David T. Kirkpatrick, Ph.D
People seem fascinated by things that appear strange or
unique. The sheer immensity of the Galapagos tortoise is a big part of
its popularity with the zoo-going public. The size of the African
Spurred tortoise, Geochelone sulcata,
boosts its popularity in the pet trade. Another tortoise that has been
a perennial pet trade animal because of its unique appearance is the
Pancake tortoise, Malacochersus tornieri. Its bizarre,
flattened profile makes it a sought-after animal in both zoological
institutions and private collections. This desirability has affected
the native populations of Pancake tortoises, effects which currently
are being investigated by researchers. New research such as this is
also answering many questions concerning the natural history of this
fascinating tortoise.
The Pancake Tortoise in Profile
The nooks, crannies and crevices in rock piles and outcrops can
provide protection for a number of species of animals. Tortoises with
their hard shells may seem an unlikely animal to utilize this habitat,
but the Pancake tortoise has evolved to do just that. Unlike most
tortoises, Pancakes do not possess rigid, high, thick shells. Although
they can reach a length of approximately seven inches, they rarely
exceed an inch to an inch and a half in height. With this flat,
pancake-like profile, Malacochersus tornieri is able to fit into narrow crevices and cracks, and thus exploit an environment that no other tortoise is capable of using.
The shell of a Pancake tortoise is very flexible and can be bent and
depressed with only mild pressure, allowing the tortoise to squeeze
into very tight openings. Years ago, before the common name "Pancake
tortoise" became popular, Malacochersus tornieri
was known as the "Softshell" tortoise because of this pliability. The
softness of the shell comes from the underlying structure of the bones.
Most tortoises' bones are solid, with very little space between the
individual bones under the carapace and plastron. However, in the
Pancake tortoise these bones have many openings, or fenestrations, in
them. Juveniles of other tortoise species possess similar fenestrations
in their bones which fill in as the tortoise grows, leaving the
carapace and plastron solid and inflexible. This growth apparently does
not occur in Malacochersus tornieri. Pancake tortoises
are incredibly well adapted for the rocky outcrops, called kopjes, of
south-eastern Africa where they are found. Other adaptations in
addition to their flexible, flattened profile aid the tortoise in its
home. When a tortoise is in its favorite crevice, it rotates its legs,
bracing itself and forcing its carapace up against the rock. In this
position it is almost impossible to remove. There have been conflicting
opinions concerning the ability of the Pancake tortoise to expand its
body to help wedge itself into narrow crevices. Early reports by
Loveridge and Williams indicated that such an inflation did occur, but
L. C. Ireland and Carl Gans in 1972 examined captive Pancakes and found
no evidence for it. However, more recently, Richard Moll and Michael
Klemens inspected tortoises in their native environment and reported
that they could expand their bodies. They showed that the tortoise
possesses a diamond-shaped region on its plastron that is extremely
flexible, moving out when the tortoise draws in its legs. The
combination of these two defensive maneuvers renders Pancake tortoises
virtually immovable.
Unfortunately, cracks and crevices only provide protection if you can
reach them. Luckily for the Pancake tortoise, less bone means a lighter
animal, so Pancakes can move more quickly than tortoises with a thick
shell. It is quite possible that they are the fastest tortoises in the
world. When threatened, a Pancake will not crouch down and withdraw
into its shell. Instead, it will make a dash for the nearest rocky
shelter. Pancake tortoises tend not to stray very far from protection,
and they also seem to be able to locate their favorite hideaways
quickly when displaced. Finally, the Pancake's flat shell and extreme
agility allow it to flip itself over quickly when it lands on its back,
a handy ability for a tortoise that spends most of its time climbing
around on boulders and rocky hills.
In their natural element, individual animals can be very hard to spot.
Although they leave their cracks and fissures to bask in the sun and to
eat, the brown or horn color of their carapace, combined with a random
pattern of radiating lines on each scute, allows Pancake tortoises to
blend into the background, making them difficult to see. In this
regard, their coloration is similar to other smaller tortoises, such as
the Padlopers (Homopus species) of South Africa or the more widely distributed Hingeback tortoises (Kinixys
species). The coloration and patterning of the carapace and plastron is
quite variable, and can fade with age. The shapes of the Pancake
tortoise's head, legs, feet and other body parts are similar to those
of many other tortoises. Males can be identified by their longer and
thicker tails relative to the females and by their smaller overall size.
The Life of a Pancake Tortoise
Pancake tortoises are confined to a small natural range in
south-eastern Africa, occurring in Kenya and Tanzania. Most groups of Malacochersus tornieri
can be found in dry areas of scrub brush on rocky hills or
outcroppings. The kopjes populated by Pancake tortoises reach an
elevation of 1800 meters. Tortoises living at these higher elevations
have adapted to cooler temperatures; average temperatures in their
range usually are around 24 to 30 degrees C, but can drop as low as 12
degrees C. The natural history of Pancake tortoises in Tanzania
has recently been investigated in depth by Don Moll and Michael
Klemens, greatly expanding our knowledge of the tortoise's habits. The
researchers found that although there is some variation in Pancake
tortoise habitat, there are some common elements. Most of the inhabited
crevices were quite deep, had uncluttered rock floors and were located
near a convenient route to the ground, presumably to allow the
tortoises easy access to feeding areas. The crevices also usually
tapered to a height of 5 centimeters at some point. Tortoises can wedge
themselves into this narrow area for protection. Crevices that fit
these criteria are usually found in weathered, but not disintegrating,
outcrops. Older kopjes are often too broken up to provide suitable
shelter, while unweathered rocky areas do not have deep crevices.
Suitable habitats of sufficient size to support a viable population of
Pancake tortoises can be separated by large distances. Within one
habitat, however, tortoises coexist peacefully, with multiple
individuals sharing favored crevices. The usual grouping found by Moll
and Klemens was a male-female pairing, but up to ten tortoises have
been seen in one crevice. The data collected by the researchers
indicate that males may move from crevice to crevice, while females
tend to stay at a single location. However, although intriguing, these
data are still preliminary. Other reptiles were also found within the
Pancake tortoises' homes in Tanzania by Moll and Klemens. These
included agamas, geckos, skinks, and plated lizards. Presumably these
animals take advantage of the protection of cracks and crevices in the
same manner as the Pancake tortoises. Moll and Klemens found a number
of Pancake tortoises that had been killed. The most likely culprits
were small predators such as mongooses.
Grasses and vegetation constitute the majority of the diet of a Pancake
tortoise. The exact food is dependent which species grow in the area
and on the season of the year. Plants such as star grass, red oat
grass, aloe, and Achyranthes leaves were eaten by tortoises in the
Tanzanian study group. Other researchers have reported similar diets,
although some populations of tortoises also eat seeds and nuts.
Standing water is rare in the kopjes except during the rainy season.
Presumably during the rest of the year, the vegetation upon which the
tortoises feed provides an adequate supply of water.
Of course, in order to eat Pancake tortoises must leave the safety of
their crevices. Tortoises in Tanzania were seen outside their crevices
at many different times during the day, spending approximately one half
hour each time foraging and occasionally resting. Other researchers
also have reported Pancakes basking or moving about in search of food.
Pancake tortoises, especially the males, are reported to become
somewhat more active during the breeding season. Mating among Pancake
tortoises in the wild occurs near the beginning of the year, with
nesting in July or August. Females that have successfully mated will
usually lay a single egg, burying it under three to four inches of
loose, sandy dirt. One female can lay multiple eggs over the course of
a single season, with eggs appearing every six weeks to two months.
Each egg is about two inches long, but only half this in width.
Incubation seems to last for 4.5 to 6 months, but incubation lengths of
over eight months have been reported.
Hatchling Pancake tortoises look like hatchlings of many other tortoise
species. Typically, they are dark yellow, with brown or black markings
on the scutes on both their plastron and carapace. Their carapace is
even slightly domed, unlike that of their parents! Upon hatching,
juvenile Pancake tortoises are about one and a half inches long, and
more circular than adults. As they age, they gradually adopt the more
normal rectangular shape of an adult Pancake tortoise.
Pancake Tortoises in the Pet Trade and in Captivity
A second study by Klemens and Moll examined the status of Malacochersus tornieri
in its native habitat, and the effect that the extensive trade in
wild-caught animals has had on the Pancake tortoise population in
Tanzania. While it has long been assumed that the high level of trade
in these tortoises has had a severe impact on the wild populations,
real data have been lacking. Now, with this study, the common
assumption has been proven to be correct. Habitat that is
suitable for Pancake tortoises is not common or extensive when found,
limiting the size of the Pancake tortoise population in those habitats.
Klemens and Moll investigated habitats that were pristine and habitats
that had been raided for the pet trade. They found that unexploited
areas have a higher population density, with more adults than in the
exploited populations. Juveniles made up a higher percentage of the
tortoises found in raided areas, probably because young tortoises are
harder to locate and extract from crevices, as they can retreat further
than the larger adults. Given the low reproductive rate of Pancake
tortoises, populations that have been plundered may take a long time to
recover, if they haven't been reduced past a sustainable level already.
Habitats within protected areas such as national parks are less likely
to be ransacked, but even there some populations appear to have been
impacted by collecting.
Tortoises are collected by local hunters who deal with a local
middleman. Animals are occasionally stockpiled in local areas until an
order for tortoises arrives from an exporter. These exporters contact
the local middlemen, obtain the necessary permits, and ship the animals
to wildlife importers in Europe and the United States. Individual
collection sites can be responsible for the collection of hundreds of
tortoises at a time. Local hunters only receive a few cents per
tortoise, with the middlemen making less than 50 cents per animal. Once
collected, tortoises face a potentially long wait until exported, and
then must survive the stressful exportation process. Recently the
Tanzanian government has reduced drastically the number of exported
tortoises, and the European Economic Community has banned their import.
The number of Pancake tortoises entering the United States has dropped,
and prices for Pancake tortoises have risen in the last few years.
Perhaps these changes will convince more commercial turtle breeders to
begin working with Pancake tortoises. Given the documented problems
with wild-caught tortoises, anyone wishing to keep Malacochersus tornieri should locate a reputable Pancake tortoise breeder.
The small size and unusual appearance of Pancake tortoises make them
desirable animals for both individual and institution collections.
Fortunately they can be hardy captives if their needs are properly
addressed. Although small compared to some tortoises, they still
require a large area with multiple hiding spots, at least equal to the
number of Pancakes kept, and preferably more. The area should be
furnished with a variety of surfaces, including rocks, for the
tortoises to climb around and over. When designing the environment,
keep in mind the common elements of their natural crevices. A sand pit
four or five inches deep should also be available, especially if
breeding is desired. Remember that Pancake tortoises are excellent
climbers - they will scale any wall that is too low and disappear under
the refrigerator, stereo cabinet, or similar heavy item of furniture if
indoors, or disappear entirely, probably forever, if outdoors.
Pancake tortoises in captivity will eat many of the same things as they
will in the wild, and drier grasses and alfalfa should be provided to
add bulk and fiber to their diet. Tortoises will also take food such as
lettuces, squash, carrot, broccoli, green beans, cabbage, some melons,
and occasionally other fruit as well. Vitamin supplements are not
essential if a varied diet is provided, although a small amount can be
given infrequently. A water bowl can be provided, although they may
only use it rarely. Alternately, tortoises can be misted heavily with a
house plant mister once or twice a week. A once or twice monthly soak
in warm water can also be beneficial.
In captivity tortoises will mate year-round, but breeding success can
be increased by providing the Pancakes with a yearly light cycle in
which the length of the day varies over the course of the year, similar
to that provided for other turtles, snakes, and lizards. If two or more
males are kept together, they will sometimes fight over the females,
who tend to ignore the males unless the males are actively pursuing or
circling them. One male in our collection consistently waited until the
females were eating in the morning before approaching and mounting them
from behind. The females would often continue eating for quite a while
before noticing the presence of the male. Some breeders report
increased success with larger groups of tortoises, as combat between
males may stimulate mating and increase fertility. Although most
females only lay one egg at a time, each Pancake can produce multiple
clutches with a six to eight week gap between layings. The egg is
approximately two inches long and one inch wide - surprisingly big
relative to the size of the tortoise! Eggs are usually laid in sandy
soil, although some tortoises will deposit eggs in out-of-the-way
places in the cage if they find the nesting area unsuitable. Females
that are producing eggs should have calcium and vitamin supplements
added to their diet to allow for proper egg and embryo development and
to prevent vitamin and calcium deficiencies in the adult.
Unfortunately, some breeders have reported low fertility in eggs laid
in captivity. A number of things may play a role in this infertility,
including dietary inadequacies, a missing factor or factors in the
captive environment, or incompatibility between tortoises from
differing parts of their native range. Eggs incubated at approximately
30 degrees Celsius seem to take from 140 to 190 days to hatch. For
example, animals hatched after 122, 145, 147, and 160 days (Slavens,
1994) of incubation. However, incubation lengths of over eight months
have been reported. Hatchlings and juveniles will consume the same
foods that adults eat, although growing animals should be given
additional calcium and vitamin supplements to insure proper growth.
Hatchlings should not be overfed, as this may adversely affect their
growth.
Pancake tortoises can be hardy and long-lived in captivity. Frank
Slavens' Reptiles and Amphibians in Captivity (1994 edition), notes
that the National Zoo in Washington D.C. has a female that has been in
captivity for over a quarter of a century, as it was acquired in 1965.
Captive breeding programs have been successful in zoos and private
collections around the country and few problems have been reported in
rearing captive born animals. These successes in breeding and long-term
care are heartening. Anyone keeping Pancakes should strongly consider
establishing a breeding group. Given the fragility of native
populations, only captive-born tortoises should be entering the pet
trade. Successful breeding projects for other tortoises such as Leopard
tortoises, Sulcatas, and Redfoots have shown that animals need not be
continually removed from wild populations to satisfy people's desire to
keep these fascinating creatures, and hopefully the Pancake tortoise
will be another success story in tortoise husbandry.
Recommended Reading/References
Connor, M. J. (1992). The Pancake Tortoise. The Tortuga Gazette 28(11): 1-3.
Darlington, A. F. and R. B. Davis (1990). Reproduction in the Pancake Tortoise, Malacochersus tornieri, in Captive Collections. Herp Review 21(1): 16-18.
Eglis, A. (1967). Flat and Fast: The Pancake Tortoise. International Turtle and Tortoise Society Journal 1(2): 29, 44-45.
Ernst, C. H. and R. W. Barbour (1989). Turtles of the World. Washington D.C., Smithsonian Institution Press.
Highfield, A. C. (1990). Keeping and Breeding Tortoises in Captivity. Avon, GB, R & A Publishing, Ltd.
Kirkpatrick, D. T. (1993). The Pancake Tortoise. Reptile & Amphibian Magazine 22 (May/June): 2-9.
Klemens, M. W. and D. Moll (1995). An assessment of the effects of commercial exploitation on the pancake tortoise, Malacochersus tornieri, in Tanzania. Chelonian Conservation and Biology 1(3): 197-206.
Moll, D. and M. W. Klemens (1996). Ecological Characteristics of the Pancake Tortoise, Malacochersus tornieri, in Tanzania. Chelonian Conservation and Biology 2(1): 26-35.
Pritchard, P. C. H. (1979). Encyclopedia of Turtles. Neptune, N.J., TFH Publications, Inc.
Slavens, F. L. and K. Slavens (1994). Reptiles and Amphibians in
Captivity: Breeding, Longevity and Inventory (Current January 1, 1994).
Seattle, Slaveware.
This article copyright © 1997 by David T. Kirkpatrick.
Reprinting of this article for non-profit purposes is permitted
provided that it is unaltered and appropriate attribution, including
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