[Music] spider silk with the scent of a female he just needs to follow it wherever it leads him [Music] [Music] other males have gone on the same quest and have come to a grisly end [Music] here's the female and she doesn't look very amorous in fact she kills every male who doesn't match up to her expectations what can he do to win her over [Music] dance dance for his life he will need a show-stopping trick to avoid becoming lunch [Music] with his fan unfurled he begins an ever more complicated series of dance moves to try
and seduce her [Music] the at last she succumbs to his advances and allows him to mate with her [Music] he matched her expectations but she kills him anyway the Namib Desert one of the most exposed places on earth [Music] as the Sun climbs high everybody takes cover from the extreme heat everybody except the hot rod and as others take refuge their day is just beginning cleaning out the nest the Sun can reach a scorching 70 centigrade the ants long legs raise their bodies above the surface where it's 10 degrees cooler but if they stand still
they will fry they must keep moving or risk the same fate as their quarry the creatures that have collapsed from heatstroke too deeply buried but it would place to cool off foraging decisions must be fast to be perfect back to the nest before they also died but they strayed into a minefield [Music] each of these strange tone shaped pits is a deathtrap with a brutal predator at its center here live antlion larva tiny ambush predators with venom filled pincers [Music] some ants managed to escape but the antlion has other tricks flinging sand into the air
it creates an avalanche in this cone of death the walls are so angled that the sand slips beneath the ants feet as boulders rain from the sky escape seems almost impossible [Music] few northern Australia has the highest tides in the tropics which expose vast areas of shoreline and here lives a truly extraordinary species of octopus [Music] octopuses are marine animals they live and breathe underwater at low tide most octopuses will be imprisoned in their rocky booze [Music] but this is no ordinary octopus [Applause] [Music] [Music] it's the only one especially adapted to walk on land
it pulls itself along using the hundreds of tiny suckers that line its arms hunting for crabs it walks from pool to pool [Music] a potful rather startled fish this one is empty so the octopus moves on a rough fool may seem like a safe refuge but the octopus's suckers enable it to move just as stealthily in water as out of it [Music] [Music] nowhere is safe when this octopus is around in Papua New Guinea the bowerbird has lovingly rebuilt and redecorated his bowel another visitor this time it's a female this is just where he wants
her time to begin the show first he expands his pupils alternately [Music] it's an oddly mesmerizing display a spot of limbering up accompanied by a weird and wheezy call from deep in his throat now it's time for his grand performance he waves his wing like a Matadors cape she appears to be transfixed this is certainly eye catching but it seems he needs to do more generously she drops him a hint it's the bird equivalent of a bouquet of flowers [Laughter] it's all going so well it's time to get physical with a few head butts to
her chest one final flourish to cap weeks of effort but something's wrong his rival is back and at the worst possible moment what should he do [Applause] for the female the moment has gone sometimes whatever you do things just don't work out while our brains get swamped with information about patterns and color through Callie's eyes fast movement trumps everything [Music] as she stalks the flies her eyes send signals to the brains visual cortex which analyzes what's changed between one picture and the next up to 70 times every second faster than the human brain [Music] and
a far bigger proportion of the neurons in Callie's brain are dedicated purely to the detection of movement she almost can't help but pants cats wild ancestors relied on low-light vision and the ability to detect movement to stalk prey but these evolutionary adaptations have a downside cats can't focus on anything closer than around 30 centimeters in front of them but where their eyes fail them cats have another perfectly adapted sense to go in for the kill the team has set up an experiment to reveal just how our cat's secret weapon works so the camera can do
in full HD resolution up to 2,700 frames per second I was thought 2030 times we'll get it John Bradshaw is hoping these ultra-high speed cameras will capture this extraordinary sensory organ in action it really is very very quick I've seen still photographs of it happening but there's nothing like actually seeing the whole motion so I think we got it there but it's very very very quick John's trying to observe the cat's whiskers as they move forward into the attack position let's just take the toy away for a second and that's can we ever look at
what we've just taken okay so here we go the cat realizes the masses within his grass but he wants to know exactly where it is in relation to his mass its eyes give up because they can't focus very close that's where the whiskers take over so what we can see here is the whiskers suddenly being swept forward and now the claws are coming into action so we got here look the whiskers are pointing almost directly in front of the cat's nose it finally is catching them with his claws as he sweeps around trying to catch
the mouse but the little muscles at the base of each whisker are really tugging hard to swing those forward completely out of the normal position is this really extraordinarily detailed I've never expected to see all of this it's all seems to take place in about a fifth of a second which just shows how fast cats reflexes really are from the point where they sweep the whiskers forward with the muscles contract and then relax back and the whiskers spring back again the mass doesn't have a chance far thicker and longer than normal hares whiskers also sit
three times deeper in the skin where they attach to nerve endings telling the cat how far each one is being bent back and how quickly their whiskers are the same width as their body allowing cats to navigate the narrowest spaces you cats also have whiskers above their eyes and on their ankles sending them a constant stream of information as they sense the world around them there will be no easy meals on this island walruses are the largest seals in the world they weigh over a ton and are armed with tusks a metre long [Music] exhausted
from his shrim the bear must regain his strength the next day a sea fog shrouds the island the wallace's sense that they're in danger using the fog as cover the bear approaches the herd the adults close ranks around their young presenting a wall of blubber and high he tests the man but it stands firmly it appears that the world's largest land carnivore has met his match [Music] there must be a in the armor somewhere [Music] here [Music] this female walrus is shielding her puppy if he can just prise her off [Music] the bear's claws and
teeth can't penetrate her thick hide [Music] with the herd retreating to water the bear must move quickly [Music] having failed with one he heads straight for another [Music] the chance of his first meal in months is slipping away [Music] he seems increasingly desperate it's now or never he must avoid the stabbing tusks if he's the win [Music] the flailing walrus is immensely powerful and drags the bear away from the shallows towards the safety of the herd [Music] [Music] it slips from his grasp at this time of year polar bears on average succeed only once in
20 hunts if the hunter is skinny like this one that may not be often enough all she can do is keep trying [Music] [Music] to prevent her scent betraying her she makes a wide sweep to get downwind of the seal getting tous she's now right behind the seal [Applause] [Applause] incredibly she caught the seals underwater it's only small but even so it's blubber alone will contain a hundred thousand calories enough to sustain the spare for a week [Music] and in that time she might even catch another [Music] but this can't go on forever as summer
continues temperatures are rising each hunt requires more energy draining the bears of their reserves wolves these in northern Canada are the largest and most powerful in the world and they're setting out land [Music] the pack is 25 strong a sign that the prey they're seeking is formidable [Music] these bison are even bigger than their southern cousins and the largest land animals in North America for generations wolves and bison here have been shaped by their battles with each other making each the most impressive of its kind the Bison will not stay long among the trees they're
not safe here the wolves are closing in but their chance of ambushing the Bison in the woods has passed their prey are now in the open and grouped together for safety the wounds will need to work as a team with their to make a kill they circle the herd try to unsettle it and spit it up but the Bison are armed and dangerous they will be safe as long as they stick together the Wolves up their game hurrying the herd a ploy to trigger a stampede and spit away one of the smaller ones the Bison
form a defensive circle around their young horns pointing outwards [Music] the Wolves need a bison to break rank but the tables are turning and now the wolves have to retreat [Music] the back focus their attention on the rear of the herd and the Bison begin to panic [Music] a young bison falls behind even this yearling Dwarfs the words [Music] running head down the Hertz only thought is escape [Music] a stroke of luck for the Wolves the kill will feed the pack for several days but then they will have to resume the chase that the frozen
ends of our planet the struggle for survival never eases it's called Darwin's bark spider and the female has a remarkable strategy [Music] [Music] like a real-life Spider Woman she sprays strands of silk they one long continuous flow the threads fan out like a sail and drift on air currents blowing across the water every few seconds she crimps the strands together to stop them spreading too widely the breeze will do the rest blowing the threads into a single line and a 25 meter bridge now she must reinforce her bridge because her web will hang from it
[Music] but there's something bouncing the line at the other end another Darwin spider is trying to take advantage of her hard work [Music] she must deal with the intruder head on [Music] the cut line is an inconvenience but no more than that with hopes on the tips of each leg she gathers in the thread [Music] it won't go to waste as he'll eat it later when it's all reeled in she sprays again out streams another 25 meter bridging line how a spider no bigger than a thumbnail can produce so much silk so quickly has baffled
scientists and it's no ordinary silk it's the toughest natural fiber on the planet tougher than steel and it needs to be tough to span the wide river with the bridge taught and the ground anchor in place it's time to construct her trap [Music] [Music] these spiders can build the world's largest orb webs up to 2 metres wide a [Music] few hours from the first spray of bridging line the job is done [Music] now her strategy is simple sit and wait [Music] and there's one final bout of silk production shrink-wrapping her food for later it's early
morning and ticker spots a strange black cat on a nearby roof and listen to this chittering may simply be a sound of frustration but no one's really sure rocky out for a stroll in the afternoon [Music] makes this noise when another cat blocks his way but the story of cat communication is a lot more surprising than this there's one noise we've hardly heard it rarely happens when the cats are out with each other to understand what's going on we have to go back to the beginning and the youngest members of the study biologists dr. John
Bradshaw can explain why these 1 week old kittens meow the meow starts off as a kitten vocalization it's something that kittens use in order to call their mothers over and and as you can see it's very effective in doing that the mother is very attentive to those meows and then as the kitten grows up it gradually stops meowing presumably just because the meows stops working the mother wants to wean the kitten and stops responding with a pet cat which is constantly meowing at its owner it's a way of getting the owner's attention that's because we
are not very vigilant creatures we spend a lot of our time with our noses buried in books or computer screens or TVs and the cat each cat learns independently we think that using this piece of kitten behavior is a good way of getting our attention so meowing is a good we're getting to look up and find out what it is they want from us there you go Henry so cats have two different languages one for each other and one for us [Music] scientists have found cats make a huge range of meows and they wondered if
there was a universal cat human language there's a troll that was quite yeah that's it they make that funny little noise ago scientists have discovered that every cats meows are unique each cat learns which noises work best in certain situations developing a special language that only their owner will understand when they want food it's a much more prolonged meow hungry Oh Miss Piggy's learned how to say milk so she doesn't prefer milk meow meow yeah what is it nice and when are cats meow there's one thing that almost every owner in the study said they
did did you go hunting today talk back good to go you're pretty cool your mama's pretty go big see you lovely girl yeah talking comes naturally to us and every kitten that spends time with people learns that to communicate with us they have to make a noise
