On the edge of the Atlantic lies a world of rock and water.
Wind-scoured and rugged, yet full of grace and beauty.
Exposed to a restless ocean and Europe's wildest weather,
the animals of these islands face challenge after challenge.
For a year, we'll follow life in this magical
but unpredictable place...
..revealing secret lives...
..and mysterious worlds...
..rarely seen...
...and never filmed here before.
Here on Scotland's wild west coast..
..here in the Hebrides!
In Britain, the Outer Hebrides are as far west as you can go.
Of all the islands on the edge,
these are the most exposed to the raw power of the Atlantic.
They form a long chain,
and carry an ancient
sense of place in their names.
Berneray,
Benbecula,
Uist,
Lewis,
and Harris, with mountains made from the same rock as the moon.
There's an otherworldliness here
that sets these islands apart from anywhere else in Europe.
Along this final frontier are even more remote satellites -
outlying rocks and stacks,
and these reveal why the Outer Hebrides are so special.
On these islands are some of the largest seabird colonies in Europe.
Northern gannets alone number more than 100,000 birds...
..the greatest gathering on the planet.
It's mid-June and all the Hebridean seabirds
have just a few short months to raise a family.
Summer is brief here, even by Scottish standards,
and this year the weather has been particularly cruel.
In Spring, the Hebrides were hit by a devastating storm,
the worst for many years.
Its effect was catastrophic.
Many birds lost eggs and nests, they had to put their breeding
season on hold, just as it was starting.
An already brief summer is now even shorter.
On the outlying islands there's a real sense of urgency
in the huge puffin colonies.
The torrential rain flooded many burrows,
and it's been hard work digging them out again.
Deep in the back of this burrow
nestles a single, three-week-old chick - a puffling.
Her parents have been together for many years.
They constantly re-affirm their bond with ritualized head-flicking.
Every day they fly out to sea to bring her food,
each clocking up to a hundred kilometres.
Because of the setbacks this year,
the parents are under even greater pressure than usual.
They must feed the puffling quickly and often,
so she'll be ready to leave by autumn.
And there's another problem.
Great skuas - locally known as bonxies,
make a living mugging other seabirds.
They can bully gannets twice their size into coughing up their catch.
At a third of the skua's weight, puffins are a pushover.
The bonxies prowl the colony,
seizing any opportunity that comes their way.
They're quite capable of dragging a puffling
from its hole and devouring it...
..so the chick must stay well-clear of the entrance.
For thousands of years,
the seas around these islands have sustained not just seabirds,
but people.
On the east coast of the Isle of Lewis,
sheltered from Atlantic gales, lies the town of Stornoway.
It's easily the best harbour in the Outer Hebrides.
In the days when travelling across Europe was slow and dangerous,
Stornoway was an important crossroads for people using the sea.
Bronze-age traders, Celts and Vikings all came here
and made this a cosmopolitan place.
Even the town's name comes from the ancient tongue of the Vikings.
Stornoway has always been an important fishing port
and it's still home to many boats.
A group of grey seals hangs out in the harbour
waiting for the returning fleet.
This mature bull has realised that the boats can supply him
with a free fish supper.
Living here certainly means you don't need to work too hard
to earn regular meals.
Back in the puffin colony,
getting a meal is a matter of life and death.
The bonxies are hunting hard. They're hungry, too.
The three-week-old puffling is keeping safe at the back of the burrow.
But another youngster has made a fatal mistake.
It's a lucky escape for the puffling...
..but now the bonxies turn their attention to its parents.
To deliver this precious catch, they have to run the gauntlet.
Every time they feed their puffling, it's a triumph!
The chicks which survive can live for more than 30 years -
little birds with a lot of experience.
The seas around the Outer Hebrides are rich,
and despite the storms earlier in the year,
it's turning out to be an exceptionally good year for fish.
There's plenty of food here to support large shoals.
But you still have to know where to find them.
In the sound of Barra,
a pod of 15 bottlenose dolphins know all the tricks of the trade.
They can read these complex tidal waters as only true residents can.
Sometimes they save energy by bow-riding fishing boats
which are going the same way.
After all, fishermen need to read the currents and tides, too.
This pod will work these waters all summer,
making the most of this short time of plenty.
Now the local residents are joined by long-distance travellers.
Missing the spring storms by just a few weeks,
a flock of migrants arrives on the warm south wind - Arctic Terns.
They've flown almost 19,000 kilometres from the Antarctic to the island of Lewis.
Here, just north of Stornoway town, they're checking out
a small river island, rich with blooming sea pinks.
It seems ideal - there are no ground predators here,
and on the doorstep is a great source of food.
Broad Bay is sheltered
and the many animals already feeding here are proof of how rich it is.
Otters fish the rising tide
while eider ducks dive for mussels.
The terns decide to settle here.
They explore the river island, working out where they want to nest.
Terns, like so many seabirds, mate for life.
And these kinds of decisions take time.
After coming so far, they might as well get it right!
Now that's done, the male needs to cement their relationship.
All he has to do is to head out into the Bay,
and find a small gift for his mate.
Shrimps are too slippery.
A plump sand eel, from further out, might be better,
once he's got a good grip.
Now it's just a case of getting it back home.
But once again, there are pirates waiting in the wings.
This time, they're arctic skuas - swift, manoeuvrable and persistent.
A bonxie moves in on the colony.
This needs teamwork.
But it's all worth it to hand over the prize.
There's a good reason that nesting birds cling to the islands' edges.
The interior of Lewis is vast,
but it's not fertile like the surrounding seas.
Lashed by strong westerlies,
the rocks are covered by layers of peat and studded with small lochs.
Fish don't thrive in these isolated pools
and that's good for damselflies.
Their vulnerable young live underwater.
But first they have to get there - and that means laying eggs.
On one of the first really warm days of summer,
a male damselfly has found a mate and the pair lock together.
She needs his help to break through the surface, so he's pushing her under.
But he's slipped.
And then, disaster!
A gust of wind breaks them apart.
He can't help her now but she presses on alone.
Underwater, she must split open the stem and lay her eggs.
But getting out again without the male's help
is going to be very tricky.
On the other side of the pool, one of Britain's rarest birds
sits on recently laid eggs -
a red-throated diver!
This pair's first nest was washed away by the storms.
This is their only chance to raise young this year.
The watery world of the Western Isles is vital to the divers.
Their legs are so well adapted for swimming
that they can't walk properly,
so they can only nest right on the edges of pools like this.
And that makes changeovers a clumsy affair,
more like falling in and out of bed.
While the female takes her turn on the eggs,
the male heads out to sea in search of fish.
But while he's away, the female is exposed to danger.
It's a black-throated diver - bigger,
more powerful, and looking for a new home.
At the edge of the lochan, a damsel is in distress.
The female damselfly can't break free of the water's surface
without the male to help her.
But then she manages to flip a wing up -
and another!
And like tiny sails, they catch the breeze.
Predatory dragonfly larvae are close by.
They'll kill her if they notice she's there.
She's drifted against a stem.
It gives her some leverage out of the water,
and, at last, a safe place to dry out.
But she still has more eggs to lay,
so tomorrow she'll go through it all over again.
The male red-throated diver
arrives back and discovers the blackthroat on his lochan.
The smaller diver starts to panic
but it must defend the female on the nest.
For all their ungainliness above water,
these birds are like torpedoes underneath.
Their bills are like knives - a stab from below could be lethal.
The commotion draws the female redthroat off the nest to help her mate.
But the blackthroat is heading straight towards her.
And suddenly they're on top of one another.
The blackthroat is taken completely by surprise...
..and the female redthroat seizes
the chance to lure the intruder away.
It's all too much.
Rattled, the blackthroat makes a hasty exit.
It's back on the eggs as quickly as possible.
If they're left too long, they'll chill and won't hatch.
It's early July.
With 18 hours of daylight,
conditions are perfect for growing crops.
But even now, farming in the Outer Hebrides is never easy.
The islands of Uist and Benbecula appear the most unforgiving.
Scraped by long-gone glaciers, they're now as much water as land.
But running down the Atlantic side
of the islands is one of the jewels of the Hebrides...
..the machair.
Lying between the unfertile moorland and the sea,
it's like a Scottish Garden of Eden.
Over centuries, the winds have blown shell-sand up onto the islands,
balancing out the acid of the peat.
But the machair wouldn't be this rich if it wasn't for people.
Generations of crofters have carried seaweed onto the land
to make it more fertile,
and they leave the small fields fallow in some years -
allowing wild flowers, insects and birds to move in.
In high summer, the machair hums with rare bees
like the moss carder
and the great yellow bumblebee - extinct in most of mainland Britain.
Meadows like this hardly exist there any more because of intensive farming.
There are always corners for the corncrake -
whose surreal rasping call is heard almost nowhere else in Britain.
It's flourishing here in the Uists.
The rich supply of insects makes this an ideal home for skylarks.
Their nest is well hidden amongst the flowers.
The chicks are brilliantly camouflaged
with tendril-like feathers on their heads
helping them blend in with the grass.
The machair is also globally important
because it's home for birds like lapwings which nest on the ground.
In a normal year, they'd have finished raising their chicks by now,
but they were also hit by the storms.
So along with other local residents like redshanks
and oystercatchers, they're sharing the machair with recently arrived migrants.
It's much more crowded than usual
and the lapwings are kept busy defending their patch.
Wader chicks hatch fully fluffed-up and ready to go.
It's like keeping control of half a dozen wayward toddlers all at once.
The mother lapwing has a real job on her hands
to keep her brood together - and safe.
Living in this world of rock and water is tough for people and animals alike.
But in the Outer Hebrides, people have found remarkable ways of surviving.
The most unusual human community of all lay on a group of islands
40 miles to the west of the Uist machair...
..St Kilda.
The islanders who lived here were the last pure hunting community in Britain.
Living almost entirely on a diet of puffins, gannets and fulmars,
they'd think nothing of scaling the thousand-foot cliffs barefoot to harvest the seabirds.
These cliffs still support the biggest seabird colonies in Western Europe.
The fang-like Stacs are home
to the single largest gannet colony on the planet.
One fifth of the world population lives here.
Now in mid-July,
the colony is full of plump young gannets locally known as gugas.
They were a key food for the St Kildans
and are still sometimes eaten in parts of the Outer Hebrides.
The St Kildans' way of life was so unusual and self-contained,
it simply couldn't survive contact with the modern world.
Worn down by disease and the loss of fit young people to a life
over the sea, the last 36 islanders asked to be evacuated in 1930.
Their community could adapt no further,
but they left other inhabitants behind - and they ARE changing.
Like a Scottish Galapagos, St Kilda now gives scientists a chance
to watch evolution in action.
The wrens on St Kilda can't fly strongly enough to leave,
and they're growing larger.
They're now 25% heavier than their mainland cousins.
They have a deeper song and lay larger eggs, too.
Maybe they've had to toughen-up to these exposed conditions.
The islanders' Soay sheep are changing too,
but in the opposite direction - they're shrinking.
Like red deer, they have an autumn rutting season, and these pint-sized
rams are preparing themselves by sparring on the hillside.
The island has a field mouse too, but it's moved into the village,
finding homes in the dry-stone walls and houses.
But needs must, as every castaway knows, and the mice have
turned into carnivores - feeding on dead sheep and seabirds.
They're also growing larger.
Could St Kilda be seeing the evolution
of a giant sheep-hunting rodent?
IT ROARS
Perhaps not!
Sitting under its veil of cloud, St Kilda is rarely dry and sunny.
But back on the machair, it's a different story.
The unseasonal spring storms have been
followed by one of the driest summers in living memory.
It hasn't rained for weeks.
Throughout July, the ground-nesting birds work frantically.
The skylark chicks that seemed so small and defenceless
just weeks ago are now chasing their parents for food.
The plants are wilting,
but there's still plenty of insects for the many young wading birds.
They're growing fast, but still can't fly.
The lapwing chicks have grown, but the brood is down to just two.
It's a bigger loss of life than you'd expect
in a place without ground predators.
It's suspicious.
BIRDS CALL
The alarm goes up.
A ferret, an escaped domestic animal,
is on the loose and causing chaos.
The waders mob it,
trying to drive it away from their flightless chicks.
But it's too late, it's got one.
It vanishes into the long grass, but the damage is done.
Introduced animals like ferrets can cause havoc in this fragile place...
..but that's not the only problem.
The Uist machair is less than two metres above sea level
in many places.
Now the climate is changing, and with it, the sea is slowly rising.
These low-lying islands
are in danger of being claimed by the ocean.
Here, where change is a fact of life,
they say, "what the wind brings, the current takes away".
It's a reminder that, whatever we might like to believe, living here,
on the outermost edge of the Hebrides, is on the ocean's terms.
It's August, and the Outer Hebrides appear almost tropical
as the sun beats down day after day.
The drought is causing a real problem...
..for Atlantic salmon.
After a life at sea, they're gathering by the mouth
of their home river, close to Amhuinnsuidhe Castle on Harris.
To complete their life cycle, they need to swim upstream to spawn.
They've travelled here from Greenland to do this...
..but the last stage of their long journey is impossible,
as the river is too low.
It's not a problem for dippers.
They work the river bed for insects which thrive in the bubbling water.
Unable to advance, the waiting salmon are being picked off
by grey seals.
It'll take a great deal of rain
to raise the river enough for the fish to advance.
In the hills above the castle, a family of red-throated divers
are also at a turning point in their lives.
The two chicks are growing fast and they're hungry.
But one is larger and more aggressive.
It's quite rare for a second chick to even get this far.
Usually, it would lose out on most of the feeds and die.
But fish have been so plentiful this year
that both chicks are almost ready to head out to sea.
They just need to learn how to fly.
The parents take off and land
to show their youngsters exactly how it's done.
But it's a challenging skill to master.
This chick still has some way to go.
You also need a lot of extra lift
when your home is surrounded by mountains this steep.
Nearly.
THUNDERCLAP
They don't have long. There's a change in the air.
Autumn will be closing in soon.
THUNDERCLAP
Storm clouds are building.
In a narrow sea loch in South Uist, 60 pilot whales have become trapped.
They're creatures of the open ocean, but they may have followed
a shoal of squid into this dangerous place.
It's not good.
They're not used to being hemmed in like this,
and the younger whales are starting to panic.
Several have cut themselves on the sharp rocks.
Their distress grows.
The shore is dangerously close.
Stranding is now a real possibility.
But luck is on their side.
The tide is rising, opening the door of their prison,
and the pod starts to move back towards safety in the open ocean.
It's almost a relief, after four weeks of drought,
when normal Hebridean weather returns.
High in the mountains of Harris, the rivers are swelling,
and the water thunders towards the sea.
The salmon are finally on their way.
The summer rain has replenished the machair lands, too.
Crops are ripening as the wild flowers set seed.
In the Uists, crofters will soon be bringing the harvest in.
But there's always seed to spare for small mammals,
which is good news for birds of prey.
A recently fledged short-eared owl chick watches
one of its parents quarter the fields, hunting for mice and voles.
The machair is quieter now.
The wading birds have moved off the fields, and onto the beach.
Seaweed, washed up by the spring storm,
is rotting quickly in the midsummer heat.
Hordes of insects have been attracted in
to feed on the decaying piles.
Springtails eat bacteria that break down the kelp.
As the tide sweeps in, they swarm into clusters.
On the surface, they're fair game for passing terns.
In time, these piles of kelp will be laid on the machair,
and the richness of the ocean will revitalise the crofters' fields.
It's September, and across the Uists,
ancient machinery grinds into life.
It's harvest time.
Once the crops are cut, they're gathered into sheaves,
and then piled into stooks and stacks.
It's a system practiced here for centuries.
It works for people...
..and it works for wildlife, too.
But the knowledge of how delicately it all fits together is fading,
along with this generation of crofters.
The high school on Benbecula is addressing this dilemma,
by offering a special crofting course.
Students get hands-on experience
of the fine art of stooking and stacking.
Up, just keep it tight in together
so the water's going to shed off one onto the next one.
Hold on. And what do we call it in Gaelic? You've probably heard it.
Croitearachd!
Oh, yeah.
Start from here.
It's not just popular, it's oversubscribed.
It's up to this generation of school-leavers to decide
whether the machair lives on.
And these are exactly the people who will be most tempted
to leave the outer isles for a mainland, mainstream life.
As summer turns to autumn, the gannets, divers and terns
will leave these islands, and spread out across the globe.
Under the cover of darkness, the pufflings will slip out to sea
to spend many long months on the open ocean.
But they'll be back.
Because there's nowhere better than the Hebrides.
These precious islands on the edge are some of the best places
for wildlife anywhere in the world.
Next time, the people of the Hebrides.
In these islands on the edge,
wild animals and humans have lived side by side for centuries,
sharing the same landscape and the same challenges.
But the world is changing fast...
..and so are the pressures on people and animals alike.
Could the people of the Hebrides have found a new way forward,
through their special relationship with the natural world?
Subtitles by Red Bee Media Ltd