[Music] world whatever your feelings about snakes you can't deny that they have an extraordinary beauty their lack of Limbs compels them to deal with life's problems in ways that are utterly different from [Music] ours but nonetheless the techniques they've developed are spectacularly [Music] successful snakes have one of the simplest of body shapes essentially just a long thin tube but they have some remarkably effective ways of getting around they can climb a tree simply by embracing its [Music] trunk some can flatten their bodies so that they catch the air beneath them and glide by hitching up their undersides they can inch themselves forward in a straight line a sinuous wle enables them to skate across loose sand and the same action works equally well in water there some swim close to the surface others explore the depths and can stay underwater for hours on end one believe it or not can [Applause] [Music] [Applause] [Music] jump so legless hardly seem such a handicap but how did snakes get that way well their remote ancestors 100 million years ago at the time of the dinosaurs did have legs rather like today's lizards doubtless they were very effective Runners but some also started to borrow in search of prey below ground legs are a hindrance and over Generations they became smaller today burrowing lizards such as skinks seem to be going through the same process many have tiny but recognizable legs in others the limbs have become nothing more than functionless Flaps in this burrowing lizard the process has gone even further the animal still has the face of a liard but its legs have disappeared totally it seems that the ancestral snakes went through just such a process way back in geological history some 95 million years ago so what did these very first snakes look like well the answer can be found in Asian jungles in American woodlands and Gardens and even in flower pots like this it may look like an earthworm but actually it's a flower pot snake and it's completely blind it doesn't need to see because it spends all its life underground I'll put it back in its flower pot and put a flower on top and it will live perfectly happily there in this flower pot all by itself providing it has enough food and there's a surprising amount for a small snake to eat underground ant ly for example these early legless reptiles flourished and remained underground for a long time then around 50 million years ago some of them returned to the surface why well by this time the dinosaurs had disappeared and the early mammals had arrived they were more nutritious than beetles and worms so the snakes began to catch them instead and became so good at doing so that today they are among the most skillful Hunters on Earth here in North America there's a snake that combines its great speed and extraordinary senses in a remarkable hunting strategy we are only just beginning to understand a timber rattlesnake the morning sun has warmed its body giving it energy and it starts to move it's searching for a place where it can conceal itself and wait for prey to come within Striking Distance a little chipmunk it's in no danger yet the rattlesnake can't move fast enough to Chase and catch it but small mammals tend to use the same paths as they run over the forest floor and they leave behind a faint trail of scent the rattlesnake can detect that scent with its tongue it can also locate the warm-blooded chipmunk if it's nearby with heat detectors in a pair of pits beneath its eyes as it moves it carefully holds its rattle above the ground so it makes no noise it's chosen the place to wait at the bottom of this tree stump its coloration matches the ground so closely it needs no further concealment now it's just a matter of time seeing a rattlesnake actually catching its prey is a very very difficult thing to observe in fact some scientists have watched rattlesnakes for years years without seeing that particular crucial moment but we have a chance partly because rattlesnakes are Ambush Hunters so we know exactly where to put up our gear and partly because in that gear we've got the very latest in surveillance equipment there are remotely controlled cameras and infrared lights on stands and there are detectors that will switch on the cameras if anything moves so I needn't wait alongside if anything happens the cameras will switch on automatically later I check the replay there's a mouse just along that log that obviously came to nothing but the cameras have started recording again and the snake is moving he's checking out the trail with his tongue see that's exactly where that mouse was running it's pitch dark and the the mouse clearly has no idea that the snake is there but the snake is well aware of the mouse thanks no doubt to those heat detecting pits a snake strikes by sudden is straightening the curve in its neck but at the moment the mouse is not within [Music] range he worked out that that is the path along which the mice run and he's getting himself properly adjusted so he can strike when he next gets a chance now once again waiting that's what snakes are so good [Music] at oh my goodness that's a dead mouse all right slow down that shot and you can see that the snake stabs the mouse just once after three convulsive kicks the Mouse is dead snake is moving again he's going back now to look for the one that he knows is dead back there where is it ah now it looks as though he's really got it that's his dinner and that can last him for 3 weeks four weeks if necessary rattlesnakes are among the least obtrusive inhabitants of the forests of North America and they're probably far more numerous than many people realize like many other animals snakes use their nostrils to detect smells but the most sensitive and accurate information about the world around them comes from that constantly flickering [Music] tongue with this a snake gathers molecules from the air and carries them back for evaluation to a pair of extremely sensitive organs in the roof of its mouth to see just how important scent can be to a snake I've come here to carac Island just off the coast of Western Australia it's home to a large population of Highly venomous tiger snakes snakes have been established here for many years but there's something odd about this particular population many of them have damaged heads and some of them are blind like this one and yet puzzlingly in spite of the fact that they're blind they all appear to be very well fed so how do their heads get damaged and how in that condition when they can't see anything can they catch all the prey they need the snakes of course are not the only inhabitants of the island it's also home for a large colony of silver gulls the gulls breed throughout the year so their chicks are a source of food for the snakes that never ends in fact the snakes eat pretty well nothing [Applause] else but the snakes don't get it all their own way the gulls are Valiant Defenders of their nests and their chicken their stabbing beats are powerful sharp and strong and the gos always go for the snake's [Applause] head one in 10 of the snakes are totally blinded tiger snakes don't have those heat sensitive pits that rattlesnakes have so these blinded Hunters must be guided entirely by their Fork tongue it's a superb Direction finding device the snake can measure the strength of a smell separately on each of the two forks of its tongue and if it wishes to follow up a smell then it simply detects the one which has the stronger smell and goes in that direction gold chicks are an ideal prey for a blinded snake because they're programmed to stay on their nests once a snake has located it a chick is doomed snakes it must be admitted have had a bad reputation ever since one appeared in the Garden of Eden but in reality even the most aggressive venomous snake will avoid biting a human being if it can why waste Venom and risk violent retribution by biting something you're not going to eat to prevent misunderstanding most venomous snakes warn other animals including human beings to keep out of their [Music] way some snakes do that with sound others such as cobras give a visual signal by expanding the skin around their heads to form a conspicuous Hood the threat of a bite is far better defense for a snake than the bite itself however there are some snakes that not only use their V them to kill their prey but have also found a way of using it to deter their enemies without even biting them this mosambique Cobra has a very special way of doing that to demonstrate this with some degree of safety I'm going to wear this viser which has been coated with a substance that turns pink in contact with Venom see what happens it's watching me waiting to see if I get too close for its liking Venom spurts from its fangs as it spits it turns its head from side to side so that the Jets have the best chance of hitting my eyes well I was well and truly sprayed every one of those pink dots is a bead of Venom and if any one of them had gone in my eye I would be now blind and in extreme pain so it's a fair warning from that snake to me not to get any closer and I dare say if I did uh I would deserve what I would get which would be a bite I have no intention of doing that on the other hand some snakes which may appear to be venomous are in reality quite harmless these two snakes look very very similar and they both occur here in the Southern United States so you're quite likely to meet one or the other here one of them however is harmless it's called a king's sake the other one is is a colal snake and highly venomous one bite certain death the question is which is which well the key lies in the order of the colorings people here have a local saying red and black venom lack red and yellow can kill a fellow and this one has red and black so I guess that's a king snake we'll [Music] see so far so good yeah this is a king snake and what a beautiful snake it is a really lovely reptile the king snake pretends to be venomous when it's not and there's another snake that pretends to be dead when it isn't snakes being coldblooded seem to relish the warmth of sunbaked roads and often bask on them and as a result of course many get run over but things aren't always exactly what they [Music] seem he looks kind of dead but in fact this hognose snake is perfectly all right he was just feigning death so that things that might have been interested in living snake are not and once more he's uh produced rather remarkable smell in fact the smell as it were of Rotting Flesh so maybe he was pretending too that he was not only dead but decomposing very convincing off you [Music] go the lack of of Limbs that might seem to us to be such a huge handicap has not stopped snakes from getting around in all kinds of ways and neither does it prevent them from tackling all kinds of meals this South African snake has become a specialist in swallowing a particularly awkward mouthful it's as accomplished a tree climber as you'll find among snakes [Music] the trees it frequents also hold colonies of masked Weaver birds that suspend their nests from the very tip of the branches but the snake is a skilled enough climber to reach them the Weaver Birds know it well and recognize it as a [Music] threat [Music] it's well accustomed to these [Music] [Music] attacks these Defenders however are just too determined and it Retreats but it doesn't give up all together this Nest is unguarded and this is what the snake is after the eggs each is several times bigger than the snake's head but its jaws are linked by ligaments that are amazingly elastic once the egg is engulfed by the snake's Jaws powerful throat muscle push it down its gallet moving x-rays enable us to see exactly what's happening soon the egg reaches a part of the backbone that has downward pointing spines on it the snake arches its backbone and then squeezes the shell cracks and the spines on the backbone slit the membrane the shell is crushed and Rich nutritious yolk flows into the snake's gut then what's left of the shell is regurgitated but that of course was a small meal some snakes can tackle much bigger meals than that an African rock pip one of the biggest of all snakes that can grow over 7 m 20 ft long and it is eating an antelope it too has an elastic ligament connecting its jaws it killed the antelope not with Venom but by squeezing it so tightly that it was unable to breathe a Python's teeth can't cut or rip it has to swallow its prey whole or not at all and that may take a day or more without limbs the python can't push the antiope down its throat instead it hitches its jaws diagonally back and forth so that they as it were walk along and over the prey its tube likee body has to stretch so extremely to accommodate such a gigantic meal that its flanks have torn but such injuries heal very [Music] quickly the last of the antelope its hooves are about to disappear [Music] gone the python will now hide itself away and begin the long process of digestion everything will be dissolved skin hair Hooves even horns [Music] this python will not need to eat again for a year or [Music] more wherever it's warm and there are animals of some kind there will be snakes to hunt them no matter how difficult the conditions and how awkward the mouthful crabs are in p beautiful Supply in this Mangrove swamp there must be 50 on any one of these trees around me they're all up there waiting for the tide to go out so they can feed in the mud below so there is a meal for a snake here but crabs are not easy to tackle they're strong armor plated and covered in spines for the snake to tackle one of these would be like me trying to eat a lobster twice the size of my head with my hands tied behind my back but there is a snake that knows how to do so the crabs cling to the arching struts of the mangroves to keep out of the way of predatory fish but as the tide Retreats it becomes safe for them to climb down and start looking for such edible bits as the tide has left behind on the [Music] mud for the moment they're safe but soon the sun will set then the snakes will come out of their Burrows they hunt in the darkness but we'll be able to follow them with our infrared cameras it's now very dark indeed and the snake has to find its way around entirely by touch and smell finding crabs is not difficult they swarm all over the mud and the snake is almost bound to encounter one sooner rather than later the snake is armed with Venom and has short strong fangs which can Pierce a crab shell and stun it but that's only half the problem it's what it does after it's caught its crab that sets it apart from all other snakes it has it now what the crab is so large that the snake can't swallow it whole slowly and deliberately the snake dismembers the crab each leg contains nutritious muscle but the crabb's armored body is simply discarded too difficult there are hard shelled creatures in fresh waters as well as in salt not nearly as many but sufficient number for some snakes to specialize in eating them and in in the eastern United States many rivers contain crayfish like crabs they have a hard protective shell and they have particularly powerful pincers as well the Queen Snake however eats crayfish and nothing else but not just any crayfish it's very selective crayfish as they grow shed their armor every 3 to four weeks a split appears across the back of its shell the old Shell hinges away and the crayfish hauls itself out and expands its body which is soft it's now that the snake has its chance [Applause] a newly moled crayfish looks much the same but it gives off different chemicals that the snake can detect in the water with its tongue and from some distance [Applause] away [Applause] it can swallow this grayfish because since it's newly mated it's as soft as a boiled egg on occasion snakes have to Grapple not only with their prey but with one another in disputes over mates and territory this is one of the most formidable the king cobra highly venomous and about 4 M 14 ft [Music] long disputes between rival male king cobras are potentially very dangerous indeed for this species specializes in eating other kinds of snakes so they observe strict rules in their fights which prohibit the use of their lethal [Music] bite slowed down it's a performance full of grace as each contestant strives not to kill his opponent but simply to to slam him to the [Music] [Music] ground [Music] [Applause] the defeated male leaves the arena and no harm has been [Music] done snakes must also find a way of preventing their courtship from becoming lethal this is a Californian king snake a male he has detected the scent of a female ready to mate [Music] like all snakes his eyesight is not good but he can tell from the taste of the air that she's close by in fact she is within [Music] inches [Music] for some time the two follow one another nose to [Music] tail the male begins to caress her sensually jerking and rocking his body as he holds her close he has a pair of sexual organs one of which can project to the left and the other to the right so no matter which side of him she happens to lie he can reach her at last Union is [Music] achieved [Music] they may remain together for several [Music] [Music] hours in a few weeks time the female will lay a clutch of eggs it may take six or seven weeks for them to hatch but the regions where most snakes live are warm enough for them to develop without any help from the parents cobras lay them on the ground in the leaf litter their soft parchment likee shell is easily split when pushed from [Music] within the front end of a cobra hatchling is quite capable of giving a bite even while the back end is still within the [Music] shell [Music] their fangs may be small but since it only takes a tiny drop of Cobra Venom to kill an animal these youngsters can be as lethal as their parents [Music] they already have that characteristic warning signal the hood not all snakes lay their eggs in some species the female retains them within her body until they're ready to hatch so so she gives birth to live young the marshes of Northern Argentina home to one of the largest of livebearing snakes the [Music] Anaconda this is a female and she's heavily [Music] pregnant it's morning and she's chilly so she moves out of the water and onto the swamp to warm herself in the [Music] sun slowly the day begins to warm up now it's getting a little too hot for her so she moves back to the water to cool off in this way she manages to keep her body close to 29° Centigrade perfect for the babies developing within her but she won't give birth here and now there are Cayman around at last she finds the quiet pool that she needs and her contractions start [Music] [Music] the first of her babies has [Music] arrived up it goes to the surface to take its first breath of [Music] air but there are more babies to [Music] come eventually she produces 15 in fact that's quite modest for an anaconda they can produce up to 40 right from the beginning of their lives they're totally independent and get no care or protection from their [Music] mother the Anaconda spends so much of its time in water and is such a powerful swimmer that it can be properly considered aquatic snakes have become adapted to almost every environment including even the sea as this one has uh it doesn't often bite but it does have an extremely powerful Venom so I'm not going to handle it but I will help it a little with this stick as you can see it has a very flattened paddle at the end of its tail but on land it's pretty helpless however if I assisted in getting into the sea and now it's in its element sea snakes have had to modify many of the features that enable their far distant ancestors to colonize the land they still have a lung with which to breathe in like other snakes but they can also absorb oxygen from the sea waterer through their skin salt inevitably gets into a sea snake's body but the snake manages to get rid of that by excreting it from a gland under its tongue it also needs to drink fresh water so in calm seas it waits at the surface for rain sea snakes really are truly Marine creatures they can live out here in the open ocean and the only clue you have to their link with the land is that they have to come up every quarter of an hour or so for a gulp of air most sea snakes like this barbeled species hunt fish they have one of the most lethal Venoms known which kills almost instantaneously and that is a very important quality if you hunt fast swimming oceangoing prey but paradoxically the most highly specialized sea snake of all has abandoned Venom all [Music] together it has a beak like a turtle and a wholly different way of feeding [Music] ing reef fish don't like to have it around they mob [Music] it it doesn't even retaliate it's not interested in [Music] them it's after their eggs these the fish have stuck to the ston branches of the [Music] coral the snake's hardened turtle-like top lip enables it to scrape them off [Music] it's such a slow moving browser that algae and other small organisms grow on its skin as they do on the bottom of a [Music] boat the loss of Limbs could seem to be a handicap and certainly makes the snakes seem alien creatures to us but but it is that very loss that has enabled the snakes to colonize every environment from below the ground to above the ground from bushes to trees to the air and even to the Sea and it is that absence of Limbs too which has enabled them to do it with such elegance and Grace filming venomous snakes presented a lot of special problems to the life in Cold Blood team but the toughest was trying to film a rattlesnake hunting in the wild a rattlesnake making a kill has rarely even been seen and never before filmed and for several reasons for one thing rattlesnakes are so well camouflaged they're very difficult to find we inlisted the help of snake expert Harry Green and his team they've been stud studying a group of Timber rattlesnakes using radio telemetry which enables them to find their rattlesnakes at any time of day or night most of us will never find them and they're superb the camer exactly but that's been one of the wonderful things about radio telemetry is we can have an animal that we can dial up to have any chance of success the crew had to be able to find the rattlesnakes on their own so producer James Bickle had to take a course in Telemetry techniques himself you point a little bit more on this way each snake has been implanted with a tiny transmitter if you dial its frequency you can pick up a beeping sound and that gets louder the nearer you get to the snake and so it's just like if you were trying to find your favorite rock and roll station or something but now we're going to find our favorite rattlesnake so you just punch in its number it's on the air it sounds simple in the Theory but there's a snag it's here somewhere just be really careful guys in a forest the signal can bounce off trees and give you a false reading so that it can seem that the snake is everywhere and you don't want to think a reading is false and then tread on your snake by mistake you're fine he's he's up there somewhere let's find him James it's starting to get dark he's in there I H James be careful where you go and it isn't just the one snake you're tracking there are dozens of others in the area that aren't tagged follow my hand there he is it's about 20 ft six six M and so at last the crew meet a very special snake called Hank Hank is in a perfect position for his ambush to film The Action without disturbing him or his prey cameraman Mark mccuan has fitted his camera with motion detectors from a burglar alarm they will turn on the camera without anyone having to be there so for the first time they set up their gear in front of a live snake they could now leave Hank and track another of Harry's snakes so that means you know individual snakes over a long period of time do they differ very much absolutely absolutely now there are species differences so certain rattlesnake species are more sort of nasty tempered than others but even among a within a population you'll have one that just never gets riled up and one that you know you just can't get too close to without it getting upset with one camera set up on Hank James decides to track another snake and to do so in the dark which is when most rattlesnakes hunt but in the pitch Blackness there was a distinct possibility that James would accidentally get so close to the snake he was looking for he would step within Striking Distance quite unnerving if you haven't done it before it's um it's actually pretty dangerous walking around in the middle of the night trying to find the rattlesnake in these conditions he's already close come here over near these logs I think the snake's about probably 5 10 met away it' be easier to find a needle in a hay stack and to find a reptile that looks like a load of Dead Leaves and a huge pile of Dead Leaves a negative Mark we we've got to a huge pile of logs and wood the team decideed to abandon tracking the second snake and instead check on the camera they left on Hank in the afternoon I think it's too dangerous actually to go poking around in there and anyway you wouldn't be able to get the lights and the camera in so we're going to wrap on it and come back we've seen things on your videos we've never seen before which is kind of surprising I mean we've watched snakes a lot we I mean all the all rattlesnake biologist and uh we've seen things on your videos we haven't seen before so it's I think it's actually kind of exciting to can to think about how this kind of collaboration might really be a feedback between the media and the public and Science and so forth and something very surprising had happened at our very first attempt and in broad daylight a chipmunk had tripped the motion detectors and Hank makes a kill right in front of the cameras we've got a ready we've got it I thought you winding up James there's um Something's Happened Here I thought well that's just a classic wind up first first night to get we hadn't got the eating shot but it's a start and then the camera is set off again by a second chipmunk behaving very strangely we showed the recording to Harry and he was fascinated now now what was that chipmunk doing was it perceiving something that the other chipmunk left as some kind of alarm odor or something was it perceiving the odor of the rattlesnake or was it something I can't even imagine yet but something was going on there that I didn't know to expect anyway it's in your film Hank could clearly be the star of the show so the crew decide to concentrate all their efforts on him and to track him for two weeks Around the Clock they quickly learn that despite his ability to hurt one of them very seriously he seems pretty unconcerned in fact he never even rattles a warning at them the more they get to know him the more they think they've got a good chance of filming another hunt but then there is a serious problem it's just been raining here non stop for the past 3 days and they say that Tuesday afternoon's hard rainstorm was the straw that broke the camel's back just as things are looking so promising New York state has its worst floods for a decade and all filming comes to a standstill as you can see the weather's awful won't affect the rattlesnake at all he's perfectly happy he'll we sat down in here somewhere just waiting but it does affect the mammals and the Chipmunks and the mice they'll just be hunkered down somewhere not doing anything very much and it affects us but he'll be fine it's just we can't film anything so it's just a matter of waiting now after tracking him in the rain for 10 days there's a break in the weather and Hank starts hunting again he chooses a position for an ambush in a very accessible spot the team has another chance to use their remote cameras this time operating in night vision Dame just be careful where you come in don't go that way I think that's the direction is headed in you got something have you um mate we've got him hitting a mouse in the middle of frame and swallowing this time they get more than the strike this time Hank decides to eat his dinner very obligingly right in front of the camera mate that is the most incredible piece of behavior you have ever seen so after 2 weeks and a lot of effort they succeed in capturing a crucial and intimate moment in the life of this very special snake people don't automatically love snakes most of them don't and yet if you can show them things about the lives these animals that impress them with the fact these are animals with complex daily activities these aren't things that are waiting around for an opportunity to kill people you tell people things like that then they they get drawn in and hopefully when we show them your films they'll be drawn in well you've drawn me in thank you very much oh pleasure and when I get to see the footage it's fair to say that I'm just as knocked sideways as the crew had been there's the mouse oh my goodness yes that's a dead mouse all right [Music] oh