{172}{316}For a hundred and sixty million years|the dinosaurs ruled this world.
{317}{402}While living in their shadows was a|group of animals
{392}{467}which couldn't have been more different.
{459}{602}These were our ancestors, small furry|creatures called mammals,
{583}{660}clinging to safety wherever they could.
{779}{862}But the mammal's time would come.
{869}{972}Sixty-five million years ago volcanic|activity started to
{959}{1020}poison the atmosphere.
{1055}{1175}The last dinosaurs were already|living on a sick planet
{1165}{1306}when their nemesis arrived - from space.
{1330}{1470}A meteor ten kilometres wide slammed|into earth to mark the end of
{1455}{1522}the reign of dinosaurs.
{1892}{1982}This series is about what happened next.
{2071}{2204}The survivors of the extinction all had|one thing in common -- their size.
{2185}{2287}Nearly every animal over ten kilograms|had been wiped out leaving
{2274}{2394}a world of little creatures,|among them were the mammals.
{2389}{2484}In Walking With Beasts you will witness|how mammals left behind these small
{2469}{2587}beginnings and took over the world.
{2717}{2800}In the course of twenty million years|mammals got more and more
{2790}{2959}successful until they were the biggest,|fiercest and most spectacular
{2936}{2977}animals on the planet.
{3007}{3109}Whatever the climate, whatever the|habitat mammals made it their own.
{3107}{3210}Their great strength was|their ability to adapt.
{3239}{3320}They grew to gigantic sizes.
{3339}{3491}They evolved into powerful killers|like the famous sabre-toothed cats.
{3484}{3561}And they even laid claim to the oceans.
{3619}{3734}Then around four million years ago|came mankind's own origins
{3718}{3858}in a type of ape that came down|from the trees and walked upright.
{3860}{3955}Our story of this epic time|finishes just thirty thousand years
{3943}{4073}Ago with the lce Ages, when our|planet turned cold but our ancestors
{4059}{4137}Hunted in the realm|of the mammoth.
{5184}{5298}It is a time called the Eocene and|earth has healed itself from
{5285}{5374}the ravages of the massive meteor strike.
{5363}{5453}Much has changed since|the time of the dinosaurs,
{5440}{5552}it is far hotter now and lush|tropical rain forests have sprung
{5538}{5661}up on every continent from|the Arctic to Antarctica.
{5645}{5791}In this flowering new Eden meteors|no longer present as much of a threat.
{6035}{6103}Under the forest canopy thrives|a menagerie of weird and
{6096}{6162}wonderful creatures.
{6153}{6264}Here the rule of scaly reptiles|is a distant memory.
{6248}{6384}The animals that dominate now are|covered in feathers or fur.
{6368}{6432}Mammals have adapted well to|the new world and there is
{6424}{6478}a staggering variety of them,
{6473}{6554}but they are still small|and as before live under
{6543}{6633}the shadow of bigger deadlier animals.
{7729}{7833}The dinosaurs might be long gone|but they left the world
{7818}{7872}a vicious legacy.
{7951}{8018}Their direct descendants are the birds.
{8013}{8146}For the first and only time in|its history birds rule the earth.
{8862}{8958}This is the story of just|twenty-four hours in one part of
{8946}{9060}the Eocene's mysterious global|forest in an area that will
{9043}{9113}one day become Germany.
{9116}{9246}It is dawn and at the base of a|fig tree one animal has already
{9228}{9304}Had its first brush with death.
{9469}{9535}This is a female Leptictidium.
{9527}{9620}She is a metre long and a common|sight in the forest of fifty
{9608}{9653}million years ago.
{9658}{9741}Her kind have survived virtually|unchanged since the time
{9729}{9777}of the dinosaurs.
{9775}{9856}Life though is scarcely|any easier now.
{9846}{9941}This is still a perilous world|where she must live fast and
{9930}{9994}will probably die young.
{10046}{10135}A typical mammal, she looks after|her offspring until they are old
{10122}{10179}Enough to fend for themselves.
{10171}{10272}But with so many predators about|today is a bad day for her litter
{10259}{10316}to leave the nest.
{10355}{10431}She however has to feed|whatever the risk.
{10421}{10515}She only has a short window of|opportunity to do so and
{10502}{10579}that window is fading fast.
{10633}{10736}The cool early morning is an ideal|time to catch the frogs,
{10722}{10790}Iizards and insects she feeds on.
{10818}{10942}Being cold-blooded they have yet|to warm up and are still sluggish.
{10928}{11050}She however is warm blooded and|fast moving twenty-four hours a day.
{11033}{11114}This is one of the mammals|ancient advantages.
{11255}{11362}Also to help track down her prey|she has an incredibly acute sense
{11348}{11469}of hearing and a distinctive|super-sensitive nose that can twitch
{11451}{11544}to locate food among the leaf litter.
{11735}{11850}And she is agile enough to catch|even flying insects.
{12081}{12190}The best morning hunting lasts|only an hour or two and time
{12174}{12201}is ticking.
{12198}{12283}She must keep moving to find more.
{12333}{12417}At this time in Europe's history|Germany is at the centre of much
{12408}{12517}volcanic activity and this little|patch of forest is riddled
{12500}{12568}with geo-thermal springs.
{12559}{12658}In places these form seething mud pools.
{12820}{12937}Oily water, poisonous gas and|earthquakes are ever present threats
{12921}{12995}that the animals have|learnt to live with.
{12994}{13094}But not every hazard here is|so easy to ignore.
{13086}{13206}As the sun gets higher the daylight|creatures are becoming active
{13194}{13391}and that brings out the forest's|more menacing side... The birds.
{13385}{13493}They are the top predators in|this weird forest.
{13501}{13641}This is the largest, Gastornis|a half ton pile of muscle and feathers
{13622}{13693}as tall as a grown man
{13783}{13885}This is a female and for the last|two months her whole life has
{13869}{14017}Revolved around the one egg in her|nest now only hours from hatching.
{14020}{14168}She is fiercely territorial and|when another Gastornis gets too close
{14180}{14263}she moves to protect her nest.
{14303}{14414}Since the great extinction birds|have been a success like mammals.
{14400}{14467}But what is more,|they have got big.
{14458}{14570}Big enough to take over the role of|the predatory dinosaurs.
{14775}{14835}The two giants clash.
{14827}{14894}The small mammal escapes.
{14895}{14992}There are echoes here of a bygone age.
{15478}{15570}The Leptictidium needs a lot of|food for her size.
{15558}{15633}Like all mammals this is the price|she pays for
{15624}{15689}a warm-blooded metabolism.
{15700}{15805}There is usually plenty of prey|down by the lakeside but this morning
{15795}{15842}there is only trouble.
{15960}{16052}There is a newcomer down by the lake.
{16212}{16323}Stirring in the morning's early|rays is an Ambulocetus,
{16307}{16419}a bizarre beast that has swum up|the river from the nearby coast.
{16509}{16562}He is a predator.
{16679}{16762}Her hunting is interrupted|once again, she must move
{16752}{16817}on and quickly.
{16978}{17100}The three metre long carnivore|waddles awkwardly towards the lake.
{17095}{17215}Although his ancestors hunted on|land, Ambulocetus has evolved to
{17198}{17267}Be far more at home in the water.
{17405}{17504}In fact his descendants will take|this to a greater extreme.
{17495}{17596}You are looking at the very|earliest form of whale.
{17584}{17699}Ambulocetus in fact means|walking whale.
{17711}{17807}With another ten million years of|evolution the limbs will become
{17797}{17886}flippers and the tail|will become a hoop.
{17875}{17977}His style of swimming already|has the look of a whale or a dolphin.
{17962}{18080}His body moves up and down and|not side to side like the fishes
{18063}{18139}or crocodiles he shares|the water with.
{18178}{18280}He is the most powerful predator|in this lake.
{18303}{18455}But he is far from safe here.|There is a hidden peril.
{18480}{18599}Huge quantities of volcanic gas|are trapped in the lake bed.
{18585}{18670}If enough of this gas were to|escape at one time it would
{18660}{18747}suffocate the animals for|miles around.
{18790}{18893}The lake is a time bomb.
{18914}{19016}But the Ambulocetus thinks|he has found the ideal spot
{19002}{19289}for practicing his|deadly speciality... Ambush!
{19381}{19505}A Propalaeotherium, an early form|of horse presents the day's
{19487}{19567}first good chance of a kill.
{20160}{20283}This time the Ambulocetus fails|But the day is long and he will
{20265}{20344}try again and again.
{20499}{20596}For the Leptictidium the forest|is now too dangerous and the
{20582}{20646}time for hunting is over.
{20644}{20729}The mother returns to the safety|of her nest.
{20718}{20832}She has not done well this morning|and it is vital her next hunting
{20816}{20872}trip is more successful.
{20902}{21009}She will sleep now until the|evening, when hunting will be easier
{20994}{21130}and the low light will help|her evade the sharp-eyed birds.
{21303}{21422}Noon, and temperatures climb|above thirty degrees.
{21404}{21505}The only movement is the Gastornis|chick starting to break free
{21493}{21540}from the egg.
{21609}{21718}Not far away the Leptictidium|family are still in their nest.
{21706}{21796}But in their sleep they are|totally defenceless against
{21785}{21851}one particular predator.
{22139}{22346}Giant, carnivorous ants...
{22361}{22450}This is the largest species|of ant ever.
{22529}{22618}They are on the lookout for|prey - any creature that can't
{22607}{22666}get away in time.
{22853}{22946}This is the vanguard of an ominous|killing machine.
{22940}{23032}Behind them is an army of half|a million others marching
{23019}{23121}through the forest|stripping it's prey to the bone.
{23235}{23317}The ants have their next victim.
{24495}{24594}Mid afternoon and the|Propalaeotherium are busy foraging
{24581}{24655}for grapes from the forest floor.
{24663}{24761}By modern standards these|primitive horses are tiny,
{24749}{24825}but this is how horses started|out -- small,
{24815}{24874}forest dwelling animals.
{24880}{24945}At this stage they're not|much bigger than cats and
{24936}{25092}have yet to even develop hooves,|having instead four hoof-like toes.
{25217}{25315}In a forest where every tree could|hide a predator the horses live
{25307}{25417}on a knife-edge, ready to spring|at the slightest sound.
{26349}{26507}As the light drops before sunset|the Leptictidium stirs from her nest.
{26484}{26542}It's time to hunt again
{26646}{26761}But first she must clear away|escape paths around the tree.
{26746}{26829}This will give her a slightly|better chance of outrunning
{26817}{26925}any predator she meets and|every little bit counts.
{26981}{27049}Her young are eager to join|her this evening.
{27042}{27126}Until now she has managed to|keep them safe from the dangers of
{27114}{27197}the forest by suckling them|in the nest.
{27192}{27278}But there comes a time for all|mammals when they can no longer
{27267}{27329}rely on their mother's milk.
{27659}{27738}The young must now learn to find|food for themselves,
{27733}{27837}and their only hope is to follow|their mother's example.
{27831}{27880}These are important lessons.
{27876}{27956}By smelling the insects|she has caught they can recognize
{27946}{28006}what is safe to eat.
{28075}{28159}However their chances of|survival are slim.
{28147}{28249}Most won't make it to adulthood.
{28372}{28493}As dusk approaches the predators|are still out in numbers.
{28491}{28579}The Ambulocetus has yet to make|a kill today and is preparing
{28567}{28657}Another ambush near the shore|of the lake.
{28648}{28751}Although he has no ears he listens|for approaching prey by putting
{28737}{28842}his jaw to the ground and|detecting vibrations.
{28833}{28935}It is the same mechanism that|allows him to hear underwater.
{28969}{29108}If any animal strays too close|he'll be waiting.
{29842}{29958}The Propalaeotherium appear less|alert than usual.
{29942}{29992}Throughout the afternoon|they have continued to eat the
{29988}{30064}fermenting grapes off the ground.
{30061}{30150}They contain only the smallest|amount of alcohol,
{30141}{30244}but it is enough to dull|their usually sharp senses.
{30488}{30560}This is a bad time to get careless.
{31754}{31914}The Leptictidium scurry to|safety... just!
{32441}{32616}This is a world where|birds eat horses.
{32782}{32879}At dusk the Gastornis returns|to her nest.
{32874}{32969}Only now does she discover the|fate of her off spring.
{33072}{33216}The biggest predator here humbled|by the smallest...
{33314}{33416}Her size forces her to nest on|the ground and now
{33400}{33458}she has paid the price.
{33450}{33557}Months of dedication wasted.
{33801}{33885}Despite everything this evening|the Leptictidium have fed well
{33874}{33985}and all the young have survived|their first outing.
{33971}{34050}The night is usually a safe|time for them.
{34047}{34132}Tonight will be different.
{34729}{34867}After a day of slumber this|nocturnal Godinotia is stirring.
{34853}{34945}This is a type of primate|a new group of mammals that
{34934}{35009}specialise in living in trees.
{35005}{35129}Primates possess keep vision and|amazingly dextrous hands,
{35115}{35216}which not only help them to|move among the branches
{35200}{35307}but also to wheedle out their|favourite insects,
{35296}{35389}even when they're beneath the bark.
{35384}{35466}They are inventive and resourceful|animals and although
{35456}{35600}these Godinotia are solitary,|primates have a sociable future.
{35577}{35662}Among their descendants in|millions of years time will be
{35652}{35759}a hairless type of ape|called man.
{35851}{35950}At the lakeside the Ambulocetus|is still maintaining
{35941}{36037}his patient vigil,|waiting for prey.
{36199}{36280}At night a whole different cast|of animals comes down
{36269}{36403}to the water's edge and eventually|a small predator chooses the wrong
{36385}{36463}bit of lake to drink from.
{37092}{37186}The Ambulocetus's killing|technique is simple.
{37172}{37336}His vice like jaws hold the|struggling prey until it drowns.
{38030}{38134}The dark hours go by and some|of the Godinotia are becoming
{38121}{38178}Iess solitary.
{38197}{38283}Copulation among these primates|is all part of the normal
{38271}{38340}rhythm of the night.
{38400}{38490}But this is not a normal night.
{38878}{38996}An earth tremor.|These are common here
{38978}{39058}but this one is bigger than normal
{39130}{39236}The gas at the bottom of the|lake is suddenly shaken free,
{39222}{39326}releasing a deadly cloud of|carbon dioxide.
{40002}{40116}Driven by the wind the gas sweeps|through the forest undergrowth,
{40100}{40189}suffocating every animal|in its path.
{40699}{40771}The day has come full circle.
{40760}{40901}The poisonous cloud has cleared|leaving a trail of corpses.
{41121}{41192}The Leptictidium however was lucky
{41186}{41304}She and her litter escaped death|only because their nest lay away
{41286}{41357}from the path of the deadly gas.
{41361}{41448}But her struggle to survive|never stops
{41445}{41509}It's time to hunt again.
{41614}{41718}Once more the Ambulocetus is|lying in her path.
{41706}{41793}But she instinctively knows|he is dead.
{41796}{41871}Today the Leptictidium|is the survivor,
{41861}{41935}but ironically the future holds|a different outcome
{41926}{41961}for these mammals.
{41958}{42050}The Leptictidium and her kind|are destined to become extinct
{42039}{42157}when this hot wet world gets|cooler and drier and the world's
{42145}{42239}forests start to disappear.
{42235}{42301}Ambulocetus is the one with|the big future.
{42299}{42371}He is the ancestor of the whales|the most magnificent
{42361}{42421}dynasty of mammals.
{42415}{42528}And mammals are about to|take over the world.
{42590}{42697}Next time we move forward|fifteen million years to
{42681}{42781}when the descendants of the|Ambulocetus become the true masters
{42766}{42818}of the oceans.
{42857}{42987}On land too, mammals shrug|off their small beginnings to
{42972}{43139}evolve into the largest and|fiercest animals on the planet.