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00:00To be continued...
00:30Reptiles and amphibians are sometimes thought of as primitive, dull and dim-witted.
00:44In fact, of course, they can be lethally fast, spectacularly beautiful, surprisingly affectionate and very sophisticated.
01:00They have remarkably varied ways of catching their prey, and of defending themselves.
01:10They can produce a great turn of speed, and fight with impressive zest.
01:17Some have spectacular colours and show off to one another.
01:34They communicate with calls.
01:43And with gestures.
01:45And there, that's it.
01:51The fool works.
01:55Reptiles have scaly skins.
02:00And amphibians, soft, moist ones.
02:03None of them live at a uniform pace, but switch from the fast to the slow lane within a year or an hour.
02:14Unlike us, they get their energy directly from the sun.
02:22And although being called cold-blooded might suggest they are unemotional, they can be touchingly warm-hearted.
02:31As mates.
02:32As mates.
02:38And as parents.
02:39And that's just the beginning.
02:53There are a whole lot of other warm-hearted truths to be discovered
02:58that give the phrase, life in cold blood, a completely new meaning.
03:02The Galapagos Islands.
03:16Some of the reptiles that live here are particularly skilful at solving the problems of getting their energy directly from sunshine.
03:24Marine iguanas face a major thermal challenge every morning of their lives.
03:33During the night, their bodies cool.
03:36And now they must warm up quickly in order that they can become active and start feeding.
03:43Their bodies and skins are black, which is very efficient at absorbing heat.
03:48And they bask with their black flanks broadside to the sun.
03:59The rate at which they absorb warmth is invisible to the naked eye, but very clear indeed to a thermal camera.
04:09First thing, they're cold and purplish-blue.
04:12But slowly, as they warm up, a golden glow spreads through their bodies.
04:19And eventually, after half an hour or so, they become as hot as the rocks beneath them.
04:25Once they're thoroughly warmed up, marine iguanas can maintain their body temperature just about as constantly as I can.
04:33And what's more, at about the same level, or indeed slightly higher, around 37 degrees centigrade.
04:40Now they need to feed.
04:45There's nothing to eat on or around these barren rocks except seaweed.
04:49And to get that, they'll have to swim.
04:53But the sea around here is surprisingly cold.
04:57Around 15 to 16 degrees centigrade.
05:00And only the bigger iguanas can absorb enough heat to power the dives to enable them to go to the seaweed at any depth.
05:14However, their bodies are now thoroughly warmed up.
05:17The thermal camera shows them as golden yellow as they clamber down over the cold blue rocks and dive into the sea.
05:26Although their islands lie almost exactly on the equator, the sea here is permanently chilled by a cold current that sweeps up from the depths of the ocean.
05:44So they won't be able to stay in the water for very long.
05:58They have no time to waste.
05:59In the shallows, close to the shore, the seaweed has been heavily cropped.
06:07To get a good meal, they may have to dive to at least 15 feet, 5 meters.
06:12They're able to reduce the chilling effect of the cold water by closing down the blood supply to their limbs and the outer part of their bodies.
06:24But even so, their body temperature may drop by 10 degrees or so.
06:29A cooling like that would kill a human diver.
06:32After five to 10 minutes on the sea floor, most iguanas have had enough.
06:41And they return to the surface and the life-saving warmth of the rocky shore.
06:51A recently emerged iguana is black. It's chilled to the bone.
07:02Now they need heat in order to be able to digest that meal of seaweed.
07:07And they get that by spread-eagling themselves on these black, hot, sun-baked rocks.
07:17Their image warms from black...
07:21...to purple...
07:24...and then from red to orange.
07:26In the evening, the temperature falls, and they huddle together to retain their warmth as long as possible.
07:42They will have to wait until the following morning before they can re-warm themselves sufficiently to feed again.
07:49Most kinds of lizards have this daily schedule.
07:55Side-blotched lizards in California certainly do.
07:59You can see from the colour of my face that my body is warm.
08:03That's because I've got a central heating system which I've fuelled with my breakfast.
08:09In fact, about 80% of what I eat is used in keeping my body temperature high and steady.
08:15These lizards, however, squander very little of the energy they get from their food on warming themselves.
08:23They, like the marine iguanas, get nearly all they need for that by basking on the warm rocks.
08:29And so important is the need for warmth that the females actually choose their males on the basis of which has the best underfloor heating.
08:41Each male sits on his pile of boulders doing press-ups to signal his ownership and to warn off other males.
08:52Intruders are confronted immediately and, if necessary, attacked.
08:57And the victor returns to sit on his wonderfully warm throne.
09:15Look at his rocky kingdom with a thermal camera and it's immediately clear why it's so precious.
09:27The rocks are very much hotter than the surrounding grassland and big tall ones catch the sun earlier and retain its heat longer.
09:35So, not only does the sun warm him from above, his rocks do from beneath.
09:42The most powerful dominant male has, naturally, the best pile of rocks.
09:47And, not surprisingly, almost all the females.
09:51But, is it the males themselves or their assets that the females are interested in?
10:04To find out, let's move their hot rocks and give them to a subordinate male.
10:09The females quickly recognise that a more desirable residence has appeared in the neighbourhood and start to move across.
10:30And, the sex-starved wimp suddenly finds himself amazingly popular.
10:44So, the females do indeed go for the males with the hottest rocks.
10:50These lizards, on a small island off the shores of Menorca in the Mediterranean, get their heat from another, and very unusual, source.
11:04Ow!
11:08Sorry!
11:11They're very curious.
11:12I'm the new boy on the block, the new object in their environment.
11:17And that one just gave me a little nip.
11:23They investigate the world around them by tasting it, and they're still trying to work out what I am.
11:34Their island is rocky and not particularly rich in food.
11:38The lizards are primarily insect-eaters, but during the flowering season they also take nectar.
11:43They collect it from plants, like spurge, which is very common.
11:47And they have a very special relationship with this flower.
11:52It's called the dead horse arum.
11:55And it certainly looks like carrion, and...
11:58Oh boy!
12:00It smells very strongly of carrion.
12:02As a consequence of both its looks and its smell, it attracts carrion flies.
12:09And, of course, it's the flies that the lizards are after.
12:14But as well as providing food for the lizards, this extraordinary flower helps them in another way.
12:21If this central part, which is called the spadix, is slightly warm, as you can see from a thermal camera.
12:32The chemical process that produces the disgusting smell also creates heat,
12:38and raises the temperature of the flower by up to five degrees above the surroundings,
12:43sufficiently high for a lizard to warm itself on it on a cold morning.
12:48And in case you find that hard to believe, here is confirmation from the thermal camera.
12:52The purplish-blue lizard quickly takes on the same temperature and colour as the arum.
13:05And sitting on arums brings another benefit.
13:12Breakfast.
13:14A fly, lured by the smell, crawls inside.
13:17The lizard hears the fly buzzing within.
13:26The fly, of course, can't find anything it wants, but now it can't get out.
13:31The entrance to the flower is blocked by the lizard.
13:33And the lizard gets an easy meal.
13:56Two months later, the arum flowers have shrivelled and produced their fruits.
14:00Until twenty years ago, the lizards ignored these withered bundles.
14:07After all, they hardly looked like food.
14:10But then, a particularly inquisitive individual sampled a fruit,
14:15and found the soft flesh around the seed rather good.
14:18The habit spread, and now the whole lizard population, uniquely in the Mediterranean,
14:24have become arum fruit-eaters.
14:25They do take a bit of swallowing, but seeds passing through a lizard's gut not only survive,
14:35but germinate even more easily.
14:38As a result, the arums, which were rather scarce here twenty years ago,
14:43have suddenly become abundant all over the island.
14:45A cold, windswept island off the coast of South Africa is not the first place you'd go to
14:54if you were looking for reptiles.
14:55But here on Dasan Island, among penguins and seagulls,
15:00there's one of the greatest concentrations of tortoises to be found anywhere on Earth.
15:04There are about 5,000 of them on this one tiny island.
15:05There are about 5,000 of them on this one tiny island.
15:06The penguins, and other birds!"
15:11are looking for reptiles. But here on Dasan Island, among penguins and seagulls, there's
15:18one of the greatest concentration of tortoises to be found anywhere on earth. There are about
15:255,000 of them on this one tiny island. The penguins and other birds, thanks to their
15:36warm blood, are active no matter how cold it is. But the tortoises have to wait for the
15:41day to warm up before they can get about their business. They bask in the sunshine, powering
15:53up their bodies to the optimum working temperature of 33 degrees centigrade, and then they go off
16:00to feed. As the day progresses, the temperature rises quickly, and even before noon it's too
16:22hot for comfort. The tortoises have to head for shade.
16:41In the late afternoon, it gets cooler and the tortoises venture out again. For them, this
16:47is the best time. They're thoroughly warmed up, they've digested their morning meal, and
16:53they've got energy to spare.
17:02The males begin to fight, jousting like medieval knights, using a projection on the front of
17:10the shell, like a lance.
17:17The technique is to get the spike under your opponent, and then flick him over onto his back.
17:28Contests can last for half an hour.
17:40No comment to illustrate the cru Efrain series'
18:00prochains delve everything's alive.
18:05The loser tries to right himself, but the winner keeps biting his nose. He's going to be
18:08but the winner keeps biting his legs.
18:24At last, the victor loses interest
18:26and goes off to find the female who caused the argument in the first place.
18:31As for the loser, if he doesn't manage to right himself soon,
18:35he may cook in the sun.
18:38.
18:46Tortoises are able to sunbathe out in the open
18:49because their strong, bony shell
18:51gives them almost complete protection from predators.
18:58Less well-armored reptiles, like lizards,
19:01are vulnerable, of course, to hawks and coyotes and foxes and cats.
19:08And in the morning, when those warm-blooded animals are already active,
19:12the lizards are cold and can't move fast, so they have a problem.
19:17But they also have a solution.
19:21Secret sunbathing.
19:23You really can't see them until you're right on top of them.
19:28And there's one there.
19:32I'm in Arizona, and that at my feet is a lizard buried in the sand up to its neck.
19:41Even while it's buried, it can use the sunshine to warm its whole body.
19:47It can control the supply of blood to its head so that it pools in a cavity behind the eye.
19:53Soon, the blood there is as much as five degrees above the temperature of the rest of its body.
20:00Then the animal opens the major blood vessels in its neck,
20:04and the hot blood circulates so that its whole body is thoroughly warmed,
20:09even though it's still mostly below ground.
20:11This is a horned lizard, and very beautiful too.
20:27This particular species is called the regal horned lizard
20:31because it has this splendid crown of spikes at the back of his neck.
20:36When he's hidden, they break up the outline of his head,
20:40and so you hardly see him at all.
20:42And now, in the warmth of my hand and in the sunshine,
20:46I guess he's warmed up quite a lot.
20:48And if I put him down, he now, at last, may be able to run for it.
20:53And indeed he does.
20:56South African armadillo lizards, which live on these rocky outcrops,
21:09have a different solution to the problem of safe sunbathing.
21:13They've turned it into a social activity.
21:17Whole families of them live together in the crevices among the rocks,
21:23and in the morning they all emerge to warm up in the sun.
21:28Of course, there is safety in numbers.
21:32There are lots of eyes to spot danger if it appears.
21:38And when one sunbather takes fright, they all dive for safety.
21:55If a predator is quick, it is possible to grab one.
21:59But even then, an armadillo lizard is not going to be an easy meal.
22:03No!
22:04They have an additional form of defence.
22:09They bite their tails.
22:11The reason they do that is that it covers up their vulnerable underside
22:19and exposes only these very sharp spiny scales,
22:24which is very good protection against predators like snakes or mongooses.
22:30And they stay like this for quite a long time
22:34before they are confident enough to uncurl.
22:37I'll put him down and see how he does.
22:54Sunset necessarily brings an end to activity for most reptiles.
23:02Not for all.
23:05A leopard gecko.
23:06It, like most geckos, is nocturnal,
23:08and it manages to get all the heat it needs from the rocks,
23:11which retain something of their warmth
23:13for several hours after the sun has set.
23:18This male is in search of a mate.
23:21She is less brightly coloured.
23:28They inspect one another.
23:35He collects her scent with his tongue
23:37and discovers that not only is she female,
23:39but she's sexually available.
23:48He's interested.
23:50He nibbles her neck and strokes her flanks,
23:57all part of his elaborate courtship routine.
24:08Copulation begins.
24:13This is the time in Mammals and Birds
24:15when the sex of the young is determined,
24:18but not in a number of reptiles, including geckos.
24:22Once again, it's temperature
24:24that profoundly influences their lives.
24:29The female goes away to lay her eggs.
24:34She has chosen a place where the temperature is about 31 degrees.
24:38As her body is the same temperature as her environment,
24:42she can't heat her eggs by sitting on them
24:44as warm-blooded birds do.
24:46So they're exactly the same temperature as the rocks beneath.
24:52After a couple of months, both eggs begin to hatch.
24:55The first to emerge is a male.
25:12And the second will be two.
25:14It's the temperature which has determined that.
25:17If it had been a few degrees lower,
25:19both eggs would have developed into females.
25:22Crocodiles have their sex determined by temperature in a similar way.
25:37This clutch belongs to the Indian fish-eating crocodile, the gharial.
25:52The female has heard the calls from below ground
25:57made by her hatching young
25:59and is helping them to dig their way out of the sand.
26:13They immediately make their way down to the water.
26:16And mother goes too.
26:35Here, of course, they are nice and warm.
26:39Water retains its daytime heat better and longer than rock,
26:43so unlike many other reptiles,
26:45gharials and other crocodilians
26:47have enough energy to feed actively all night.
26:50Water retains its daytime heat better and the water becomes perfect.
26:53Water retains its daytime heat whenever this is green.
26:55It's a black-kissed out of the sea.
26:56Water retains its daytime heat.
26:58And that's still an amazing looks at the sea.
27:00The sea has always got a little bit of rain.
27:03The sea has always been the first to go out of the sea.
27:05A little bit of rain after this is long,
27:07and the sea has always been the most beautiful.
27:09From the sea O'erreceptor,
27:11it's a way to the sea.
27:12While being nocturnal is unusual among reptiles, it's the norm for amphibians.
27:27Their skin is not scaly and watertight like a reptile's.
27:30It's soft, moist and permeable.
27:33If they exposed themselves to sunlight for any length of time, they would dry out and
27:38die.
27:39So most frogs only leave their shelters at night.
27:47Since they can't absorb sunshine directly, they either get their heat from their surroundings
27:53or draw their energy from the fat reserves that they built up when the feeding was good.
27:58But even so, they seldom hop unless they have very good reason to do so.
28:05This frog, however, the South American waxy monkey frog, is exceptional.
28:12It's one of the few that can tolerate direct sunshine for any length of time.
28:17And that is because it secretes a wax from glands on its neck.
28:37No human sunbather goes to more trouble than they do to make quite sure that every part
28:43of their skin is properly anointed.
28:45The sunshine may also bring them an extra benefit.
28:53It probably protects them from the fungal infections to which many moist skinned amphibians are prone.
29:07In the rainforests of Central America, the air is heavy with moisture.
29:25So the poison arrow frogs can risk basking in the little patches of sunshine that dapple the
29:40forest floor, and if they begin to dry out, they can retreat into the leaf litter.
29:44The sunshine gives them sufficient energy to permit the extravagance of calling almost continuously
29:55in defense of their territories.
30:01They even have enough spare energy to indulge in long battles with their neighbors.
30:06And the rain will be out of them.
30:23You're in the rainforest.
30:27You're in the rainforest.
30:30You're in the rainforest.
30:32You're in a rainforest.
30:33These fights can go on for well over half an hour at a time
30:58until both contestants are completely exhausted.
31:03So, a moist skin limits not only where amphibians can live, but how energetic they can be.
31:17Out in the sunshine, dry-skinned reptiles have more options.
31:23By collecting solar power so efficiently, reptiles need to use very little of the energy
31:29they generate themselves to warm their bodies.
31:33In fact, they use around a tenth compared with a mammal of a similar size.
31:38That means they don't have to eat very often.
31:42A puff adder, like this one, can wait almost indefinitely for its next meal.
31:48Amongst predators, patience really is the virtue.
31:53Whilst waiting for a meal to wander within striking distance, a snake shuts down its
32:02body processes so that it uses the minimum amount of energy.
32:07Only the equivalent of a pilot light is left on.
32:11And it can remain like this for weeks.
32:16All around it, mammals are expending their energy in a way that, compared with a snake, seems
32:22extraordinarily extravagant.
32:24a snake.
32:26But when a snake needs to move fast, it can do so with lightning speed.
32:42Once its prey is secured, a snake can take its time over its meal.
32:59This gigantic python is feeding on a deer.
33:04A python kills its prey by wrapping its coils around it and squeezing its victim so tightly
33:10and for so long that it can no longer breathe.
33:14But swallowing its meal takes time.
33:18The deer will go down head first.
33:20It's much easier that way.
33:33The ligaments connecting the snake's upper and lower jaw are elastic so that it can engulf
33:38the deer's head even though it is much bigger than its own.
33:43With its mouth stretched tightly around its meal, the snake can't breathe in a normal way.
33:49But it's able to push the top of its windpipe right out of its mouth and so continue to take
33:55in air.
34:13After some hours, all that can be seen of the deer are its hind legs.
34:33Once the meal has been completely swallowed, the inner workings of the snake's body change
34:38greatly.
34:42Its digestive processes switch to full power and increase their activity 40 times.
34:48There is an explosion of biochemical activity.
34:52The liver, the secretions of which power digestion, doubles in size within two days.
35:00The heart grows by some 40%.
35:07It will take the python at least a week to completely digest this enormous meal.
35:12But then it will not need to feed again for months or even a year.
35:21This ability to switch off helps reptiles and amphibians in another way.
35:28A baby North American painted turtle.
35:31It and the rest of its clutch have only just hatched.
35:36But it's late in the year and the chill of winter has already begun.
35:41If the hatchlings clambered out of their hole now, they would find nothing to eat, so they
35:46stay where they are.
35:48The temperature will fall to minus 10 degrees.
36:00Ice crystals grow around the babies and even inside their bodies.
36:05But their tissues are protected by a kind of antifreeze.
36:12This would kill any mammal or bird.
36:19They remain in this deep freeze for up to six months.
36:30But spring comes at last.
36:39The ice melts around them and eventually within them.
36:46Slowly, they begin to come to life.
37:13It takes quite a time for them to become fully functional.
37:16But eventually, they're ready to face the outside world.
37:33So by allowing their bodies to cool, they have avoided the hard times.
37:38With the arrival of spring, their parents are now preparing to breed again.
38:01The male courts the female by gently strumming her cheeks with his long claws.
38:12And she responds.
38:20Cold blood is clearly no barrier to affection.
38:23In fact, reptiles can conduct as complex and as sensitive a courtship as many a mammal.
38:38This is the biggest of all living reptiles, and one of the most feared.
38:44If one creature were to be labelled a cold-blooded killer, it would be this, a saltwater crocodile.
38:50A monster that can grow to a length of 20 feet, six meters, and weigh a tonne.
39:03But male and female, when they caught, blow bubbles at one another.
39:16He is three times her size and could easily crush her, yet he treats her with great gentleness.
39:28He strokes her back.
39:42Slowly, he aligns his body with hers.
39:49So union is achieved.
40:16Cockediles are among the most ancient of reptiles.
40:31Their ancestors appeared at about the same time as the dinosaurs.
40:35But what about them?
40:37Were dinosaurs similarly cold-blooded?
40:41The rocks of the North American West are particularly rich in dinosaur fossils.
40:48A hundred million years ago, this was a horizontal mudflat at the edge of the sea.
40:57And across it came an adult dinosaur with a smaller, younger one trotting alongside,
41:04leaving their footprints behind to be fossilised.
41:09They were iguanodons, a herd of them, together with some bird-footed dinosaurs.
41:17Were these all solar-powered?
41:19Some of the ancient reptiles had specific adaptations to help them collect heat.
41:28This is a plate from the back of a stegosaurus.
41:34And you can still see the lines where the blood vessels ran, which collected the heat and carried it to the rest of the body.
41:41So for the stegosaurus at least, the need to collect heat seems to have been just as important as it is for its relatives alive today.
41:52But there are clues that suggest that ancient reptiles were better at maintaining their temperature than their modern counterparts.
42:01This is the jawbone of a very large and very famous dinosaur.
42:11In life, its head would have been 18 feet 6 metres above ground.
42:20This is the jaw of Tyrannosaurus rex.
42:24An animal as big as this has a very large body mass, which retains heat very well.
42:37So perhaps these huge dinosaurs were, in fact, warm all the time,
42:42simply because they were too big to lose all their heat overnight, as a smaller reptile would.
42:48But what about when they were small?
42:52Were adolescent Tyrannosaurs able to maintain a steady body temperature?
42:57Were they, in short, warm-blooded?
43:01Evidence on that can be found in the microscopic structure of their bones.
43:06This is the leg bone of a young Tyrannosaurus, and it has bands in it.
43:23The inner section, formed when the animal was young, has an open structure like the bone of a fast-growing warm-blooded mammal.
43:31The outer part is more dense, more like that of today's reptiles.
43:37But whether dinosaurs were really, truly warm-blooded, we may never know.
43:44What we do know, however, is that dinosaurs were extraordinarily successful
43:49and dominated the Earth for 150 million years.
43:54But there are some reptiles today that can keep their body temperature well above that of their surroundings.
44:03And these are the tracks of one of them.
44:07These giants haul themselves up out of the sea along beaches like this in many parts of the tropics.
44:15But in order not to disturb them, I'll turn this light out and we'll look for them with infrared cameras.
44:28Leatherback turtles.
44:30Like crocodiles, turtles are very ancient creatures, having first appeared at about the same time as the early dinosaurs.
44:38Today, leatherbacks are the biggest of all reptiles and the most widely distributed.
44:44For they're found all the way from these warm tropical waters to the freezing seas of the Arctic.
44:58These have come ashore on a beach in Trinidad, where almost certainly they were hatched.
45:03Now they, in their turn, are laying their eggs here.
45:14Netherbacks, we know, can generate heat internally.
45:20And there is proof of that if you have a look at her eggs that she's laying right now on that thermal camera.
45:27They are emerging from her body and, lo and behold, they are bright yellow, verging on white, proving that they are warmer than their surroundings.
45:43And she generates that heat within her body from special deposits of fat so that she can maintain her internal body temperature up to eight degrees centigrade above that of the water through which she swims.
45:56As she sweeps away the surface sand, you can see that the sand too is yellower, warmer than the outside of her shell, for it still retains the heat it acquired during the day.
46:09So how do leatherbacks retain that precious and expensive internally generated heat?
46:23Well, to start with, they have their huge size to help them. They really are massive animals. This one is getting on to two metres, six feet long, and they can grow to weigh a tonne and a half.
46:37And, of course, big objects retain their heat very much more readily than small ones do.
46:44And there's another reason. Our eye, bright yellow going into white, which shows that I'm losing a great deal of my heat.
46:55But she, on the other hand, is very much darker. And that is because she has an internal layer of fat, an insulating layer, just beneath the shell, which wraps round her body.
47:10The leatherbacks are the only reptiles in the world to have this kind of insulation.
47:17Her eggs laid, she fills in the hole with sand.
47:32And now, she's on her way back to the sea.
47:39Life in Coblan has been a great success. It has, after all, endured for some 350 million years.
47:48But how did it all begin?
47:51To find the answer to that, we have to go back in time and back to the water,
47:56to the age when strange fish were hauling themselves up onto the land.
48:02Fish that were the ancestors of the amphibians.
48:20Amphibians and reptiles are not easy creatures to film.
48:24They certainly do interesting things, but they also spend a great deal of time doing nothing much.
48:34We needed the help of scientists who really understood these creatures.
48:41Some workers have spent over 20 years studying their animals, both in the lab and in the field.
48:47They investigate the lives of their chosen species using all kinds of gear.
48:52Some sophisticated, some perhaps less so.
49:04With their help, we had a rare chance to get under the skin of some of our subjects.
49:11Madagascar was going to be a very important location for us.
49:26It's a huge island, a thousand miles long, with a great variety of habitats,
49:30and it's extraordinarily rich in reptiles.
49:39I first went to Madagascar back in 1960, filming for a series called Zoo Quest.
49:45Back then, I was trying to film all kinds of creatures, including the monkey-like lemurs and many rare birds.
49:57But I was particularly fascinated by the island's chameleons.
50:00There are, in fact, more species of chameleons in Madagascar than in all the rest of the world put together.
50:14There is one, the pygmy leaf chameleon, which was said to be only an inch or so long.
50:20I yearned to see it, but I never found it.
50:23Now I was back, and this time, reptiles were our sole subject.
50:35Although Madagascar is only separated from the east coast of Africa by 300 miles of sea,
50:40its people, and particularly its animals, are very different indeed from those on the continent,
50:46with hundreds of species that are found nowhere else in the world.
50:50Once again, I was in search of chameleons.
50:57Then, all television was black and white,
51:00but now I could film and record chameleons in colour, and what colours they have.
51:20We had come in the rainy season, when most creatures, including reptiles, tend to breed,
51:31and are therefore particularly active and interesting.
51:35And this time, I had the help of Bertrand Razahamatra, a Malagasy naturalist who's made a particular study of chameleons.
51:43He's worked on them for over ten years, and knows most kinds very well.
51:48I asked him about the pygmy species that had fascinated me for so long.
51:53So, I mean, that really is full-grown?
51:55Yes, full-grown.
51:57But then it's only that big?
52:00Yes, it's very small.
52:05He suggested that although chameleons are mostly active during the day,
52:09we should look for them at night,
52:12because most of them turn pale in the dark,
52:14and are therefore easily picked out in the light of our torches.
52:18Mm-hm, probably.
52:19Yeah.
52:23Ah!
52:28What is that?
52:30This is...
52:31What species?
52:32This is ustalets.
52:34Ah, ustalets, aye, aye.
52:36And male or female?
52:38Female.
52:39How do you know?
52:40The colour.
52:43Is there another one? Oh, there's another!
52:45This one was far from upset at being woken up.
52:51Ah!
52:54It's fed!
52:56That's absolutely extraordinary.
52:58It can't possibly feed normally in the darkness.
53:03It just takes advantage of our light and finds an insect.
53:06Bravo!
53:08Let's go and see if we can find more.
53:10Bertrand explained that there was another reason
53:15why night was the best time to look for chameleons.
53:18When they go to sleep,
53:19they climb to the very far end of branches,
53:22where they're out of the way of predators such as snakes.
53:25Here's another.
53:27And, of course, that was where we found them, just as he said.
53:31Oh, that's... that's a big one.
53:48Beautiful.
53:52Yes.
53:54Oh.
53:56This one is just a baby.
53:58And how old do you think that is?
54:01I think just a few days.
54:03A few days.
54:07So even when it's nearly hatched,
54:10it knows to come to the end of the branch.
54:12Yes.
54:14Yeah.
54:16Look, they chose the tip of a branch.
54:18Yes.
54:20Well, very difficult to get.
54:21Yeah.
54:22Of course, if it was in the day, a bird could get it.
54:24Yeah.
54:25But at night...
54:26But at night, it's safe.
54:29Back in 1960,
54:30my chameleon hunting techniques weren't quite so expert.
54:44However, I did discover that if you put a stick in front of a chameleon,
54:48it will usually obligingly walk onto it.
55:00But now, with Bertrand as my guide,
55:03we could search for the wonderful species that I had failed to find before.
55:07Would they be down here?
55:11It lives on the ground, almost invisible among the leaf litter.
55:15But Bertrand spotted it.
55:16How extraordinary.
55:18This is a pygmy-leaf chameleon.
55:21The smallest chameleon in the world.
55:22In the world?
55:23Yeah.
55:24And probably the smallest riptile in the world.
55:26The smallest chameleon in the world.
55:27In the world?
55:28Yeah.
55:29And probably the smallest riptiles in the world.
55:30Of any kind.
55:31Mm-hmm.
55:32You know, I'd heard about these, and I was here in Madagascar,
55:3447 years ago.
55:35Mm-hmm.
55:36And I read about these, and I was here in Madagascar 47 years ago.
55:37Mm-hmm.
55:38And I read about these, and I was here in Madagascar 47 years ago.
55:42Mm-hmm.
55:43And I read about these, and I never saw one.
55:44Mm-hmm.
55:45And I think it was because I never knew they were small.
55:46And probably the smallest riptiles in the world.
55:47Of any kind.
55:48Mm-hmm.
55:49You know, I'd heard about these, and I was here in Madagascar 47 years ago, and I read
56:02about these, and I never saw one.
56:07And I think it was because I never knew they were as small as this.
56:14That is absolutely extraordinary.
56:17It's about the size of a bluebottle.
56:21Mm-hmm.
56:22A blowfly.
56:23Mm-hmm.
56:24And what does it feed on?
56:27A small fly.
56:29Small flies.
56:30Mm-hmm.
56:31How?
56:32Yeah.
56:33I don't see.
56:34I don't see wonderful.
56:36I am astonished.
56:40That is the most marvellous thing I've seen for a very, very long time.
56:48Finding the pygmy chameleon would not have been possible without Bertrand's expertise and sharp eyes.
56:54He's just one of the scientists who has helped to reveal to us the secret lives of reptiles and amphibians.
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