Life in the Freezer (1993) s01e03 Episode Script

Summer in Antarctica,
and the seas around the outer islands
are teeming with life.
Fur seals are streaming in their thousands
to their traditional beaches
on the island of South Georgia.
It's November,
and the race to breed has started.
Some bull seals have already
claimed territories on the beach
and are prepared to defend them
against all comers.
You have to be fairly cautious
how you approach Now, now!
these big bulls,
because they have very sharp teeth
and can be extremely aggressive.
At the moment,
there's not much problem with them,
but in two weeks I wouldn't dare
set foot on this beach,
because by then all the females
will have come ashore too
and there will be over 100,000
fur seals on this one beach.
Each dominant bull in this dense
and seemingly structureless crowd
rules over a territory
of about 30 square metres,
enough to accommodate about a dozen females.
The frontiers between these territories
are invisible to our eyes,
but very clear to the bulls.
When neighbours meet face to face
across a boundary,
they put on a ritualised display of force,
but won't fight as long as each stays
on his own side of the frontier.
The heavily-pregnant females
arrive two or three weeks after the males
and head for the prime territories
near the high-water mark.
Only if these are fully occupied
will they join ones lower down the beach.
By December,
over a million Antarctic fur seals -
95% of the world's population -
have landed here on South Georgia.
One or two days after their arrival,
the cows give birth.
Each baby is greeted
by a flock of hungry skuas,
keen to feast on the afterbirth
that comes with it.
A mother will refuse to be parted
from her vulnerable pup
for the next seven days.
The pups grow rapidly on the rich fatty milk
and double their weight in 60 days.
It will be eight years
before they have to fight for territory.
This is just play.
The bulls must now be on their guard,
for the females
are becoming sexually available
and, offshore, males without
territories are hanging around.
They keep a sharp eye out for
a weakened bull or an abandoned territory,
and will dash ashore to claim it
if they see a chance.
Once they've got a territory,
they can mate with its females.
Lots of these young hopefuls
wait in the shallows.
One of them thinks he sees his opportunity.
(AGGRESSIVE BELLOWING)
No luck. He's not big enough - yet.
The urge to breed is so strong
that there is always some youngster
prepared to try his luck
and, three or four times every day,
there are major battles on the beach.
(DIN OF BELLOWING AND SNARLING)
These fights can be really damaging.
Most territory-owning bulls
carry severe wounds.
Their flippers get split,
their necks badly gouged.
Mothers try to keep their pups
out of harm's way.
Another challenger concedes.
But he's still in trouble,
for he'll have to dodge other outraged bulls
on his way back to the sea.
Although few are actually killed
during these fights,
many will die later from their wounds
or from sheer exhaustion.
By Christmas, in the middle
of the Antarctic summer,
breeding is over and the battles
on the beaches have largely come to an end.
But further south, the race to breed,
having started later,
is still in full swing.
Chinstrap penguins are returning
from their feeding grounds, 20 miles offshore,
to feed their chicks.
Now, in midsummer,
there is almost 24 hours of daylight,
and here on Deception Island
there is continuous traffic from the beach
up a two-way highway
to the nesting sites high in the hills.
Each day,
100,000 commuters make the trip.
It's nature's greatest rush hour.
The trek to the higher slopes
takes the Chinstraps over an hour.
The first obstacles they must cross
are the torrential streams
pouring from a melting glacier.
Chinstraps, like all penguins,
are tough and persistent,
and a rough and tumble
in the white water doesn't deter them.
They are accomplished mountaineers
and have elected to nest high up
on the steep exposed slopes of volcanic ash.
The stiff quills of their tails
provide invaluable support,
preventing them from slipping backwards.
Exposed ridges are the first suitable
nesting grounds to be free of snow,
and to make the best use
of the short Antarctic breeding season,
penguins will make
immensely long climbs to reach them.
(TREMENDOUS DIN OF SQUAWKING)
There are over 200,000 birds
here on Deception Island,
each pair with its own tiny nesting territory,
evenly spaced from its neighbours.
Incredibly, in spite of the din and confusion,
returning birds are able to find their nest
and partners without any difficulty,
and the reunion is always marked
with a jubilant display.
The parents will now swap duties.
The one just arrived will feed
the chicks and guard them
while the other, having fasted
for a couple of days,
will go down to the sea to feed
and collect more food for the youngsters.
Those that are nesting
on the lower slopes are lucky.
Others have to climb so high
that their nests are up in the clouds
for much of the time.
The trek down from the nest
can take another hour,
but it has to be done if the chick is to be fed.
When at last they reach the sea,
their journey, that has so far
been merely arduous,
becomes very dangerous indeed.
A leopard seal.
A single leopard seal may catch
up to six penguins in an hour.
During the season, it will kill hundreds.
A wounded bird, having escaped
almost miraculously from the seal,
must now face the merciless skuas.
In spite of its injury,
it still struggles upwards towards its nest.
The Chinstraps only nest on islands
that are released by the sea ice
early in the season.
As the summer advances,
the ice continues to retreat,
until even the edge
of the continent becomes free.
By January, at the height of summer,
there is almost continuous daylight
and along the Antarctic peninsula
temperatures regularly rise above freezing.
Fjords that were locked in ice
for the last eight months
are now littered with ice floes.
Leopard seals haul out to bask in the sun.
Now, for a short time,
Antarctica's wildlife can afford to relax.
With temperatures climbing,
snow and ice turns into Antarctica's
most precious commodity -
fresh water.
And that makes it possible
for the continent's sparse
vegetation to resume its growth.
Banks of moss are the home
of a whole population of tiny animals.
Deep within the crevices, ice still remains,
imprisoning some
of the hardiest creatures on Earth -
the only land animals
that can survive the Antarctic winter.
Barely larger than a pinhead,
these tiny mites
contain a natural anti-freeze
that allows them to supercool
to minus 30 degrees centigrade.
As the ice disappears, they come to life.
These minute creatures
have no fixed breeding season.
They're opportunists
and reproduce whenever temperatures
creep above freezing.
Often thousands cluster together.
Most are herbivores
that feed on the moss and dead vegetation.
But they themselves are food
for a few tiny carnivores.
Hunters and hunted -
this is Antarctica's own miniature Serengeti.
In just a few places, there is enough
meltwater to create freshwater ponds.
They are havens
for another range of invertebrates -
little crustaceans and insect larvae.
Green is a rare colour
on the Antarctic continent,
for moss can only grow
where there is both fresh water and soil.
But one kind of vegetation
manages to survive on bare rock alone -
lichens.
They are able to dissolve rock
and extract nutrients from it.
But that takes a very long time,
especially at these low temperatures.
Growth is incredibly slow.
A miniscule forest like this
may have taken centuries to reach this size.
(WHISTLING WIND)
I am now a thousand miles farther south still.
The South Pole lies about 800 miles over there.
If I was as far away as that from the North Pole,
I would expect to find among these rocks
at least a hundred different species
of flowering plant.
In fact, in the whole of Antarctica,
only two species
of flowering plants have been found,
and neither of them grows as far south as this.
All that grows on these rocks
are tiny lichens like this.
One or two species of moss
occur in these latitudes,
but otherwise only lichens
grow farther south than this -
and some of them get
to within 200 miles of the pole.
Antarctica's commonest organism
is not a lichen but a plant - an algae.
It lives in the snow
and paints great areas of it bright pink.
In summer, the melting snow
releases the algae into the sea.
Just off-shore,
icebergs, moving back and forth with the tide,
are also disintegrating.
All these changes
release minerals and nutrients.
Suddenly, the inland waters become very rich
and floating algae - phytoplankton -
bloom in vast clouds.
Icebergs scouring the sea floor
make things difficult for life of any kind,
but in sheltered areas and deeper water
there is a surprisingly large
and varied community of sea creatures.
Life here, in temperatures
close to freezing, is very slow.
An individual sponge or starfish
may live for over 40 years.
There are fish here, too,
and blue-eyed shag dive down
to depths of over 100 metres
in search of them.
(CRIES OF MANY BIRDS)
The shags' feeding grounds
are never far away from their colonies
on the few rocky crags that are free of snow.
Uniquely among Antarctic birds,
their chicks hatch without down
and at first rely totally
on their parents for warmth.
(FRENZIED CHIRPING)
Many of these chicks may die
if the summer storms are severe,
but shags, like most Antarctic birds,
are long-lived and the pair will produce
many young during their lifetime.
Blue-eyed shags don't nest along
the southern part of the Antarctic peninsula
because there is very little open water there.
But one bird is not daunted by that.
Antarctic terns patrol the bays
in search of small crustaceans and fish.
Their breeding season is long,
and even in late summer,
chicks are still hatching.
In some years,
bad weather and predatory skuas
cause heavy losses of eggs and chicks,
but Antarctic terns have the rare ability
to lay two or three times in a season.
Not until February,
the very height of summer,
does the winter sea ice
finally retreat to its minimum extent
and release isolated outcrops
of rock in the deep south.
This is the Scullion monolith,
one of the very few areas
of bare rock for many miles around,
and here, 300,000 Antarctic petrels
come to breed.
Adelie penguin colonies,
that in the spring were cut off
from the sea by miles of winter sea ice,
are now directly accessible to open water,
and adults, with hungry chicks to feed,
can at last swim directly back to the beaches
although some, rather optimistically,
decide to stop for a rest on the way.
There is now
constant activity on the beaches
as both adults must collect food
to satisfy the demands
of their well-grown and ever-hungry chicks.
Returning adults have to find their chicks
amongst hundreds of others
But a chick can instantly recognise
the call of its parent,
and a mad steeplechase
that can last several minutes
helps to separate
the rightful chick from imposters.
The strongest chick of a pair
is always fed first.
In years when food is scarce,
younger chicks are rarely fed,
and skuas are constantly
on the look-out for such weakened birds.
Repeated harrying from above
sends panic through the colony.
Many penguins are forced
to regurgitate their meals
and the skuas feast on the spilt krill.
Small unattended chicks
are quickly attacked.
As the pressure
to complete breeding increases,
there is a constant battle
between penguins and skuas.
This time, the chick is lucky.
Attacks by skuas are very nasty and brutal
but are not the main danger to the colony.
Adelies always choose
very windy nest sites.
Breeding so early in the season,
they rely on the wind to clear away the snow
because they can only
lay their eggs on bare rock.
Now, at the end of the season,
they pay the price.
Soon, the sea will re-freeze
and autumn storms will cover
the bare rock with snow.
In our next programme,
we will watch as wildlife
hurries to finish breeding
before winter really takes hold.