Monday, October 7, 2013

For children, - The survival tactics of polar animals

Emperor Penguins
Emperor penguins are able to dive to depths of 500 meters (1,640 feet)
for up to 20 minutes with no adverse effects to their respiration or
blood pressure. They also possess the ability to adapt to these
conditions in different ways. While diving, they are able to lower
their heartbeats from 200 a minute to only 60, thus allowing them to
store extra myoglobin.
How Can Penguins Hold Their Breath for So Long?
Myoglobin is a protein present at high levels in these birds' muscles.
These myoglobin proteins bind to themselves high numbers of oxygen
molecules. In other words, the penguin conserves the oxygen it will
need not in the air held in its lungs, but directly inside its
muscles. This lets penguins swim underwater for long periods and to
dive as deep as they wish, without relying on the breathed-in air held
in their lungs..
Why Do They Not Suffer from the Bends?
Penguins are able to continue swimming even when the oxygen in their
blood drops to the lowest levels. Human beings suffer from the bends
under such conditions. The level in question is 20 mm Hg for penguins
and 25 mm Hg for humans. However, scientists have been unable to
explain how penguins can to overcome this in the water without being
affected by low levels of oxygen in the blood.
How Can They Go Without Food for 65 Days?
Male penguins have a secret that lets them survive without eating
anything for 65 days, until the females arrive to take of the young in
order to protect their eggs: they possess a structure capable of
blocking their digestive systems..
Their Magnificent Diving Costumes
Adult penguins on the ice eat nothing for months until after they
shedd their coats in the summer. All their old feathers are shed, and
new ones emerge from underneath. The result is a windproof, insulated
and waterproof diving suit that prevents cold—whether from icy wind
or frigid water— reaching their skin. The most striking feature of
their new plumage is that it appears just when the penguins need it
most— when the time to migrate has arrived.
Brief Facts from the Pole
In the middle of winter, daylight at the North Pole last for only
three hours. In order to protect themselves from the freezing cold
during the other 21 hours, penguins huddle up against one another in
the dark.
By huddling up to one another, the male penguins are able to raise
their body temperatures to up to 20° C (68 oF).
Since solitary penguins are unable to benefit from other penguins'
body heat, they cannot survive in temperatures any lower than -10° C
(14 oF)
Under Such Conditions, How Can Penguins Walk for Many Kilometers with
Such Large Bodies and Short Legs?
In order to conserve energy when they walk, penguins waddle from side,
to side, which tires their muscles less. In this way, at the end of
every step, they store up enough momentum for the next. If they
employed a normal gait, their short legs would force them to expend
twice as much energy as any other animal their own size. However,
penguins exert the most energy only when they start to walk and when
they want to stop.
These features of penguins are some of the greatest proofs of Allah's
affection and compassion for living things. Walking in such a way as
to conserve energy by using the conversion of kinetic and potential
energy and back again is something no bird can learn on its own. No
penguin can know about potential-kinetic energy conversion and develop
such a gait as to take advantage of this, unless so inspired by Allah.
Allah's sovereignty over living things is revealed as follows in one
verse of the Qur'an:
"I put my trust in Allah, My Lord and your Lord! There is not a moving
creature, but He hath grasp of its fore-lock. Verily, it is my Lord
that is on a straight Path." (Surah Hud, 56)
How Do Seals Locate Their Prey in the Dark?
A seal locates its prey without using its eyes by following traces
that its quarry leaves behind it in the water. These traces, invisible
to the naked eye, are hydrodynamic waves set up by the movement of the
prey. Just by following these traces, a seal is able to catch its
prey. Thanks to this ability, seals have no difficulty in hunting in
the dark or in murky water.
Secret Whale Feeding Techniques
The cold waters of the North Pole are actually very rich in
nutrients—for which reason, whales deliberately migrate to these from
warmer waters. During their time near the Pole they consume small,
shrimp-like fish known as krill, and store up nutrients in their
blubber.
When a pod of whales locates a school of fish or krill, they act in
unison. When the fish sense danger and start diving to the bottom, the
whales dive down even deeper, en masse, and immediately begin exhaling
air bubbles, which form a kind of stockade or barrier cage around the
fish. These bubbles that spread around the fish and stop them getting
away form a round wall. Then all the whales need to do is to open
their mouths as they begin returning to the surface through the middle
of this ring. Thanks to this planning and joint action, they are
easily able to engulf their prey.
For all this astonishing behavior, there is only one explanation:
These birds and marine mammals behave in accordance with the
inspiration of Allah, their Creator.

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