BBC Wild South America_4of6_Andes
Transcript
00:00You
00:30You
00:41This is a journey down the longest mountain chain on earth
00:52These are the Andes the spine of South America
00:57They span the length of the continent over 5,000 miles from the tropics almost to the Antarctic
01:13Surviving in the Andes is one of the greatest challenges in the natural world
01:17It's a truly hostile place to live bitter cold thin air relentless wind
01:28Even the volcanic forces of the earth itself
01:38Faced with trials like these how can anything survive here let alone flourish?
01:48You
02:00Our journey begins in the tropics at the northern end of the range
02:06The highest peaks in the Andes rise to nearly 7,000 meters and some are still growing
02:13Measured on a scale of geological time the Andes are still young
02:34The mountains mark a line where two great plates of the earth's crust collide
02:38The impact crumples the continent and huge volcanoes break through
02:45As the mountains rise into the clouds their slopes are colonized by forest
02:52Cloud forest
03:01In the warmth of the tropics trees can grow high on the mountains to well up the mountain's
03:06Trees can grow high on the mountains to well over three and a half thousand meters
03:17Animals were quick to exploit the new opportunities these forests provide
03:23Isolated in a maze of ridges and valleys all sorts of new species developed
03:28These Andean cloud forests rival the Amazon rainforest for diversity
03:35There are more kinds of hummingbird here than anywhere else in the world
03:43Almost every hillside has its own unique plants and animals
03:46The cloud forest also has its very own bear the spectacled bear named after the markings on its face
03:59This is the only bear in South Africa
04:04It's the largest bear in the world
04:08It's the largest bear in the world
04:11This is the only bear in South America, there are just a few thousand left
04:21Most kinds of bear are good tree climbers, but here that skill is essential
04:27Spectacled bears get much of their food from the treetops. So climbing trees is one of the first lessons this baby has to learn
04:41The cub is well-grown, but it still has a long way to go to match its mother's skills
04:51The trees here can be 20 meters high so it can't afford to make a mistake
04:59These high forests have few monkeys, so there's plenty of food for bears that are willing to climb
05:05But for an animal that can weigh well over a hundred kilos, that's quite a challenge
05:11Even when it's mastered the art of climbing, the cub still has to learn what to eat
05:19The bear's favorite food are bromeliads, plants that perch on branches high in the canopy
05:41They're especially fond of the fleshy base of the leaves
05:48Bears are adaptable animals, and there's only one kind here
05:53Other animals are more specialized, so several species can coexist
05:57like the hummingbirds
06:00These damp cool forests have few flying insects, so many of the flowers rely on birds for pollination
06:07Plant and pollinator have a unique relationship
06:11Each hummingbird's beak is perfectly adapted to reach the nectar in its chosen flower
06:20As the hummingbird moves from flower to flower, it transfers pollen and so fertilizes them
06:26In exchange, it gets sugar-rich nectar to fuel its hovering flight
06:30At high altitude, the air is thinner and has less oxygen. It's hard to hover
06:48Most bromeliads win their place in the sun by growing high in the trees
06:53But some kinds have gone a step further
06:56They've left the forest behind and climbed the mountain
07:02The Puyas grow in the Paramo, a zone of alpine grassland above the forest
07:08After several years, they throw up a stupendous five-meter flower spike
07:13It's the largest flower spike in the world
07:17After several years, they throw up a stupendous five-meter flower spike
07:22and then die
07:24With just a once-in-a-lifetime opportunity, it's vital that the flowers are pollinated
07:30Puyas have their very own hummingbirds
07:34like the Andean hill star
07:37It lives higher than any other hummingbird
07:40Up here, the air is even thinner and hovering is even harder
07:43So whenever it can, it perches rather than flies
07:52As it moves from flower to flower, it transfers more than pollen
08:01Tiny pollen-eating mites live in the flowers
08:05They crawl onto the hummingbird to hitch a lift to another plant
08:14At the next stop, some passengers get off and others get on
08:24Not every animal works in such harmony with the Puyas
08:31The growing flower spikes are an irresistible honeypot for spectacled bears
08:36They can destroy a lifetime's work in seconds
08:44For bear cubs, learning how to tackle Puyas brings a sweet reward
08:50The spikes are rich in sugar to make nectar for the hundreds of flowers
09:00They're packed with energy, but how do you get at it?
09:06The Puyas have a special way of doing it
09:09But how do you get at it?
09:17A little parental guidance is called for
09:40Spectacled bears are versatile animals
09:44But each new generation has to learn the tricks of the trade
09:51The mountains are an unpredictable place to call home
09:59Massive volcanoes rise above the cloud forest
10:03At any moment, they can burst into violent life
10:10The Puyas are the largest volcanoes in the world
10:20As you travel south down the chain of the Andes, you pass a line of brooding giants
10:27Among them are the highest active volcanoes in the world, rising to more than 6,000 metres
10:40They're so high that even in the tropics, their summits are crowned with ice and snow
10:53In the heart of the Andes, volcanic activity has built more than mountain peaks
10:59It's thrust a high desert plateau three miles up into the sky, the Altiplano
11:06Sulfurous steam from the world's highest geyser field rises into cold, thin air
11:13A vision of Earth before life began
11:36Much of the water here evaporates in huge, caustic lakes
11:41This must be one of the most extreme environments on Earth
11:45How could anything possibly live here?
12:05The Altiplano Salt Lakes
12:09The Altiplano Salt Lakes
12:31Incredibly, the Altiplano Salt Lakes actually attract animals
12:36Flamingos come here to breed
12:39Their season starts with a massed courtship dance
13:06Three kinds of flamingo nest on these caustic lakes
13:10These ones are Andean flamingos
13:36These lakes are prime flamingo habitat
13:40With no outlet, dissolved salts washed down from the surrounding mountains are concentrated by evaporation
13:48Ideal conditions for the flamingo's favourite food, brine shrimps
13:53They thrive in water ten times as safe as the Altiplano Salt Lakes
13:58The three kinds of flamingo have different sized filters
14:02so they can live together by exploiting different parts of this briny soup
14:08Only a handful of other water birds can live here
14:12The Altiplano Salt Lakes
14:15The Altiplano Salt Lakes
14:29Andean avocets obsess on fly larvae
14:40The key to success up here is being a specialist
14:44Brine flies live in a world that's wafer thin, sandwiched between the salt and the piercing wind
14:52But their swarms are large enough to support a lizard
14:55Brine flies are its staple diet
14:58Being cold-blooded, it hunts only when the temperature has risen enough for it to move
15:07For a lizard living on the edge of what's possible, even a patch of fly-blown salt pan is worth fighting for
15:25The Altiplano Salt Lakes
15:28The Altiplano Salt Lakes
15:31The Altiplano Salt Lakes
15:34The Altiplano Salt Lakes
15:37The Altiplano Salt Lakes
15:40The Altiplano Salt Lakes
15:43The Altiplano Salt Lakes
15:46The Altiplano Salt Lakes
15:49The Altiplano Salt Lakes
15:52The Altiplano Salt Lakes
15:55Even the steaming outflow from a geyser attracts life
15:59This frog also survives on flies, but this really is living on the edge
16:04A few hops one way and it would be boiled alive
16:07A few the other, and it would freeze to death
16:20This desert on the roof of the world even has mammals
16:25Vicuña, South American relatives of the camel
16:29But what can they eat up here?
16:33There's more to the Altiplano than caustic lakes, and not all the springs are hot and salty
16:40Fed by meltwater from the snow-clad peaks, some run cold and fresh
16:45They water small patches of marsh called bofidales
16:49In the drier parts of the Altiplano, these green oases are the key to the vicuña's survival
16:59They provide grazing and fresh water to drink
17:03All sorts of animals depend on them, like viscachas, rabbit-sized rodents
17:19Early in the morning, the marsh is frozen hard
17:22So the viscachas bask in the sun until the ground warms up
17:26Along with the leaf-eared mice that share their jumble of boulders
17:30Only when the grass has thawed can they start to graze
17:42In the drier parts of the Altiplano, little grows away from the bofidales
17:46The few flowers give a sip of nectar for the Andean hillstar
17:51Up here, perching is vital to save energy in the thin air
18:01There may be no woods here, but there is a woodpecker, the Andean flicker
18:06It nests underground and hunts for insect grubs in the marsh
18:11At this extreme altitude, the main problems any animal has to face are cold and lack of oxygen
18:21Viscachas overcome the cold by having incredibly thick fur
18:25But they have to keep it in good shape if it's to save them from freezing
18:31To make better use of the thin air, some animals have a high concentration of red blood cells and specialised lungs
18:40It also helps if you don't exert yourself
18:43Viscachas hardly ever move more than a stone's throw from their protective rocks
18:52Nothing moves fast without a good reason
18:55But up here, even a small patch of grass is worth fighting for
19:11The Andean hillstar is the largest of the Altiplano
19:15It is the largest of the Andean hillstars and the largest of the Altiplano
19:20It is the largest of the Andean hillstars and the largest of the Andean hillstars
19:24It is the largest of the Andean hillstars and the largest of the Andean hillstars
19:28It is the largest of the Andean hillstars and the largest of the Andean hillstars
19:32It is the largest of the Andean hillstars and the largest of the Andean hillstars
19:35It is the largest of the Andean hillstars and the largest of the Andean hillstars
19:50Deciding whether to use hard-won energy reserves can be a matter of life and death
19:56The arrival of a red fox means it's decision time
20:00Up here the air is so starved of oxygen that a sustained chase is impossible
20:06The fox has to try and take its prey by surprise
20:10Not easy in this open country
20:17The viscachas are rarely more than a short dash from safety
20:30Viscachas have thin muscle walls to their lungs so they can breathe more freely at high altitude
20:37But a rapid escape is exhausting, even for them
20:52The panic's over for now. It's time for everyone to catch their breath
21:00On the Altiplano the air is in such short supply that neither hunter nor hunted can afford to waste it
21:17It's at night that the effects of the high altitude bite hardest
21:22When the sun goes down, the air is too thin to retain its heat
21:27When the temperature plummets
21:38For the Andean hillstar, every night is like a winter
21:43Even at lower altitudes, hummingbirds save energy at night by slowing down their movement
21:48Almost as if they were hibernating
21:54Up here, that ability can make the difference between life and death
22:01Just three hours after sunset, it's already 20 below
22:08Even running water freezes hard
22:19This is the moment of truth for the hillstar
22:23Now, all it can do is wait
22:48With the rising sun, the hillstar comes alive again
22:52It picked its roosting place so the very first rays reach in to warm its chilled body
23:00This is the moment of truth for the hillstar
23:03Now, all it can do is wait
23:06Even running water freezes hard
23:09This is the moment of truth for the hillstar
23:13Now, all it can do is wait
23:16This time, it's won through
23:19Every night is a battle to survive a 12 hour winter
23:25But the Altiplano also has a true winter
23:29For a few weeks each year, its savage climate becomes even more severe
23:36For those who can, this is time to leave
23:41They must search for food in lakes lower down than ours
23:45In the mountains
24:06When the flamingos have gone, the high Altiplano is left to the elements
24:11Those animals that have no choice but to sit it out
24:16The cold can be so severe that even the salt lakes freeze over
24:29Any birds that breed late in the season can be trapped here
24:34Their young can't yet fly and their food is now out of reach, locked beneath the ice
24:40Many of these stragglers will die, frozen into the ice
24:45Their fate is already sealed
25:09But some places never freeze
25:19The Andes' inner fires keep the geysers and hot springs free of ice
25:24Here at least, winter will never come
25:27In this tiny island of warmth, in the most marginal and extreme of worlds, life hangs on
25:40The Altiplano may be extreme, but there's somewhere even more severe
25:46As you travel south down the chain of the Andes, winter becomes even harder
25:54The mountains here may not be as high as the giants further north
25:59But they're much closer to the Antarctic
26:01The snow line creeps lower and lower, and in the deep south, the ice never melts
26:07This is Patagonia
26:20Three huge ice streams meet here
26:23The Altiplano is the largest in the world
26:27Three huge ice sheets dominate the Patagonian Andes
26:32Covering over 7,000 square miles, they're the largest expanse of ice outside the poles
26:39So vast that they generate their own weather
26:57Towers of rock rise from the edge of the ice
27:01The remnants of ancient volcanoes stripped bare by the glaciers
27:27Only the condor soars among these icy peaks
27:37This is one of the windiest places on earth
27:42Chilled air spills from the edge of the ice sheet
27:46Funneled down the glacier into the ice
27:48Almost nothing lives on the ice sheet itself
27:51Surviving even on its edge requires unimaginable stamina
27:55Funneled down the glaciers and between the peaks, these freezing blasts can reach 100 miles an hour
28:04Almost nothing lives on the ice sheet itself
28:08Surviving even on its edge requires unimaginable stamina
28:20The Guanaco, the southern cousin of the Vicuña
28:24It's larger and has a thick woolly coat
28:27And it needs it to survive the Patagonian winter
28:43Snow is not the only peril the Guanacos face
28:46The Puma, the lion of the Andes
28:51This most adaptable of big cats lives throughout the mountain chain
28:55From the cloud forest to the high desert and the snows of Patagonia
29:00But it's secretive and hardly ever seen
29:09For all the hunters here, winter is a lean season
29:13For all the hunters here, winter is a lean season
29:17They're poorly camouflaged against the snow
29:20The grey fox follows the Puma to scavenge any scraps from its kills
29:25She has hidden stores of food during the summer
29:29If she can sniff them out, she'll survive the winter
29:43The really hard times last four months
29:47But slowly the days get longer and the land comes back to life
30:01The snow line creeps back up the mountains
30:05This is what the condors have been waiting for
30:13As the snow retreats, the casualties of winter are revealed
30:18Animals killed by cold or starvation
30:22And the remnants of Puma kills
30:26Condors are the vultures of the Andes
30:30They have superb eyesight, they can spot food from miles away
30:34And can locate even more distant carcasses by watching for other condors gathering
30:43The grey fox is a scavenger too
30:47The winter survivors are lean and hungry
30:51And there's stiff competition for any chance of a meal
31:04There's a well-defined pecking order at carcasses
31:08One fox may defer to another, but neither of them can argue with a condor
31:23With a three-metre wingspan and weighing up to 15 kilos
31:27It's the world's largest flying bird
31:31The fox simply can't compete
31:36At this feast, the condor is king
31:44Caracaras have to wait their turn too
31:48Or make do with the rest of the food
31:52The condor is the king
31:56Caracaras have to wait their turn too
32:00Or make do with scraps that fall from the condor's table
32:14Spring brings a flood of migrants to take advantage of the brief Patagonian summer
32:20Like buff-necked ibis
32:23They waste no time in starting to breed
32:41Great grebes overwinter on the coast
32:45But as soon as the lakes are free of ice, they move inland and start fighting for territory
32:54Only the winners will have a good chance of raising a family
32:58The losers are forced onto lakes higher in the mountains
33:02Where the summer is no longer an option
33:06It's time for them to find a new home
33:23But it's that much shorter
33:31Territory is also the key to breeding for male guanacos
33:35They gather a group of females on their patch of ground
33:39And guard them closely against rival males
33:43He must always be on watch
33:47Younger males will seize any opportunity to raid the harim
33:54Soon the reed beds are alive with nesting birds
34:04And where there are nests, there are nest thieves
34:13As soon as eggs are laid, the fox is quick to take advantage
34:24She's found the nest of an upland goose
34:28Now the birds will have to start all over again
34:35There's little a bird can do to drive a fox away from its nest
34:42But a male guanaco packs more of a punch
34:48Soon there'll be baby guanacos to defend
34:51And he's not taking any chances
35:11Male guanacos are exceedingly territorial at this time of year
35:15And they won't tolerate intruders of any kind
35:22The fox already has a family to feed
35:26Her cubs will be safer away from the aggressive guanacos' territory
35:30So she moves them to another den
35:45There can be as many as five cubs in a litter
35:48Their mother has to carry each individually to the new den
35:52So moving house takes a lot of energy
35:56Even so, foxes often move their cubs several times
36:00The longer a den is occupied, the greater the chance a puma will find it
36:09The cubs are still dependent on their mother's milk
36:13But soon she'll be weaning them onto solid food
36:16By the time winter returns, they'll have to look after themselves
36:32Few of these cubs will live as long as a year
36:36If they're to survive, they have a lot to learn
36:40And only a brief summer to learn it
36:46High summer in Patagonia
37:16At the edge of the great ice sheet, the mountains are almost clear of snow
37:27This far south, midsummer days are long
37:31And occasionally, it can even be warm
37:37Patagonia seems almost benign
37:42The puma hunts mostly at night
37:44But summer nights are short
37:48There may be more food at this time of year
37:51But there's less time for the puma to catch it
37:59At dusk, a deadly game of cat and mouse begins
38:15The guanacos move to the ridgetops
38:18From there, they have a better chance of spotting a prowling puma
38:25But under cover of darkness, the odds are stacked in the big cat's favour
38:44This time, the puma killed a full-grown guanaco
38:48But the most vulnerable are the young
38:51The cat won't have long to wait for the new season's baby guanacos
39:15All the births are concentrated over just a few days
39:19That way, the puma is spoilt for choice
39:22And it can't take all the young
39:30The sooner a newborn infant can stand and run
39:34The better its chances of surviving the summer
39:45Within days of giving birth, the female guanacos come on heat
39:52For the males, this will be the payoff for all the hard work
39:56They've put into defending their harina
39:59But they can't afford to relax their guard
40:03This is when other males are most tempted to intrude
40:08The guanacos are the most vulnerable
40:11This is when other males are most tempted to intrude
40:17First, there's a standoff
40:26Fighting's dangerous, so males try to intimidate their opponents by posturing
40:32But this time, threat has to be backed by physical force
40:50Guanacos are heavy, powerful animals, and they can inflict a vicious bite
40:55This neck-wrestling is a way of avoiding being bitten
40:58Guanacos are heavy, powerful animals, and they can inflict a vicious bite
41:28Guanacos are heavy, powerful animals, and they can inflict a vicious bite
41:31Guanacos are heavy, powerful animals, and they can inflict a vicious bite
41:57The battle over, the winner takes his reward
42:02So long as he can fend off intruders, the resident male will mate with all the females in his group
42:09And sire a whole new generation
42:21This may be midsummer, but at any time, the mountain can spring a cruel surprise
42:32On a sunny summer's day, ferocious storms can strike out of the blue
42:50From behind its fringing peaks, the ice cap hurls a frozen blast down the mountains
43:01These sudden winds can reach a hundred miles an hour
43:32For everything that lives here, these sudden storms are part of the Patagonian summer
43:55For everything that lives here, these sudden storms are part of the Patagonian summer
44:00They can strike almost daily
44:07Even in the strongest winds, the grebes keep fishing
44:14All kinds of grebe carry their young on their back, but here in Patagonia, it's a lifesaver
44:23From their earliest days, the chicks feel the brutal force of the Andes
44:29But these birds are great survivors, and if they can make it through the storms, this is an ideal home
44:48Sometimes, grebes feed feathers to their chicks
44:51This may help bind the fish bones together, so they can be regurgitated safely as a pellet
45:00Young of all kinds have to grow fast if they're to survive the coming winter
45:08The young guanacos build up their stamina by playing in the last of the summer sun
45:30The mother fox has only a few more weeks to teach her cubs how to fend for themselves
45:36Carrion from a puma kill gives them their first taste of red meat
45:41But meat is a luxury
45:43To survive, they'll have to eat insects, fruit, leaves, even grass
45:54They may be playing now, but in a few weeks they'll be hunting for real
45:59On their own
46:02Only the most resourceful can live through an Andean winter
46:10All along the chain of the Andes, survival depends on adapting to some of the harshest conditions on the planet
46:18Thin air, bitter cold, relentless wind
46:30But for those that can live here, the mountains provide all their needs
46:50Our journey of over 5,000 miles ends here, almost in the Antarctic
46:56Where the glaciers of Patagonia plunge towards the southern ocean
47:27The mighty force of the mountains can give life, but at any moment it can take it away
47:34Living in the Andes is one of the greatest challenges in the natural world
48:56You