BBC Documentary Walking with Beasts (5-6) - Sabre Tooth.en.txt

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{1149}{1297}For 40 million years the plains of|South America have been ruled by
{1277}{1361}an awesome group of predators
{1434}{1521}The aptly named terror birds.
{1797}{1884}But recently all this has changed.
{1933}{2064}A new breed of killer has arrived|one fierce enough to terrorise the
{2048}{2100}terror birds.
{2385}{2492}Smilodon, the f abled sabre tooth.
{2561}{2669}The most powerful big cat of all time.
{2996}{3100}There is no such thing as|a sabre tooth tiger.
{3088}{3189}The correct name for these beasts is|sabre tooth cats and there have
{3177}{3235}been many different species.
{3229}{3365}The largest, at over 300kgs,|is this one, Smilodon,
{3348}{3395}which means ''knife tooth''.
{3391}{3476}Originally from North America|they came to South America two
{3466}{3508}million years ago.
{3505}{3589}The balance of life here changed as|they took over the role
{3581}{3629}of top predators.
{3635}{3752}They live in tightly knit clans and|this is the story of three dramatic
{3737}{3859}months in the life of one particular|group led by a seven year old male
{3843}{3900}called Half Tooth.
{3929}{4002}Right from the beginning|Half Tooth has problems.
{3994}{4078}Recently a pair of|rival males have appeared.
{4179}{4257}And they want Half Tooth's crown.
{4565}{4658}Half Tooth's territory spans several|hundred square kilometres of
{4647}{4761}grassland on one of the strangest|continents on earth.
{4751}{4830}Since splitting from Antarctica|30 million years ago,
{4820}{4918}South America has been isolated from|the rest of the world and,
{4905}{4986}as a result, its animals are unique.
{4984}{5056}Oddities thrive here,|like Deodicurus,
{5049}{5176}a spiky-tailed relative of|the armadillo the size of a car.
{5196}{5277}Even the large herds of|herbivores are exotic.
{5267}{5374}These Macrauchenia are unrelated|to any modern mammal.
{5390}{5466}And then of course there are|the native predators,
{5457}{5531}the flightless terror birds.
{5536}{5653}These are three metres tall and|called Phorusrhacos.
{5659}{5759}But the isolation of these animals|came to an end when the movement
{5747}{5868}of the South American continent caused|it to collide with North America.
{5870}{5978}Across a land bridge came new groups|of mammals to colonise
{5965}{6011}this exotic world.
{6008}{6096}Life here would never be the same again.
{6161}{6222}Cats were among those colonists.
{6217}{6344}No cat had ever set foot in South|America before but now sabre
{6327}{6405}tooths ruled the grasslands.
{6433}{6522}Half Tooth took over this clan|three years ago,
{6512}{6584}breaking one sabre in the process.
{6583}{6660}The group is now made up of|four adult females and
{6651}{6705}their offspring.
{6718}{6799}All the youngsters are Half Tooth's.
{6870}{7014}During his reign, Half Tooth has seen|of many challenges from rival males.
{7052}{7139}But none as serious as this one.
{7132}{7245}Two rival males have wandered deep|into Half Tooth's territory.
{7235}{7320}As usual he is quick to respond.
{7349}{7461}But these are brothers and|they are working together.
{7509}{7608}Even by Smilodon standards|Half Tooth is a very large
{7595}{7726}male but he has never before f aced|two opponents at once.
{7709}{7793}The odds this time are|stacked against him.
{7988}{8076}The females read the signals and|start to retreat.
{8066}{8169}Their only concern is to|protect their offspring.
{8273}{8370}These fights can be brutal and|Half Tooth has the most to
{8359}{8496}lose - not only control of the clan|but possibly his life.
{9058}{9182}No match for the brothers,|Half Tooth is quick to back down.
{9230}{9339}He has at least escaped serious injury|but his problems are just
{9324}{9483}beginning. Life for a lone male is|a grim battle for survival.
{9664}{9780}Half Tooth hasn't had to feed himself|for three years because it was
{9765}{9850}the females in the clan|that did the hunting.
{9840}{9956}Outcast from the rich grasslands|now controlled by the brothers
{9941}{10052}he heads into the scrub forest|on the edges of his old territory
{10038}{10114}where he must learn|to scrape out a living.
{10146}{10248}With many of the creatures here|he stands no chance.
{10243}{10329}Doedicurus, for instance,|are not only well armoured,
{10319}{10367}they are huge.
{10367}{10447}These are ancient relatives of|the armadillo yet they weigh
{10438}{10518}almost 300 times as much.
{10648}{10765}Their spiked tail clubs alone|can weigh 40 kilos, as much as
{10751}{10797}a cannonball.
{10800}{10887}Although fearsome defensive weapons|the males mostly use their
{10877}{10923}tails on each other,
{10920}{11023}to batter rivals into submission|during hormone fuelled
{11010}{11060}jousts for a mate.
{11086}{11196}The loser ends up with more than|just his pride dented.
{11385}{11561}ln the clan, tensions are running high.|The females will not accept the
{11536}{11619}brothers while they still have young.
{11767}{11873}Defeating Half Tooth was only|part of the battle.
{11978}{12080}lf the brothers are to gain authority|over the clan they'll have to
{12068}{12117}kill the cubs.
{12267}{12354}Meanwhile, Half Tooth has pushed deeper|into the scrub forest
{12344}{12394}in search of food.
{12390}{12481}lf anything his task is g|etting more difficult.
{12479}{12633}The dense undergrowth harbours|another colossus, a sloth.
{12611}{12681}But this is no ordinary sloth.
{12716}{12839}This is Megatherium,|a giant ground sloth.
{12851}{12998}lt has huge claws, is six metres from|nose to tail and weighs more than
{12978}{13021}an elephant.
{13018}{13095}A very different beast from|its distant relatives,
{13087}{13148}the gentle tree sloths.
{13184}{13240}Half Tooth moves cautiously.
{13289}{13382}The sloth also boasts|impressive defences.
{13415}{13520}Small bones beneath his skin|act like chain mail.
{13506}{13601}Adults are virtually indestructible.
{13635}{13737}Half Tooth wisely gives|them a wide berth.
{14009}{14123}Weeks pass and the wet season|is in full swing.
{14189}{14281}The females have done their best|but only two of Half Tooth's
{14270}{14390}cubs survive and the brothers|are a constant danger.
{14459}{14563}They spend much of their time|patrolling their new territory,
{14551}{14683}spraying the boundaries with scent|as a warning to other males.
{14857}{14946}They will not attack the cubs while|the mother is present but
{14935}{15011}she must abandon them to go hunting.
{15008}{15112}This is when they are most at risk|and so this mother protects them
{15099}{15175}by hiding them in the dense undergrowth.
{15310}{15413}While the females are absent,|the brothers are spotted dangerously
{15401}{15472}close to the hiding place.
{15541}{15632}The cubs' lives hang by a thread.
{15647}{15747}Now their only hope is|to remain motionless.
{16281}{16393}Out on the plains there are large|herds of Macrauchenia.
{16378}{16514}Unique to South America, this species is|the last of their kind.
{16532}{16627}They are prime targets for Smilodon.
{16948}{17106}Macrauchenia are f ast, wary animals|and getting close enough to kill
{17083}{17143}one takes endless patience.
{17164}{17297}The females hunt together as a pack|inching forward to set the trap.
{17289}{17379}They have been closing in on this herd|for two hours now.
{17380}{17477}Gradually they f an out with the lead|female moving wide,
{17466}{17541}trying to encircle their pray.
{17563}{17689}Smilodon are powerful killers and|able to accelerate explosively
{17672}{17746}but they are not built for long chases
{17745}{17842}Unless they get close,|they don't stand a chance.
{18323}{18455}One f alse move and they will|have to start all over again.
{18921}{19028}The lead female drives the herd|towards the other females.
{19922}{20028}Having chosen their target,|the cats close in.
{20322}{20412}Macrauchenia have outstanding|manoeuvrability.
{20405}{20520}The victim jinks,|completely wrong-footing her pursuer.
{20547}{20632}But that's why Smilodon hunt in groups.
{20621}{20689}A second cat brings her down.
{21087}{21189}Surprisingly, as the cats fight to|restrain their prey,
{21177}{21305}they do not use their inf amous teeth|in case they break them.
{21388}{21492}First they work together to pin down|the struggling animal under
{21480}{21535}the weight of their bodies.
{21646}{21795}Only when the prey is totally subdued|are the f amous sabres drawn.
{21897}{22000}They are extraordinarily precise and|accurate tools for killing.
{21988}{22077}Their teeth simultaneously sever|the blood supply and strangle
{22068}{22111}the windpipe.
{22108}{22174}One bite and the prey is dead.
{22173}{22246}But these are the original|double-edged swords.
{22238}{22382}The lethal 20cm sabres are|actually quite fragile.
{22370}{22465}They cannot bite into bone and|so Smilodon can only eat
{22454}{22516}the fleshier parts of a carcass.
{22510}{22554}This is very wasteful.
{22551}{22678}Something that hasn't gone unnoticed by|other carnivores on the grasslands.
{22882}{22970}The terror birds are|supreme opportunists.
{22961}{23041}They may have been replaced as|top predators but they have
{23032}{23149}quickly found new ways of surviving,|thanks to the cats.
{23509}{23601}Eventually the Smilodon have eaten|as much as their sabres
{23590}{23622}will allow them.
{23621}{23713}They live the kill for|the birds to pick over.
{23755}{23861}South America is not the only place|terror birds are doing well.
{23847}{23929}Once the land bridge opened to|North America they were
{23921}{24008}one of the few creatures|to spread north successfully.
{23998}{24082}While these terror birds eat Smilodon's|leftovers,
{24073}{24171}their cousins are running riot|in Texas and Florida.
{24256}{24368}They only died out just before|modern humans appeared.
{24510}{24614}After the hunt, the mother returns|to where she hid the cubs
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