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BBC Life in Cold Blood Dragons Of The Dry Lizards

about 340 million years ago a brand new family of animals was evolving in the primeval swamps. They were to go one step further than the amphibians that had emerged onto dry land before them. For they would eventually completely cut their ties with water. They were the ancestors of today's lizards. They evolved scaly impermeable skins and moved up into the forests. They diversified into a multitude of different shapes and sizes. They developed signaling systems to communicate with one another. And they squabbled as animals do over mates and territory. For food they hunted insects that were already well established on the land in great numbers. And here without returning to water they produced their families. They powered their bodies not only with food but with the heat that they drew directly from the sun. As they diversified so they spread into the harshest of the lands habitats. The baking waterless deserts which eventually they would come to dominate. The bigger ones are truly powerful and fearless. Rearing up they're well able to defend themselves with their front legs if they're threatened. This is a very intelligent animal. It is observing me just as I am observing it. It's a monitor lizard and its king of this country the Australian outback. It is frightened of pretty well nothing obviously including me and it will chase and hunt and eat pretty well anything. There are several thousand lizards round the world and they are truly the dragons of the dry. Their eggs on land had to be encased in shells to prevent them from drying out. And what better place to lay them could a mother lizard find than a termites nest? Worker termites labor unceasingly to keep the temperature and humidity virtually constant for their own benefit. But that also makes their mound a near-perfect incubator for eggs of others. After 10 months they're beginning to hatch. These are baby lace monitors. But they face a major problem. A termite nests walls can be a foot thick and extremely hard too hard for the young monitors to break through. They are imprisoned with no food. For a week after hatching they're sustained by the last of the yolk that remains in their stomachs. But when that comes to an end they could starve. An adult lace monitor is nearby. It may or may not be the baby's mother. If not then it could be a threat for monitors are hunters and will eat most small animals including baby lizards. She's nearing the termite nest within which the young are trapped. She could be looking for a place to lay her eggs. Alternatively she might be searching for food such as little lizards. The babies are released unharmed. Perhaps she is indeed the babies mother and not only remembered exactly where she laid her eggs a year ago but knew that her babies would need her help to escape from the incubator. The young however are free. But the outside world is a dangerous place. They head for safety up into the trees. In the branches there are other kinds of lizards. Jacky dragons. Each has its own territory and warns others to keep out. A wave of the front leg and a bob of the head is a jacky dragon's way of claiming territory. Here the action is slowed down. In reality the leg flick is so swift it's hard for us to see but it's very plain to another jacky dragon. But sometimes signals are not enough. Physical violence is needed. He's won. The vanquished acknowledges his defeat with a different signal a slow leg wave with no head bob. The winner returns to his territory in the branches and announces his victory which his neighbor acknowledges. So now both can live alongside one another in peace. Once jacky dragons stop signaling it is quite hard to spot them up in the branches. American anoles are so well camouflaged they're virtually invisible. There's one on this tree right in front of me. But he too needs to draw attention to himself to warn off rivals and then to disappear from predators. Lizards for the most part are not known for being caring parents but there are exceptions. Its spring in the woodlands of North America. An American robin is nesting warming her eggs with the heat generated by her own body. And below on the forest floor a five-lined skink is warming her cold-blooded body by basking in the sunshine so that she can do the same thing. She has a nest below the log. It can get quite chilly in these woodlands and she warms her eggs by transferring to them the heat that she has collected from the sun. She takes just as much care of her eggs as the robin does. A month later and her eggs are hatching. The robin's eggs have hatched too. Her nestlings are helpless and need constant feeding. The young skinks however are already capable of finding food for them. Within a day or so they've left their mother and are independently exploring the woodland floor for themselves. But there are other skinks whose family life lasts rather longer. These fields in South Australia are home to a little lizard that is so rare that it had been thought to be extinct for over 30 years until it was rediscovered in 1992. And of course this explains why no one has seen these little lizards for so long. They're very difficult to find. But what's really special about this little lizard is its family life. It's a long and strenuous business for a mother shingle back. She produces not a small egg like the five-lined skink but a live baby. It's a whopper. And there's another one to come. Together the two weigh as much as a third of her body weight the equivalent in human beings of carrying a 3-year-old child. Like the Cape chameleon in South Africa the female has been acting as a mobile incubator seeking out the warmest spots she can find in order to bask. Producing such well-developed young is the shingle backs response to the fact that it can get quite cold in South Australia. Her young are so advanced that they soon leave her. But when spring returns the same male and female will once again seek one another out and mate again. In fact a pair will remain faithful to one another for as long as 20 years or more. The bond between them may even endure after death. They're slow-moving creatures and only too often when crossing a road they're unable to get out of the way of a passing car. If one of the pair is run over the other will often remain at its side for days tenderly nudging it. You might even say that it was grieving. On the other side of the world there are lizards with a very different lifestyle. They gather together in groups with densities higher than you can find anywhere else. And the reason they are able to do so you can see alongside the waters of this the Orange River in South Africa. The river is the breeding ground for vast swarms of black flies. Excellent food for a lizard if it can catch them. In the early morning the Augrabies flat lizards emerge from the cracks in the rocks where they spent the night and bask in the sun to warm up. The males are the brightly coloured ones as you can see from his marvelous blue head. But it's not his head that impresses his rivals so much. It's the underside which if he is a high-status male will be bright orange and yellow. And if another one turns up he will try and impress his rival by exposing that. These awkward-looking postures reveal why these creatures are called flat lizards. For them there is more to life than just dinner. And some wont take no for an answer. The females want food. They need a square meal to nourish the eggs that are developing within them. But they won't get any peace until they leave the restaurant and get back home where life is better regulated. The high-octane social life of the flat lizards with its constant squabbling seems to be very stressful but for other lizards fighting are less frequent but altogether more impressive. A Mexican beaded lizard. One of the few lizards in the world with a poisonous bite. And a very virulent one it is too. In the spring rival males fight according to a very specific set of rules. They use neither their sharp powerful claws nor their poisonous bite in their battles. At first they grapple rather warily to assess each others strength. Then they begin to wrestle in earnest each trying to pin down the other on the ground. These two are evenly matched. Neither can get the crucial throw. It's rather like an arm-wrestling contest and the bout can continue for several hours. The eventual winner is the one who ends up on top most frequently. It's a controlled test of strength in which despite their lethal weaponry no one gets seriously hurt. Other lizards defend themselves not with physical strength but by deceit. The South African desert. A bushveld lizard. This is another. It looks very different but that is because it's a baby. It not only has different coloration it also walks in a very different and quite extraordinary way. It appears to be imitating one of the local beetles that one. And to discover why I'm going to take defensive measures with these goggles. This beetle is known as an oogpister an eye-spitter. Thats because its squirting formic acid at me. Oh yeah and if any of that got into my eye it would be extremely painful. It's a defensive system and the lizards are benefiting by imitating a beetle with that kind of armoury. A young lizard closely matches the beetle both in its appearance and its walk so birds that prey on lizards assume it has a nasty spray and leaves it alone. Lizards can cope with dry hot conditions so well that they dominate the fauna in tropical deserts around the world including those in central Australia. Their 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. Some wear the most elaborate suits of armour. This is surely the most enchanting of lizards. It is called the thorny devil or Moloch after Moloch the god in the Bible who ate little children. Both names surely are a slander on such an engaging little animal. It feeds entirely on ants and as you can see there's not much of a meal in any one of them. But the good thing about ants as far as Moloch is concerned is that there's always some around. And this little creature will sit by an ant trail patiently for hours on end simply picking off one ant at a time. The Australian desert is also home to one of the most powerful of the family. Monitors are the kings of lizards. And this is the perentie the biggest species of monitor in Australia. It can grow up to two metres long six feet and it's a highly intelligent animal. It has got very acute senses of sight and hearing and taste and smell. And like all monitors it can do something no other kind of lizard can do. It can run continuously for a very long time and that enables it to become an endurance hunter chasing down its prey. Most 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. But monitors have big muscular throats which they use like bellows to pump air into their lungs and they can do that even then they're running. This special way of breathing enables them to reach speeds of over 20 miles an hour. Over distance they are one of the fastest of all reptiles. The cold-blooded perentie can even outrun a warm-blooded rabbit. So the lizards have colonized the world from swamps to rainforests from woodland to desert. And in doing so they've revealed such a variety of form and behavior that they truly can be called the dragons of the dry. Much of our filming for this programme was done in Australia. There are lizards everywhere. Just walk around in the bush and you'll see them. But usually you won't get much more than a brief glimpse. To film their intimate behavior we needed help from experts. We had travelled to Australia to meet an expert called Mike Bull. He knows Australian lizards as well as anyone. He and his team study many species in one small area north of Adelaide using all manner of gadgets and gizmos to investigate every part of their lives. We were particularly interested in the lizards that Mike understands best of all the shingle back or sleepy lizard. He knows 10000 of them individually. On the face of it the sleepy lizard doesn't seem to do a lot. But Mike knows so much about them that we were able to make them one of the stars of our film. He's discovered that they're the only lizards in the world that remain faithful to one partner for all their lives. But that wasn't the reason that he began to study them. Tell me first how you first saw sleepy lizards and what attracted you to them. I first started because I was interested in parasites that live on the lizard. To find the parasites I actually had to look at the lizards as well and I discovered they were doing things that were more interesting than the parasites. And for me I think they're one of the most handsome animals that you'll ever find. The other thing is that it's probably the only animal that you know if you're driving along in a car and you see one 100 metres down the road you know you've caught it. And its also one that I think I'm going to be sufficiently agile to keep on catching until I'm well past 80. I might have to even I think could scrag a sleepy lizard. Ill sees whether I can manage it. Sleepy lizards like to bask on warm roads so they're easy to find and they move so slowly they're easy to pick up. So the team was able to weigh and measure a whole population and thus discovered that pairs remain together in a way that was previously known only in birds and mammals. But that was just the start. Next they turned to technology some of it advanced some a little bizarre. They used remotely controlled rubber sleepy lizards to test how lizards reacted to one another. In this case not very much. Mikes team suspected there's another lizard in the area. The gidgee skink had an even more complex social life. But this was difficult to prove because when approached the skinks wedged themselves in cracks in the rocks making it impossible to identify who's who. The solution was to microchip each lizard so it could then be scanned just like your supermarket shopping with a barcode reader on the end of a pole.


 
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In the branches there are other kinds of lizards, jacky dragons
In the branches there are other kinds of lizards, jacky dragons
  They use not only gestures but body colours, they're chameleons
They use not only gestures but body colours, they're chameleons
  That is a very rare little creature, it's a pygmy blue-tongued skink
That is a very rare little creature, it's a pygmy blue-tongued skink
  A shingleback or as its called here in its home in Australia a sleepy lizard
A shingleback or as its called here in its home in Australia a sleepy lizard
 
This clever use of technology revealed what looked like a jumble of lizards on a pile of rocks to be actually a little lizard family with young that stay with their parents for life. I'm sure that there are going to be many other complex social organizations that will be uncovered in those species if we just simply take the time to look at them. But it's just the time and the patience to watch them. And watching a lizard is very unrewarding because they will come out and bask and sit by a bush. And if they see you're there then they'll decide they're not going to do very much for the rest of the day. Just what sleepy lizards get up to when no ones around Mikes team use a rather bizarre device they call a waddle meter. It may look a little odd but it records the lizards GPS coordinates counts its steps and even notes whether it's in sun or shade all without troubling the lizard and without anyone having to be there. So you think there's probably the secret world of the lizard which no human being has ever seen because if a human being is there the lizard won't behave that way? I'm sure that's part of it. It's the uncertainty principle. The closer you get to watch something the less normally its behaving. And so it's only by getting these remote and new technologies that allow us to really get into the secret world of the lizards that we can find these really amazing things that they're doing. How extraordinary. One of their latest techniques uses miniature cameras which they use to study a very special lizard that we were also particularly keen to film. It's so rare that it was thought to be extinct for over 30 years until it was thrust back into the public eye when it was discovered in some very unusual circumstances. There was a group of biologists who were doing a standard biological survey. They were just coming back to town to pick up supplies and just on the road they saw a dead brown snake. Now most people just wouldn't even look at it because they're so common around here but these were dedicated biologists. They stopped and had a look at it.     Lets see what it's been eating. Opened it up and there was this lizard that no one had seen for 30 years a pygmy blue-tongued lizard. How lovely. Though I dare say it wasn't all that lovely when they actually saw it. Miniature cameras have produced images that are slowly helping to build up a comprehensive picture of the life of these rare little creatures. Their burrows are more than just homes. They're also hiding places where they can wait in ambush for spiders and crickets. But they don't seem too keen on ants. They also serve as bolt holes when danger approaches. Despite all this work Mikes team had never recorded their life underground. So we were able to help with a little of our own technology and record the first ever pictures of a pygmy blue-tongued family. Three babies alongside their mother in their little hole. But all this technology ingenious though it is no substitute for years of dedicated observation. Mikes approach of simply driving for miles across the Australian outback is very fruitful. And you see lots of other things as well as lizards. Up here is just a wonderful place for lizards Oh boy. Yeah kangaroos. Eastern grey. Beautiful wasn't it? Yeah. Now you won't catch a lizard doing that. Oh look there's a pair just down there. It turned out that Mike had spotted two old friends. This is the male and the female. This is 1172 and 3342. I think they've been together for about 10 years this pair. Really? Wave got some other pairs that have been together for over 20 years. They 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 well find them back together again usually in the same place along this road too. They use their tongues to pick up chemical signals and you can see they're actually sensing each other at the moment. I think that's really very touching. I say that's a risky business. With obsessive dedication and ever-advancing technology who knows what Mike and his team will uncover about the secret lives of sleepy lizards?