Alyeska: The Great Land (1986)

[Music] [Music] Oh [Music] hi I'm Jorge page for nature Alaska is a land of superlatives it's the largest state in the Union over twice the size of Texas it has the highest mountain Mount McKinley more than 3 million Lakes and over a hundred million acres of forest as well as reaching further north than any other part of the United States it's also a land of breathtaking beauty and it's a refuge for many animals that are rapidly disappearing from the lower 48 states maybe because Alaska's human population is still small roughly only one person a square mile yet Alaska doesn't teem with many different kinds of wildlife the extremes of climate have seen too that the plants and animals have had to adapt and specialized to ensure their survival and the dependence of each on the other can often be seen more clearly in Alaska than anywhere else [Music] winter comes abruptly to Alaska the place the Aleut Indians named Alaska the great land [Music] [Music] winter is a long hard test of survival for plants and animals snow cover and freezing temperatures may last for eight months in September just before winter settles in moose gather for the rut that decides which Bulls sire the next generation willow ptarmigan are among the very few birds that stay to face winter they've gathered into flocks and have started to change into their white winter plumage which blends with the snow and helps them avoid predators plant activity has effectively retreated underground plants survive by storing sugars in their roots as snow accumulates the grizzly bear digs them up high energy food for its long winter sleep in a few days this pregnant female will retire to an underground den deep sleep is her way of surviving the winter it makes fewer demands on her stores of energy moose are the largest deer in the world antler size signals a Bulls rank to other males the fittest mature Bulls have the largest racks and this sign of authority is respected by younger bulls the dominant bull in an area attracts a harem of cows around him he regularly digs a shallow pit into which he urinates this excites the cows his urine contains hormones that arouse them and probably help synchronize their breeding condition until his cows come into heat he must ward off the attentions of all neighboring bulls rival bulls with equally massive antlers pose a serious challenge to his dominance which is met head-on the loser retreats fights are trials of strength to decide which bow mates with the most cows the victorious bull cautiously checks the sexual readiness of one of his cows inhaling her odor is part of this procedure the cow moans because she's not quite ready a receptive cow lingers the bull gently taps her rump with his chin to get her used to his presence each cow is in heat for only 24 hours and is mated only once each year copulation is over in seconds moose live mainly in forested areas Alaska spruce forests form part of the vast conifer belt called taiga that circles the world's northern regions the most extensive least disturbed forests on earth and an Alaska bounded by some of the most majestic mountains [Music] [Music] [Applause] [Music] at the height of the last ice age 17,000 years ago much of North America was engulfed by glaciers shown here in blue the animals and plants and their paths were wiped out or pushed south in Alaska however sparse snowfall prevented the ice from covering two large areas which served as refuges where moose and other animals survived to recolonize the North when the ice sheets retreated today what was the northern of these refuges is now the North Slope treeless plains called tundra extending to the Arctic Ocean the Brooks Range divides the North Slope from the other former Ice Age refuge the Alaskan interior wedge between two great mountain ranges it's mostly covered by spruce forests the caribou like the moose survived in the unglaciated areas of Alaska now as winter sets in they migrate south from the North Slope and to the relative shelter of the Interior forests here they are forever on the move in search of food mainly lichen which covers the ground and much of the interior by October willow ptarmigan have almost completed their change of plumage they have a highly specialized diet nearly all of it consists of willow buds willows are the most widely spread in successful shrubs in northern regions and ptarmigan have adapted to exploit this abundant source of food they feed mainly on the ground and avoid flying the saving energy there at home in the snow up-up-up up oh they're so at home in it that they will even roost under the snow at night where they're better insulated against the bitter cold the Moose rut is over the cows are carrying new life to survive the winter moose depend on their reserves of accumulated fat cows are more likely to survive than Bulls the dominant Bulls especially are at risk they've already drawn heavily on their fat during the exertions of the rut this bull may have mated with many cows but this has placed his own survival in doubt he has no chance of replenishing lost energy reserves until fresh greenery is available again 8 months from now at the end of the long Arctic winter [Music] [Music] [Music] surprisingly under the snow brown lemmings remain active they tunnel through the snow in search of food the blanket of snow protects them from the driving wind and cold outside where the air temperature can be 75 degrees below zero under the snow it rarely falls much below freezing the flower buds of cotton grass provide an important winter food for limbing they were produced by the plant before winter and are packed with nutrients lemmings are one of the very few animals which may actually breed in the depths of the Arctic winter if there's a good supply of cotton grass and willow buds [Music] you [Music] three weeks later new life arrives in a nest beneath the snow lemmings are prolific breeders and every three to five years their numbers increase dramatically but a population explosion is quickly followed by a crash because the lemmings dwindling food supply cannot support them in such numbers some however always survive to raise a new generation under the snow [Music] it's April and the days are rapidly growing longer the caribou start their Trek northward this is their most urgent journey it's led by pregnant cows who must make their way hundreds of miles to the North Slope where they will give birth what actually triggers the migration is still a mystery involving many environmental factors their migration North usually begins before the spring thaw turns the snow soggy and difficult to walk through this helps conserve energy while the snow stays powdery progress is fairly easy especially walking in single-file stepping in the tracks of the animal in front passing over the mountains they seek out areas where the wind has blown away most of the snow making both travel and feeding that much easier often their route takes them thousands of feet up into the Brooks Range [Music] the warmth of spring gradually releases the land from snow melt water streams drain into valleys and swell the rivers placing strings on their mantle of ice [Music] [Music] [Music] you you [Music] the willow flowers one of the first plans to respond to the longer days of spring willow ptarmigan are still feeding on willows but now they prefer the catkins which contain more sugar than the buds the winter flocks of ptarmigan have disbanded now each male establishes and proclaims his territory [Music] intruding males are aggressively repelled the winning mail returns to his mate she has already changed into her camouflaged plumage which matches the ground where she will soon nest the male stays conspicuous for longer which helps advertise his presence to rivals as the land is released from the grip of winter the first geese arrived they spearhead a massive influx of migrants that come to breed here in the mountains the female grizzly has emerged from her long winter sleep and with her are two three-month-old Cubs this is the first excursion into the world outside the underground den where they were born their exuberance is clear Grizzly's eat almost anything their diet changes with the seasons as different food becomes available in early spring there are succulent roots to feed on for the first few months she keeps to high ground avoiding the valleys and the male bears that prefer to feed their males have been known to attack and eat young cubs she's an extremely attentive mother play is often a prelude to nursing she will suckle her cubs several times a day for up to two years until they're fully weaned in the valleys a mass of fresh greenery appears in early summer the cow moose gave birth to her twin calves just as the young leaves began to open now especially after winters lean months she needs plenty of nourishment for herself and for them she browses mostly on leaves but she also eats bark it's calcium content enriches the milk for her calf plants make the sun's energy edible all plant eaters depend on this northern plants have a very short three-month growing season and the moose have had to adapt to it they must eat constantly not only to supply their daily energy needs but also to replenish their fat reserves where they consume in this short time will sustain them for the whole year baby moose stick closely to their mother the Spyder size they are still vulnerable to predators many of them are killed by Grizzlies this male will eat everything except the scannin hooves in early June summer in the interior is well underway but further north it is yet to begin the geese are nearing the end of their journey from the south flying between peaks of up to 9,000 feet they cross the great barrier of the Brooks Range 700 miles long and 50 miles wide it divides the Alaskan interior from the North Slope the geese have come to their tundra nesting grounds braving the spring snowfall from as far away as Mexico they're drawn by the promise of abundant summer grazing and must hatch their young and time to take advantage of it these white-fronted geese mated during their journey so the females are ready to lay within a week of arrival but everything is governed by the unpredictable weather while there's snow on the ground she can't nest the longer she has to wait the fewer eggs she'll lay and in a bad year she might not lay it all the pregnant caribou have also crossed the Brooks Range and arrived on the North Slope to calve after snow melt much of the North Slope is a vast waterlogged plain a foot or so below the surface the ground is permanently frozen permafrost as hard as concrete it extends to depths of up to 2,000 feet the shallow soil layer cracks as it thaws and refreezes each year meltwater cannot drain through the permafrost and collects in countless ponds and lakes all this shallow water is of great importance to one tiny life-form billions of mosquito larvae have hatched from eggs that survived winter frozen under the snow and ice although they're individually minut collectively they'll have a massive impact on the life of the tundra virtually all the caribou calves are born within a week of each other they're nourished by the richest milk produced by any land mammal and they grow amazingly fast within days they're able to keep up with their mothers as they travel towards the North slopes rich summer grazing areas the Bulls traveled separately but now they all come together to feed during the long daylight hours with only about three months to complete their lifecycle tundra plants grow very quickly even on soil chilled by the underlying permafrost their rapid growth is possible because in the summer the Sun never sets [Music] throughout winter the roots held stores of nutrients now they pump them into leaves and flowers the tundra becomes a carpet of nutritious young plants which attract fantastic numbers of caribou [Music] [Music] [Music] as many as 200,000 mass on the north slope and one of the greatest natural concentrations of grazing animals in the world many species of shorebirds breed on the North Slope they all migrate thousands of miles to do so when they're nesting in the open Tundra they must be well concealed from predators the northern phalaropes nest is hidden within a dense grass tussock other birds are beautifully camouflaged like the buff breasted Sandpiper to avoid attracting predators the semi palmated Sandpiper warily walks to her nest instead of flying nearby a parasitic Jaeger settles on her nest parasitic Yeager's prey mainly on the eggs and chicks of other birds they are bold and conspicuous creditors of the tundra on one warm day in late June and ponds all over the tundra adult mosquito start forcing their way through the water surface the North Slope becomes a vast mosquito hatchery within hours the tundra is swarming with millions of mosquitoes [Music] as mosquitoes take to the wing thousands of shorebirds are hatching their breeding is perfectly timed so that the eggs hatch just when the first swarms of adult and sexy marriage the ruddy Turnstone chicks have also hatched out and like all the shorebirds they must fend for themselves immediately they're never fed by their parents they can't fly yet and don't have the probing bills of the adults all these different chicks are totally dependent on an accessible supply of insects primarily mosquitoes that simply can be pecked from the vegetation the abundance of insects explains why such a diversity of shorebirds fly so far to breed on the North Slope this golden plover has flown more than 8,000 miles from Argentina to raise her brood here while her chicks are wandering around looking for food they're vulnerable to predators like this parasitic Jaeger the male does all the hunting for his mate and the newly hatched chick on returning to the nest he regurgitates the prey whole this is much too large to be fed directly to the chick so the female pulls it into pieces which she then swallows later she coughs up the half-digested pieces whenever the chick becomes hungry the male has to work hard to satisfy the chicks appetite but eating is hard work - this is the territory of the rough leg Hawk they nest on cliffs overlooking the flat plain of the tundra the female alight on her eye Lee and shades her young chicks from the heat of the midsummer sun's she's waiting for her mate who is out hunting he leaves the prey and resumes the search for food the female divides it among her chicks rough leg Hawk sometimes catch young birds but they hunt mainly for lemmings and voles [Music] on the plains the mosquitoes are still hatching the female mosquito requires a rich meal of blood to speed the development of her eggs on warm still days mosquitoes swarm and with no wind to prevent them they settle on the caribou which close ranks and head off to seek relief from the intolerable irritation of thousands of bites at the height of the mosquito season a caribou can lose up to a quart of blood in a week deer grazing is interrupted so much they become undernourished and weak the mosquitoes drive the caribou to the shores of the Arctic Ocean here cool winds blowing off the melting ice pack help disperse the mosquitoes [Applause] [Applause] [Applause] in extreme cases the caribou are forced offshore right into the sea to seek relief by August shorter days signal the end of the brief flowering season now plants must produce their seeds like the cotton grass [Music] [Music] the mosquitoes have lay their eggs and died now the caribou are free to move away from the coast and dispersed inland to lush grazing pastures they must feed unceasingly to restore their strength for the travels of autumn to put on fat to see them through the winter they drift slowly south toward the interior making their way back into the foothills of the Brooks Range with the arrival of autumn on the North Slope most of the animals have left the green of summer disappears as plants draw nutrients from their leaves and store them in roots the tundra flushes with color the weather deteriorates rapidly on the North Slope clouds and freezing mist swirl into the Brooks Range for a short while the mountains will shelter the interior from the onset of winter in late summer flying squirrels feed mainly on fungi under the forest floor truffles are fruiting these fungi are related to the prized European truffles but they're not nearly so tasty to humans because they're underground they can't disperse their spores into the air but they give off a distinctive scent irresistible to the flying squirrel the squirrel digests the truffle and later excretes the spores truffles like many forest fungi are essential for the healthy growth of the trees the flying squirrels extraordinary gliding ability ensures that the truffle spores are dispersed through the forest and this way the flying squirrel helps maintain the health of the forest upon which its own survival depends by September the antlers of the bull moose are fully developed they're shed and regrown each year the made of bone and while they're growing they're covered in a velvety sheath of skin when the antlers have finished growing the velvet shrivels and is rubbed off two bulls are half-hearted practicing for the serious rutting duels which begin in order [Music] you [Music] many Arctic animals do not hibernate those which remain active in winter must store enough food to see them through the red squirrel sets about it with feverish urgency they cut thousands of spruce cones for their winter food supply and toss them from the treetops the cones are full of ripe seeds and our stockpiled and a network of underground chambers where the squirrels live during the winter in the mountains a [ __ ] a relative of the rabbit is also busy preparing for winter but always alert for predators like the golden eagle once the danger is past the FICA can get on with cutting grasses and herbs again he counties each mouthful back to his home under a jumble of rocks here he stacks the cuttings and loose piles he must gather enough winter fodder to last about eight months he turns his harvest to dry it in the Sun and then stores it deep inside the rock pile the snow line creeps inexorably down the mountains as autumn progresses the grizzly bear scours the hillside looking for food since their emergence in spring her Cubs have greatly increased in size and have grown a thick winter coat they will sleep with her in the den this winter before leaving next year to fend for themselves berries are essential for the Grizzly because they are rich in sugars that can easily be converted into layers of fat this provides the energy Grizzlies need to keep warm during their long winter sleep having crossed the Brooks Range the caribou make their way into the interior the great summer herds have disbanded strung out over wide areas as the animals filter back toward their wintering grounds there are excellent swimmers and usually cross the rivers and their paths easily [Applause] [Applause] [Music] [Applause] caribou need a lot of room to survive and they cover immense distances in their unending search for food these Arctic herds roamed tens of thousands of square miles each year the health of Alaska's wilderness is reflected in the vitality of these herds winter follows themselves the temperature drops rapidly a film of ice on the river indicates that the freeze is not far away in October thousands of waterfowl such as these brant geese stopover at sheltered coastal areas of southern Alaska after leaving their tundra nesting grounds a large proportion of the world geese ducks and shorebirds breed in the Arctic there's nowhere else on earth that provides such a burst of plant growth or explosion of insect life and it's this which enables them to raise their young [Applause] the Arctic is a land of stark contrast we tend to think of it locked as it is and an icy embrace for up to eight months a year as barren and forbidding yet it supports an amazing abundance of wildlife only the extraordinary productivity of the brief Arctic summer makes this possible bathed an almost continual sunlight plants and insects are able to crowd a whole season of growth and reproduction into a few weeks time many species of birds travel thousands of miles and synchronize their breeding seasons in order to reap the incredible bounty of the Arctic summer the rapid growth of their chicks fuelled by the seasonal profusion of life prepares them for the strenuous journey south the geese fly from winter leaving behind what for the present can still be called the great land Elias [Music] [Music] [Music] you [Music] [Music] much of the state of Alaska is protected by the toughest conservation laws ever passed by Congress but as well as being America's greatest wilderness area Alaska also represents the last frontier a land of great natural resources beckoning to the prospector large and small some mistakes have already been made some ecosystems damaged but we're slowly learning about the interrelationships that operate in this delicate web of life and yet we need more knowledge and the will of the people before we can be sure that it's possible to harness the potential of the land without destroying this great northern wilderness I'm George Paige for nature [Music] [Music] you [Music] [Music] you

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Keywords: Alaska

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Length: 56min 17sec (3377 seconds)

Published: Sat Jun 06 2015