BBC Life in Cold Blood E03 Dragons of the Dry
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00:30about 340 million years ago a brand-new family of animals was evolving in the
00:43primeval swamps they were to go one step further than the amphibians who had
00:54emerged onto dry land before them for they would eventually completely cut
01:01their ties with water they were the ancestors of today's lizards they
01:13evolved scaly impermeable skins and moved up into the forest
01:24they diversified into a multitude of different shapes and sizes
01:45they developed signaling systems to communicate with one another
01:55and they squabbled as animals do over mates and territory for food they
02:03hunted insects that were already well established on the land in great numbers
02:16and here without returning to water they produced their families
02:28they powered their bodies not only with food but with the heat that they drew
02:34directly from the sun
02:38as they diversified so they spread into the harshest of the land's habitats the
02:45baking waterless deserts which eventually they would come to dominate
02:54the bigger ones are truly powerful and fearless rearing up they're well able to
03:01defend themselves of their front legs if they're threatened this is a very
03:11intelligent animal it is observing me just as I'm observing it it's a monitor
03:21lizard and it's king of this country the Australian outback it is frightened of
03:29pretty well nothing obviously including me and it'll chase and hunt and eat
03:36pretty well anything there are several thousands lizards around the world and
03:43they are truly the dragons of the dry
04:00their eggs on land had to be encased in shells to prevent them from drying out
04:08and what better place to lay them could a mother lizard find than a termites
04:14nest worker termites labor unceasingly to keep the temperature and humidity
04:20virtually constant for their own benefit but that also makes their mound a near
04:26perfect incubator for eggs of others
04:34after ten months they're beginning to hatch
04:56these are baby lace monitors
05:10but they face a major problem a termite nests walls can be a foot thick and
05:17extremely hard too hard for the young monitors to break through they are
05:22imprisoned with no food
05:26for a week after hatching they're sustained by the last of the yolk that
05:35remains in their stomachs but when that comes to an end they could starve
05:48an adult lace monitor is nearby
05:57it may or may not be the baby's mother if not then it could be a threat for
06:05monitors or hunters and will eat most small animals including baby lizards
06:16she's nearing the termite nest within which the young are trapped
06:27she could be looking for a place to lay her eggs alternatively she might be
06:35searching for food such as little lizards
06:57you
07:12the babies are released unharmed perhaps she is indeed the baby's mother
07:18and not only remembered exactly where she laid her eggs a year ago but knew
07:23that her babies would need her help to escape from the incubator young however
07:33are free but the outside world is a dangerous place
07:40they head for safety up into the trees
07:51in the branches there are other kinds of lizards Jackie dragons each has its own
07:59territory and warns others to keep out a wave of the front leg and the bob of the
08:06head is a Jackie dragons way of claiming territory here the action is
08:11slowed down in reality the leg flick is so swift it's hard for us to see but
08:17it's very plain to another Jackie dragon
08:24but sometimes signals are not enough physical violence is needed
08:37he's won the vanquished acknowledges his defeat with a different signal a slow
08:54leg wave with no head bob the winner returns to his territory in the branches
09:02and announces his victory which his neighbor acknowledges so now both can
09:17live alongside by another in peace once Jackie dragons stop signaling it's quite
09:27hard to spot them up in the branches
09:31American animals are so well camouflaged they're virtually invisible there's one
09:38on this tree right in front of me but he too needs to draw attention to himself
09:45to warn off rivals and then to disappear from predators this mirror may persuade
09:53him to reveal his solution to the problem now then what do you think of
09:57that
09:59who's that yes the rival
10:08tail wag yes you're not gonna get rid of me that way
10:19show us your signals well press up certainly is a keep away a challenge the
10:34fool works ah lovely once more thank you and again come on he obviously thinks
10:51that his position is being contested and he is displaying to show that he's as
10:58good as anybody else so I guess I'll leave him in peace
11:05and an old throat flap appears for only a second or so and then vanishes and its
11:12owner after sending his message returns to camouflaged obscurity
11:19another family of lizards living in the treetops has an even more varied
11:25repertoire of signals they use not only gestures but body colors
11:43they're chameleons
11:47a stronghold is the island of Madagascar and here there are over 60 different
11:57species of them almost more than in all the rest of the world put together this
12:04is a panther chameleon and it's marvelously adapted for life among the
12:12branches its toes are divided into two bundles three and two and that means
12:20that it can use them just like forceps their grasping feet supplemented by
12:29their gripping tail enable them to become remarkable slow-motion acrobats
12:43I suppose chameleons are best known for their ability to change color and that
12:50does help in camouflage but actually they also use color change as a way of
12:57communication and expressing their emotions
13:02when a male panther chameleon spots a rival he expresses his fury in glorious
13:13technicolor
13:22Malawi in Central Africa may not have as many species of chameleon as Madagascar
13:28but it has one of the largest Mela's chameleon that can be 60 centimeters
13:34nearly two feet from nose to tail
13:46rival males when they deploy a range of threats that is truly formidable
14:28if signals don't deter then they start to joust
14:58it's not only males that fight there are also battles between the sexes this
15:26is the South African dwarf chameleon a male in full courtship costume this
15:37somewhat less colorful is a female
15:41she is not welcoming his advances
15:55as her mood darkens so does her skin
16:11she's driven him away but why
16:30there is a reason she's pregnant her home the South African cape can get
16:40quite cold so instead of laying her eggs on the ground as most chameleons do
16:45she retains them within her body and warms them by seeking out the sunniest
16:50places and sunbathing now they're ready to emerge alive
16:59producing babies in the branches might seem to be a risky business but the
17:11membrane enclosing each one will stick to a twig if it hits one
17:18and when at last the babies disentangle themselves they immediately deploy their
17:24formidable chameleon grip
17:59you
18:20by the time they're properly dried out the babies are as much at home in the
18:25branches as their mother
18:29but for the most extraordinary chameleons of all you have to look not up
18:57in the trees but down here on the leaf litter a whole range of species live on
19:09the ground many of which have only recently been discovered this is surely
19:19the most extraordinary of all chameleons it's the pygmy leaf chameleon
19:28this is a male and he's fully grown believe it or not and yet within this
19:35tiny little body all the anatomical details of a normal-sized chameleon
19:50like all chameleons it catches its food with its tongue it eats tiny flies grass
20:04hoppers are popular with normal-sized chameleons
20:19the tongue contains a tapered rod encircled by muscle as a muscle contracts
20:37the tongue shoots forward off the rod the tip physically grasps the prey and
20:45then 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
20:54itself
21:05the whole action in reality is completed in a second or so
21:15the canopy of a tropical forest is full of food and lizards clamber around
21:27looking for it in many ways chameleons use their toes to grip the twigs and
21:33geckos use theirs to stick to leaves for their toes have adhesive pads on the ends
21:41most geckos feed on insects but some take nectar from flowers and a few
21:47collect liquid from insects in much the same way as we take milk from cows
21:56insect a tree hopper is sitting head down drinking sap from the tree it would
22:01be invisible were it not vibrating its abdomen and that is what the gecko wants
22:08from it a drop of honeydew honeydew is what remains of tree sap after the
22:14hopper has extracted the protein from it it's very sweet and the gecko plainly
22:19loves it other less colorful species of gecko also drink honeydew and some order
22:25it from the hopper by vibrating their heads
22:38the hopper tells the gecko that a drink is on the way by waggling its abdomen
22:57how the hopper benefits from this arrangement is not clear perhaps the
23:03gecko keeps predatory insects away and the honeydew is protection money most
23:11geckos are much less conspicuous and are very difficult to see
23:23it's the Madagascan leaf-tailed gecko and its tail has wide flanges on either
23:31side so that it has become leaf-shaped but these are the only flanges it's also
23:37gotten all out its toes its legs and down its flank and the consequence is
23:44if it presses itself close to the bark and spreads those frills it sheds no
23:51shadow at all the irises of its eye are also part of this amazing camouflage
23:59they have a kind of mottled pale surface which makes them look exactly like one
24:05of these little blotches of lichen on the bark all in all it's a most extraordinary disguise
24:13it and indeed the majority of geckos only really become active at night
24:30here in Bangkok as in cities throughout the tropics geckos have discovered that
24:35mankind's lights attract a great banquet of insects
24:45as a result almost every building has its own resident gecko population
24:59lizards for the most part are not known for being caring parents but there are exceptions
25:12it's spring in the woodlands of North America an American robin is nesting warming her eggs
25:20with the heat generated by her own body and below on the forest floor a five-lined skink
25:28is warming her cold-blooded body by basking in the sunshine so that she can do the same thing
25:43she has a nest below the log
25:51it can get quite chilly in these woodlands and she warms her eggs by transferring to them the
25:57heat that she's collected from the Sun
26:13she takes just as much care of her eggs as the robin does
26:18a month later and her eggs are hatching
26:30the robin's eggs have hatched too her nestlings are helpless and need constant
26:49feeding the young skinks however are already capable of finding food for themselves
27:01within a day or so they've left their mother and are independently exploring the woodland
27:10floor for themselves but there are other skinks whose family life lasts rather longer these
27:25fields in South Australia are home to a little lizard that is so rare that it had been thought
27:32to be extinct for over 30 years until it was rediscovered in 1992 and the equipment you
27:40need to find it is believe it or not a fishing rod now let's see if I can tempt him out with this
27:47oh gosh now come up a little farther so we can see what you look like that is a very rare little
28:01creature it's a pygmy blue-tongued skink and it lives in the holes that are made by trapdoor
28:11spiders and this one is clearly very hungry come on come out a little more come on just
28:20show us oh it won let's have a closer look I can do that with this optical probe with
28:33this viewing screen on the end it's quite a long way down there he is all safe and snug and he
28:44really is safe down here even a bushfire sweeping by wouldn't harm him and of course this explains
28:51why no one had seen these little lizards for so long they're very difficult to find but what's
29:01really special about this little lizard is its family life just look at these shots that we got
29:09with that optical probe that is a close-up of an adult's head and they're just beside the head
29:17tiny little head of a baby that's one and if we push past her there's a baleful look of mum who
29:27doesn't appreciate this and beyond two two more babies so that's three quite a crowded little
29:39home so there they are a nice little lizard family and the babies will stay in that crowded hole for
29:48three weeks or so before they're ready to be able to go out into the outside world and look for a
29:55spider's burrow for themselves there's another skink here whose family relationships last for
30:06decades this 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 maybe that
30:24confuses a predator but if you get closer it quickly shows which end is which by threatening
30:33with this cave display oh you're very perky and I have to be reasonably careful because it can bite
30:46but at this time of the year in the spring it also has another are the more gentle side
31:02a female catches the eye of a male
31:17he starts to follow her wherever she goes
31:28couples stay side by side for up to two months
31:47he caught her by gently nudging licking
31:51six months pass and then eventually the results of this prolonged courtship begin to arrive
32:22it's a long and strenuous business for a mother shingleback
32:28she produces not a small egg like the five lion skink but a live baby
32:58it's a whopper
33:28and there's another one to come together the two weigh as much as a third of her
33:38body weight the equivalent in human beings of carrying a three-year-old child
33:43like the Cape chameleon in South Africa the female has been acting as a mobile incubator
33:56seeking out the warmest spots you can find in order to bask producing such well-developed
34:04young is the shinglebacks response to the fact that it can get quite cold in South Australia
34:10her young are so advanced that they soon leave her
34:26but when spring returns the same male and female will once again seek one another out and mate again
34:34in fact a pair will remain faithful to one another for as long as 20 years or more
34:48the bond between them may even endure after death
34:53they're slow-moving creatures and only too often when crossing a road they're unable to get out
35:01of the way of a passing car if one of the pair is run over the other will often remain at its
35:11side for days tenderly nudging it you might even say that it was grieving
35:16on the other side of the world there are lizards with a very different lifestyle they gather
35:29together in groups with densities higher than you can find anywhere else and the reason they're able
35:35to do so you can see alongside the waters of this the Orange River in South Africa
35:42the river is the breeding ground for vast swarms of black flies excellent
36:11food for a lizard if it can catch them
36:29in the early morning the agrabia's flat lizards emerge from the cracks in the
36:36rocks where they spent the night and bask in the Sun to warm up
36:45the males are the brightly colored ones as you can see from his marvelous blue head but it's
36:53not his head that impresses his rivals so much it's the underside which if he's a high status
37:02will be bright orange and yellow and if another one turns up he will try and impress his rival
37:09by exposing that these awkward looking postures reveal why these creatures are called flat
37:18lizards by regularly displaying their vivid badges the males repeatedly confirm their
37:27place in the pecking order and so keep fighting to a minimum
37:35as a female moves from one territory to another so each male courts her in turn
37:41and now they're really warmed up and active and whole groups of them are beginning to
37:58travel down across the rocks towards the river where they'll find their food
38:02but down here where the flies swarm it's a free-for-all and that causes a lot of trouble
38:17catching flies is necessarily an acrobatic business
38:21but you can't leap for flies and still keep properly spaced out so there are inevitably
38:37quarrels between rival males
38:39females on the other hand are only interested in getting a good meal fired up males however
38:55have other ideas for them there is more to life than just dinner
39:09and some won't take no for an answer
39:29the females want food
39:30they need a square meal to nourish the eggs that are developing within them
39:48but they won't get any peace until they leave the restaurant and get back home where life is
39:54better regulated the high-octane social life of the flat lizards with its constant squabbling
40:02seems to be very stressful but for other lizards fighting is less frequent but altogether more
40:10impressive
40:25a Mexican beaded lizard one of the few lizards in the world with a poisonous bite and a very
40:40virulent one it is true in the spring rival males fight according to a very specific set of rules
40:55they use neither their sharp powerful claws nor their poisonous bite in their battles
41:02at first they grapple rather warily to assess each other's strength
41:33then they begin to wrestle in earnest each trying to pin down the other on the ground
41:54these two are evenly matched neither can get the crucial throw it's rather like an arm wrestling
42:01contest and the bout can continue for several hours
42:31the eventual winner is the one who ends up on top most frequently it's a controlled test
42:49of strength in which despite their lethal weaponry no one gets seriously hurt
42:54other lizards defend themselves not with physical strength but by deceit
43:03the South African desert a bush felt lizard
43:10this is another it looks very different but that is because it's a baby it not only has
43:23different coloration it also walks in a very different and quite extraordinary way
43:38it appears to be imitating one of the local beetles that one and to discover
43:44why I'm going to take defensive measures with these goggles
43:48this beetle is known as an orchestra and I spitter that's because it's squirting formic
43:58acid at me oh yeah and if any of that got into my eye it would be extremely painful
44:04it's a defensive system and the lizards are benefiting by imitating a beetle with that
44:12kind of armory the young lizard closely matches the beetle both in its appearance and its walk
44:20so birds that prey on lizards assume it has a nasty spray and leave it alone
44:35lizards can cope with dry hot conditions so well that they dominate the fauna in
44:41tropical deserts around the world including those in Central Australia
44:50their tough scaly skins prevent their bodies from losing moisture so that they
44:56can flourish in these arid baking hot lands that other animals find so testing
45:00some where the most elaborate suits of armor
45:13this is surely the most enchanting of lizards it's called the thorny devil or
45:31Moloch after Moloch the God in the Bible who ate little children both names surely are a
45:40slander on such an engaging little animal it feeds entirely on ants and as you can see there's
45:49not much of a meal in any one of them but the good thing about ants as far as Moloch is concerned is
45:57that there's always some around and this little creature will sit by an ant trail patiently
46:04over hours on end simply picking off one ant at a time the Australian desert is also home to one
46:18of the most powerful of the family monitors are the kings of lizards and this is the Perenti the
46:29biggest species of monitor in Australia it can grow up to two meters long six feet and it's a
46:39highly intelligent animal it'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 it can run continuously for
46:56a very long time and that enables it to become an endurance hunter chasing down its prey
47:03most lizards inflate their lungs using the same muscles they use for walking so they can't run
47:15and breathe effectively at the same time but monitors have big muscular throats which they
47:28use like bellows to pump air into their lungs and they can do that even when they're running
47:34this special way of breathing enables them to reach speeds of over 20 miles an hour over
47:48distance they are one of the fastest of all reptiles the cold-blooded Perenti can even
47:56outrun a warm-blooded rabbit so the lizards have colonized the world from swamps to rainforest
48:07from woodland to desert and in doing so they've revealed such a variety of form and behavior that
48:15they truly can be called the dragons of the dry much of our filming for this program was done in
48:33Australia there there are lizards everywhere just walk around in the bush and you'll see
48:40them but usually you won't get much more than a brief glimpse to film their intimate behavior
48:50we needed help from experts we traveled to Australia to meet an expert called Mike bull
49:00he knows Australian lizards as well as anyone he and his team study many species in one small area
49:08north of Adelaide using all manner of gadgets and gizmos to investigate every part of their lives
49:15we were particularly interested in the lizards that Mike understands best of all the shingle
49:28back or sleepy lizard he knows 10,000 of them individually on the face of it the sleepy lizard
49:39doesn't seem to do a lot but Mike knows so much about them that we were able to make them one of
49:45the stars of our film he's discovered that they're the only lizards in the world that remained faithful
49:51to one partner for all their lives but that wasn't the reason that he began to study them tell me
49:57first how how you first saw sleepy lizards and what attracted you to them? I first started because I was
50:04interested in parasites that live on the lizard to find the parasites I actually had to look at
50:08the lizards as well and I discovered they were doing things that were more interesting than the
50:11parasites for me I think they're one of the most handsome animals that you'll ever find the other
50:16thing is that it's probably the only animal that you know if you're driving along in a car and you
50:21see one a hundred meters down the road you know you've caught it and it's also it's also one that
50:26I think I'm going to be sufficiently agile to keep on catching until I'm well past 80
50:30even I I think could scrag the sleepy lizard I'll see what I can manage it. Sleepy lizards like to
50:40bask on warm roads so they're easy to find and they move so slowly they're easy to pick up so
50:46the team were able to weigh and measure a whole population and thus discovered that pairs remain
50:52together in a way that was previously known only in birds and mammals but that was just the start
50:58next they turned to technology some of it advanced some a little bizarre they used remotely controlled
51:09rubber sleepy lizards to test how lizards reacted to one another in this case not very much
51:16Mike's team suspected that another lizard in the area the Gidgee skink had an even more complex
51:27social life but this was difficult to prove because when approached the skinks wedged
51:32themselves in cracks in the rocks making it impossible to identify who's who the solution
51:39was to microchip each lizard so it could then be scanned just like your supermarket shopping with
51:46a barcode reader on the end of a pole this clever use of technology revealed what looked like a
51:55jumble of lizards on a pile of rocks to be actually a little lizard family with young that stay with
52:02their parents for life I'm sure that there are going to be many other complex social organizations
52:11that will be uncovered in those species if we just simply take the time to look at them but
52:15it's just the time and the patience to watch them and watching a lizard is very unrewarding because
52:22they will they will they will come out and bask sit by a bush and if they see you there then they'll
52:30decide they're not going to do very much for the rest of the day to find out just what sleepy
52:35lizards get up to when no one's around Mike's team use a rather bizarre device they call a
52:41waddle ometer it may look a little odd but it records a lizard's GPS coordinates counts its
52:48steps and even notes whether it's in Sun or shade or without troubling the lizard and without anyone
52:54having to be there so you think that's probably the secret world of the lizard which no human
53:00being has ever seen because if a human being is there the lizard won't behave that way I'm sure
53:06that's part of it it's you know the uncertainty principle the closer you get to watch something
53:10the less normally it's behaving and so it's only by getting these remote and new technologies that
53:17allow us to really get into the secret world of the lizards that we can find these really amazing
53:22things that they're doing how extraordinary one of their latest techniques uses miniature cameras
53:29which they use to study a very special lizard that 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
53:45the public eye when it was discovered in some very unusual circumstances there was a group of
53:53biologists who were doing a standard biological survey they were just coming back to town to pick
53:57up supplies and just on the road they saw a dead brown snake now most people just wouldn't even
54:03look at it because they're so common around here but these were dedicated biologists they stopped
54:08and had a look at it they noticed there was a bulge in it but they thought let's see what it's
54:11been eating open it up and there was a this lizard that no one had seen for 30 years the big me blue
54:18tongue lizard how lovely died yes he wasn't all that lovely when they actually saw it miniature
54:25cameras have produced images that are slowly helping to build up a comprehensive picture of
54:30the life of these rare little creatures their burrows are more than just homes they're also
54:39hiding places where they can wait in ambush for spiders and crickets but they don't seem
54:45too keen on ants they also serve as bolt holes when danger approaches
54:56despite all this work Mike's 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 tongue family three babies alongside their mother in their little hole
55:13but 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
55:33see lots of other things as well as lizards up here is just a wonderful place boy Eastern
55:42grey beautiful you won't catch a lizard doing that
55:54oh look there's a pair just down there
56:04it turned out that Mike had spotted two old friends
56:13yes here's the male and the female this is 1172 and 3344 I think they've been together for about 10 years this pair
56:23really we've 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
56:32but the next year the same two lizards will find them back together again usually in the same place along this road too
56:38aren't they terrific
56:41they use their tongues to pick up chemical signals and you can see they're actually sensing each other at the moment
56:48I think that's really very touching
56:52I said it's a risky business
56:54with obsessive dedication and ever-advancing technology who knows what Mike and his team will uncover about the secret lives of sleepy lizards
57:24you