The Race to Breed Life in the Freezer

Summer in Antarctica - and the seas around the outer islands are teeming with life.

Fur-seals are streaming in their thousands to their traditional breeding beaches

on the island of South Georgia.

It's November and the race to breed has started.

Some bull-seals have claimed territories on the beach and will defend them against all comers.

You have to be fairly cautious how you approach... Now, now, now!

..how you approach these big bulls because they've got very sharp teeth and can be extremely aggressive.

At the moment, it's not too bad,

but in two weeks, 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 thirty square metres which will accommodate about a dozen females.

The frontiers between these territories are invisible to us, but very clear to the bulls.

When neighbours meet face-to-face across a boundary, they put on a display of force,

but they won't fight if 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 full will they go lower down.

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 watch 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 an opportunity.

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.

Three or four times a day, there are major battles on the beach.

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 killed during these fights, many will die later from their wounds or from exhaustion.

By Christmas, in the middle of the Antarctic summer, breeding is over, as are the battles on the beaches,

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.

Here, on Deception Island, there is continuous traffic from the beach

up a two-lane 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 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 both tough and persistent.

A rough-and-tumble in the white water doesn't deter them.

Accomplished mountaineers, they have elected to nest high up on the steep exposed slopes of volcanic ash.

The stiff quills of their tails provide 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.

There are over 200,000 birds on Deception Island,

each pair with its own tiny nesting territory, evenly spaced from its neighbours.

PENGUINS ARE IN FULL VOICE

In spite of the din and confusion,

returning birds are able to find their nest and partners without any difficulty.

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 young.

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, so far, has been merely arduous

becomes very dangerous indeed.

A leopard-seal.

A single leopard-seal may catch up to six penguins 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 antifreeze

that allows them to supercool to minus thirty 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 melt-water 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 freshwater and soil.

But one kind of vegetation manages to survive on bare rock alone - lichens.

They can dissolve rock and extract nutrients from it,

but that takes a very long time, especially at these low temperatures.

This miniscule forest may have taken centuries to reach this size.

I am now 1,000 miles further south still.

The south pole lies about 800 miles over there.

If I was that distance from the north pole,

I would expect to find among these rocks at least 100 species of flowering plants.

In the whole of Antarctica, only two species of flowering plants have been found.

Neither of them grows this far south. 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.

Some of them get to within 200 miles of the pole.

Antarctica's commonest organism is not a lichen but a plant - an alga.

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 offshore, 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 large and varied community of sea creatures.

Life here, in temperatures close to freezing, is very slow.

A sponge or starfish may live for over 40 years.

There are fish here too.

Blue-eyed shag dive down to depths of over 100 metres in search of them.

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.

Many chicks may die if the summer storms are severe, but shags, like most Antarctic birds, are long-lived

and a 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 the 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 Scullin Monolith, one of the few areas of bare rock for many miles.

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.

The adults, with hungry chicks to feed, can 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 that wait patiently in creches.

But a chick can instantly recognise the call of its parent.

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 that stray from the creche 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 they are not the main danger to the colony.

Adelies choose windy nest sites.

Breeding so early in the season, they rely on the wind to clear away the snow

as they can only lay their eggs on bare rock, but now, at the end of the season, they pay the price.

Soon the sea will freeze and autumn storms will cover the rock with snow.