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regard to their food, all the land forms being herbivorous, while of those frequent-
ing the water some subsist on vegetable, and others on animal substances.

By far the most numerously represented genus of the whole
Land-Tortoises. ....... i r i 4 * t

tamily is the one including the true or land -tortoises, or which

there are rather more than forty existing species (counting a few that have
been exterminated within the historic period). These tortoises, of which a few
are more or less aquatic in their habits, have the upper and lower portions of
the shell completely welded together, the former being frequently very convex
and much vaulted ; while the top of the head is covered with large horny
shields. The limbs, which are entirely adapted for walking, are of a club-
like form, and are covered with large horny scales or tubercles; their toes
being unwebbed and furnished with strong, claw-like nails. The tail is always
short, its proportionate length not being greater in the young than in the adult.
More important characters are, however, furnished by the bony shell ancl skull, to
observe the former of which it is of course necessary that the horny shields
should be stripped off. In a shell thus treated it will be seen that the unpaired
median neural bones of the carapace are relatively short and wide, and so
arranged that a four-sided one is interposed between two that are octagonal,
although in some cases they are mostly hexagonal; while the costal or lateral
plates are alternately narrow above and broad below. Moreover, the line dividing
the costal horny shields from the marginals usually corresponds with the suture
between the corresponding bones of the carapace, whereas in the other members
of the family one is above the other ; while a further peculiarity of most species of
the genus is that there is but a single caudal horny plate at the hinder end of the
carapace. In the skull the palate is provided with one or two ridges on each side ;
while the hinder aperture of the nostrils is situated on the line of the eyes. It
may be mentioned here that, as in the majority of the representatives of the order,
the form of the shell differs considerably in the two sexes; the male having the
central region of the plastron deeply concave, while in the females it is ilat
or slightly convex.

True tortoises are distributed over Southern Europe and Asia, the whole of
Africa, the southern portions of North America, and South America, (inclusive
of the Galapagos Islands). They are strictly herbivorous in their diet; and certain
species, now confined to oceanic islands, attain gigantic dimensions, and are by far
the largest representatives of the family. The species inhabiting colder regions
hibernate during the inclement season by burrowing in the ground, whereas those
found in more genial climates are active throughout the year. All the species



LAND- TOR TOISES.



49



appear to be diurnal in their habits, and although they are all fond of water,
the common European species always withdraws into its shell at the slightest
shower. These reptiles will live to an enormous age, which, in some instances at
least, may be reckoned by centuries. According to the classification adopted by
Mr. Boulenger, the species of this extensive genus may be arranged under seven
groups, of which we proceed to notice representative species.

The land-tortoises of North America include three species, of
which one of the best known is the Florida tortoise (Testudo poly-
pliemus), inhabiting the South-Eastern United States. All these species may be



Florida Tortoise.




BRAZILIAN TOKTO1SE Q- Uat. size).



easily recognised by the anterior extremity of the palate of the skull having a
median longitudinal ridge, instead of the deep pit characterising all other members
of the genus. In the Florida tortoise, as well as in the allied Agassiz's tortoise
(T. agassizi), the length of the shell is more 'than twice its height, while the beak
is not hooked, and the fore-limb is broadest at its extremity. On the other hand,
in Berlandier's tortoise (T. berlandieri), from Mexico and Texas, the shell is
proportionately shorter, the beak is hooked, and the fore-limb widest at the elbow.
These species are all of small size, not exceeding 10 inches in length.

Brazilian The Brazilian species (T. tabulata), figured above, represents a

Tortoise. group by itself, of which the distinctive characters are as follows.

The carapace is much elongated and somewhat depressed, with its margins not

VOL. V. 4



50 TORTOISES AND TURTLES.

everted; its general colour being dark brown or black, with a yellowish centre to
each of the shields on the back. The nuchal shield of the carapace is wanting;
while in the plastron the gular shields, although well developed, are prolong* I
anteriorly into hem-like processes. The head and limbs are marked with orange
or red spots, on a dark ground. This handsome tortoise, which attains a length
of nearly 22 inches, is an inhabitant of tropical South America, to the east of the
Andes, and also of the Windward Islands, ascending to an elevation of about two
thousand feet. In many wooded districts it appears to be very abundant, feeding
not only on leaves and grasses, but likewise on the fallen fruit which is to be met
with in great quantities. In the hot season it constructs a nest of dry leaves,
wherein are deposited its eggs, which may be a dozen or two in number. When
first hatched, the young are of a uniform yellowish brown colour, with their shells
still soft. The young, and to a less degree the adults, have, according to the
Prince of Wied, numerous enemies. Against the puma and jaguar the stout shell
of even the adult seems to be no defence, since, according to native reports, those
animals, on finding one of these tortoises, will set it up on end and scoop out the
flesh with their paws ; while from the occurrence of broken shells in the forest it
would seem that in some cases they are actually able to tear the plastron away
from the carapace. As the flesh is devoid of smell, it is likewise eagerly sought
after by both Indians and Portuguese, who are in the habit of keeping these
tortoises known in Brazil by the name of schabuti in stews, where they are
fattened for the table. They are also allowed to run about the houses, where they
are fed chiefly on plantains.

Burmese The four species belonging to the third group, of which the

Brown Tortoise. Burmese brown tortoise (T. emys) is an example, are characterised by
the presence of some very large conical, bony, spur-like tubercles on the lower
portion of the hind-leg, and the circumstance that the length of the union in the
middle line of the anal shields of the plastron is considerably less than that of the
abdominal shields; the colour of the carapace in the adult being either uniform
brownish, or yellowish brown closely spotted with black. The Burmese In-own
tortoise, which attains a length of 18 inches, while, agreeing with the species above
noticed in the possession of a nuchal shield on the front of the carapace, differs in
that the caudal shield at the hinder extremity of the same is divided, as in tilt-
terrapins. The shell of this species is much depressed, with the anterior and
posterior borders of the carapace serrated ; the adult being dark brown, or blackish
in colour, while in the young the carapace is yellowish brown, with dark brown
markings. In addition to the spur-like tubercles on the back of the heel, the,
whole of the front of the fore-limb is overlain with imbricating bony tubercles,
arranged in four or five longitudinal rows, and there are some conical ones on fin-
back of the thigh, as well as others on the lower surface of the hind-foot. This
species is an inhabitant of Assam, Burma, Siam, the Malay Peninsula., and Sumatra,
where it frequents moist wooded districts, and is believed to be largely aquatic in
its habits. The association of a divided caudal shield, with habits reputed to
resemble those of the terrapins, is somewhat noteworthy.

In the other three members of this group the nuchal shield is want ing, and
the caudal single. Of these, the Argentine tortoise (T. argentine^) of South



LAND- TOR TOISES. 5 1

America, and the spurred tortoise (T. (xilca/rata,) of Africa, are characterised by
their flattened and uniformly brownish-coloured carapaces. On the other hand,
the handsome leopard-tortoise (T. pardalis) of Southern Africa, has the carapace
highly vaulted, and closely spotted with black upon a yellowish brown ground ;
its anterior margin being very deeply notched.




SIDE VIEW OK SHELL OF BURMESE BROWN TORTOISE.

(From Giinther, Proc. Zool. Soc., 1882.)

The fourth group comprises about ten very beautifully coloured
Tortoise.

small, or medium-sized, tortoises, the great majority of which are

ifined to South Africa, although the species here figured (T. eleyans) is an
labitant of India and Ceylon. All these species are easily recognised by the
ipace being extremely convex, and either black in colour, with yellow lines
liating from the centre of each of the shields of the back, or yellow, or brownish,
irked with radiating black lines. Frequently, moreover, the shields of the back
swollen, so as to form more or less prominent bosses. The Indian species,
Aether with an allied one (T. pl(jdynot(Ji), from Burma, is distinguished from all
the other members of the group by the absence of the nuchal shield at the front
the carapace. Of the other eight species no less than seven arc South African,
die the radiated tortoise (T. radiata) is from Madagascar ; one of the best
lowii members of the group being the common geometric tortoise (T. gcomctrica)
of the Cape, which attains a length of some 5- inches. In the eyed tortoise
(T. oculifcra) the pectoral shields of the plastron may not meet in the middle
line, as is the case in some individuals of the Burmese brown tortoise. While the
elegant and geometric tortoise have the carapace black, with narrow yellow rays,
in the eyed tortoise the markings take the form of brownish yellow and dark
brown, rays of nearly equal width.

An admirable account of the habits of the elegant tortoise is given by Capt.
T. Hutton, from which the following extracts are made. These tortoises are fairly
common in dry, hilly districts, where they inhabit the high grass-jungles at the
foot of the hills. Nevertheless, they are by no means easy to find, owing to their
colour and appearance harmonising so closely with the rocky ground, and from
their habit of remaining in concealment beneath shrubs or tufts of grass during
the heat of the day. They are tracked by the Bhils of Meywar to their hiding-



52 TORTOISES AND TURTLES.

places by following the trail of their footsteps in the dry sand ; the same method
being employed by some of the wild tribes of South Africa in the case of the
allied species inhabiting that continent. In the rainy season the elegant tortoise
is, however, extremely active, and wanders about in search of food at all hours of
the day. At the approach of the cold weather these reptiles select a sheltered
spot, where they conceal themselves by thrusting their shells into thick tufts of
bushes or shrubs, in order to be better protected from the cold. There they
remain in a kind of lethargic, although not truly torpid, state, till the hot season,
when they issue out to feed only after sunset and in the early morning.
Specimens kept in captivity were observed to be very fond of plunging into water




EI.HCANT TORTOISE ( liat. size).

during the hot season, where they would remain for half an hour at a time.
They also drank large qualities of water at this period of the year, which tin -y
took by thrusting in their heads and swallowing in a series of gulps. About
November the female lays her eggs in a shallow pit excavated by herself. One of
the aforesaid captive specimens in the course of about two hours " succeeded in
making a hole six inches in depth and four inches in diameter; in this she
immediately deposited her eggs, four in number, filling up the hole again with the
mud she had previously scraped out, and then treading it well in, and stamping
upon it with her hind-feet alternately until it was iilled to the surl'aer, \\lieii she
bent it down with the whole weight of her body, raising herself behind as high as




QIAK1 TORTOISES OF T1IK GALAPAGOS ISLANDS.




LAND-TORTOISES. 55

she could stretch her leg's, and suddenly withdrawing them, allowing herself to
drop heavily on the earth, by which means it was speedily beaten flat ; and so
smooth and natural did it appear that, had I not detected her in the performance
of her task, I should certainly never have noticed the spot where she had
deposited her eggs. She did not immediately leave the place after finishing her
work, but remained inactive, as if recovering from her fatigues." In disposition
these tortoises are decidedly pugnacious, this being especially the case with the
males. These combats seemed to be chiefly trials of strength, " one male confronting
the other, with the hind and fore-legs drawn into the shell, and the hind-feet
planted firmly on the ground, and in this manner striving against each other until
one or both became fatigued. This was done chiefly when they wanted to pass
each other in any narrow space ; and sometimes if the one could succeed in placing
his shell a little beneath the other, he tilted him over on his back, from which he
had great difficulty in recovering himself; and I have frequently found them
sprawling thus, making desperate efforts with head and feet to throw themselves
back to their natural position, which they were unable to' effect unless the ground
chanced to be very uneven, so as to assist them."

During the Pliocene, or later division of the Tertiary period,
.t Tortoises. J

gigantic land-tortoises were, as attested by their petrified remains,

dely distributed over the continents of the world ; species having been obtained
>m India, France, and North and South America. The largest of these was the
well-known atlas tortoise (T. atlas) from the Siwalik Hills of Northern India, in
which the length of the shell was about 6 feet ; the species itself being apparently
allied to the existing Burmese brown tortoise already referred to. Probably more
or less abundant during the epoch in question, with the advent of the ensuing
Pleistocene epoch giant tortoises seem to have disappeared entirely from the
continental areas, to survive on certain oceanic islands where they were free from
the competition of large animals of higher organisation. Some of these insular
species, like those of Madagascar and Malta, did not apparently survive the
Pleistocene epoch ; while in other regions they flourished and multiplied till the
ft '11 presence of man led to their partial or total extermination. At the present
day the few survivors of these monstrous reptiles are being rapidly reduced in
numbers, and unless special means be speedily taken for their preservation, they
will ere long entirely cease to exist. During the historic period the islands where
giant tortoises are known to have existed constitute three distinct groups. Two
of these are situated in the Indian Ocean, and comprise Aldabra, to the north-west
of Madagascar, and the Mascarene Group including Reunion, Mauritius, and
Rodriguez lying to the east of the same ; while the third or Galapagos Group,
taking its name from the Spanish word for tortoise, is situated in the far distant
South Pacific, off the western coast of South America. During the sixteenth and
seventeenth centuries, the tortoises are stated to have existed in enormous numbers
in all the above-named islands ; but as they afforded a most valuable supply of
food, and could be kept alive on board ship, their numbers were rapidly reduced in
those of the Indian Ocean, and Aldabra is now the only island in that area where
they still exist in a wild state. Many of these tortoises were, however, exported
the Seychelles, and it is believed, as we shall notice below, that one carried






56 TORTOISES AND TURTLES.

thence to the Mauritius is the only living example of the species that formerl
inhabited Rodriguez. Regarding the abundance of these tortoises in the latt
island, Fram;ois Leguat, writing in HiO I, observes that " there are such plenty
land-turtles in this isle, that sometimes you see a three thousand of them in
flock, so that you may go above a hundred paces on their backs." In Mauritius
they were still abundant in 1740; but about 1761 they were probably scarcer, as
thousands were then imported from Rodriguez as food for the patients in the
hospitals of the Mauritius. The continued exportation, some ships taking ,-is
many as four hundred at a time, coupled with the destruction of their eggs and
young, finally led to their extermination in both Mauritius and Rodriguez; this
extirpation having probably taken place early in the present centur} r . The
Reunion tortoise, of which very little is known, seems to have disappeared at a
still earlier date ; while of the Galapagos species, we shall speak later.

The total number of species of giant tortoises known to have existed within




ELEPHANT-TORTOISE.



the historic period is about fourteen ; the whole of which are characterised by their
large size, their long necks, and the uniformly dark brown or black colour of their
shells. They may be divided into four groups, according to their geographical
distribution, each characterised by certain structural peculiarities. The first group
comprises the four Aldabra tortoises, characterised by the presence of a nuchal
shield on the front of the carapace, and the distinctness of the gulars on the front
of the plastron. On the other hand, in the four best known Mascarene species,
constituting the second group, the nuchal shield is wanting, while the two gulars
have coalesced into one ; the plastron being characterised by its extreme shortness.
Lastly, the third, or Galapagos group, with six species, presents a condition inter-
mediate between that existing in the two others, the nuchal shield of the
carapace being absent, while the gulars of the plastron remain double. We
proceed to notice some of the species of each group.

The best known of the four species from Aldabra is the elephant-
'tortoise (T. elephantina), which differs from the other three in having



LAND- TOR TOISES. 5 7

the horny shields of the carapace; concentrically striated, and the plastron of the
adult notched behind. One of the species (T. gigantea) with smooth shields on a
truncated plastron is peculiar in having the caudal shield divided, as in the
Burmese brown tortoise. The elephant- tortoise appears to be one of the largest of
all the species, attaining a length of about 4 feet. At the present day it is very
scarce in its native island, where the few survivors receive a certain amount of
protection from the Government of Mauritius, to which Aldabra belongs. There
arc, however, a few individuals living in Mauritius and the Seychelles.

Mascarene Of the Mascarene species, the three species from Mauritius

Tortoises. ^ indica, trisserrata, and inepta), all of which are extinct, are
characterised by the thinness of their carapace, of which the margins are thickened.
The Rodriguez tortoise (T. vosmceri) has a still thinner carapace, which in the
male does not shelve down in front in the usual manner. Allusion has already
been made to the numbers in which these tortoises existed in Leguat's time ; but
till quite recently it was thought that the species was totally extinct. It appears,
however, that in the Artillery barracks of Port Louis in the Mauritius, there lives
a very ancient tortoise which, in the opinion of Dr. Gtinther, is probably of this
species. This tortoise is one of two which were imported into the Mauritius by
the navigator, Captain Marion du Fresne from the Seychelles in 1766 ; one of
these having been subsequently presented to the London Zoological Gardens in
1832 by Sir C. Colville. The latter weighed 289 Ibs., and its shell measured 4 feet
4i inches in length along the curve, and 4 feet 9 inches in width ; while in the
Port Louis specimen the circumference of the shell is 9 feet 3 inches, and its height
2 feet. Marion's tortoise, as the Port Louis example is called, is thus definitely
known to have lived for a hundred and twenty-seven years, and as it was doubtless
of large size when brought from the Seychelles, and since all these tortoises take
an immense time to reach large dimensions, it is highly probable that it is an
actual survivor from the enormous herds that existed in Rodriguez in Leguat's
time. From a peculiarity in the structure of the hinder vertebrae of the neck, it
appears that the tortoises of this species have the power of raising their necks to a
nearly vertical position, which would give them a wide range of vision. This
elevated range of vision would accord well with the account given by Leguat, who
writes concerning these tortoises as follows. " There's one thing very odd among
them ; they always place sentinels at some distance from their troop, at the four
corners of the camp, to which the sentinels turn their backs, and look with the
eyes, as if they were on the watch."

Galapagos The various islands of the Galapagos Group, such as Abingdon,

Tortoises. Albemarle, Chatham, Hood, and Charles, are the respective homes of

: one or more species of giant tortoise. Of the various species inhabiting these

i islands, the blackish tortoise (T. nigrita), which is the one given in the illustration
on p. 54, agrees with two others (T. nigra and T. vicina) in having the horny
shields of the carapace concentrically striated in the adult ; the figured species
differing from T. nigra in having the plastron notched, instead of truncate

! behind. In the other three species the shields on the back are smooth, while
the plastron always has its hinder end truncated. In the North Albemarlo

j tortoise (T. microphyes), the width of the bridge connecting the upper and lower



58 TORTOISES AND TURTLES.

shells is of considerable length, and the shell itself stout. On the other hand, in
the saddled tortoise (T. ephippium) and the Abingdon tortoise (T. abingdoni) the
same bridge is relatively short, and the shell is remarkable for its thinness; tin-
carapace being much narrowed anteriorly, where it is so pinched in at the sides as
to have a sharp ridge on the back. In the former of these two species the shell
still retains the usual bony framework, but in the second it is soft and leathery.
Both have very long necks, which are carried nearly vertically; and in the
Abingdon species the notches in the front end of the shell are so large that in a
front view the animal appears merely to have a kind of mantle thrown over the
body. It is hard to see what can be the object of this softening and atrophy of
the shell ; but it is quite clear that it renders the animals very liable to injury, and
thus probably accounts for the fact that none of them have been brought alive to
Europe. The carapace of this species attains a length of 38J inches, and the
weight of one individual was just over 200 Ibs.

The best account of the habits of the Galapagos tortoises is one given by
Darwin, regarding the species figured in our engraving, which inhabits, apparently,
most of the islands of the group. These tortoises frequent in preference the high
damp parts, although they likewise live in the lower and arid districts. Very
numerous in individuals, some grow to such a size that it requires six or eight men
to lift them, while they will yield as much as 200 Ibs. of meat. " The old males are
the largest, the females rarely growing to so large a size; the male can be readily
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, which is
acid and austere, and likewise a pale green filamentous lichen, that hangs in tresses
from the boughs of the trees. The tortoise is very fond of water, drinking large
quantities, and wallowing in the mud. The larger islands alone possess springs,
and these are always situated towards the central parts, and at a considerable
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



Online LibraryRichard LydekkerThe new natural history (Volume 5) → online text (page 7 of 62)