(air whooshing)
Bleak to the extreme,
harking back to the struggles of the last great ice age.
The Tundra pushes life to the limits.
(soft music)
But with the most dramatic seasonal changes.
(soft music) (birds chirping)
It offers rich rewards,
but those tough enough to take on the challenge.
The creatures here are some of the toughest,
most highly adapted,
and fascinating,
all playing a role in balancing a delicate landscape.
(birds chirping)
One that despite its remoteness,
is already coming under pressure from us.
The Tundra, is a landscape which affects us all
in ways we are only just coming to understand.
(wolf howling)
Maybe we can learn from its hardy inhabitants.
(horns clacking)
(wind whistling)
(birds cawing)
If you travel north across our planet
somewhere around latitude 60 and 70 degrees
you'll run out of forest.
Beyond them, a drying hostile barren
and bitterly cold wasteland,
too harsh even for trees to take root.
(air whooshing)
(soft music)
This is the Tundra,
a word that means barren, treeless plains.
It straddles North America and Eurasia,
making a great icy ring around the Arctic.
The coldest driest habitat on earth might appear lifeless
but look again.
(soft music)
Looking tiny, insignificant,
little more than a glorified hamster,
lemmings are anything but.
They must be one of the toughest creatures on earth.
One of very few mammals
that thrive on the Tundra year round.
The miniature models are actually vital,
pillars supporting an entire plant and animal community.
During winter, they dig tunnels under the snow
using the white blanket to trap heat
while they forage on the Tundra's surface as normal.
Most rodents could not do this.
Winter temperatures hover around -35 to -45 degrees Celsius.
For most little mammals, life here would be impossible.
And for the few that can make it,
the only option in winter is hibernation.
For the eight crippling months of winter,
the Arctic ground squirrel escapes to a world of fairy tales
in a long, deep slumber.
Slowing his metabolism, lowering his heartbeat,
he can actually let his body drop below freezing.
Occasionally he shivers,
a little fidget is enough to keep him alive,
while winter surges overhead.
For more than half a year, winter owns this wasteland.
At its heart the Tundra endures weeks of darkness,
where the sun's arc is too low to break the horizon.
Without light, no plants can grow.
There is zero productivity.
This is the ultimate test of life.
(wolf howling)
And yet life endears.
For the hardy, a globe gradually returns to the horizon.
Muskox had been fighting against the hardships of winter
here for tens of thousands of years,
leftovers from the time mammoths roamed these parts.
Their shaggy coats are their greatest defense.
They are wrapped in quilts of wool, known as qiviut,
which is said to be eight times warmer than sheep's wool.
The long curtain of guard hairs over the top
helps rain runoff and act as a windbreak.
Ice crystals form in their curtains of hair.
They huddle in larger groups to help conserve their heat,
though the proximity isn't always easy.
Food is incredibly scarce.
Huge horns and giant hooves service snowplows
to dig and expose what they can.
But there's a strict hierarchy,
and with competition for meager resources, tempers fray
(soft music)
But the light is slowly gaining strength.
The first feeble beams of sun offer respite
to their cold bodies,
a promise that better times approach.
As the hours of daylight gradually build,
activities beneath the snow change.
(soft music)
Lemmings like a bit of personal space,
but in snow tunnels it's not always an option.
But the rising temperatures and sunlight
trigger hormone changes
that make the rodents a little more feisty.
A desire to breed causes a bit of friction
and eventually the need comes to make a break for freedom.
Dashing from colony to colony,
they can seek some positive interactions.
For the little male, every household has mating promise,
but also the chance of competition.
Like speed dating, he dashes on,
hoping for a better outcome in this lemming lucky day.
His efforts are being watched.
Arctic foxes are just one other of a tiny handful of species
that stick out Tundra winters.
(soft music)
Many molt to white coats for winter to blend into the snow.
This one is part of the exclusive one percent
that stayed dark year round, known as blue wolf.
It's still cold.
Instead of wasting precious energy
dashing after turbocharged lemmings,
she turns to her fridge freezer.
Arctic foxes are experts in collecting food
and stashing it for later.
The success of Lemmings can have a massive impact
on the fortunes of foxes and other predators.
She plays maybe warming herself up
or perhaps she's trying to defrost her meal.
(soft music)
The reason these rodents tunnel above the ground
instead of below it,
is that it would be like digging into concrete.
One thing that defines Tundra is the presence of permafrost.
Though the very top layer of soil,
10 or 15 centimeters deep,
might defrost and refreeze each year,
below that, the earth is frozen solid
to depths of up to 1,000 meters
and has been for thousands of years.
It's this IC barrier to the underworld
that prevents tree roots from taking hold.
Creating the uniquely open icy Tundra,
ice locked barren and inhospitable,
it doesn't look very appealing,
but this is a dynamic landscape.
It only takes the sun to rise a few degrees
above the horizon and the Tundra Springs to life.
At first it's quiet, a few residents that weathered winter
make the most of the weak sun.
Muskox shovel the slightly softening snow
to see what they can find.
And the paths they clear create opportunities for others.
Arctic hares in winter white coats,
nibble at any exposed plants the giants have unearthed.
The hares are good diggers too, and need to be.
Compared to other Tundra specialists,
they can only store limited amounts of fat on their bodies.
During winter storms,
they dig holes into the snow to take shelter
but the rest of the time they stick it out.
As hares go, they're short legged and have smaller ears,
reducing the amount of surface exposed to the frigid air.
Though they are leafy eaters, like other hares and rabbits,
they'll make the most of what they find,
even nibbling dead animals or fish.
The squirrels have been sleeping soundly beneath their feet,
but now groggy ground squirrels are beginning to stir.
But there's no time for lazy lions.
(birds chirping)
Summers go fast here,
so for animals to stand a chance of breeding
they need to be quick.
Ground squirrels have just a few weeks
when females are receptive,
so this male needs to get busy.
(birds chirping)
Finding a date is the easy part.
It's jealous boyfriends that presents the challenge.
The male splashes himself with aftershave
from a gland on his tail.
It doesn't go down well,
jealous squirrels go nuts.
(suspenseful music)
But the stakes are high, not only risking physical injury,
but also this year's chance to be a dad.
It's time for a new chapter on the Tundra.
Here there isn't much in the way of Spring or Autumn,
just a really long Winter and a short burst of Summer
that no one can afford to miss.
(birds chirping)
(water dripping)
(wind blowing)
As the snow melts, the lemmings find themselves homeless.
Their tunnels collapse around them,
leaving them exposed and vulnerable.
So they need to get busy
looking for natural bolt holes in rocks.
(soft music)
As the tunnels vanish, the lemming leftovers are revealed
and this is a vital clue into the Tundra's richness.
Soil hair is thin, frozen and of poor quality.
But lemmings are so abundant and busy year round
that they have scattered a thin layer of fertilizer
all over the Tundra's surface.
It's the fertilizer all plants are going to need
as the growing season gets underway.
The thinning snow reveals a brown and empty wasteland,
but not for long.
With only a few precious months of sunlight,
plants that have laid dormant in the soil waste no time.
Most of them spend summer producing food from sunlight
but storing it underground in their roots,
ready to push forth the following season.
With no time to waste in producing offspring
they explode with flowers,
carpeting the Tundra in rainbow colors.
Flowers need pollinators and no sooner than they bloom,
as if by magic insects appear.
(flies buzzing)
It's a miracle of the Tundra
that such tiny, delicate animals can survive here.
Some 2,000 species of insects call Tundra home.
Many of them overwintered by shutting down their bodies
and lying dormant.
The most abundant of bugs are midges and mosquitoes.
They convert the water in their bodies to glycerol,
which acts like a natural antifreeze.
The bees here are hairier for warmth,
flapping their wings creates heat
and the fur helps to store it in their bodies.
Each with their own defenses against the cold,
these tiny creatures get to work,
pollinating the abundant plant life.
(soft music)
They are joined by visitors from the other end of the world,
long tailed skewers.
After a winter spent at sea, plundering the Southern oceans
where they are known as pirates for their habit
of bullying other birds to steal their food,
this aggressive pair have come here to breed.
After an incredible 10,000 kilometer journey,
they waste no time in making their arrival felt.
The snowy owl sometimes slip to the nearest forests
to shelter in winter, which is toughed out on the snow,
which means they are here at the start of summer
and ready to breed,
but they don't have the place to themselves.
The skewers are laying out a perimeter fence
around their proposed nesting site.
Boundary lines that they will uphold at any cost.
(birds cawing)
Not a great way to build relations with their new neighbors.
Though scavengers and fish eaters at sea,
here the skewers become deadly predators
and rodents specialists,
spreading fear through the lemming colony.
The vanishing snow leaves them exposed
easily spotted by the aerial raids.
Caught in the open, it tries to keep a low profile.
Fortunately there are still a few patches of deepest snow.
A second lemming is less fortunate.
The perfect picnic.
Best shared.
Life is challenging for the lemmings.
The snow is melting, but the ground beneath is frozen.
There's nowhere for the water to run.
So it pools on the surface.
Another Tundra characteristic,
over summer, much of it is a giant bulky wetland.
Fortunately, lemmings are good swimmers.
Invertebrate life flourishes in the pockets of water.
It's the perfect breeding ground
for mosquitoes and other bugs.
(water splashing) (bugs buzzing)
The growing insect population
is starting to attract a crowd.
(birds cowing)
The start of summer is the start of Tundra rush hour.
Hundreds of thousands of birds
who moved south to escape the winter now flock back.
Arctic summers get long hours of sunlight,
fueling plant growth, feeding a blossoming insect community.
This is the perfect place for birds to raise their young.
A lot of small waiting birds;
plovers,
turnstones
and knot,
and ducks, and geese.
An Ida duck nests close to the skewers.
It's a bit of a headache,
but she chose nasty neighbors over the alternative.
There are no trees on the Tundra,
birds have no choice other than to nest on the ground
and predators are abundant.
The ida knows it's in for some regular dive bombing
but so is anything else that comes too close.
Arctic foxes are one of the biggest threats
to the ground nesting birds.
Most are vulnerable.
(fox grumbling)
But not skewers.
These confident aerial acrobats mean business.
(soft music)
So while the ida lives in a rowdy neighborhood,
she knows her nest is well guarded.
But that doesn't mean she's in for an easy ride.
(soft music) (birds chirping)
It's still early in the season.
The weather is unpredictable
and winter is ready to leap back in an instant.
All of the animals will feel the Arctic's fury.
(birds cowing)
The Ida's eggs would freeze and die instantly,
only her body heat can keep them alive.
So she has no choice other than to sit tight
and let the snow build.
(soft music)
The Tundra is transformed back to a winter white out.
But putting up with the code
is the trade-off for food and sunlight in abundance.
(birds cowing)
Another strategy for keeping your family safe
is to band together and present a united front.
That is the strategy for snow geese.
A wolf could certainly snag a goose,
but only with the element of surprise.
The alert flock spots him in plenty of time.
(soft music)
Calmly they keep enough distance to allow a takeoff
if he gets too close.
parting the sea before him, the Wolf carries on his way.
(wolf howling)
The wolves pack is nearby.
The family has cubs
and everyone is expected to protect them.
But they are caught off guard.
Now that it's warmer,
the musk ox herds are broken into small groups.
The big adult males are mostly solitary and roam the plains.
And this one has roamed into the heart of the packs home.
This is a delicate situation.
Buffalo on the African plains will kill lion cubs
stopping a potential threat in its tracks.
The muskox could easily do the same now.
He weighs as much as the entire wolf pack combined.
The last thing they want to do, is make him angry.
The pups are clearly nervous,
but everyone tries to remain calm.
It's not ideal for the muskox either.
He's surrounded by his main enemy.
One of the adults ushers the pups to a safer hiding spot.
Almost there.
But as a departing gesture, the bull makes a statement.
Don't mess with me.
Point taken, the wolves politely step aside.
The stakes are too high on both sides.
And the intense encounter is brought to a close.
(soft music)
There are babies all over the place,
but the prize for productivity goes to the lemmings.
Unlike most animals here,
they are not tied to a breeding season,
and can churn out youngsters year round.
With half a dozen or more babies delivered
every month or so,
and each being able to breathe for themselves
at just a month old,
lemming populations are limited only by food.
(soft music)
On lean years their populations shrink,
but on a good year can explode.
And the abundance of rodents is critical
to successful breeding seasons for the Tundra's predators.
Many populations like the snowy owls
will go through the same peaks and trumps
in response to the numbers of lemmings.
Even a good year won't ensure the survival
of all of the outlets.
They have an unusual insurance strategy,
having more chicks than they need.
The oldest and biggest always gets fed first,
though if something happens to it,
they prioritize the next in line.
With this favoritism,
the youngest in the family rarely survive.
The skewers keep it simple, with just one or two chicks,
and the mother guarding
while the father does most of the hunting.
(upbeat music)
Of course, both are quick to defend their young.
At just a few days old, the chicks know to flee the nest.
Having both in one place
makes them more at risk of disaster,
they can spread out and hide.
but the parents aren't going to let any intruders through.
The chicks don't have to brave the cold for long.
(birds chirping)
Their nesting grounds are visited by passing nomads.
Only one day a thrives on the Tundra,
known as reindeer across Eurasia
and caribou in North America.
They are perpetual travelers, always on the move,
following the seasonal growth to survive harsh conditions
and find the best food.
But for the herds and all life here, things are changing.
(soft music)
Many herds of caribou and reindeer are decreasing.
They are suffering from increased numbers
of parasites and diseases.
The pests are building up because of a milder climate.
Because of climate change, accelerated by human activities
that plow carbon into the atmosphere,
the Tundra is under threat and changing fast.
Polar bears are often considered marine animals.
They spend their winters out on the sea ice.
In summer, they are landlocked
and forced to search for food on the Tundra.
We all know about shrinking sea ice
and the problems it causes for the bears,
but it's changing things for them on the Tundra as well,
with both summers and winters milder
than they have been for millions of years.
The Tundra is not as inhospitable
as it used to be.
Creatures less adapted to the poles are able to move in.
Grizzly bears are making themselves more at home
in the extreme north, and they can breed with polar bears.
Their offspring known as pizzly or grolar bears
are diluting the polar bears pure gene pool.
Arctic foxes face a similar problem
where once they had the monopoly,
truly the only small predators
that could handle life on the Tundra,
now they have competition,
an invasion of red foxes.
And these larger, more wily cousins will drive them off,
out competing and in some places
reducing the Arctic fox population.
It's not just animals, plants like trees and bushes,
are able to grow much further north.
The Tundra is being modified,
the impact of which will be felt all over the world.
(air whooshing)
For several million years
the Tundra has been a carbon sink.
Carbon collected from the air by plants
is transported into the ground.
But because of the permafrost, plant remains are frozen,
they can't rot, so the carbon can't be released.
(water splashing)
Now, because of climate change,
the Tundra's permafrost is melting more and more every year.
(birds whistling)
Thousands of years worth of stored carbon is being released.
(water splashing)
And worse still, because the Tundra is so boggy,
a lot of the rotting takes place in low oxygen bulks,
where instead of carbon dioxide, methane is released.
(water dripping)
(air whooshing)
Carbon dioxide is a major greenhouse gas,
but methane is 25 times worse.
And the release of all this Tundra gas
will just fuel the change, accelerating global warming.
(soft music)
The Tundra has always been a carbon sink
containing one and a half times the carbon
of our entire atmosphere.
But it's melting is flipping this great asset
from a carbon sink to a carbon source and a great threat.
(water splashing)
All of us should be very worried about the impact
of the Tundra's health on the world's climate,
which is already unstable and threatening all life,
including ours.
(soft music)
And for the wildlife of the Tundra,
it already has enough to deal with
just trying to make it through the year,
living in the most challenging habitat.
The growing season on the Tundra lasts only two months.
In the blink of an eye, the evenings are creeping in.
Change is in the air. (birds cawing)
The Tundra provides wealth
for those willing to tough it out,
and in a final act of generosity, produces a sea of berries
just in time for the ground squirrels to bulk up.
The Arctic fox's cubs are all but ready to leave home
and are figuring out
what they can and can't eat on the Tundra.
(soft music)
Muskox are probably off the menu,
but still it's fun to wind these giants up.
The rich carpet of mosses, lichens, and fungi
have also fueled the muskox herd,
(Ox sniffing)
energy they now need for their rut.
Sharp horns point forwards
and a horny boss, a massive matted hair
forms a crash helmet and shield to absorb any blow,
which is just as well.
Let the games begin.
(upbeat music)
But soon waves of sleet put a cooler on their games.
(soft music)
(air whooshing)
The days are getting shorter.
It's time for most species to escape.
(bird cowing)
Birds head south, lands begin to wither under the frost.
Cocooned in their mossy nests,
the ground squirrels slow their metabolisms,
ready to skip the winter in their peaceful slumber.
(soft music)
The tougher residents
prepare for another long, dark, lonely winter.
(soft music)
And the lemmings literally laying the foundations
of the Tundra, both through the food chain
and ground fertilization, carry on like normal,
but under their sky of snow.
As darkness claims the Tundra once again,
these hardy and iconic animals face an uncertain future,
especially if they can't count on us
to reduce our impact on the environment,
and to their Tundra home.
(soft music)