Generally in
nature, an animal must seek shelter from bad weather or from a threatening
situation. Imagine a creature carrying its shelter or its house
with it wherever it goes. When threatened, it simply retreats into
its house and locks the door. That’s es-sentially how turtles
live their lives. The turtle’s shell is a remarkable feat
of natural engineering, a protective gift from God. The shell has
two parts?the carapace, the upper section and the flat belly section
called plastron. They are connected by bony bridges leaving gaps
for the head, tail and four legs. The turtle’s vertebrae and
ribs have actually become an integral part of the carapace and do
not move separate from the shell. When the turtle with-draws into
this shell, it’s almost im-possible for a predator to get
at it.
The shell accounts for about one third of the weight of a turtle,
yet most turtles are agile, strong walkers or swimmers and many
climb with great ease. They have developed strong legs, especially
in giant species, like the Ga-lapagos tortoise which travels great
distances, although slowly. They could carry the weight of a man
on their back and keep right on going. The tor-toise travels about
4 miles a day. On the other hand, sea turtles have devel-oped flipperlike
legs and sleek shells. They swim at about 20 miles an hour. The
distance a sea turtle might travel in one hour would take a week
for a tortoise to cover.
Turtles are ancient life forms. The earliest fossils recognized
as turtles date from the Triassic period, about 200 million years
ago. Turtles were in existence prior to the emergence of the great
dinosaur groups and survived the demise of the dinosaurs, continuing
to adapt and flourish. Turtles occupy al-most every imaginable habitat—woods,
ponds, rivers, lakes, marsh-lands, prairies, deserts and the open
ocean, and they eat food as varied as insects, tender seagrasses,
carrion, fruit and fish.
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Turtles have great similarity yet great
variation as well. The Galapagos tortoise evolved on islands with
no predators and little competition. They grow very large—500-600
pounds—and live 100-150 years. Desert tor-toises are much
smaller. They eat cac-tus fruit and desert grasses and be-cause
of their environment, God has given them adaptations to be able
to survive without water. They get the moisture they need from the
food they eat.
The pancake tortoise of Africa has a flat, soft shell, instead
of the hard dome common to most turtles. It looks sort of like someone
dropped a frying pan on him. This allows him to easily climb rocks
and lie under them. When threatened, he will wedge himself into
a rocky crevice and then inflate his body so he’s almost impossible
to pull out.
The red toad-headed turtle with its brilliant red head is an example
of the variation in bright and beautiful col-ors. Various beautiful
design patterns on the shell show God’s wondrous creation.
These include map turtles, so named because of the intricate patterns
of yellow lines that actually look like lines on a topo map; the
radiated tor-toise of Madagascar has yellow circles with lines radiated
out from them; and the leopard tortoise of Africa whose shell is
covered with distinctive and beautiful yellow spots.
One fascinating turtle species is the alligator snapping turtle,
which may grow to 200 pounds. He lives on muddy river bottoms, sitting
quietly with his brown shell blending with the mud. He keeps his
mouth open and wiggles his tongue which is a bright pink. Like a
lure, this attracts fish which swim right in and the turtle sim-ply
snaps its mouth shut. They may move no more than a few feet their
whole lives.
Tortoises live almost exclusively on land. Many turtles move between
land and water. Sea turtles spend virtually |
their whole life in water. The female
comes out to lay eggs and she will re-turn to the very beach where
she was hatched. The whole process is truly amazing. She comes on
shore, usually at night, and digs a nest into which she lays up
to 100 eggs. She buries the eggs and leaves. As the embryo grows
into a fully developed hatchling, the shell that has offered nourishment
and protection becomes a kind of prison from which the baby turtle
must es-cape. God has provided an “egg tooth,” actually
a horny projection lo-cated on the tip of the snout (which disappears
as the turtle grows). The tiny hatchling uses it to pierce its shell,
then pulls it apart with his forelimbs. All eggs in a nest hatch
at virtually the same time and they use that commu-nity spirit in
order to escape from the nest. Experiments with single eggs show
that few break free on their own. Together the baby turtles scrape
down the walls and ceiling of the nest and instinctively climb upward
till they break free.
Then these hatchlings, only a couple of inches long, know that
they must scramble for safety, perhaps a hundred yards or more across
the open beach to the sea. And it’s not just the hundred-yard
dash that’s difficult; predators of all kinds are waiting—birds,
dogs, skunks and others seem adept at know-ing where nests are and
when they will hatch. Only a fraction make it to the sea and even
then they are easy pick-ings for large fish and sea gulls.
Little is known of the first year of wild hatchlings. They simply
disap-pear from sight, going weeks without food if necessary and
struggling to es-cape predators of all kinds. Those that survive
to adulthood will spend their lives, perhaps 50 years, swimming
around in the open ocean.
The male turtles may never leave the ocean their whole life; the
female only to lay eggs. We do not understand how turtles, migrating
over great
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