The Ice Retreats Life in the Freezer

It's September - early spring in the southern hemisphere.

The Antarctic continent is encircled by sea-ice

that extends for hundreds of miles northwards around its coasts and encloses all but a few islands.

These ice-free islands, like South Georgia, are very precious,

for here the sea never freezes and any sea-animal that needs to, can always get ashore.

First to return each spring are the bull-elephant seals.

They are about to land on a breeding beach

and each one knows that when he does, he will have to face rivals.

A full-grown male weighs over three tonnes.

Half the world's population will come here, 8,000 to this beach alone.

This immense gathering of elephant seals extends for two miles along this beach.

It might appear to be totally disorganised, but there is a pattern to it.

All these are females, they came ashore about a month ago to pup,

and now they're ready to breed again.

And they all belong to this one male.

This is a beach-master and there are a dozen or so like him spaced out along the beach.

Each one of them has his own harem and I estimate that this one has about a hundred females in his,

and his sole object in life at the moment is to make sure that he, and he alone,

mates with every single one of them, and to do that he must fight.

He's won. But he'll have to battle many times every day if he is to keep control.

The females gave birth soon after they arrived.

They now have three weeks in which to feed their pups

before they themselves have to go back to sea to feed.

In that short time, they have to transform a near-empty bag of skin

into a full bag of blubber.

As they come to the end of suckling, the females become sexually receptive again.

That is the moment the beach-master has been waiting for.

But while he is busy,

a rival is also busy on the edge of the harem.

That can't be tolerated.

A roar is enough. The interloper retreats.

But many conflicts will only be settled by violence.

Males get ripped - and those that get in the way

are likely to get crushed.

Every now and then, the beach-master proclaims his dominance with a roar.

The bigger the bull,

the louder and deeper his voice.

A rival can judge from it whether or not he has a chance in a straight battle.

If he's going to persevere with his challenge, he must now fight.

The pair rear up to over 8 feet.

Their only weapons are their teeth,

but they can do a lot of damage with them.

The hide on the neck is particularly thick and prevents serious injury.

A bout can go on for quarter of an hour. Eventually, the battle is brought to an end by exhaustion.

On the grassy slopes above the battleground, the scene is more peaceful.

Black-browed albatross are returning from the sea.

Grey-headed albatross are here too,

hanging on the up-draughts

caused when the ever-continuing wind is deflected upwards by the cliff face.

Throughout the past winter,

these birds have been flying alone over the vast ocean, searching for food.

But now they're returning to breed and are assembling in colonies several thousand strong.

Breeding pairs from previous seasons are re-united,

and each uses exactly the same nest mound as they used before.

But it does need a bit of renovation.

Mutual grooming renews the bond between them.

Both grey-headed and black-browed albatross are faithful for life - 20 years or so -

and only need a brief repetition of their courtship ritual before they mate.

Two weeks later, the female lays a single egg

and for the next 70 days, the two take turns to incubate it.

While one keeps the egg warm,

the other flies off to feed,

and may have to travel thousands of miles before it gets what it needs.

Most kinds of albatross nest in colonies.

One special one, however, prefers a more solitary life.

Light-mantled sooty albatross are the last to return to the island.

The males come first.

One that is still unpaired settles on a ledge and calls to passing females.

Having listened to many, she eventually selects one.

The next stage in courtship involves a certain amount of nodding and dancing.

And then there follows a most beautiful,

perfectly synchronised display flight.

During the day, the skies belong to the albatross,

but as darkness comes, some nervous and more numerous birds come to the island.

Thousands of small petrels and prions fly agitatedly around the cliffs in the darkness.

Twenty-two million nest amongst the tussac-grass on South Georgia alone.

Being so small, the prions are vulnerable to attack by skuas

and for the safety of the chicks during the day, they make their nest in burrows.

Outside, the white-chinned petrels assemble.

Duetting pairs defend the territories around their burrows

that can extend two metres beneath the tussac-grass.

The chick stays safely inside the burrow for two months.

It is fed with a mixture of squid and krill.

Before dawn - and danger - all the adults will have disappeared from the island

and returned to the open ocean.

The hillside is jam-packed with macaroni penguins and virtually nothing else.

There are some 80,000 here, but even this vast assemblage

is only a tiny proportion of the total population of South Georgia,

which is estimated to be more than 10 million,

demonstrating that although the Antarctic is virtually lifeless over vast areas,

there are one or two small oases that teem with life.

After spending the winter wandering around the northern fringes of the southern ocean,

the macaronis return with remarkable punctuality.

In just ten days, this empty stadium is packed tight.

The males come first, the females a week later.

The macaroni is very much the penguin of the northern rim of the Antarctic.

Very few of them venture farther south than the subantarctic islands

but here they constitute over 50% of all the seabirds.

Now, at the beginning of the breeding season,

each pair fights noisily to hold its own tiny nest site.

Each new arrival has to make its way through a barrage of pecks from outraged nest-owners.

Macaronis must be the noisiest and most bad-tempered of all penguins

and their fights can be really vicious.

Eventually, a female finds her male and is rewarded with a greeting display,

and a comforting preen.

Ten days later, she's produced two eggs.

Remarkably, the darker, smaller one is nearly always abandonded.

Why, is not certain.

It may, perhaps, be an insurance against the loss of the bigger one.

The colony has its own squad of refuse collectors - sheathbills.

During the summer, they normally eat penguin droppings.

An abandonded, if addled egg, must make a nice change.

Sheathbills are one of the few birds here that do not rely on the ocean for food.

They are totally land-based.

All the wildlife here in South Georgia,

the penguins, the albatrosses, the seals, is virtually restricted to the outer rim of Antarctica.

Farther south it's a harsher world.

There, ice dominates.

But with the arrival of spring, the sea-ice is retreating, and animals are returning,

animals that are especially adapted to life in the frozen south.

Most of Antarctica is still locked in by sea-ice,

but as the days lengthen, so that slowly retreats.

First to be freed is the Antarctic Peninsula,

a long arm of the continent that reaches up northwards.

For a few months, it's possible to reach its coast by sea.

Antarctica is nowhere lovelier.

But even at the height of the summer, only 2% of the continent is free from ice, most of it here.

But no sea-animal will reach those distant rock slopes until the sea-ice breaks up.

Gentoo penguins are among the first to make it.

They need bare rock for their nests,

but even now it's so scarce they may have a hard climb to reach it.

These are on their way to relieve their mates

who, for the past three days, have been looking after the eggs.

The eggs were laid in November, almost a month after the gentoos' up in South Georgia.

There's no soil or vegetation to make a nest,

just a few small stones.

And even the stones are in short supply, and may have to be 'borrowed'.

Nobody likes to see their nest disappearing from beneath their feet.

But when thieves come from all sides, there's not much you can do.

After five weeks of incubation,

the chicks start to hatch.

Unlike the macaronis, both the gentoos' eggs hatch.

For three weeks the adults protect them from the cold.

They take turns to bring meals of small fish and krill.

The labour of doing so is enormous. The snow slope has to be traversed,

and penguins were not designed for skiing.

As spring advances, more and more of the Peninsula becomes ice-free,

and humpback whales appear along the coast, seeking krill.

The sea-ice, as it disintegrates,

forms a sort of soup of loose blocks.

This is the pack-ice. The whales will go no further.

At its outer edges, the pack is easy to get through,

but further south, the floats become bigger and more closely-packed.

Only the most powerful ice-breaking ships can force a passage

through the vast band of broken ice that rings the continent.

In places, it's 200 miles across.

This - surprisingly - is home of the most numerous large mammal in the world,

apart from man:

crab-eater seals.

Up to 30 million live around the continent in this in-between world of ice and water.

Here they rest, and here the pup. They never come to land.

Despite their name, they live on krill.

They sieve sea-water through their interlocking teeth

and consume 20 kilos of it every day.

Even farther south, beyond the pack ice,

there still remains mile after mile of winter ice that has not yet broken up.

Very few creatures can get across this to the land beyond. But one does.

The adelie penguin breeds farther south than any other penguin.

They can't wait for the ice to break, and have to walk.

In some years they march for over 60 miles to reach their traditional breeding grounds.

The Antarctic summer is short indeed. They must hurry.

Their journey is remarkable enough. But one creature makes an even longer one.

Snow petrels are smaller than pigeons.

Yet they fly across ice that never melts

and climb to altitudes of 3,000 metres

right up and onto the vast Antarctic ice-cap.

Here, over an area larger than Australia, the ice is several miles thick.

Only the summits of the tallest mountains project through it - as nunataks.

These few tiny patches of rock, isolated in a sea of ice,

are as precious as an oasis in a desert.

Only 2% of the continent is ice-free, most of it near the coast.

But snow petrels can't lay their eggs on ice,

They have to find bare rock.

One of their nests was found on a nunatak like this 144 miles from the coast.

Snow petrels bring life to this, the most lifeless part of our planet.

They breed farther south than any other bird.

Even at the height of summer, temperatures don't rise above minus 30 degrees.

There is no unfrozen water and they have to bathe in snow.

As soon as the winds have swept the bulk of the snow from the higher rock slopes,

the snow petrels take possession of them.

But even then, there is much to do.

They may have to excavate a metre of snow to find a nest site that suits them.

In the coming season, they will have to make the journey of over 200 miles back to open water,

again and again, to collect food for their chicks.

But with their arrival, spring has at last come to the deep south.

Subtitles by Wilma Campbell BBC Scotland 1993