"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 that wait patiently in crèches." "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 that stray from the crèche 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."