00:00Nuestro planeta es el más grande puzzle de viviendo en el universo.
00:05Un colección de mundos dentro de mundos.
00:08Cada uno un ecosistema de self-contained,
00:12llorando con la vida.
00:17Pero cómo funcionan?
00:20El intercambio web de relaciones y la influencia de las fuerzas naturales
00:26hace cada micro-world complejo y único.
00:33Así que para descubrir sus secretos,
00:36tenemos que explorarlos uno por uno,
00:39untargar sus piezas interlocking,
00:42y finalmente revelar la pieza vitala,
00:46la clave a la vida itself,
00:49hidden deep within
00:51cada uno de los micro-worldes.
00:56La scotteria de los colectivos
01:00Un 초, un áncero internacional de herida.
01:07La cintena de margen,
01:08un áncero haylande de herida
01:10de herida.
01:13Craggy peaks pierden
01:15en un terreno de fíj complete
01:16y de open espacio
01:17y un amplio de abrucciones.
01:20Dos habitantes
01:22unidos cumpridos
01:24con sus batallas
01:26presided over by Scottish emblems
01:31like golden eagles
01:33and red stags
01:36and it's home to some of the rarest animals in Britain
01:40the hand of man has been felt throughout the history of the highlands
01:46and yet its wildlife remains iconic
01:49how have the highlands remained a home for these species
01:58despite the pressure of the modern world
02:00to find out let's explore its deep forest
02:05and open heather moors
02:07discover the impact of the elements on these landscapes
02:10and the role of their key characters
02:13in keeping this remote corner of the British Isles
02:17wild
02:18there's a famous saying about Scotland
02:28it doesn't have a climate
02:30just weather
02:32nowhere is this more true
02:39than in the highlands
02:41it's a landscape at the mercy
02:45of gale force Atlantic winds
02:47winters have been known to hit minus 20
02:52and when it rains it pours
02:58have the elements had a hand in keeping this place wild
03:01up to five meters of rain fall here every year
03:06that's the same as in some rainforests
03:09with most other parts of Britain
03:12receiving less than a quarter of this
03:14it's easy to see why humans might have chosen to set up shop elsewhere
03:19but the highlands wild residents are made of sterner stuff
03:24in fact
03:26some rely on rain
03:29from the soggy earth emerges a creature feared throughout the highlands
03:36the scourge of Scotland
03:40the midge
03:42this tiny millimeter long vampire hatches from eggs laid in the rain-soaked ground
03:50as the midge feeds
03:57it sends off a chemical signal
03:59inviting others in the area
04:01to join the feast
04:02cutting the skin with their scissor-like mouthparts
04:06and sucking up the pooling blood
04:13and with an estimated 40,000 capable of landing on a deer or similar sized animal within an hour
04:20they can make life unbearable
04:25midges die off before winter
04:27but the change in seasons doesn't make life in the highlands any easier
04:32as the rain turns to snow
04:37on cue the mountain hare population turns from russet brown to brilliant white
04:46the new coat is thicker and warmer
04:49but it also helps to keep the hair safe from predators
04:53a brown hair on a white background would stick out like a sore thumb
05:04the ptarmigan employs the same color-changing tactics
05:09its feathery feet increase the surface area
05:12acting like snowshoes
05:14preventing the ptarmigan from sinking into the deep snow
05:18humans would struggle to live in these cold conditions
05:22but surprisingly these hardy animals can only survive here
05:27because of the highlands extreme weather
05:29as britain melted from its most recent ice age around 12,000 years ago
05:36animals adapted for arctic conditions
05:39were forced back to the very highest coldest points of the british isles
05:44while humans busily colonized the rest of the newly temperate uk
05:49the highlands provided a climate in which these animal refugees could survive
05:56so has the tough climate kept the highlands wild
06:04while it's true that is a rule the highest coldest wettest parts of the world
06:10are some of the least developed
06:12actually the highlands share a similar climate with major cities in other parts of the world
06:17so if weather alone does not keep a place wild the highlands must have another secret up their sleeve
06:25there's less than 50 people per square mile here compared with 600 in the rest of the uk
06:32perhaps the landscape has a part to play
06:37there's one very special ancient habitat that's found nowhere else in the united kingdom
06:47the caledonian forest dominated by the gigantic scots pine
07:00growing up to 20 meters high and a solid 3 meters in girth
07:06each tree can live for a very respectable 250 years
07:13during which time it supports an array of scottish wildlife
07:19it's the backbone of the caledonian community
07:23a familiar character is on the hunt for food among its branches
07:31the red squirrels agility allows it to reach the very top branches of the pine
07:36home to some of the choices cones
07:46it's been estimated that a single squirrel can eat the seeds from as many as 20,000 pine cones in a year
07:53squirrels have the sharp incisors common with the rest of the rodent family
08:03which they use to tear the tough cone apart
08:08perfect tools for the job
08:10but even so these teeth will need to grow as much as 15 centimeters a year to keep up with wear and tear
08:16the squirrel knows just how tough the winters can be
08:27so it plans ahead burying stores for leaner times
08:33scent glands in its cheeks help to guide it back to the cache
08:39but it might be months before the squirrel needs to excavate its hoard
08:46and unsurprisingly some seeds are forgotten or dropped by messy eating
08:56on the forest floor they have a chance of germinating
08:59bolstering the pine population
09:02it's a mutually beneficial relationship that's been going strong for millennia
09:07food is not the only reason the squirrel prefers the Scots pine
09:14the bark blends perfectly with its rusty red fur
09:19and camouflage is all-important when you have a predator that's equally at home in the branches
09:32the pine martin rivals the squirrels agility
09:35and in a high treetop chase is one of few predators able to catch it
09:42a smaller male wants in on the meal but he's testing his luck
09:58this pine martin is in no mood for sharing
10:05and chases the chancer out to a thin branch
10:10the squirrel makes a good meal in an environment where every calorie counts
10:19the young male will just have to find his own food
10:26and by the looks of it he could be going hungry
10:35pine martins are agile enough to also prey on the pines resident birds
10:40like the scottish crossbill
10:45an endemic species found in highland caledonian forests
10:49the bird's shape reveals its close relationship with the pine
10:57its curved slightly crossed beak is perfectly adapted to prize seeds from tough cones
11:04it eats little else
11:11the tiny crested tit one of britain's rarest birds is equally at home in the caledonian forest
11:19the tit supports the pine by winkling insects from crevasses in the bark
11:28and preventing burrowing larvae from doing serious damage
11:31but birds are not the only species that groom the tree
11:36the caterpillars of the pine looper moth and sawfly mimic the needles that they feed on
11:46these caterpillars can defoliate a whole tree
11:51but the scott's pine has an ally
11:57wood ants on patrol
12:04they detect their prey by vibration stalking and attacking
12:18the larvae may be twice the size of the ant but this poses little problem
12:22because these ants are team players
12:28dragging the larvae from the needles back to their nest
12:33the largest ant in britain has a suitably impressive home
12:37each meter high mound holds up to a hundred thousand ants at a time
12:43the nest is constructed almost entirely from pine needles
12:50with a queen ants living for anything up to fifteen years
12:55the nest must be constantly repaired and improved to see out her rain
13:00each one is a feat of engineering
13:04with the scott's pine providing both food and construction material for the wood ant
13:13it's no wonder that their nests are a common site throughout the caledonian forest
13:18in fact so many of the forest species are interconnected with the scott's pine
13:26relying on it for a food source a nursery or a home
13:31that it's known as a keystone species
13:34the backbone of the forest community
13:37and where many trees grow together
13:40the forest habitat supports larger species
13:43this strange call belongs to the capa cale
13:54the largest member of the grouse family
13:59the turkey-sized bird lives across much of europe
14:03but in britain is predominantly found in the highlands
14:07this is actually a mating call
14:10it might not sound particularly enticing
14:13but it's widely believed that the subtleties of the love song
14:16are too low for human ears to register
14:19capa calees have been breeding in the highlands
14:22since the ice age gave way to forest
14:32stands of scott's pine set a stage for their mating displays
14:36from the highlands to western asia
14:38and the males are dressed to impress
14:49with the affection of the more drably colored hens at stake
14:55testosterone-fueled tussles regularly break out
15:18the chance of injury is very real
15:25the victor gets his girl
15:27and the chance to mate
15:35the caledonian forests and their scott's pine
15:38are synonymous with the highland wilderness
15:43but they're only one habitat within this microworld
15:46the forest exists side-by-side with another completely contrasting landscape
15:56moorland as open as the forest is dense
15:58scotland's largest living land mammal the red deer needs both these habitats
16:11deer feed on new pine shoots but need open space to breed
16:28large males bellow across the heather advertising their superiority
16:36the stag rounds up a herd of females
16:40by keeping them under his watch
16:42he can ensure that no other male breeds with them
16:45and that only his genes are passed on
16:47but that's easier said than done
16:53other males will want the females for themselves
16:56and are ready to fight for the right
16:59these are ferocious battles to prove strength and determine dominance
17:14the rut has been fought in the open heather moorlands for more than 11,000 years
17:29it's the perfect arena
17:31stretching for miles without a single tree
17:34let alone sign of human habitation
17:36without natural shelter it's no wonder humans avoided the moors
17:43but deer are not the only animals to thrive
17:47despite first appearances the open moorland is as rich with life as the pine forest
17:54the red grouse is as dependent on the heather as its cousin the cappa caile is on the pine
18:05feeding on seeds flowers and shoots as the seasons change
18:11the heather like the scots pine relies on the relationships with other species
18:17its striking purple flowers are pollinated by bees while passing animals help to distribute its seeds
18:30and it creates a territory for one of the most powerful birds on earth
18:36the golden eagle
18:38a symbol of the wild highlands
18:42it's a predator adapted for purpose
18:46keen eyesight allows it to scour the heather for movement from up to two kilometers away
18:53powerful talons and beak help it to dispatch prey many times its body weight
19:00and this formidable bird needs these open spaces
19:07to hunt
19:11following a particularly cold winter the snows melted but the mountain hare's fur hasn't quite caught up
19:26the white that provided camouflage a month before is now more of an advertisement
19:33with its two meter wingspan the eagle soars on wind currents constantly spotting for movement below
19:46while the hare is unaware of the danger overhead
19:51the eagle locks in
19:54but the hare is no sitting target once it spots the threat it will sprint through the heather
20:01by using pre-practice routes that it knows are obstacle free the hare is capable of hitting 60 kilometers an hour
20:09but with the eagle topping out at three times this it needs something more than speed to survive
20:22so the hare dodges and weaves throwing itself out of the eagles trajectory
20:28a last-minute zigzag saves the hare by a whisker
20:43heather plants can grow for around 30 years
20:48after this time they degenerate and die back bacteria in the soil will break them down
20:55the increased nutrients that this breakdown provides is just enough for larger hardy plants to begin to grow
21:02over time heather will be replaced by trees
21:07and eventually forest
21:10but something doesn't quite make sense
21:14if this natural succession was taking place
21:17the highlands should be full of trees
21:22instead caledonian forest only exists in small pockets
21:29this explains why some of the species that it supports are so rare in britain
21:35as there's just not enough habitat to go around
21:39but it hasn't always been this way
21:43some ten thousand years ago
21:46after the end of the last ice age
21:49scotland was covered in trees
21:52these primordial forests would have been rich with life
21:56wolves, bears, wild boar
22:00animals missing from scotland today
22:03so what has happened to the highlands?
22:06how does a forest just disappear?
22:10what has allowed the heather to take hold in such vast areas?
22:15and how has the natural succession of the trees been halted?
22:23the soil below the heather reveals the answer to this conundrum
22:29by studying remnants of the habitats from thousands of years back
22:33scientists have been able to determine
22:35that there was still forest in the highlands up to 5,000 years ago
22:41before disaster struck
22:46the climate changed
22:50a small fluctuation compared with the chill of the ice age
22:54but enough to make the highlands wetter
22:57the deluge that followed was far more serious than the worst of modern day scottish winters
23:04the forests literally drowned
23:08it's thought that three quarters of the original caledonian forest rotted away
23:15creating vast bare spaces
23:18which suited not only the tough heather
23:22but another species
23:24humans
23:27open land allowed communities to farm crops
23:32build homes
23:34and raise livestock
23:35for the first time
23:38humans became a dominant highland species
23:41the climate eventually settled
23:45but only a tiny 10% of the once vast caledonian forest remained
23:52the landscape that we recognize as the scottish highlands today
23:56had been created
23:58this was of course great news for open space loving species like the grouse and mountain hare
24:06but many of the animals that relied on the forest
24:13wolves
24:14the kappa kelly
24:16red squirrel
24:19and bears
24:20became extinct
24:21those species that could survive were excluded to small pockets of woodland
24:29over the centuries
24:32over the centuries
24:33the land use of the highlands shifted
24:35farms were cleared to make way for deer and grouse hunting
24:39the highlands were kept bare
24:42trophy species relied on healthy heather
24:45and so patches were burnt to encourage new growth
24:49and extend the plants natural 30 year cycle
24:53a new habitat was created
25:00a patchwork of old and young heather growing side by side
25:05in which not only the grouse but all moorland species could flourish
25:10but this wasn't a natural habitat
25:15man was artificially managing the highlands wild populations
25:26humans have become an intrinsic part of the ecosystem
25:33scotland's heather moorlands were thriving
25:36but the few remaining areas of forest and their inhabitants were still isolated
25:42it was an environmental disaster that triggered the demise of the caledonian forest 5,000 years before
25:49so it's fitting that another would start to bring it back
25:53but this time it wasn't brought about by natural forces
25:57two world wars left britain's natural resources ravaged
26:11new trees needed planting
26:13and although their primary purpose was for timber
26:16these forests also encouraged species back into scotland
26:19that hadn't been seen in decades
26:24red squirrels recolonized supporting greater numbers of their predators pine martins
26:33pine loving populations of the rare crested tit and the crossbill grew
26:43landowners began to take responsibility for the wildlife
26:47the focus shifted to forest protection and regeneration
26:52but this posed a dilemma
26:55left to its own devices the forest would naturally replace the heather habitat
26:59that now supported many more species than just the grouse
27:02the regeneration of one couldn't come at the expense of the other
27:08for these two habitats to co-exist in the highlands
27:15then humans would need to be actively involved
27:20they'd have to site manage
27:27today the scottish highlands are celebrated as the last truly wild place in britain
27:32but it is a wilderness under supervision
27:39forests are being planted and the heather managed
27:43species have been reintroduced
27:46it's a micro world under reconstruction
27:49one in which humans are as fundamental to success
27:52as any of its other animals or plants
27:55the scottish highlands are at once both wild and controlled
28:07people have had to learn how to go about regenerating an ecosystem
28:14a long and delicate process that's still not complete
28:18but the hope is that under careful guardianship
28:22these iconic characters and ice age survivors
28:25will have a place in the highland landscape
28:30for centuries to come
28:33and going into undiscovered worlds with steve actual this evening on bbc2
28:46mind-blowing adventure in mexico
28:48in the largest network of unexplored caves
28:51and six
28:52thanks today the mystery of our tides
28:54enclosed
28:55the mystery of our tides
28:58day
28:59in the midwest
29:02our dream
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