Lizard Kings

PBS Airdate: October 20, 2009

NARRATOR: On this island, there lives a hunter that smells its prey with its tongue, that will ambush pigs, deer, even people, tearing them apart. It looks primitive, like a dinosaur, though it's not.

Komodo dragons are lizards, specifically, monitor lizards, which means they're far from primitive. Of the almost 5,000 types of lizard, monitors are the smartest; some can even count. And while they vary in size as much as an elephant and a mouse, they share a distinctive temperament.

ERIC PIANKA (Ecologist The University of Texas at Austin) : Monitor lizards are lizards with an attitude. They know that they're top predators, and they act like they're top predators. They aren't afraid of anything. They are smart.

NARRATOR: But could there be a side to monitors we've missed? That they're not only cunning, clever and fearless, but in some cases downright cuddly? Hungry, sometimes, not for a meal, but a pat or a bath?

ERIC PIANKA: I dare anybody to go to a major zoo and look a monitor lizard in the eye. It's looking back at you. Other lizards don't do that.

NARRATOR: Lizards as you've never seen them, up next on NOVA: Lizard Kings .

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NARRATOR: Beneath Central Australia's great deserts, eggs, still and silent for nearly nine months, are showing signs of life. But no doting mother attends the new arrivals. They either make it out of their shells or not, either gain mastery of their bodies, or die trying. And die they well might.

They have no future in this burrow. Their only chance at survival is to claw their way straight up, through more than three feet of baking sand, to the open air. Here, they must seek cover fast, before adults of their own kind take notice and eat them.

No question, it's a hard beginning. But such hardship has molded some extraordinary creatures: a family of about 60 lizard species known as monitor lizards or "Lizard Kings."

Sixty-five million years ago, a cataclysm wiped out the ruling reptiles, the dinosaurs, but monitor lizards survived.

Of the nearly 5,000 types of lizard found today, the monitors are the undisputed kings. Almost half of the monitor species live in Australia. In this desert, one has become top predator, a position usually occupied by mammals. And it's no accident.

True, like all lizards, this species, called the perentie, cannot regulate its body temperature internally, but that doesn't mean they're sluggish. Give them some rays and they have the stamina, speed and smarts of a mammal. And they're big, sometimes six feet long, commanding home ranges of up to 2,000 acres.

Australia's outback harbors all kinds of creatures, not just lizards. It may look barren; actually, it's a patchwork of different habitats, each sheltering its own species. But the lizards stand out, giving the region its nickname, "Land of Lizards," and making it the perfect place for lizard hunters.

ERIC PIANKA: I saw my first lizard when I was a little boy, and I thought it was the neatest thing I'd ever seen. I can't believe that I've been lucky enough to spend my whole life studying lizards.

NARRATOR: Known as the "Lizard Man," American biologist Dr. Eric Pianka is a world authority on lizard ecology. He's combed through the globe's deserts for over 40 years, but he's found no better place for his field studies than Red Sands, his research site in the Great Victoria Desert of Western Australia.

ERIC PIANKA: Red Sands is my favorite place on this earth. It's a beautiful, pristine, clean place. It's a desert rat's paradise. On Red Sands there's 55 species of lizards living together, including six species of monitor lizards. There's no place else in the world you can find that kind of diversity.

NARRATOR: Red Sands is teeming with skinks, geckoes and monitor lizards of all sizes. And on this trip, Eric will try new ways to get inside the monitors' mind. But finding them is no easy task, even for the Lizard Man.

Low fences lead the animals into pit traps sunk into the ground.

ERIC PIANKA: I hope we get something bigger.

NARRATOR: With these pit traps, Dr. Pianka and his field assistant, Stephen Goodyear, catch many of the smaller ground-dwellers.

Twice a day, Eric and Stephen check all of their 175 traps. By logging every lizard species, they try to work out how so many lizards can co-exist.

ERIC PIANKA: So the real appeal to me is trying to understand the high numbers of species of lizards you find together. I have to know all the players; we have to know their names and what eats what. I still occasionally stumble on something new out here, so it's just really exciting. I don't think I could bear to study a low-diversity system.

NARRATOR: In the past 20 years, Eric's pits have trapped more than 18,000 lizards. It's the most comprehensive survey of a lizard community anywhere in the world.

Not all monitors are as big as perenties, there are little ones too.

ERIC PIANKA: Now this is a lizard, lizard and a half: Varanus eremius. For me this is a real trophy. It's my favorite lizard of all. It's a lizard hunter just like me, and they roam over long, long distances, hunting other lizards.

I'll take him back to camp. Thanks.

I think it's fascinating that almost all the lizards that are out here are connected directly with other lizards, eating lizards. There is a lot of lizard-eating lizards. And one of the things I've been working on over the last 40 years is making a food web. And the monitor lizards are right at the top.

NARRATOR: Being top predators, monitor lizards hunt down anything smaller than they are, even their own kin. And in a place too hot and dry for most mammals, these lizards rule. They rival many mammals as cunning hunters.

When prowling for food they don't just follow their victim's scent, they do something else; monitors think ahead. These calculating hunters learn and memorize all the major landmarks around. They read the landscape like a map, taking short cuts to hideouts and ambushing prey to avoid energy-draining chases.

When this monitor comes across a hot scent, he follows the trail relentlessly, using special senses that guide him with lethal accuracy.

His target today is an eastern brown snake, one of the world's deadliest. It leaves an unmistakable odor trail, but it's one of many. Other animals have passed this way too. But the monitor can follow the snake's trail and ignore all the others by using his tongue.

Like snakes, monitors have forked tongues. By flicking them in the air or touching the ground, they pick up scents. Every time they pull in their tongues, they read these scents with an organ in the roof of their mouth. It's like tasting and smelling at the same time.

Even more astonishing, the monitor can tell how long ago his prey has passed and in which way it's heading. He never follows a trail backwards. As long as there's a trace of a scent, he follows it, leaving the Lizard King's quarry few options.

Hiding underground could be the snake's escape, but the monitor is as skilled at tracking below ground as above.

The snake has one last defense: its venom can kill a human with a single bite, but not the monitor; he seems to be immune.

If he can't tear his prey apart, he'll swallow it whole and head first.

Being partly solar-powered, reptiles only need 10 percent of the food we mammals need. And if food is scarce, a good meal can last the King for weeks.

Back at camp, Eric and Stephen sort through their catch of the day.

STEPHEN GOODYEAR: We've even got some monitor lizards.

ERIC PIANKA: Oh, wow! What?

STEPHEN GOODYEAR: We've got a Varanus eremius, two Varanus brevicauda.

NARRATOR: The Red Sands camp is about 250 miles from civilization, and they've been out here for more than two months of searing desert winds and the ever-present bush flies. Eric has been coming here for almost half a century, making his study of the Red Sands lizards unique. It's only long-term data like his that enables us to recognize changes in an ecosystem and understand the local effects of climate change.

On this expedition, Eric hopes to find good lizard numbers, especially monitors. As top predators, their presence or absence will indicate whether the desert community here is still healthy.

ERIC PIANKA: There, I got it. Pretty good: 27 and a half.

NARRATOR: And soon, Eric will get visitors. He'll be helping them launch a cutting-edge project, one that could give him new insights into the monitors' notoriously secretive lives.

ERIC PIANKA: This year we're doing a different project from anything I've ever done before. I'm collaborating with two ethologists, and we're going to try to see if we can put little cameras on monitor lizards out here. Monitor lizards don't let you watch them, but if you can put a video camera on one, you might be able to see things that you could never see, and learn things that, otherwise, we'd never know.

NARRATOR: Eric's collaborators, Christian Rutz and Lucas Bluff, decide to try the new invention before reaching his camp in Red Sands.

Code-named "Lizardcam," this pilot study is designed to explore the world from the monitors' point of view. And local monitor expert Rex Neindorf has lined up the first grumpy subject.

LUCAS BLUFF (Oxford University) : Hey Rex, what have you got for us?

REX NEINDORF: Oh, we've got a big one.

LUCAS BLUFF: Alright, I'll get out of your way.

REX NEINDORF: He's a, he's a big boy. He's pretty cranky too, so just keep away from that head.

NARRATOR: This large specimen is used to having people around, making him an ideal test candidate. He's big enough to carry Lizardcam and should quickly recover from all the high-tech fuss.

The next time he sheds his skin, the Velcro fixings will come off.

LUCAS BLUFF: Now we're on air.

NARRATOR: The camera sends live pictures back to a mobile receiver and has a radio tag, so it can be found later.

LUCAS BLUFF: No worries.

CHRISTIAN RUTZ (Oxford University) : I think he's ready to go.

REX NEINDORF: Are you guys happy with that?

LUCAS BLUFF: Yeah.

CHRISTIAN RUTZ: Go for it.

REX NEINDORF: Okay, I grab him right there. Okay, and if you guys just want to stand back a fraction, and we'll see how we go.

NARRATOR: And they're all set. It's Lizardcam's world premiere.

REX NEINDORF: Okay, big fellow. Off you go.

He wasn't happy with that.

CHRISTIAN RUTZ: I'm actually very happy that he doesn't try to remove the unit. It doesn't seem to bother him at all.

REX NEINDORF: It's really good. I'm very happy with that because the way the unit is sitting, there's really not much weight there at all. And it's almost just as...like there's an insect landed on him, and he's just going to completely ignore it.

CHRISTIAN RUTZ: Yeah. So it looks pretty good.

NARRATOR: With Lizardcam up and running, they can see things from a monitor's perspective.

LUCAS BLUFF: We're on air; good pictures.

CHRISTIAN RUTZ: You've got footage coming in?

LUCAS BLUFF: Yeah, it's coming in.

NARRATOR: For the first time they see what it sees.

To get the best results, Christian and Lucas must now let their subject move out of sight, yet stay close enough to receive the video signal. They can bridge a distance of about a third of a mile, room enough for the Lizard King to roam and give Lizardcam its first hard knocks.

CHRISTIAN RUTZ: What is always important for us is to get the attachment technique right. So we want to mount our video cameras in a way that it does not impair the animal's movement and natural behavior. These cameras should have no effect on the animal whatsoever.

NARRATOR: And this means the camera should drop off rather than trap its host.

LUCAS BLUFF: The packaging is the hardest thing, because we need a package that is both very rugged—it has to survive in quite a harsh environment—but at the same time it should be light. And, ideally, it can be reused time and time again.

NARRATOR: Trial and error is the only way to improve Lizardcam's design.

For nearly half an hour, the lizard has kept a low profile, but now he's on the move, exploring the surrounding scrub, apparently unaware of the video spy on his back.

And then the King does something rarely seen.

LUCAS BLUFF: Still moving. Actually, he's going up the tree. See there?

NARRATOR: Monitors like this one prefer roaming on the ground, or so it was thought. To see this species climbing is a revelation.

Lizardcam is already delivering, and, bolstered by their first success, Christian and Lucas try out a more daring design: a head-mounted camera with a power backpack. This time, the star of the show heads off towards a dirt track among sand dunes. He's picked up an appetizing smell, appetizing, that is, to monitor lizards.

It's the stench of rotting flesh from a roadkill, and a monitor doesn't turn up his nose at that. They're seasoned scavengers as well as accomplished predators.

Cooked in the sun, the mangled rabbit is irresistible, but how best to carve the roast? Monitors have sharp teeth, but they can't chew. So if the meal is too big to be gulped down whole, it has to be torn apart.

Lizardcam is like catching a glimpse into the monitor's life and mind.

CHRISTIAN RUTZ: You have this little video screen in front of you, and what you see is not some piece of recorded footage, but it is an animal behaving, and you are live on the back of a lizard. And that is very exciting. You get this very special point of view, and you also immediately realize the quality of certain discoveries.

NARRATOR: The next discoveries will be at Eric's camp in Red Sands.

Basking in the early morning sun is a rarely seen Lizard King. With a relatively long body and short tail, he's the dachshund of the monitors.

This short-tailed monitor or brevicauda is the smallest monitor in the world.

ERIC PIANKA: Oh, man, look at that.

This is an amazing lizard, and it's a real pygmy. Look at this savage thing; ahh, ooh, ahh. It's just a joke to see a little tiny thing like this acting like it's a big lizard, but they don't know they're not big.

NARRATOR: In fact, they're just as fierce as their bigger cousins.

ERIC PIANKA: Monitor lizards range in size over orders of magnitude, like four or five orders of magnitude, and that's pretty awesome. I don't think there is any other closer related group of animals on the earth. It's just like the difference between a brevicauda and a Komodo dragon is about the same as a mouse and an elephant.

NARRATOR: In contrast to this tiny hunter, in Indonesia, real-life dragons rule entire islands. And they truly are giants. Up to ten feet long and weighing as much as 200 pounds, the largest Komodo dragons are not only the biggest monitors, but also the biggest lizards now walking the planet.

They will bring down prey as large as deer and water buffalo and occasionally dine on a human. Komodo dragons can devour up to 80 percent of their own weight in a single meal. That's like a human gorging on a 130-pound steak.

Their appetite is legendary, but their minds are even more intriguing.

ERIC PIANKA: Monitor lizards are fascinating for all kinds of reasons. Not only are they bigger than other lizards, but they're also smarter than other lizards. I dare anybody to go to a major zoo and look a monitor lizard in the eye. It's looking back at you. Other lizards don't do that.

NARRATOR: London Zoo was one of the first in the world to exhibit Komodo dragons, in 1927.

And it was this species above all others that revealed monitors are more than just powerful hunters. These dragons captivated an awestruck public and their keepers. As Dr. Ian Stephen knows firsthand, they displayed a surprising intelligence.

IAN STEPHEN (London Zoo) : Ever since Komodo Dragons were kept in captivity, people realized that there was something extra. They're incredibly inquisitive. Any sort of new thing that you put into their environment, they'll come across, they'll investigate it. They always want to know. They always, sort of...they've always got one eye on you.

NARRATOR: Raja demands caution. He's ten years old but still a youngster, and each day Ian needs to stimulate his natural curiosity.

IAN STEPHEN: What's this? What's that? What's happening? What's this? Stick.

NARRATOR: Incredibly, this fearsome beast can be as docile as a puppy.

IAN STEPHEN: I've kept reptiles all my life, and you never really get a lot back from them. Whereas with Komodo dragons, they definitively give you something back. They definitively seek out your presence. And when you're stroking it or interacting with it, you can see he loves it. And I love it. And you know, all the keepers love it. And this is like working around a mammal.

NARRATOR: But when it comes to food, he has a dragon's appetite, albeit a semi-tamed dragon.

IAN STEPHEN: Raja! Hoi!

NARRATOR: Atypically for a reptile, Raja is responding to training routines you'd expect to see with intelligent mammals.

IAN STEPHEN: What's this? Good boy! What's this? Come on! Up, up! Good boy, come on. Up, up. Hoi! Good boy.

Raja relates the target to food. So we use the target as a tool to move him from A to B. But the key thing is, when the target is out of his field of vision, his feeding response is turned off, okay? So now, because Raja can't see the target, he's now quite a calm animal. When he sees the target, he then expects to be fed. So it's actually a really useful tool for...in, sort of, day-to-day management. And although you can target-train, probably, most reptiles, monitors are a lot more switched on, and they take to the target training so much quicker.

Good boy, Raja!

NARRATOR: There are even reports of dragons playing, behavior previously unheard of in reptiles.

IAN STEPHEN: He's clearly a very intelligent animal. He knows everybody's voices, everybody's smells, different cues, different noises. You spend five minutes talking to Raja and you can definitively see that intelligence in his eyes. It is hard to quantify, but I would definitively say, he's without question the most intelligent reptile I've ever worked with.

You're a spoilt boy.

NARRATOR: Observing how smart monitors are in the wild is a bigger challenge.

Take the Australian sand monitor or gouldii. This sneaky hunter is as fast as he's elusive, always on the run.

Eric knows him all too well. Sand monitors frequently steal lizards from his pit traps, leaving only their telltale footprints behind.

ERIC PIANKA: Hey, wait a minute. That looks like it might be a track. Let's see. Let's get out and check this out.

That track went right over our tire track so it was made today.

NARRATOR: But today, the sand monitor might have just run out of luck.

ERIC PIANKA: Looks like something.

STEPHEN GOODYEAR: Where?

ERIC PIANKA: Right here.

STEPHEN GOODYEAR: Oh, I think I see it.

ERIC PIANKA: Yeah, that's a gouldii track.

One of my favorite pastimes is tracking lizards across Australia's red sands.

It went right through here.

And when I find a crisp, crisp, brand new track, it just makes my heart beat faster. It's like, "Wow! There is a line, all I have to do is follow it, and I'll find a fantastic lizard." When I'm on a track, I'm just single-minded.

It went through here. Let's come up here and see if we can...there. It was there.

When you learn how to track, not only do you, do you read the sand, but you, you become the lizard yourself, if you're a good tracker. And you see the direction it's going, and then that makes it easier, because you can circle around in a big arc and find the track quicker.

NARRATOR: But given the sand monitor's stamina, even a fresh trail can stretch for miles.

ERIC PIANKA: Ah, right here you can see the classic gouldii track. They lash their tails, they lift it off the ground. It's not continuous like the perentie track.

NARRATOR: While the hide and seek continues at Red Sands, up in Australia's tropical north, Lizard Kings leave hardly any tracks behind.

This rocky landscape is home to a number of very different creatures like the Kimberley rock monitor. It's a master climber, quick as a wink and constantly on the lookout for anything small enough to grab.

The key to the monitors' remarkable survival story is the one-plan-fits-all body design, which has changed little from the time of the dinosaurs. All monitors can run, climb, dig and swim. The Mertens monitor even has valves in its nose that shut tight when swimming underwater.

But apart from size, monitor species don't differ very much, and they're all armed with the same senses.

During the dry season, Mertens forage for crabs, crayfish and frogs in widely scattered permanent pools, but they inevitably cross paths with their neighbors, and they're not about to share the spoils freely.

Rivals are not tolerated, and much head bobbing accompanies a standoff. It's part of monitor etiquette, a warning to back off or get bitten.

Mertens are skilled hunters, on land and in the water. Just like other monitors, to find food, they flick their forked tongue, except that Mertens pick up scents under water as well. They're surprisingly good fishermen. It's a skill spotted by other predators. Why try to catch fish when you can steal one?

A Lizard King is not so easily outwitted. Survival out here means staying at least one step ahead.

ERIC PIANKA: Ah, there! Stephen, bring the ax and a shovel up here. I've got a gouldii in a burrow. It's a big one.

STEPHEN GOODYEAR: Got it!

NARRATOR: Back at Red Sands, Eric's found the hideout of his lizard thief. Now he has to get him out.

ERIC PIANKA: Right in that direction. So what I'm going to do first is look for the pop hole, the pop hole where he'll jump out. And that most likely will be over about here.

NARRATOR: Monitors are a class vanishing act. They disappear from view in an instant, and they build their homes to confuse other predators and, of course, lizard hunters.

The main burrow stretches for many yards underground, and it has emergency exits or pop holes, dead-end corners and decoy tunnels, and so Eric and Stephen have to feel their way through the labyrinth of shafts.

ERIC PIANKA: Hunh, this isn't going to work. I've got to get my head down this hole.

NARRATOR: Eric has to be careful. There could be all kinds of venomous creatures down there.

ERIC PIANKA: Oh, man, this is a bad one.

NARRATOR: Two hours of digging, and they can almost smell their quarry.

STEPHEN GOODYEAR: Does this kind of look like an opening?

ERIC PIANKA: Yeah, it does. Maybe that's the pop hole.

STEPHEN GOODYEAR: Here, let me just have a look. You can see his tail.

ERIC PIANKA: Yep, okay. I told you he was in there. I told you he was going to try to come out a pop hole!

Oh, this one is, this one is powerful, man. You want to hold him? He's very strong. Watch out, he's really...don't let him go, whatever you do, hang onto that lizard for dear life.

NARRATOR: The sand monitor is a prize catch, but Eric wasn't the first to get to him.

ERIC PIANKA: Something must have bit him on the tail, something big. I think it was grabbed by a perentie like that and just barely escaped.

Well, let's go back to the truck.

NARRATOR: This Lizard King is about to make history. Soon he'll be carrying Red Sands' first Lizardcam.

ERIC PIANKA: He's big enough to carry a transmitter. I think Christian and Lucas are going to like this.

NARRATOR: While Lizardcam reveals the monitors' tactics in the wild, at the University of Tennessee, biopsychologist Dr. Gordon Burghardt is investigating their intelligence, in the lab.

GORDON BURGHARDT (Biopsychologist) : Now, the term "intelligence," of course, is a complex term because, what is intelligence? We can't define that for people. It's best for us to think about this in terms of various tasks, or problems an animal has to solve, and how good they're able to do it.

NARRATOR: Checkmate to the Lizard King might be premature, so Dr. Burghardt's team has begun with something simpler: a test to see whether monitors can discriminate between different objects.

His animals are African species, and in previous tests, these monitors have already shown they can count up to six. They were trained to leave a feeding area only after they had found six hidden snails, a remarkable performance for a lizard.

GORDON BURGHARDT: Our animals are really quite laid back. They are used to people, they are used to being handled, they get a lot of tender loving care. When they get into the environment, they get involved in it right away, rather than being like going to a doctor's office with a young kid, you know, "I don't want to go there again." That doesn't happen with our animals.

NARRATOR: Like the Komodo at London Zoo, Milo is trained to respond to a target to get a reward.

NATALIE (Student) : Milo: target!

Good girl!

GORDON BURGHARDT: Hey, you did it. Hey, hop that-a-way.

NARRATOR: All of Dr. Burghardt's monitors take to the training easily.

GORDON BURGHARDT: Okay, let's see if she can get another target here.

After we found that the animals really learned the targeting adequately, we decided: okay, without our presence, without our moving of the object—which is what we were always doing—would they be able to recognize and discriminate it from a similar object that differed in some characteristic. And so we began with the easiest discrimination, black and white.

NARRATOR: Now the monitors face two new challenges. First, they can't see their trainers and nothing in the arena moves, so there are no obvious cues as to what to do. Will they remember?

NATHAN (Student) : Tongue flicking on the left wall, going straight down.

NARRATOR: Second, they can see two balls: the black one they know and a new white one. Will they tell the colors apart?

They master the task surprisingly quickly.

GORDON BURGHARDT: What we do find is that the animals learn quite rapidly. Within 20 trials, our animals were reliably choosing the right target. And what we find that's amazing, and is not true of most reptiles, that they don't seem to care that much about the environment being simplified and artificial.

NATHAN: Tongue flicking black, tongue flicking black.

NARRATOR: Rather than being thrown by the sterile lab environment, these monitors are focused and show an ability to think ahead, which is exceptional for a reptile.

To test whether the animals are hitting the black ball by chance, the targets are swapped.

GORDON BURGHARDT: We think this is a very promising beginning. Obviously we have a long way to go, but no one has really done this kind of work before. But the fact that they are learning some of these trials so quickly, much more quickly than many other animals, even mammals, shows that monitor lizards, I think are, sort of, the primates of the lizard world.

NARRATOR: Intelligence is about learning, and the ability to adapt quickly to new experiences, in the lab and in the wild.

In Thailand, monitor lizards have learned to take advantage of new opportunities. This is the water monitor, which can grow to more than six feet long, and is known locally as the "little crocodile." It's been quick to find a perfect place to prowl: our food-filled cities.

In the center of buzzing Bangkok, the water monitor has invaded water channels and surrounding parks, embracing the urban lifestyle with ease.

Fresh food and garbage are both fair game. And the best spots for a hungry lizard, close to busy market stalls, are usually won in a fight.

Monitors are renowned wrestlers, but they fight for more than just food. These trials of strength increase just before the big rains. The rains mark the start of the mating season. Now the males are pumped up and ready to brawl over females.

This is the one time Lizard Kings break the monotony of their normally solitary lives. The next two months are highly charged, with males marking areas, driving off rivals and making passes at the opposite sex.

Males also release scents, which scientists believe may serve to cow the competition and signal their potency. But it takes a great deal of pushing and shoving to convince a lizard queen that he is the King for her.

Once the couple has found each other, they mate repeatedly. But the female will mate with several other partners, too, so her clutch of eggs will carry the D.N.A. from different males.

Such is the drive to multiply, a female can find herself overwhelmed by suitors. When it's all over, she'll dig an underground chamber and lay a dozen or so eggs. And about eight months later, the young heirs will emerge to found their own urban dynasties.

Back at Eric's camp, expectations are rising.

ERIC PIANKA: We've got to keep the tail from lashing.

CHRISTIAN RUTZ: You've got him?

NARRATOR: The Lizardcam team have arrived and they're fitting Eric's freshly caught sand monitor with a made-to-order video camera and radio tag.

CHRISTIAN RUTZ: Yeah, it's got the radio tag here, so if it comes off we...

ERIC PIANKA: We can find it.

CHRISTIAN RUTZ: ...we can find the unit.

LUCAS BLUFF: And we're going to put another tag on, so we can find the lizard if the unit drops off.

ERIC PIANKA: He's behaving very well.

NARRATOR: Cooled down for easier handling, the sand monitor takes the fitting in stride.

LUCAS BLUFF: ...seen on a single lizard before.

ERIC PIANKA: Three different signals it's sending out, that's great.

NARRATOR: Now comes the moment of truth. How is this Monitor going to react to its new backpack?

ERIC PIANKA: Oh, boy. He's going to take off running, I think. There we go.

Once he realizes he can go, we'll try to...oh, there he goes. Oh ho, neat! Wow, you can see him walking along; fantastic.

CHRISTIAN RUTZ: Okay, let's go down here and try to cut across.

NARRATOR: Swiftly out of sight, the monitor is up to his old tricks, but Lizardcam is about to reveal just how he pulls off this familiar vanishing act.

Only a few monitor species stand or run on their back legs to get a better view, and the sand monitor is one of them.

ERIC PIANKA: He's probably in between a couple of these tight spinifex.

CHRISTIAN RUTZ: I think he is. He's over there.

ERIC PIANKA: Over that way. Okay.

CHRISTIAN RUTZ: But I think we can stay here now, because Lucas gets good reception.

ERIC PIANKA: Oh, he's getting...

CHRISTIAN RUTZ: So there is no need to get closer.

ERIC PIANKA: Yeah, let's not spook him.

NARRATOR: After 40 years of watching lizards, Eric is seeing, for the first time, what they see, and he's in for a surprise.

ERIC PIANKA: Putting his head down. Oops. There, he's digging. See? He's digging.

NARRATOR: Sensing the team is hot on his heels, the monitor changes tactics.

ERIC PIANKA: He heard that. He's listening to us, flicking his tongue, yeah.

NARRATOR: Sunset is only an hour away and the temperature is dropping.

ERIC PIANKA: They're very powerful diggers. He's digging like a maniac.

NARRATOR: For a solar-powered reptile, there's only one safe way to go: down, into a warm hideaway.

ERIC PIANKA: I think he's going to dig an overnight burrow right here. Amazing he got that far that fast. I didn't know they could do that. This is great.

STEPHEN GOODYEAR: You can actually see the hole.

ERIC PIANKA: Yeah, he's making his hole, you can see it.

NARRATOR: In just 15 minutes, the monitor has excavated itself a snug refuge.

ERIC PIANKA: I didn't know they could do it this fast. I thought they, I thought they went into a burrow they'd already...knew was there.

CHRISTIAN RUTZ: Well, that's our first discovery then.

ERIC PIANKA: Yeah.

NARRATOR: Already the monitor has made up for stealing Eric's lizards. His camera will be recovered in a few days. Lizardcam has added a new dimension to Eric's research.

Bush fires are part of Australian life everywhere, from the deserts to the tropics.

To survive such devastation, each species has its own tactic, but while most animals flee, the Mertens monitor stays cool.

Water gives a degree of protection, and the flames will bring an unexpected bonus. Some predators, like birds of prey, are attracted towards the blaze and become a meal themselves. Insects taking flight from the flames and smoke also drop out of the sky, out of the fire and into the frying pan.

But there's more to bush fires than destruction and free meals. They're one of the reasons why Australia has such rich lizard communities.

Fires carve up the landscape, creating new habitats next to old unburned ones, each supporting different species.

ERIC PIANKA: It took me a while to realize how important fires were. There's lots and lots of natural fires, set by lightning, that cause massive changes in the habitat on the ground. When fires burn, they break and leave behind refuges of old unburned stuff. And so what the fires are doing is creating a spatial-temporal mosaic of habitats of different age. And that's one of the main things, I think, that contributes to the high lizard diversity.

NARRATOR: Other types of disruption, however, are less benign. Climate change and its effect on local weather and vegetation could soon make some lizard species disappear.

ERIC PIANKA: This part of Australia has 20 percent more rainfall than it used to have, and that's because of climate change. Numbers of lizards are down, compared to what they used to be. I didn't used to think humans could impact a remote place like this. I used to think lizards out here would run around like they always have, long after we went extinct, and now I'm not so sure.

NARRATOR: As one of his dreams reveals, even Eric's own effect on the lizards leaves him ambivalent.

ERIC PIANKA: Over the course of the last 40 years. I've, I've messed up thousands, 30,- or 35,000 lizard lives. So in this nightmare, I'm on trial. It's like Nuremberg, and of course the judge is a perentie. And they find me guilty and are going to hang me. And I wake up about then.

So I feel a little guilty, but at the same time, I think that I've contributed a lot of basic information.

NARRATOR: And if it's any defense, probably no one could care about these animals more.

ERIC PIANKA: To me, a lizard is a really precious thing. It's like they're the centerpiece to my whole existence. I can't imagine a world without lizards. It would be a world without some of the most spectacular creatures there are.

NARRATOR: On NOVA's Lizard Kings Web site, watch any part of this program, go behind the scenes and more. Find it on PBS.org.

This NOVA program is available on DVD. To order, visit shoppbs.org, or call us at 1-800-PLAY PBS.

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