served up in various ways. The young animals
are rather insipid, the old males tough, but the mature females are
excellent--the flesh being tender, exceedingly white, fragrant to the
nostrils, and with a very delicate game-flavour.
Within the last ten years so much new land has been brought under
cultivation that farmers have been compelled to destroy incredible
numbers of vizcachas: many large "estancieros" (cattle-breeders) have
followed the example set by the grain-growers, and have had them
exterminated on their estates. Now all that Azara, on hearsay, tells
about the vizcachas perishing in their burrows, when these are covered
up, but that they can support life thus buried for a period of ten or
twelve days, and that during that time animals will come from other
villages and disinter them, unless frightened off with dogs, is strictly
true. Country workmen are so well acquainted with these facts that they
frequently undertake to destroy all the vizcacheras on an estate for so
paltry a sum as ten-pence in English money for each one, and yet will
make double the money at this work than they can at any other. By day
they partly open up, then cover up the burrows with a great quantity of
earth, and by night go round with dogs to drive away the vizcachas from
the still open burrows that come to dig out their buried friends. After
all the vizcacheras on an estate have been thus served, the workmen are
usually bound by previous agreement to keep guard over them for a space
of eight or ten days before they receive their hire: for the animals
covered up are then supposed to be all dead. Some of these men I have
talked with have assured me that living vizcachas have been found after
fourteen days--a proof of their great endurance. There is nothing
strange, I think, in the mere fact of the vizcacha being unable to work
his way out when thus buried alive; for, for all I know to the contrary,
other species may, when their burrows are well covered up, perish in the
same manner; but it certainly is remarkable that other vizcachas should
come from a distance to dig out those that are buried alive. In this
good office they are exceedingly zealous; and I have frequently
surprised them after sunrise, at a considerable distance from their own
burrows, diligently scratching at those that had been covered up. The
vizcachas are fond of each other's society, and live peaceably together;
but their goodwill is not restricted to the members of their own little
community; it extends to the whole species, so that as soon as night
comes many animals leave their own and go to visit the adjacent
villages. If one approaches a vizcachera at night, usually some of the
vizcachas on it scamper off to distant burrows: these are neighbours
merely come to pay a friendly visit. This intercourse is so frequent
that little straight paths are formed from one vizcachera to another.
The extreme attachment between members of different communities makes it
appear less strange that they should assist each other: either the
desire to see, as usual, their buried neighbours becomes intense enough
to impel them to work their way to them; or cries of distress from the
prisoners reach and incite them to attempt their deliverance. Many
social species are thus powerfully affected by cries of distress from
one of their fellows; and some will attempt a rescue in the face of
great danger--the weasel and the peccary for example.
Mild and sociable as the vizcachas are towards each other, each one is
exceedingly jealous of any intrusion into his particular burrow, and
indeed always resents such a breach of discipline with the utmost fury.
Several individuals may reside in the compartments of the same burrow;
but beyond themselves not even their next-door neighbour is permitted to
enter; their hospitality ends where it begins, at the entrance. It is
difficult to compel a vizcacha to enter a burrow not his own; even when
hotly pursued by dogs they often refuse to do so. When driven into one,
the instant their enemies retire a little space they rush out of it, as
if they thought the hiding-place but little less dangerous than the open
plain. I have frequently seen vizcachas, chased into the wrong burrows,
summarily ejected by those inside: and sometimes they make their escape
only after being well bitten for their offence.
I have now stated the most interesting facts I have collected concerning
the vizcacha: when others rewrite its history they doubtless will,
according to the opportunities of observation they enjoy, be able to
make some additions to it, but probably none of great consequence. I
have observed this species in Patagonia and Buenos Ayres only; and as I
have found that its habits are considerably modified by circumstances in
the different localities where I have met with it, I am sure that other
variations will occur in the more distant regions, where the conditions
vary.
The most remarkable thing to be said about the vizcacha is, that
although regarded by Mr. Waterhouse, and others who have studied its
affinities, as one of the lowest of the rodents, exhibiting strong
Marsupial characters, the living animal appears to be more intelligent
than other rodents, not of South America only, but also of those of a
higher type in other continents. A parallel case is, perhaps, to be
found in the hairy armadillo, an extremely versatile and intelligent
animal, although only an edentate. And among birds the ypecaha--a large
La Plata rail--might also be mentioned as an example of what ought not
to be; for it is a bold and intelligent bird, more than a match for the
fowl, both in courage and in cunning; and yet it is one of the family
which Professor Parker--from the point of view of the
anatomist--characterizes as a "feeble-minded, cowardly group."