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Notis: Det följande är en reproduktion av artiklen
"Reptiles III: Crocodilians."
Of all reptiles, the most feared and perhaps least well known are the
crocodilians, which includes 22 species of crocodiles, alligators, caimans and
gharials. I knew almost nothing about them, except how fearsome they
look—especially when you’re sitting in a canoe and see one on the shore (that
happened for me in Florida a few years ago). I learned a lot of fascinating
things about these creatures of God.
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They’ve been around about 200 million years. They, like the turtles, were
contemporaries of the dinosaurs. As primitive as they look, they are actually
the most advanced of all reptiles, and are in fact more closely related to birds
than to lizards. They have a more efficient circulatory system; they are more
intelligent; and they are way more attentive of their young.
Crocodilians inhabit North America, Central America, South America, China
and Southeast Asia, Africa, Australia, India, Pakistan and many Pacific Islands.
The Indopacific Crocodile is the largest reptile living. It reaches 23 feet
or more, weighing maybe a ton. Even the smallest croc, the dwarf crocodile
of Africa, is about 6 feet long.
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There's a lot that's interesting about the way they care for their young.
The female makes a nest, lays eggs-it varies from species to species, but
anywhere from 20 to 80 eggs-and covers them with mud and plant material.
Then, unlike other reptiles, she stays close by. In some species even the
male stays around for protection. When the young crocs are ready to hatch
they begin to make noise inside the eggs. She will dig into the nest and
take the eggs one by one in her mouth. She rolls them gently back and forth
until the shell cracks. She then takes the tiny crocs down to the water-she
can carry up to 20 at a time in her huge mouth. They will then stay close
together for weeks or months. Some even remain in family groups for years.
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Despite all this attention and care, mortality rates are as high as 90% in
the first year. Many things happen. The female doesn't sit on the nest like
birds so climatic conditions will affect the eggs. If it's too cool, too
wet, or too hot, the eggs will not develop. In many cases, the whole clutch
will perish. Predators hang around even though the female is nearby, because croc eggs
are a prime source of food for so many other animals. Many female crocs fast
while standing guard but they do need water. Predators wait for her to go
get a drink. Lizards, birds, raccoons, foxes and monkeys all raid the nests.
If the eggs survive, the hatchlings face a lot of dangers, as the tiny crocs
also are food for all kinds of predators-frogs, snakes and turtles, herons,
raccoons and other mammals. Interestingly, if the croc survives to adulthood,
all these predators will become his prey.
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53:45 He is the One who created the two kinds,
male and female.
75:39 He made it into male or
female.
I think the most interesting thing about crocodilian offspring is that it
is truly God who decides the male and female. We know that's true for everything,
but in this case, the sex of the offspring is determined by temperature,
not by chromosomes. When the egg is laid, its sex has not been decided.
Temperatures during the first half of incubation will determine the sex of
each individual. In the American alligator, high temperature creates males,
low temperature makes females, but in the crocodile high and low temperatures
create females, only intermediate temperature makes males. A small difference
in temperature-One or two degrees-makes a marked difference in sex ratio.
Within a nest, all may be the same sex or the temperature may vary enough
to have all females in the lower layer of eggs and all males above or vice
versa. In American alligators, those who build their nests in cool marshes
will have all females; those who nest in warm mounds will have all males.
Muggers of India nest at different times throughout the season, in fact a
single female may nest twice. Those that nest early in the season will produce
mostly females; those who nest later when the soil temperature has risen
will have mostly males. I think this is fascinating. God is the One who makes
each of these creatures into male or female.
Crocodilians are well adapted as predators. When in the water, they swim
casually using a gentle "s" motion of their tail to propel them. They stay
almost completely submerged with only nostrils and eyes above the water,
looking like a small log. They may smell prey on shore from a great distance
and swim closer, with a final lunge that may carry the croc several times
its own length up onto the beach. If it gets a hold of any part of the animal,
it will win. It will pull the victim into the water where it drowns. If it
doesn't get a hold, it may knock the animal over with several blows of its
head. In addition, crocs will sneak up on a wading bird and as it takes off,
the croc can leap out of the water almost vertically. And if large game isn't
available, the croc will use its tail to sweep schools of fish toward its
mouth and gobble up as many as possible.
As to diet, one book said adults will eat "anything they want." They regularly
take down mammals that come to drink at the water's edge, like gazelle, even
zebras and wildebeest. They can crush the strong bony shells of turtles.
They may try to take a hippo or elephant calf but the mother will be protective
and have been known to crush crocs. The Nile crocodile has a reputation as
the number one killer of beast and humans on the African continent. A crocodile
wouldn't go out of his way to find a human victim but they will take anything
presented to them. A horrible incident from World War II happened off the
coast of Burma. A thousand Japanese soldiers, fleeing the allied advance,
tried to cross a mangrove swamp at night. British troops reported the horrifying
sounds, and at dawn only about 20 were found alive. The crocs were simply
following their instincts and taking advantage of an easy meal.
Had I known all this, I might not have been so blasé in my encounter
with the alligator in Florida. My sister and I were canoeing and we knew
that alligators were present. The canoe rental place had basically said not
to worry, just keep paddling. We heard a huge sound and both of us saw the
alligator at the same time. Fortunately it was at least 50 feet from us,
on shore, but looking our way. Everything stopped, including my heart. It
was a typical American alligator, about 8 or 9 feet long, and I felt incredibly
small and insignificant. I said Bismillah and started to breath again and
we kept paddling. When we came back the alligator was gone.
This was a great gift. The opportunity to see one of God's amazing creatures
in its natural habitat. I'm thankful that I don't live where I have to wash
my clothes in the same river where crocodiles lie in wait, but I'm also thankful
for the opportunity to see one and know a little bit of that fear and awe.
Och GUD
skapade alla levande varelser från vatten. En del av dem går
på sina bukar, vissa på två ben, och andra på
fyra. GUD skapar vad Han vill. GUD är Allsmäktig. (24:45)
Reptiles are awesome creatures, nearly 6000 different species, so many
variations. They walk on their bellies, they walk on two legs, they walk
on four. They are part of God's intricate interwoven plan on this earth.
We like them or we fear them, but we need to appreciate them. For their part,
they just want to be left alone, in their submission to God. Unlike dogs
and cats, they don't want to bond with us or serve us; they just want to
be allowed to do their own thing. A naturalist, Henry Beston, wrote in
The Outermost House: "For the animal shall not be measured
by man….They are not brethren, they are not underlings; they are other
nations, caught with ourselves in the net of life and time, fellow prisoners
of the splendor and travail of the earth." How true, for God says in 6:38:
All the creatures on earth and all the birds
that fly with wings are communities like you. We did not leave anything out
of this book. To their Lord, all these creatures will be
summoned.
Lydia Kelley
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