bbc黄石公园第三集英文字幕学习

1、bbc 黄石公园第三集英文字幕学习YellowstoneVolcanic wonderland .two million acres of wild space right in the heart of North America .the heat of the summer has unveiled the full of the Yellowstone wilderness and a few precious months it has blossomed .but now Yellowstone is changing ,in just a few weeks the snow a

2、nd ice of winter will be back .as the animals of Yellowstone now turn to face perhaps the biggest challenges of their year .the true value of the world s first national park is about to become clear than ever .It s late August and on Yellowstones peaks there is already adusting o fresh snow .now a n

3、ewsound marks the new season .fuelled by testosterone the bugle call of this male elk is a boast of his strength .all over the Yellowstone male elk are challenging each other for dominance .the sound of Yellowstone s autumn .they are trying to win the admiration of females and gather them into a har

4、em .only then do they stand a chance at mating with them before winter .but the female are not yet in season so they are not really that interested .and for now they have a more practical concern .winter will soon be here .they are eager to head down to lower ground before the snow comes in earnest

5、.some will move down into nearby valleys whilst others will journey much further even beyond the Yellowstone itself .Yellowstone is deep in the Rocky Mountains of North America an isolated high plateau defended by rugged peaks .in the middle is the national park .the park and the surrounding mountai

6、ns from one of most important and spectacular wilderness areas on Earth .in just two months this great plateau will become a deep freeze once more .before then the animals of Yellowstone will have to get ready or get out .but for below the snow-dusted peaks summer is lingers in the heart of Yellowst

7、one .the sun revitalized this place and now there are more leaving things here than at the any time of the year .the summer has brought visitors too who are enjoying Yellowstone at its most vibrant .as the sun now starts to gets lower in the sky the rich colors make this one of the best times to see

8、 the geysers .on the grassland the good times are already over .this bison are making the most of the grazing but is now dry and parched .from now on they will have to rely heavily on stored fat to keep them doing as these meadows become covered in more than four feet of snow .others are already thi

9、nking of leaving .pronghorn evolved to outrun a now-extinct North America cheetach so they are the fastest antelope on Earth .but unlike bison their lig htweight bodies can t store enough energy to keep them here through thewinter .so now they must head out .their journey will be the longest of all

10、.but as many are preparing to get out , some have no choice but to stay .in the remote north east of Yellowstone wilderness are the beartooth mountains .her surviving above 8000 feet a tree now welcomes the change of season the whitebark pine .all summer these trees have been soaking up the energy o

11、f the sun preparing foe this moment .nowthey offers the animals of Yellowstone a bumper crop of pine cones .the whitebark pine is gambling on the fact the animals now all the food they can get before winter and is hoping it can entice them to spread its seeds far and wide across Yellowstone .so insi

12、de the cones it has put tasty nutritious pine nuts .a pine squirrel .it snacks on a few of the nuts to keep going and then buries them one by one in a sheltered hollow beside the tree .if it hides them well and packs them carefully they should last through the winter .but this is not much good for t

13、he tree .it seeds have gone nowhere .a grizzly mother and cubs .it sunusual fora grizzly to have so many cubs .this mother has found two orphans and adopted them .but now she has four cubs to fatten up before they go into the den to hibernate this winter .she is after pine nuts too .they are 50% fat

14、 .in a good year a grizzly bear can put on five pounds a day eating nuts alone .if squirrels have done the hard work it doesntmatter that grizzlies cant climb trees .thesquirrel will just to start again .luckily this year the trees arebeing particularly generous .a clarksnutcracker .this is what the

15、 has been waiting for .with its perfectly-shaped beak it prises the nuts from the cones and tucks them one by one into a special pouch under its tongue up to 150 at a time a fifth entire body weight .then it flies as much as 15 mils away and drills the nuts into the ground in sets of 10 placing a st

16、one on top of the stash to mark the site .it goes back for more and more .over theautumn a single bird can bury 30000 nuts across an area of 100 square miles .when the winter comes it will manage to remember the location of a staggering 70% of these seeds even when hidden beneath the snow .but as th

17、e clark s nutcracker remembers its way into surviving thewinter it becomes the whitebarks greatest ally .although its featof memory is extraordinary forevery 1000 seeds it buries it still forgets 300 .for all thosemissed seeds carried far and wide across Yellowstone new whitebark pines wil l germina

18、te next spring .its now September and the elk havemade their way down to graze where the grass on the river banks is still green and they can browse the nutritious shoots of young willow trees .the males are now upping their game .this bull urinates on himself to increase his masculine appeal and by

19、 thrashing his antlers to decorate them .he hopes to make himself look more impressive .the females are paying a little more attention now .the bull has succeeded in gathering a fair-sized harem .but the females are still not quite ready to mate .they are now focused on feeding as much as they can b

20、efore moving lower still .but the elk are being watched .over the summer wolves have been less mobile because of their young pups ,but their strength is building again .the elk get twitchy and head for the cover of trees .they may be a little safe here ,but the food in the forest is far less nutriti

21、ous than on the river banks .if they want to eat well and avoid wolves this winter theyll need to keep onmoving .as theelk move down gradually downwards ,they follow the river out ofYellowstone s centralplateau .the rivers in turn follow the path of glaciers that flowed from this great bowl in the l

22、ast ice age and carved their way right through the barrier of surrounding mountains .today this valleys are escape routes for animals from the returning ice of winter .lower down the valleys broaden the rivers slow and a richer variety of trees grows in the alluvial soils ,the perfect home for Yello

23、wstones mostindustrious creature .a beaver can fell a cottonwood tree in just a few hours hundreds inn a year .the beaver doesnt chew through the wholetrunk just enough to make the treeunstable .it then retreats and lets the wind do the rest .it cuts branches into more manageable lengths and then sw

24、ims them down a network of purpose-built canals towards the dam .the pond gives beaver protection from predators and the canals allow it to forage far into the forest carrying many time sits own weight with ease .autumn is the busiest time of year beavers .it wont be soeasy to make repairs when the

25、pond is frozen over .the sound of running water is their stimulus to shore up the gaps with timber and plug leaks with mud .but the dam not only serves the beavers .moose come here from the forests around to feed on weeds that thrive in the beaver sshallow pond .the wed is rich in vital sodium that

26、the forest canteasily provide .but now thatwinter is approaching another essential role for the dam is revealed .these smallerbranches are not for fixing the dam ,theyrefor eating .the beaver secures them to the mud in the lake bottom .in just a few weeks this lake will be frozen and the beavers won

27、t be ableto cut and move trees .butthey will be able to swim right under the ice to feed from this underwater larder .moose also eat twigs and branches and often to take advantage of the beaver s hard labor .this young male isgetting a little too close to the beaver s larder .autumn is not atime for

28、 sharing .itsmid-September .as the sun drops further in the sky the aspens cottonwoods and maples start shutting down foe the winter .they now digest the green pigments in their leaves to claw back what nutrients they ca into the trunk and roots .whats left behind make the colorsofthe autumn .groves

29、of aspen all turn at the same time .each grove descended from one tree interconnected by roots color-coordinated .as cold air sinks further down from the mountains it brings autumn mist to Yellowstone svalleys .it was in the autumn of 1870 that the first official exploration party to Yellowstone beg

30、an a plan for the creation of the world s first national park ,the beauty ofYellowstone s autumn inspiring a complete change in the way we value the wild .for the last six weeks of strutting and herding male elk have eaten almost nothing .they are exhausted .this bull has donewell .he has successful

31、ly held on to his harem .and now the females are finally coming into season .but they are being distracted by another male .if a bull elk cant dominate all rivals hecant have access to the females and all his effort will have been in vain .now he must gather the last of his strength .the rival wants

32、 to take him on .the aim is to get an antler point into his neck .but they are evenly matche d .neither can penetrate the others guard .now it sall aboutpower .a well-aimed thrust or a broken neck will kill .this challenger is lucky to get off with just a parting stab in the rump .the victor returns

33、 to his females .his young will be born next spring .but the prospect are not so good for a defeated bull .after all this effort ,he will now have to wait until next autumn to try his luck again .that s if he even makes it .bull elk exhausted by the rut struggleto survive the Yellowstone winter .its

34、 now October and the winteris catching up with the elk oncemore .an early flurry of snow is a sign that its time to make adecision .to stay is to face thecertainty of snow and wolves .to go offers the chance of an easier life ,but the uncertainty of the world beyond Yellowstone .every autumn thousan

35、ds of elk do leave Yellowstone .and as they go they cross an invisible line out of the protection of the national park .here theyconfront new danger .dressed in orange to avoid each other but a color that elk can t see hunters come to thepronghornforests just around Yellowstone in October to shoot e

36、lk .elk of course have no understanding of park boundaries or of Yellowstone .to them this is simply an instinctive migration to find more hospitable land so they just keep going .beyond the ring of hunting lands the natural of forest and grass is replaced by an alien geometry .circles of irrigated

37、grass squares of maize golf courses the signature patterns of mankind .it s unlikely they ll be welcome here .by now the havepushed further than any of the Yellowstones animals .out offorests through farmland and downinto the wide prairies at the foot of the Rocky mountains themselves .their search

38、for winter grazing takes them over 100 miles to the south of Yellowstone the longest migration of any American mammal .they have made this journey every year since the last ice age .but nowadays they have a problem .their traditional winter refuges lie right above some of the richest natural gas dep

39、osits in America .the wells are no direct threat to pronghorn .but pronghorn are timid .at the slightest noise they run and when they run they run at 60 miles per hour .they evolved to avoid cheetahs nit juggernauts .trucks fences and the disturbance from the wells have put pronghorn at risk .there

40、are 1.2 million acres here ,but 75% of it has now been earmarked for gas and oil .back in the farmland the elk have found food .but this grass is notmeant for them .ranchers will tolerate elk as long as they doncompete too much with their cattle .but as the elk move in their old enemy follows them o

41、ut of Yellowstone an animal thats more difficultfor ranchers to accept .intheir minds fear of the wolf runs deep .even Yellowstone lost its wolves .they were wiped out over 80 years ago .after years of prejudice they were reintroduced in 1995 brought back by the authorities to restore Yellowstone s

42、natural balance .but the wolves have done so well that nowthey are moving out of the park looking for new territories andprey .out here it s clearer to seewhy wolves have a bad reputation .if ranchers cattle are at risk by law wolves can be shot .aswolves come back ranchers are being forced to retur

43、n to the old ways to get back into the saddleand protect their herds .but opinion is changing .working with scientists who have radio-collared the Yellowstone wolves ranchers can now keep track of them and when they know they are near shoot not to kill but to scare them away .the return of the wolf

44、will always be controversial .but evidence is now emerging that wolves are far more important than anyone imagined especially back in the heart of Yellowstone .it s nearly the end of October .the cold autumn nights havebrought a thin crust of ice to a beavers pond .unlike in the rivervalleys below u

45、p here there arenot many tall cottonwood trees .so this beaver has built his dam from the shoots of young willows sprouting all along the side of his pond .but he is something of a novelty .even by the time Yellowstone was made a national park beavers had been virtually hunted to extinction by fur t

46、rappers .they only began to reappear here in 1995 the year the wolves came back .now wolves are chasing elk again ,elk have had less time to eat willows ,so willows are sprouting everywhere .today as winter approaches all over Yellowstone beavers are using those willows to put the finishing touches

47、to a dam-building renaissance .and for every dam there is new habitat for new life and a richer more diverse Yellowstone .but just as Yellowstone reveals the complexity of life it also exposes its fragility .on its lofty ridges there are signs that all is not well with the whitebark pine .from above

48、 it looks like autumn colors have come to an evergreen world .but these trees are dying .small eruptions of resin dot the trunk of the tree evidence of an invasion .tiny beetles are chewing through the trees outerdefences .once inside they lay eggs that turn intolarvae that eat the tree .each tree t

49、hat is lost threatens all the nimals that rely on its autumn bounty .the only thing that can stop the beetles is extreme cold .but recently the climate here has been getting warmer and warmer .no national park can protect against that .this is a tree needs a cold winter .its now November and the elk

50、 have foundtheir feeding grounds just in time the snows of winter at their heels .here they join other herds who come to this place every year where the snow will be less deep and life a little easier .but today they graze on an island of grass surrounded by development .as they run from the winter .the fate of Yellowstones animalsoutside the national park is decided not by the cold but by the people .these elk are lucky .this refuge has been kept aside to give them some degree of sanctuary .so although the park isntbigenough to protect all its animals all the ti