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Unforgettable Lizard Moments | BBC Earth
Unforgettable Lizard Moments | BBC Earth
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उपशीर्षक (213)
0:04
And now the snakes are on the alert.
0:08
This is the best feeding opportunity
0:10
[music] they will get all year.
0:28
On flat ground, a baby iguana can outrun
0:31
a racer snake.
0:34
But others are waiting in ambush.
1:04
Another hatchling has its first glimpse
1:06
of a dangerous world.
1:41
>> [music]
2:06
>> A snake's eyes aren't very good,
2:09
but they can detect movement.
2:13
So, if the hatchling keeps its nerve, it
2:15
may just avoid detection.
3:28
>> [music]
3:36
[music]
3:49
>> A near miraculous escape.
3:58
The lucky survivors could begin learning
4:01
the unique way of life
4:03
demanded by this hostile island. A
4:05
female catches the eye of a male.
4:20
He starts to follow her wherever she
4:23
goes.
4:31
Couples stay side by side for up to 2
4:34
months.
4:39
>> [music]
4:50
>> He courts her by gently nudging and
4:53
licking her.
5:05
>> [music]
5:15
>> Six months pass. And then,
5:18
eventually, the results of this
5:20
prolonged courtship begin to arrive.
5:27
It's a long and strenuous business for a
5:30
mother shingleback.
5:48
She produces not a small egg like the
5:52
five-lined skink,
5:54
but a live baby.
6:09
It's a whopper.
6:12
>> [music]
6:35
>> And there's another one to come.
6:38
Together, the two weigh as much as a
6:40
third of her body weight, the equivalent
6:43
in human beings of carrying a 3-year-old
6:45
child.
6:51
He's a marine iguana,
6:58
the only lizard in the world that gets
7:00
its food from the sea.
7:15
The seaweed on which he totally relies
7:18
only grows in abundance here because of
7:20
the nutrients brought by the Humboldt
7:23
Current.
7:30
Once in the water, he has just 30
7:33
minutes to find food.
7:43
Any longer than that and his muscles
7:45
will seize up and he'll drown.
7:49
For like most [music] reptiles,
7:51
he can't handle the cold.
8:02
Chillier water isn't a problem for a
8:04
warm-blooded cormorant.
8:07
She can swim in it all day, but can only
8:10
hold her breath for a few minutes.
8:20
He, on the other hand, completes his
8:22
whole half hour trip on one single
8:25
breath.
8:28
His flat face and sharp teeth make him
8:31
an efficient seaweed cropping machine.
8:34
But with the clock ticking, he must eat
8:36
fast.
8:41
The cormorant has been caught its fish.
8:44
It goes back to the surface.
8:49
One last mouthful and it's also time for
8:52
the iguana to head for home.
8:57
But to stop his muscles from seizing up
8:59
in the cold water, he must get back
9:02
quickly.
9:07
So, he could do [music] without the
9:08
attentions of an inquisitive sea lion.
9:35
>> [music]
9:35
>> Dry land is now just m away,
9:39
but the biggest hurdle is still to come.
9:51
The surging water now fights against
9:54
him.
10:02
He's out,
10:03
but he's stayed in the cold so long that
10:05
he's lost his strength.
10:10
>> [snorts]
10:17
[music]
10:24
[music]
10:48
>> And he's made it. This is the South
10:51
African dwarf chameleon, a male in full
10:53
courtship costume.
11:00
This, somewhat less colorful, is a
11:02
female.
11:09
She is not welcoming his advances.
11:19
As her mood darkens, so does her skin.
11:44
>> She's driven him away.
11:46
But why?
11:55
There is a reason.
11:57
>> [music]
11:58
>> She's pregnant.
12:00
Her home, the South African Cape, can
12:03
get quite cold.
12:04
So, instead of laying her eggs on the
12:06
ground as most chameleons do,
12:09
she retains them within her body and
12:12
warms them by seeking out the sunniest
12:14
places and sunbathing.
12:17
Now, they're ready to emerge
12:20
alive. [snorts]
12:29
Pushing babies in the branches might
12:31
seem to be a risky business,
12:34
but the membrane enclosing each one will
12:36
stick to a twig
12:38
if it hits one.
12:42
And when at last the babies disentangle
12:44
themselves,
12:46
they immediately deploy their formidable
12:48
chameleon grip.
13:44
>> By the time they're properly dried out,
13:47
the babies are as much at home in the
13:49
branches as their mother.
14:11
I'm in Arizona and that at my feet is a
14:14
lizard buried in the sand up to its
14:17
neck.
14:20
Even while it's buried, it can use the
14:22
sunshine to warm its whole body. It can
14:25
control the supply of blood to its head
14:27
[music] so that it pools in a cavity
14:29
behind the eye.
14:31
Soon the blood there is as much as 5°
14:34
above the temperature of the rest of its
14:36
body.
14:37
Then the animal opens the major blood
14:40
vessels in its neck and the hot blood
14:42
circulates so that its whole body is
14:44
thoroughly warmed even though it's still
14:47
mostly below ground.
14:56
This
14:58
is a horned lizard
15:01
>> [snorts]
15:02
>> and very beautiful, too. This particular
15:04
species is called
15:06
the regal horned lizard because it has
15:08
this splendid crown of spikes at the
15:11
back of his neck.
15:13
When he's hidden, they break up the
15:15
outline of his head and so you hardly
15:17
see him at all.
15:19
And now in the warmth of my hand and in
15:21
the sunshine, I guess he's warmed up
15:23
quite a lot.
15:24
And if I put him down, he now, at last,
15:28
may be able to run for it.
15:31
And indeed he does.
15:41
South African armadillo lizards, which
15:44
live on these rocky outcrops,
15:46
have a different solution to the problem
15:48
of safe sunbathing.
15:51
They've turned it into a social
15:53
activity.
15:56
Whole families of them live together in
15:58
the crevices among the rocks, and in the
16:00
morning, they all emerge to warm up in
16:03
the sun.
16:05
Of course, there is safety in numbers.
16:10
There are lots of eyes to spot danger if
16:13
it appears.
16:26
And when one sunbather takes fright,
16:29
they all dive for safety.
16:32
If a predator is quick, it is possible
16:35
to grab one, but even then, an armadillo
16:37
lizard is not going to be an easy meal.
16:40
>> [laughter]
16:42
>> They have an additional form of defense.
16:45
They bite their tails.
16:48
The reason they do that
16:50
is that it covers up
16:53
their vulnerable underside and exposes
16:56
only these very sharp, spiny scales,
17:00
which is very good protection against
17:02
predators like snakes or mongooses.
17:07
And they stay like this for quite a long
17:09
time before they are confident enough to
17:12
uncurl. I'll put him down and see how he
17:15
does.
17:27
Lizards, for the most part, are not
17:30
known for being caring parents, but
17:33
there are exceptions.
17:35
It's spring in the woodlands of North
17:37
America, and American robin is nesting,
17:40
warming her eggs with the heat generated
17:42
by her own body.
17:45
And below, on the forest floor,
17:47
[laughter] a five-lined skink is warming
17:50
her cold-blooded body by basking in the
17:53
sunshine, so that she can do the same
17:56
thing.
18:05
She has a nest below the log.
18:13
It can get quite chilly in these
18:15
woodlands, and she warms her eggs by
18:17
transferring to them the heat that she's
18:20
collected from the sun.
18:35
She takes just as much care of her eggs
18:38
as the robin does.
18:48
A month later, and her eggs are
18:51
hatching.
19:05
The robin's eggs have hatched, too.
19:07
Her nestlings are helpless and need
19:10
[music] constant feeding.
19:12
The young skinks, however, are already
19:15
capable of finding food for themselves.
19:27
Within a day or so, they've left their
19:29
mother and are independently exploring
19:31
the woodland floor for themselves.
