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00:00To be continued...
00:30About 340 million years ago,
00:39a brand new family of animals was evolving in the primeval swamps.
00:49They were to go one step further than the amphibians,
00:53who had emerged onto dry land before them.
00:56For they would eventually completely cut their tithes with water.
01:04They were the ancestors of today's lizards.
01:12They evolved scaly, impermeable skins
01:16and moved up into the forests.
01:33They diversified into a multitude of different shapes and sizes.
01:38They developed signalling systems to communicate with one another.
01:49And they squabbled, as animals do, over mates and territory.
02:02For food, they hunted insects
02:04that were already well-established on the land in great numbers.
02:10And here, without returning to water,
02:20they produced their families.
02:29They powered their bodies not only with food,
02:32but with the heat that they drew directly from the sun.
02:35As they diversified,
02:41so they spread into the harshest of the land's habitats,
02:44the baking, waterless deserts,
02:47which eventually they would come to dominate.
02:49The bigger ones are truly powerful and fearless.
03:00Rearing up, they're well able to defend themselves
03:02of their front legs if they're threatened.
03:04This is a very intelligent animal.
03:14It is observing me
03:16just as I am observing it.
03:20It's a monitor lizard
03:21and it's king of this country,
03:25the Australian outback.
03:27It is frightened pretty well.
03:30Nothing, obviously, including me.
03:32And it'll chase and hunt and eat
03:36pretty well anything.
03:39There are several thousand lizards around the world
03:42and they are truly the dragons of the dry.
03:47Their eggs on land
04:04had to be encased in shells
04:06to prevent them from drying out.
04:09And what better place to lay them
04:11could a mother lizard find
04:13than a termite's nest.
04:16Worker termites labor unceasingly
04:18to keep the temperature and humidity
04:20virtually constant
04:22for their own benefit.
04:24But that also makes their mound
04:26a near-perfect incubator
04:27for eggs of others.
04:34After ten months,
04:36they're beginning to hatch.
04:37These are baby lace monitors.
04:59But they face a major problem.
05:13A termite nests' walls
05:15can be a foot thick
05:16and extremely hard.
05:18Too hard for the young monitors
05:20to break through.
05:22They are imprisoned
05:23with no food.
05:24For a week after hatching,
05:33they're sustained
05:33by the last of the yolk
05:35that remains in their stomachs.
05:37But when that comes to an end,
05:39they could starve.
05:48An adult lace monitor
05:50is nearby.
05:51An adult lace monitor is nearby.
05:54It may or may not
06:01be the baby's mother.
06:03If not,
06:04then it could be a threat.
06:05For monitors are hunters
06:06and will eat most small animals,
06:09including baby lizards.
06:16She's nearing the termite nest
06:18within which the young are trapped.
06:24She could be looking for a place
06:31to lay her eggs.
06:34Alternatively,
06:35she might be searching for food,
06:37such as little lizards.
06:38She's nearing the termite nest
06:49in that context.
06:52PHONE RINGS
06:53The babies are released unharmed.
07:16Perhaps she is indeed the baby's mother,
07:18and not only remembered exactly where she laid her eggs a year ago,
07:22but knew that her babies would need her help to escape from the incubator.
07:32The young, however, are free.
07:35But the outside world is a dangerous place.
07:44They head for safety, up into the trees.
07:52In the branches, there are other kinds of lizards.
07:57Jacky dragons.
07:59Each has its own territory and warns others to keep out.
08:04A wave of the front leg and a bob of the head
08:07is a jacky dragon's way of claiming territory.
08:10Here, the action is slowed down.
08:12In reality, the leg flick is so swift, it's hard for us to see.
08:17But it's very plain to another jacky dragon.
08:25But sometimes signals are not enough.
08:28Physical violence is needed.
08:29He's won.
08:30The vanquished acknowledges his defeat with a different signal.
08:32A slow leg wave with no head bob.
08:34The winner returns to his territory in the branches
08:37and announces his victory.
08:38He's won.
08:39He's won.
08:40The vanquished acknowledges his defeat with a different signal.
08:41A slow leg wave with no head bob.
08:43The winner returns to his territory in the branches
08:47and announces his victory which his neighbour acknowledges.
08:52If he's won, he's won.
08:55He's won.
08:56The vanquished acknowledges his defeat with a different signal.
08:58A slow leg wave with no head bob.
08:59The winner returns to his territory in the branches
09:02and announces his victory.
09:05Which his neighbour acknowledges.
09:09So now both can live alongside one another in peace.
09:24Once Jackie dragons stop signalling, it's quite hard to spot them up in the branches.
09:32American anoles are so well camouflaged they're virtually invisible.
09:38There's one on this tree right in front of me.
09:42But he too needs to draw attention to himself to warn off rivals and then to disappear from
09:49predators.
09:51This mirror may persuade him to reveal his solution to the problem.
09:56Now then, what do you think of that?
09:58Who's that?
10:01Yes, it's a rival.
10:05A tail wag.
10:10Yes.
10:13You're not going to get rid of me that way.
10:19Show us your signals.
10:21Well, press up certainly is a keep away challenge.
10:26And there, that's it.
10:31The full works.
10:36Ah, lovely.
10:40Once more.
10:46And again.
10:47Come on.
10:48Come on.
10:49Come on.
10:50He obviously thinks that his position is being contested and he's displaying to show that
10:57he's as good as anybody else.
11:00So I guess I'll leave him in peace.
11:06And Anole's throat flap appears for only a second or so and then vanishes.
11:12And its owner, after sending his message, returns to camouflaged obscurity.
11:20Another family of lizards living in the treetops has an even more varied repertoire of signals.
11:25They use not only gestures, but body colors.
11:43They're chameleons.
11:44Their stronghold is the island of Madagascar.
11:56And here there are over 60 different species of them, almost more than in all the rest of
12:00the world put together.
12:04This is a panther chameleon, and it's marvellously adapted for life among the branches.
12:15Its toes are divided into two bundles, three and two, and that means that it can use them
12:22just like forceps.
12:26Their grasping feet, supplemented by their gripping tail, enable them to become remarkable
12:32slow motion acrobats.
12:44I suppose chameleons are best known for their ability to change color.
12:50And that does help in camouflage, but actually they also use color change as a way of communication
12:58and expressing their emotions.
13:07When a male panther chameleon spots a rival, he expresses his fury in glorious technicolor.
13:22Maui, in central Africa, may not have as many species of chameleon as Madagascar, but it
13:29has one of the largest, Mellor's chameleon, that can be 60 centimeters, nearly two feet, from
13:36nose to tail.
13:47Rival males, when they do battle, deploy a range of threats that is truly formidable.
14:00They do battle, but they do battle, and they, should be the power of an angst.
14:12It is so, they have a lot of an angst.
14:14We are not the strongest in the world.
14:17What happens when it's a monster?
14:20Let's play the potential.
14:27If signals don't deter, then they start to joust.
14:57It's not only males that fight, there are also battles between the sexes.
15:26This is the South African dwarf chameleon, a male in full courtship costume.
15:36This, somewhat less colorful, is a female.
15:46She is not welcoming his advances.
15:56As her mood darkens, so does her skin.
16:03She's driven him away, but why?
16:21There is a reason.
16:35She's pregnant.
16:36Her home, the South African cape, can get quite cold.
16:41So, instead of laying her eggs on the ground, as most chameleons do, she retains them within
16:47her body and warms them by seeking out the sunniest places and sunbathing.
16:53Now, they're ready to emerge, alive.
17:06Producing babies in the branches might seem to be a risky business.
17:10But the membrane enclosing each one will stick to a twig, if it hits one.
17:19And when at last the babies disentangle themselves, they immediately deploy their formidable chameleon
17:26grip.
17:43They are in the branches of the person.
17:44They are in their limbs.
17:45There's many subscribers to the people thatopel.
17:48They are still in their mouths.
17:50They have had her at the beginning.
17:53They're in his arms.
17:54Somewhere in the lake is coming.
17:55Where is this?
17:56Maybe you haven't seen a twig.
17:57Maybe your skin.
17:58But you can't see a twig.
18:00They also have a twig.
18:02But you're in the man up with her.
18:03So, in the face of your skin is my body.
18:05By the time they are properly dried out,
18:23the babies are as much at home in the branches as their mother.
18:35But for the most extraordinary chameleons of all,
18:56you have to look not up in the trees, but down here on the leaf litter.
19:05A whole range of species live on the ground,
19:10many of which have only recently been discovered.
19:17This is surely the most extraordinary of all chameleons.
19:23It's the pygmy leaf chameleon.
19:28This is a male, and he's fully grown, believe it or not.
19:33And yet, within this tiny little body are all the anatomical details of a normal-sized chameleon.
19:41What an extraordinary creature.
19:51Like all chameleons, it catches its food with its tongue.
19:57It eats tiny flies.
20:04Grasshoppers are popular with normal-sized chameleons.
20:09The tongue contains a tapered rod encircled by muscle.
20:34As the muscle contracts, the tongue shoots forward off the rod.
20:41The tip physically grasps the prey.
20:45And then longitudinal muscles contract to pull the tongue back onto its rod,
20:50bringing the prey with it, which may weigh half as much as the chameleon itself.
20:55The whole action, in reality, is completed in a second or so.
21:10The canopy of a tropical forest is full of food,
21:25and lizards clamber around looking for it in many ways.
21:29Chameleons use their toes to grip the twigs,
21:32and geckos use theirs to stick to leaves,
21:35for their toes have adhesive pads on the ends.
21:41Most geckos feed on insects,
21:43but some take nectar from flowers,
21:46and a few collect liquid from insects
21:48in much the same way as we take milk from cows.
21:55The insect, a tree hopper, is sitting head down,
21:58drinking sap from the tree.
22:00It would be invisible were it not vibrating its abdomen.
22:06And that is what the gecko wants from it,
22:08a drop of honeydew.
22:11Honeydew is what remains of tree sap
22:13after the hopper has extracted the protein from it.
22:16It's very sweet, and the gecko plainly loves it.
22:19Other, less colourful species of gecko also drink honeydew,
22:24and some order it from the hopper by vibrating their heads.
22:40The hopper tells the gecko that a drink is on the way
22:43by waggling its abdomen.
22:45How the hopper benefits from this arrangement is not clear.
23:01Perhaps the gecko keeps predatory insects away,
23:05and the honeydew is protection money.
23:08Most geckos are much less conspicuous
23:12and are very difficult to see.
23:23It's the Madagascan leaf-tailed gecko.
23:27And its tail has wide flanges on either side,
23:31so that it has become leaf-shaped.
23:34But these aren't the only flanges.
23:37It's also got them all around its toes, its legs, and down its flank.
23:42And the consequence is that if it presses itself close to the bark
23:47and spreads those frills, it sheds no shadow at all.
23:53The irises of its eye are also part of this amazing camouflage.
23:59They have a kind of mottled, pale surface,
24:03which makes them look exactly like one of these little blotches of lichen on the bark.
24:08All in all, it's a most extraordinary disguise.
24:16It, and indeed the majority of geckos, only really become active at night.
24:21Here in Bangkok, as in cities throughout the tropics,
24:33geckos have discovered that mankind's lights
24:36attract a great banquet of insects.
24:39As a result, almost every building has its own resident gecko population.
25:06Lizards, for the most part,
25:08are not known for being caring parents.
25:11But there are exceptions.
25:13It's spring in the woodlands of North America.
25:16An American robin is nesting,
25:18warming her eggs with the heat generated by her own body.
25:23And below, on the forest floor,
25:26a five-lined skink is warming her cold-blooded body
25:30by basking in the sunshine,
25:33so that she can do the same thing.
25:38It can get quite chilly in these woodlands,
25:41and she warms her eggs by transferring to them the heat
25:43that she's collected from the sun.
25:44It can get quite chilly in the sun.
25:45It can get quite chilly in these woodlands,
25:49and she warms her eggs by transferring to them the heat
25:54that she's collected from the sun.
25:56She takes just as much care of her eggs as the robin does.
26:01A month later, and her eggs are hatching.
26:04A month later, and her eggs are hatching.
26:09A month later, and her eggs are hatching.
26:12A month later, and her eggs are hatching.
26:14A month later, and her eggs are hatching.
26:17A month later, and her eggs are hatching.
26:21A month later, and her eggs are hatching.
26:26A month later, and her eggs are hatching.
26:28A month later, and her eggs are hatching.
26:31The robin's eggs have hatched too.
26:45Her nestlings are helpless and need constant feeding.
26:50The young skinks, however,
26:52are already capable of finding food for themselves.
26:56Within a day or so, they've left their mother,
27:08and are independently exploring the woodland floor for themselves.
27:19But there are other skinks whose family life lasts rather longer.
27:24These fields in South Australia are home to a little lizard
27:29that is so rare that it had been thought to be extinct
27:33for over 30 years, until it was rediscovered in 1992.
27:38And the equipment you need to find it is, believe it or not,
27:42a fishing rod.
27:44Now, let's see if I can tempt him out with this.
27:47Oh!
27:50Let's go!
27:52Gosh!
27:53Now, come up a little farther,
27:55so we can see what you look like.
27:58That is a very rare little creature.
28:01It's a pygmy, blue-tangled skink.
28:06And it lives in the holes that are made by trapdoor spiders.
28:13And this one is clearly very hungry.
28:16Come on.
28:17Come on.
28:18Won't you come out a little more?
28:19Come on.
28:20Just show us.
28:21Oh!
28:22It won!
28:24Let's have a closer look.
28:29I can do that with this optical probe,
28:33with this viewing screen on the end.
28:36It's quite a long way down.
28:38There he is.
28:40All safe and snug.
28:43And he really is safe down here.
28:46Even a bushfire sweeping by wouldn't harm him.
28:50And, of course, this explains why no-one had seen these little lizards for so long.
28:57They're very difficult to find.
29:01But what's really special about this little lizard is its family life.
29:07Just look at these shots that we got with that optical probe.
29:11That is a close-up of the Hernanveldt's head.
29:15And there, just beside her head, is a tiny little head of a baby.
29:21That's one.
29:23And if we push past her, there's the baleful look of mum, who doesn't appreciate this.
29:29And beyond, two.
29:32Two more babies.
29:34So that's three.
29:36Quite a crowded little home.
29:40So there they are.
29:42A nice little lizard family.
29:44And the babies will stay in that crowded hole for three weeks or so,
29:50before they're ready to be able to go out into the outside world
29:54and look for a spider's burrow for themselves.
29:57There's another skink here whose family relationships last for decades.
30:10This is a shingleback, or as it's called here in its home in Australia, a sleepy lizard.
30:18And it's really quite a baffling creature because its head and the tail look very similar.
30:24Maybe that confuses a predator.
30:26But if you get closer, it quickly shows which end is which by threatening with this cape display.
30:35Oh, you're very perky.
30:40And I have to be reasonably careful because it can bite.
30:47But at this time of the year, in the spring, it also has another rather more gentle side to its character.
30:56Now, I'll let you get on with it.
30:59A female catches the eye of a male.
31:18He starts to follow her wherever she goes.
31:22Couples stay side by side for up to two months.
31:47He courts her by gently nudging, licking her.
31:52Six months pass, and then, eventually, the results of this prolonged courtship begin to arrive.
32:21It's a long and strenuous business for a mother shingleback.
32:24It's a long and strenuous business for a mother shingleback.
32:28She produces not a small egg like the five-lined skink, but a live baby.
32:35She produces not a small egg like the five-lined skink, but a live baby.
32:42It's a whopper.
32:43It's a whopper.
32:44It's a whopper.
32:45It's a whopper.
32:46It's a whopper.
32:47It's a whopper.
32:48It's a whopper.
32:49It's a whopper.
32:50It's a whopper.
32:51It's a whopper.
32:52It's a whopper.
32:58It's a whopper.
32:59It's a whopper.
33:05It's a whopper.
33:06It's a whopper.
33:33And there's another one to come.
33:35Together, the two weigh as much as a third of her body weight, the equivalent in human
33:40beings of carrying a three-year-old child.
33:48Like the Cape Chameleon in South Africa, the female has been acting as a mobile incubator,
33:57seeking out the warmest spots she can find in order to bask.
34:03Producing such well-developed young is the shingleback's response to the fact that it
34:08can get quite cold in South Australia.
34:15Her young are so advanced that they soon leave her.
34:27But when spring returns, the same male and female will once again seek one another out and mate
34:34again.
34:35In fact, a pair will remain faithful to one another for as long as twenty years or more.
34:42The bond between them may even endure after death.
34:56They're slow-moving creatures, and only too often when crossing a road, they're unable to
35:01get out of the way of a passing car.
35:07If one of the pair is run over, the other will often remain at its side for days, tenderly
35:13nudging it.
35:14You might even say that it was grieving.
35:23On the other side of the world, there are lizards with a very different lifestyle.
35:28They gather together in groups with densities higher than you can find anywhere else.
35:34And the reason they're able to do so, you can see alongside the waters of this, the Orange
35:40River in South Africa.
35:41The river is the breeding ground for vast swarms of black flies.
35:48Excellent food for a lizard if it can catch them.
35:49The river is the breeding ground for vast swarms of black flies.
36:07Excellent food for a lizard if it can catch them.
36:13In the early morning, the Agrabi's flat lizards emerge from the cracks in the rocks where they
36:37spent the night and bask in the sun to warm up.
36:44The males are the brightly coloured ones, as you can see from his marvellous blue head.
36:52But it's not his head that impresses his rivals so much.
36:57It's the underside which, if he's a high-status male, will be bright orange and yellow.
37:05And if another one turns up, he will try and impress his rival by exposing that.
37:11These awkward-looking postures reveal why these creatures are called flat lizards.
37:22By regularly displaying their vivid badges, the males repeatedly confirm their place in the pecking order
37:28and so keep fighting to a minimum.
37:35As the female moves from one territory to another, so each male courts her in turn.
37:53And they're really warmed up and active.
37:56And whole groups of them are beginning to travel down across the rocks towards the river,
38:01where they'll find their food.
38:09But down here, where the flies swarm, it's a free-for-all.
38:13And that causes a lot of trouble.
38:16Catching flies is, necessarily, an acrobatic business.
38:31But you can't leap for flies and still keep properly spaced out.
38:36So there are, inevitably, quarrels between rival males.
38:46Females, on the other hand, are only interested in getting a good meal.
38:54Fired-up males, however, have other ideas.
38:58For them, there is more to life than just dinner.
39:01And some won't take no for an answer.
39:16The females want food.
39:30They need a square meal to nourish the eggs that are developing within them.
39:41But they won't get any peace until they leave the restaurant and get back home,
39:53where life is better regulated.
39:58The high-octane social life of the flat lizards, with its constant squabbling,
40:02seems to be very stressful.
40:04But for other lizards, fighting is less frequent,
40:08but altogether more impressive.
40:11A Mexican beaded lizard.
40:21One of the few lizards in the world with a poisonous bite.
40:26And a very virulent one it is, too.
40:43In the spring, rival males fight, according to a very specific set of rules.
40:49They use neither their sharp, powerful claws nor their poisonous bite in their battles.
41:02At first, they grapple rather wary, to assess each other's strength.
41:25Then, they begin to wrestle in earnest,
41:37each trying to pin down the other on the ground.
41:40These two are evenly matched.
41:56Neither can get the crucial throw.
41:58It's rather like an arm-wrestling contest.
42:01And the bout can continue for several hours.
42:31The eventual winner is the one who ends up on top most frequently.
42:47It's a controlled test of strength,
42:49in which, despite their lethal weaponry,
42:52no one gets seriously hurt.
42:54Other lizards defend themselves, not with physical strength, but by deceit.
43:05The South African desert.
43:08A bushveld lizard.
43:15This is another.
43:16It looks very different, but that is because it's a baby.
43:20It not only has different coloration,
43:24it also walks in a very different and quite extraordinary way.
43:39It appears to be imitating one of the local beetles, that one.
43:43And to discover why, I'm going to take defensive measures with these goggles.
43:51This beetle is known as an uchpister, an eye spitter.
43:56That's because it's squirting formic acid at me.
44:00Poof, yeah.
44:01And if any of that got into my eye, it would be extremely painful.
44:05It's a defensive system.
44:07And the lizards are benefiting by imitating a beetle with that kind of armory.
44:12The young lizard closely matches the beetle both in its appearance and its walk.
44:21So birds that prey on lizards assume it has a nasty spray and leave it alone.
44:26Lizards can cope with dry, hot conditions so well that they dominate the fauna in tropical deserts around the world, including those in central Australia.
44:45Their tough, scaly skins prevent their bodies from losing moisture so that they can flourish in these arid, baking-hot lands that other animals find so testing.
45:00Some wear the most elaborate suits of armour.
45:13This is surely the most enchanting of lizards.
45:27It's called the thorny devil or Moloch.
45:34After Moloch, the god in the Bible who ate little children.
45:38Both names, surely, are a slander on such an engaging little animal.
45:42It feeds entirely on ants.
45:46And as you can see, there's not much of a meal in any one of them.
45:52But the good thing about ants, as far as Moloch is concerned, is that there's always some around.
45:59And this little creature will sit by an ant trail patiently for hours on end, simply picking off one ant at a time.
46:13The Australian desert is also home to one of the most powerful of the family.
46:21Monitors are the kings of lizards.
46:26And this is the parenti, the biggest species of monitor in Australia.
46:32It can grow up to two metres long, six feet.
46:39And it's a highly intelligent animal.
46:42It's got very acute senses of sight and hearing and taste and smell.
46:47And like all monitors, it can do something no other kind of lizard can do.
46:54It can run continuously for a very long time.
46:58And that enables it to become an endurance hunter, chasing down its prey.
47:03Most lizards inflate their lungs using the same muscles as they use for walking, so they can't run and breathe effectively at the same time.
47:18But monitors have big muscular throats, which they use like bellows to pump air into their lungs.
47:31And they can do that even when they're running.
47:41This special way of breathing enables them to reach speeds of over 20 miles an hour.
47:47Over distance, they are one of the fastest of all reptiles.
47:54The cold-blooded parenti can even outrun a warm-blooded rabbit.
48:03So the lizards have colonised the world, from swamps to rainforests, from woodland to desert.
48:09And in doing so, they've revealed such a variety of form and behaviour that they truly can be called the dragons of the dry.
48:30Much of our filming for this programme was done in Australia.
48:33There, there are lizards everywhere.
48:37Just walk around in the bush and you'll see them.
48:40But usually, you won't get much more than a brief glimpse.
48:48To film their intimate behaviour, we needed help from experts.
48:56We'd travelled to Australia to meet an expert called Mike Bull.
48:59He knows Australian lizards as well as anyone.
49:05He and his team study many species in one small area north of Adelaide,
49:10using all manner of gadgets and gizmos to investigate every part of their lives.
49:14We are particularly interested in the lizards that Mike understands best of all.
49:27The shingleback, or sleepy lizard.
49:30He knows 10,000 of them individually.
49:32On the face of it, the sleepy lizard doesn't seem to do a lot.
49:41But Mike knows so much about them that we were able to make them one of the stars of our film.
49:47He's discovered that they're the only lizards in the world that remained faithful to one partner for all their lives.
49:54But that wasn't the reason that he began to study them.
49:56Tell me first how you first saw sleepy lizards and what attracted you to them.
50:03I first started because I was interested in parasites that live on the lizard.
50:06To find the parasites, I actually had to look at the lizards as well,
50:09and I discovered they were doing things that were more interesting than the parasites.
50:12For me, I think they're one of the most handsome animals that you'll ever find.
50:15The other thing is that it's probably the only animal that you know, if you're driving along in a car,
50:21and you see one 100 metres down the road, you know you've caught it.
50:24And it's also one that I think I'm going to be sufficiently agile to keep on catching until I'm well past 80.
50:32Even I, I think, could scrag the sleepy lizard. I'll see if I can manage it.
50:38Sleepy lizards like to bask on warm roads, so they're easy to find.
50:42And they move so slowly, they're easy to pick up.
50:46So the team were able to weigh and measure a whole population,
50:50and thus discovered that pairs remained together in a way that was previously known only in birds and mammals.
50:57But that was just the start.
50:59Next, they turned to technology, some of it advanced, some a little bizarre.
51:04They used remotely controlled rubber sleepy lizards to test how lizards reacted to one another.
51:14In this case, not very much.
51:16Mike's team suspected that another lizard in the area, the Gidgee Skink, had an even more complex social life.
51:28But this was difficult to prove, because when approached, the skinks wedged themselves in cracks in the rocks,
51:34making it impossible to identify who's who.
51:36The solution was to microchip each lizard so it could then be scanned, just like your supermarket shopping,
51:46with a barcode reader on the end of a pole.
51:49This clever use of technology revealed what looked like a jumble of lizards on a pile of rocks to be actually a little lizard family,
52:01with young that stay with their parents for life.
52:03I'm sure that there are going to be many other complex social organisations that will be uncovered in those species if we just simply take the time to look at them.
52:15But it's just the time and the patience to watch them.
52:19And watching a lizard is very unrewarding because they will come out and bask, sit by a bush,
52:27and if they see you there, then they'll decide they're not going to do very much for the rest of the day.
52:33To find out just what sleepy lizards get up to when no one's around,
52:38Mike's team use a rather bizarre device they call a waddle-o-meter.
52:43It may look a little odd, but it records a lizard's GPS coordinates, counts its steps and even notes whether it's in sun or shade,
52:51all without troubling the lizard and without anyone having to be there.
52:54So you think there's probably the secret world of the lizard, which no human being has ever seen,
53:01because if a human being is there, the lizard won't behave that way?
53:06I'm sure that's part of it. It's the uncertainty principle.
53:09The closer you get to watch something, the less normally it's behaving.
53:13And so it's only by getting these remote and new technologies that allow us to really get into the secret world of the lizards
53:21that we can find these really amazing things that they're doing.
53:23How extraordinary.
53:26One of their latest techniques uses miniature cameras which they use to study a very special lizard
53:32that we were also particularly keen to film.
53:40It's so rare that it was thought to be extinct for over 30 years until it was thrust back into the public eye
53:46when it was discovered in some very unusual circumstances.
53:52There was a group of biologists who were doing a standard biological survey.
53:55They were just coming back to town to pick up supplies and just on the road they saw a dead brown snake.
54:00Now most people just wouldn't even look at it because they're so common around here.
54:05But these were dedicated biologists. They stopped and had a look at it.
54:09They noticed there was a bulge in it. They thought, let's see what it's been eating.
54:13Open it up. And there was this lizard that no one had seen for 30 years.
54:17They had a big, big blue-tongued lizard.
54:19How lovely.
54:20I dare say it wasn't all that lovely when they actually saw it.
54:25Miniature cameras have produced images that are slowly helping to build up a comprehensive picture of the life of these rare little creatures.
54:33Their burrows are more than just homes.
54:39They're also hiding places where they can wait in ambush for spiders and crickets.
54:44But they don't seem too keen on ants.
54:47They also serve as bolt holes when danger approaches.
54:57Despite all this work, Mike's team had never recorded their life underground.
55:02So we were able to help with a little of our own technology and record the first ever pictures of a pygmy blue-tongued family.
55:11Three babies alongside their mother in their little hole.
55:20But all this technology, ingenious though it is, is no substitute for years of dedicated observation.
55:26Mike's approach of simply driving for miles across the Australian outback is very fruitful and you'll see lots of other things as well as lizards.
55:35Up here is just a wonderful place for lizards.
55:39Oh, boy.
55:41Eastern grey. Beautiful, isn't it?
55:44You won't catch a lizard doing that.
55:45What's a lizard doing that?
55:54Oh, look, there's a pair just down there.
55:56It turned out that Mike had spotted two old friends.
56:09Yes, here's the male and the female.
56:12This is 1172 and 3345.
56:18I think they've been together for about ten years, this pair.
56:23Really?
56:24We've got some other pairs that have been together for over 20 years.
56:26They stay together during the springtime and they mate towards the end of the spring and then they separate but the next year the same two lizards will find them back together again.
56:35Usually in the same place along this road too.
56:37Aren't they terrific?
56:40They use their tongues to pick up chemical signals and you can see they're actually sensing each other at the moment.
56:47I think that's really very touching.
56:51I said it's a risky business.
56:53With obsessive dedication and ever advancing technology, who knows what Mike and his team will uncover about the secret lives of sleepy lizards.
57:23Like you guys, make great.
57:25That's the番ano of joy.
57:27For what?
57:30See you next week.
57:35Bye bye bye.
57:42Bye bye.
57:48encontrar music