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These are the user uploaded subtitles that are being translated: 1 00:01:10,000 --> 00:01:12,935 Water: Hundreds of thousands of tons of it, 2 00:01:13,103 --> 00:01:15,936 lying frozen on the world's mountains. 3 00:01:16,273 --> 00:01:21,267 It covers not only the poles, but caps great peaks on the equator. 4 00:01:31,121 --> 00:01:36,354 Water molecules, distilled from the sea by the sun's heat, condense in the sky. 5 00:01:36,593 --> 00:01:39,619 As they fall through the air, they pack together into shapes 6 00:01:39,796 --> 00:01:45,860 that echo their six-fold symmetry and form infinitely varied crystals of ice. 7 00:01:47,938 --> 00:01:51,999 They settle on the high mountains and compact into snow and ice 8 00:01:52,175 --> 00:01:54,609 that is, chemically, almost pure water, 9 00:01:54,778 --> 00:01:57,804 much purer than the sea from which it came. 10 00:01:58,448 --> 00:02:01,042 On Mount Rainier in the United States, 11 00:02:01,218 --> 00:02:04,619 permanent snow begins at 7,000 feet. 12 00:02:05,322 --> 00:02:11,022 You might think that this was one of the most inhospitable places on earth for life. 13 00:02:11,261 --> 00:02:15,425 After all, no vegetation grows on these snowfields, 14 00:02:15,599 --> 00:02:21,936 so there can be no animals that feed on it, like marmots or mice or rabbits, 15 00:02:22,105 --> 00:02:28,704 and if there are no herbivores, there can't be any predators like hawks or weasels. 16 00:02:28,979 --> 00:02:34,110 But in fact, there is a surprising amount of life here. 17 00:02:34,384 --> 00:02:39,947 There is some life actually within this snowfield itself, 18 00:02:40,123 --> 00:02:45,459 because this snow is not white, but red. 19 00:02:46,863 --> 00:02:50,890 The colour comes from microscopic plants: Algae. 20 00:02:51,401 --> 00:02:54,564 The redness is produced by light reflected from their cell walls, 21 00:02:54,738 --> 00:02:59,141 and is almost invisible when, under the microscope, light shines through them. 22 00:02:59,609 --> 00:03:02,544 Internally, they're green with chlorophyll. 23 00:03:02,746 --> 00:03:07,513 With its aid, they convert carbon dioxide and water into sugars. 24 00:03:07,851 --> 00:03:10,820 These, and the minerals dissolved in the melt water, 25 00:03:11,021 --> 00:03:14,149 are all the algae need to grow and reproduce. 26 00:03:14,891 --> 00:03:17,826 The winter snow will bury them feet deep, 27 00:03:17,995 --> 00:03:23,194 but in spring, when the surface melts, they divide, develop tiny beating hairs 28 00:03:23,367 --> 00:03:25,665 and swim up towards the sunshine. 29 00:03:26,269 --> 00:03:30,205 As they age and the minerals are used up, they change colour, 30 00:03:30,474 --> 00:03:35,002 forming huge smears of red in snowfields all over the world. 31 00:03:41,318 --> 00:03:45,311 Eventually, the snow algae produce spores as fine as dust 32 00:03:45,689 --> 00:03:49,682 and in that form they are blown from one snowfield to another. 33 00:03:49,960 --> 00:03:53,726 But other, bigger animals, also brought up by the wind, 34 00:03:53,897 --> 00:03:56,991 blow across the snows of Mount Rainier. 35 00:04:02,406 --> 00:04:05,068 Ladybirds. Thousands of them. 36 00:04:05,409 --> 00:04:10,676 Nobody knows why they come up in such numbers and assemble like this. 37 00:04:10,881 --> 00:04:16,114 But in late summer they fly up from the valleys up to these high peaks 38 00:04:16,286 --> 00:04:18,720 and here assemble in the rocks. 39 00:04:19,022 --> 00:04:24,255 When the winter snows come, the ladybirds remain underneath the snow in the rocks, 40 00:04:24,494 --> 00:04:29,955 and then in the spring, as now, the snow melts and the sun warms the ladybirds, 41 00:04:30,133 --> 00:04:35,867 and they become active and fly off back to the valley to feed on aphids. 42 00:04:38,575 --> 00:04:43,069 The ladybirds are only temporary residents of the Mount Rainier snowfields. 43 00:04:43,447 --> 00:04:45,813 Other insects manage, almost unbelievably, 44 00:04:45,982 --> 00:04:49,679 to live all their lives in this seemingly inhospitable snow. 45 00:04:50,153 --> 00:04:52,781 The best time to find them is at night. 46 00:05:16,379 --> 00:05:17,937 A whole community lives here, 47 00:05:18,115 --> 00:05:23,348 feeding on pollen grains and the bodies of dead insects blown up on the wind. 48 00:05:24,654 --> 00:05:28,715 Some, like this primitive relation of the cockroach, a grylloblattid, 49 00:05:28,892 --> 00:05:32,487 have a body chemistry so well adjusted to low temperatures 50 00:05:32,662 --> 00:05:36,689 that if you pick them up, your hand's warmth will kill them. 51 00:05:43,106 --> 00:05:46,303 Permanent snow lies directly on bare rock, 52 00:05:46,476 --> 00:05:51,641 but lower down, where it comes and goes, there can be a little vegetation to be grazed. 53 00:05:55,352 --> 00:06:00,312 Mountain sheep. These on Mount McKinley are the kind known as Dall Sheep. 54 00:06:12,402 --> 00:06:14,529 Little ground squirrels live up here too. 55 00:06:14,871 --> 00:06:18,034 Unlike the sheep, which retreat to lower altitudes in winter, 56 00:06:18,208 --> 00:06:20,142 the squirrels are permanent residents, 57 00:06:20,310 --> 00:06:24,713 insulated in their burrows from the frosts by the cover of snow. 58 00:06:34,391 --> 00:06:38,691 There are sheep like these in mountains all through North America, Asia and Europe. 59 00:06:38,962 --> 00:06:42,591 All carry big horns, and the senior males, in autumn, 60 00:06:42,799 --> 00:06:45,632 indulge in the most alarming courtship battles. 61 00:07:28,645 --> 00:07:31,808 It's hard for plants to grow on steep, high slopes 62 00:07:32,048 --> 00:07:37,179 The warming by day and freezing by night makes the gravelly soil slip downwards, 63 00:07:37,354 --> 00:07:39,948 so it's difficult for plants to keep a hold. 64 00:07:40,290 --> 00:07:42,622 With few plants, grazing animals are rare, 65 00:07:42,792 --> 00:07:46,057 though there may be more than there appear to be at first sight. 66 00:07:51,701 --> 00:07:54,534 These, in the Himalayas, are blue sheep, 67 00:07:54,804 --> 00:08:00,140 so nimble and sure-footed they can reach almost any vegetation on the steep slopes. 68 00:08:07,050 --> 00:08:13,114 But if these are rare, rarer still is the animal that preys on them, the snow leopard. 69 00:08:20,630 --> 00:08:24,760 In summer it stays at between 12,000 and 15,000 feet, 70 00:08:25,035 --> 00:08:28,698 hunting small rodents and birds as well as mountain sheep. 71 00:08:48,091 --> 00:08:51,925 Snow leopards have been seen as high as 18,000 feet in summer. 72 00:08:52,095 --> 00:08:57,431 But with winter's heavy snowfalls, it retreats to the valleys. 73 00:09:06,943 --> 00:09:12,848 Game is now so scarce that there's barely enough to support more than one leopard, 74 00:09:13,016 --> 00:09:15,280 so this animal hunts alone. 75 00:09:22,459 --> 00:09:25,292 Its thick, dense fur is now paler. 76 00:09:25,495 --> 00:09:29,261 It has a thick, woolly undercoat and cushions of hair under its paws 77 00:09:29,432 --> 00:09:32,196 which prevent it from sinking in the snow. 78 00:09:43,313 --> 00:09:49,149 The mountains of Africa, although so near the equator, are permanently snow-capped. 79 00:09:49,319 --> 00:09:53,119 Kilimanjaro, 19,000 feet high, is a volcano. 80 00:09:53,523 --> 00:09:59,758 Mount Kenya, also volcanic, is 2,000 feet lower but still has its own glaciers 81 00:10:00,029 --> 00:10:02,862 Each has its own animals and plants 82 00:10:03,032 --> 00:10:05,933 specially adapted to life at low temperatures. 83 00:10:06,336 --> 00:10:12,275 Here, at about 13,000 feet, grow some most beautiful and dramatic plants: 84 00:10:12,442 --> 00:10:15,002 Giant groundsels and giant lobelias. 85 00:10:15,245 --> 00:10:17,338 At these altitudes, plants like these 86 00:10:17,514 --> 00:10:22,281 have to face two totally conflicting problems every 24 hours. 87 00:10:22,485 --> 00:10:27,752 Every night the temperature falls so low that they're in danger of freezing solid. 88 00:10:27,957 --> 00:10:32,326 And every day the sun beats down so strongly in this very thin air 89 00:10:32,495 --> 00:10:37,228 that it threatens to rob them of their moisture by evaporation. 90 00:10:37,534 --> 00:10:40,628 But look how this lobelia deals with those problems. 91 00:10:41,871 --> 00:10:46,035 This little pond of water in the leaf rosette freezes over every night, 92 00:10:46,342 --> 00:10:50,972 and this shield of ice prevents the water beneath from freezing, 93 00:10:51,147 --> 00:10:57,313 so that it acts as a liquid jacket, preventing the frost from reaching the heart of the plant. 94 00:10:57,854 --> 00:11:04,623 But as the day wears on and it gets warmer, this water is in danger of evaporating 95 00:11:04,794 --> 00:11:08,093 and the plant of losing its night-time insulation. 96 00:11:08,498 --> 00:11:12,798 But it isn'tjust rainwater that's accumulated in this rosette. 97 00:11:13,069 --> 00:11:17,836 It's been secreted by the plant itself and it's slightly slimy. 98 00:11:18,007 --> 00:11:22,637 It contains pectin, a colloidal substance which greatly reduces evaporation. 99 00:11:23,012 --> 00:11:24,980 But there's another kind of lobelia 100 00:11:25,148 --> 00:11:28,276 which deals with these two problems in a quite different way. 101 00:11:34,457 --> 00:11:37,756 This one grows very tall and has extremely long leaves, 102 00:11:37,927 --> 00:11:42,261 each fringed with tiny hairs which act like an animal's fur, 103 00:11:42,432 --> 00:11:46,528 trapping air between them, insulating the stem from chills. 104 00:11:46,736 --> 00:11:49,830 They also prevent the wind from robbing the plants of moisture. 105 00:11:52,308 --> 00:11:55,300 Each group of lobelias is owned by a pair of sunbirds 106 00:11:55,478 --> 00:11:57,878 which collect the insects the plants attract. 107 00:11:58,214 --> 00:12:01,012 They keep themselves warm with fluffed-up feathers. 108 00:12:02,752 --> 00:12:05,243 And among the rocks are hyrax. 109 00:12:12,095 --> 00:12:18,227 The reason these little creatures are so tame and I can get so close to them 110 00:12:18,401 --> 00:12:21,302 is just because they're living so high up. 111 00:12:21,771 --> 00:12:25,002 Up here, there are few creatures to prey on them. 112 00:12:25,208 --> 00:12:30,544 An occasional leopard may come up and hunt them, but apart from that, nothing. 113 00:12:31,047 --> 00:12:35,643 And so they can come out during the few brief hours of sunshine 114 00:12:35,818 --> 00:12:38,912 and bask on the rocks without any fear, 115 00:12:39,122 --> 00:12:40,487 just as they're doing now. 116 00:12:44,394 --> 00:12:47,454 Hyrax also live down on the hot plains below, 117 00:12:47,630 --> 00:12:52,829 but these, in response to the cold, have developed particularly long fur. 118 00:12:53,169 --> 00:12:57,629 Despite their shape, they often climb trees to crop leaves. 119 00:12:57,874 --> 00:13:01,275 But at these altitudes, there's only grass and lobelias, 120 00:13:01,444 --> 00:13:03,935 and they share it with the little furry-eared rat. 121 00:13:13,056 --> 00:13:16,321 Mount Kenya, like its neighbours Kilimanjaro and Ruwenzori, 122 00:13:16,492 --> 00:13:21,930 is an isolated patch of snow and ice surrounded by the baking hot African plains. 123 00:13:23,066 --> 00:13:24,693 But the great mountains of South America, 124 00:13:24,867 --> 00:13:29,702 like Cotopaxi, 19,000 feet high, are very differen 125 00:13:30,006 --> 00:13:34,705 These volcanoes, some active, some dormant, are not isolated peaks 126 00:13:34,877 --> 00:13:38,904 but part of a continuous range that runs the length of the continent 127 00:13:39,082 --> 00:13:43,849 and is surrounded by the high, cold plains of the altiplano, 128 00:13:44,020 --> 00:13:48,184 so their flanks support a large and varied population of animals, 129 00:13:48,358 --> 00:13:52,818 all adapted to life at high altitudes and low temperatures. 130 00:13:53,496 --> 00:13:57,626 Here lives a wild South American camel, the vicuna. 131 00:13:58,001 --> 00:14:01,835 Its coat is fine, silky and protected so well from the cold, 132 00:14:02,005 --> 00:14:05,771 that it has, paradoxically, led to its near-extinction. 133 00:14:06,075 --> 00:14:10,478 Men have recognised that vicuna wool has an unexcelled softness and warmth 134 00:14:10,647 --> 00:14:14,139 and hunted the animal for it until it's close to extinction. 135 00:14:21,324 --> 00:14:25,283 The people of the Andes have domesticated another wild camel, the guanaco, 136 00:14:25,461 --> 00:14:28,953 to produce heavy-fleeced versions which produce excellent wool 137 00:14:29,132 --> 00:14:30,963 and serve as beasts of burden. 138 00:14:31,534 --> 00:14:38,064 Here, in Ecuador and Peru, near the equator, wild camels live at around 14,000 feet. 139 00:14:39,976 --> 00:14:44,970 But as you travel south down the Andes, the snowline gets lower. 140 00:14:45,348 --> 00:14:48,476 Half-way down, 2,000 miles south of Cotopaxi, 141 00:14:48,651 --> 00:14:54,112 the line of permanent snow has dropped from 16,000 feet to 13,000 feet. 142 00:14:56,292 --> 00:15:00,319 A thousand miles farther south still, the mountains are not so high 143 00:15:00,496 --> 00:15:06,662 but are almost completely covered with snow, to within a few hundred feet of the sea. 144 00:15:08,471 --> 00:15:13,773 So, on the southernmost tip of South America, in Patagonia and Tierra del Fuego, 145 00:15:13,943 --> 00:15:18,846 the guanaco doesn't live at great altitudes, but almost at sea level. 146 00:15:19,449 --> 00:15:25,445 Yet it needs its warm coatjust as much, for here, even in summer, it's very cold, 147 00:15:25,621 --> 00:15:28,988 and during the winter the whole land is snowbound. 148 00:15:41,704 --> 00:15:46,403 The reason it gets colder nearer the pole is not complicated. 149 00:15:46,676 --> 00:15:50,874 The sun's rays strike the earth at the equator at right angles. 150 00:15:51,114 --> 00:15:53,708 But as you travel round the earth, 151 00:15:53,883 --> 00:15:56,215 the rays become more and more glancing. 152 00:15:57,754 --> 00:16:00,484 So a given amount of heat falling on the equator 153 00:16:00,656 --> 00:16:04,752 is distributed over a much greater area in the polar regions 154 00:16:04,927 --> 00:16:10,058 and has to travel through more of the earth's atmosphere, which weakens it still further. 155 00:16:11,400 --> 00:16:17,202 So down in Patagonia, the sun's rays are very much less intense and carry much less heat, 156 00:16:17,373 --> 00:16:20,831 and the glaciers flow right down to the sea. 157 00:16:33,556 --> 00:16:37,652 Farther south still, across the near-frozen seas off Cape Horn, 158 00:16:37,827 --> 00:16:40,625 you reach chains of small volcanic islands 159 00:16:40,797 --> 00:16:44,563 that run down towards the Antarctic continent itself: 160 00:16:44,801 --> 00:16:46,462 Remote, little-known archipelagos 161 00:16:46,636 --> 00:16:51,039 such as the South Sandwich and, here, the South Orkneys. 162 00:16:52,508 --> 00:16:59,846 There are only two flowering plants that can manage to survive in this bleak, icy country. 163 00:17:00,049 --> 00:17:05,112 One is a kind of thrift and the other is a small, stunted grass. 164 00:17:05,354 --> 00:17:09,848 And apparently, no land-living animals of any kind. 165 00:17:10,760 --> 00:17:15,459 But when the snows melt in summer, they reveal that the rocks and the boulders 166 00:17:15,631 --> 00:17:20,227 are covered with over 100 different kinds of mosses and lichens, 167 00:17:20,469 --> 00:17:24,633 some of them rounded green cushions, others like miniature trees. 168 00:17:26,576 --> 00:17:31,172 The capacity of these simple plants to endure cold is phenomenal. 169 00:17:31,380 --> 00:17:35,817 Some species can even survive being frozen solid for weeks on end. 170 00:17:41,691 --> 00:17:47,186 Within this miniature tangled jungle lives a whole menagerie of tiny animals. 171 00:17:49,398 --> 00:17:51,491 Primitive creatures little bigger than pinheads 172 00:17:51,667 --> 00:17:57,128 manage to survive by slowly chewing away at the lichens and mosses during summer. 173 00:17:57,506 --> 00:17:59,701 In winter they almost grind to a halt, 174 00:17:59,876 --> 00:18:04,939 yet they survive unfrozen because their blood contains a kind of antifreeze 175 00:18:05,114 --> 00:18:09,517 and remains liquid even when the temperature falls well below zero. 176 00:18:14,724 --> 00:18:19,252 The majority are vegetarians, but there are also carnivorous mites among them 177 00:18:19,428 --> 00:18:21,828 which clamber around the grazing herds, 178 00:18:21,998 --> 00:18:24,762 picking off individuals as they fancy. 179 00:18:26,502 --> 00:18:30,495 In this extreme cold, the processes of life are greatly slowed down, 180 00:18:30,673 --> 00:18:35,337 not only those of growth, but those that lead to old age and death. 181 00:18:35,745 --> 00:18:39,647 So such tiny creatures, which elsewhere might live for merely months, 182 00:18:39,815 --> 00:18:43,581 survive for two or three years within the green mossy carpets. 183 00:18:46,522 --> 00:18:50,458 The seas around these Antarctic islands are strewn with ice. 184 00:18:50,927 --> 00:18:54,055 The pack ice that litters the surface is frozen sea water, 185 00:18:54,230 --> 00:18:56,994 and in winter forms a solid cover to the sea. 186 00:18:57,333 --> 00:18:59,062 The icebergs are different. 187 00:18:59,235 --> 00:19:04,070 They're made of fresh water and have broken away from glaciers flowing into the sea. 188 00:19:06,275 --> 00:19:10,371 This is the source of those bergs: The edge of a glacier. 189 00:19:11,347 --> 00:19:14,908 Beyond it, the continent of Antarctica. 190 00:19:16,218 --> 00:19:18,686 It's huge, bigger than the whole of Europe, 191 00:19:18,854 --> 00:19:22,722 and, for the most part, it seems totally devoid of life. 192 00:19:25,728 --> 00:19:28,925 But not all of Antarctica is snow-covered. 193 00:19:29,165 --> 00:19:34,626 In parts of the interior there are valleys where almost no snow ever falls. 194 00:19:35,972 --> 00:19:39,499 This is as desolate a part of the earth as exists. 195 00:19:39,909 --> 00:19:44,209 The cold is extreme, it's drier even than the centre of the Sahara, 196 00:19:44,380 --> 00:19:46,905 it's dark for half the year 197 00:19:47,083 --> 00:19:51,315 and it's scoured by a never-ending howling wind. 198 00:19:52,521 --> 00:19:56,048 And the wind is responsible for these carvings in the solid granite. 199 00:19:56,425 --> 00:19:59,917 Crystals of salt form beneath tiny flakes on the surface, 200 00:20:00,096 --> 00:20:04,965 and grow slowly, but so powerfully that particles are broken loose. 201 00:20:05,234 --> 00:20:10,467 The wind then sweeps them up and hurls them at the rock face, eroding it still further. 202 00:20:14,777 --> 00:20:19,714 Desolate though this waste of shattered rocks may seem, there is life even here. 203 00:20:27,957 --> 00:20:31,984 Algae. Beneath the stone, the wind doesn't dry it out, 204 00:20:32,161 --> 00:20:34,425 and it's protected from the cold. 205 00:20:34,930 --> 00:20:39,299 It gets the light it needs to grow through the translucent rock. 206 00:20:45,408 --> 00:20:48,502 There are also green patches actually within the rock. 207 00:20:48,844 --> 00:20:53,247 Algae have penetrated the microscopic spaces between the rock's constituent particles 208 00:20:53,416 --> 00:20:55,509 and there managed to grow. 209 00:20:58,020 --> 00:21:00,181 Glaciers flow down these dry valleys, 210 00:21:00,356 --> 00:21:04,019 fed by the ice cap covering the continent's centre. 211 00:21:04,360 --> 00:21:10,697 They're among the world's fastest moving, advancing as much as 300 feet in a year. 212 00:21:11,067 --> 00:21:16,835 As they surge downwards, their surface is torn into thousands of crevasses. 213 00:21:32,354 --> 00:21:35,323 During the summer, even though the winds are bitterly cold, 214 00:21:35,491 --> 00:21:39,655 the sun is sufficiently strong to melt a little of the glacier's surface. 215 00:21:41,664 --> 00:21:45,691 Where it accumulates in pools, blue-green algae grows vigorously, 216 00:21:45,868 --> 00:21:50,737 its dark colour enabling it to absorb a high proportion of the sun's feeble heat. 217 00:21:54,944 --> 00:21:59,677 These pools and streams are the only places in all of Antarctica's interior 218 00:21:59,849 --> 00:22:02,215 where life flourishes in any abundance. 219 00:22:03,853 --> 00:22:06,981 The earth, at the beginning of the history of life 220 00:22:07,156 --> 00:22:10,216 before any higher plants or any animals had appeared, 221 00:22:10,392 --> 00:22:13,122 must have looked something like this. 222 00:22:18,968 --> 00:22:23,462 Yet here, mysteriously, lie the corpses of large animals. 223 00:22:24,473 --> 00:22:27,874 A crab-eater seal. It looks comparatively fresh, 224 00:22:28,043 --> 00:22:33,345 but examination of its tissues show that it is about 300 years old. 225 00:22:33,849 --> 00:22:36,443 This extreme climate has freeze-dried it. 226 00:22:36,785 --> 00:22:39,583 It must have lost its way, perhaps because of sickness, 227 00:22:39,755 --> 00:22:44,021 and misguidedly crawled up here from the coast, 25 miles away. 228 00:22:46,028 --> 00:22:51,728 Although the land of the Antarctic is almost steri its waters are extremely fertile, 229 00:22:52,101 --> 00:22:57,869 so its margins, particularly the beaches of its off-shore islands, are rich in life. 230 00:23:06,882 --> 00:23:10,682 These fur seals in South Georgia flourish in great numbers 231 00:23:10,853 --> 00:23:12,548 because the surface waters of the seas 232 00:23:12,721 --> 00:23:17,624 are thick with shoals of floating shrimp: Krill, which is their main food. 233 00:23:18,260 --> 00:23:22,424 Every year they come ashore to the beaches to pup and mate. 234 00:23:25,301 --> 00:23:30,830 They're not true seals but eared seals, for they have small external ears. 235 00:23:31,006 --> 00:23:35,807 Their hind flippers can be brought forward, enabling them to move quite fast on land, 236 00:23:35,978 --> 00:23:38,139 something that true seals can't do. 237 00:23:38,514 --> 00:23:43,747 These fur seals retained and thickened the fur of their land-living ancestors, 238 00:23:43,919 --> 00:23:51,485 so that now some of these big males have manes which give them the name sea lion. 239 00:23:51,860 --> 00:23:55,159 This fur lies in two layers. 240 00:23:55,331 --> 00:24:00,064 There's an outer guard hair and then a thick layer close to the skin, 241 00:24:00,236 --> 00:24:07,267 and that traps air in it and keeps the animals warm when they go swimming. 242 00:24:07,443 --> 00:24:09,911 But the trouble with fur as an insulator 243 00:24:10,079 --> 00:24:16,348 is that if you dive too deep, water pressure squeezes out the air. 244 00:24:16,619 --> 00:24:21,454 So fur seals, for the most part, fish in the surface waters. 245 00:24:23,325 --> 00:24:28,388 True seals, like these elephant seal pups, have a different kind of insulation. 246 00:24:28,631 --> 00:24:29,996 Their fur is sparse, 247 00:24:30,165 --> 00:24:34,761 but beneath the skin is a thick layer of oily fat, blubber, 248 00:24:34,937 --> 00:24:37,201 which surrounds their entire body. 249 00:24:37,506 --> 00:24:40,532 Elephant seals dive to great depths to hunt squid, 250 00:24:40,709 --> 00:24:44,668 navigating in the dark with sonar and huge eyes, 251 00:24:44,947 --> 00:24:49,884 but they don't get chilled, for pressure has no effect on blubber's insulating qualities. 252 00:24:50,452 --> 00:24:55,719 With every year, the blubber which kept them so warm in the freezing seas 253 00:24:55,891 --> 00:24:57,188 loses its power. 254 00:24:57,593 --> 00:25:01,222 Because every year the sea elephants have to moult, 255 00:25:01,397 --> 00:25:07,825 and in order to grow new skin they have to bring a blood supply close to the surface. 256 00:25:08,070 --> 00:25:10,163 Blood vessels open up through the blubber 257 00:25:10,339 --> 00:25:14,799 and the skin is flushed with blood just below the surface. 258 00:25:15,044 --> 00:25:18,775 If they stayed in the sea like that, they'd chill very quickly. 259 00:25:19,048 --> 00:25:21,414 But they don't. Instead... 260 00:25:24,253 --> 00:25:29,316 ...they haul themselves up onto the beaches or into mud wallows like this one. 261 00:25:29,658 --> 00:25:31,785 And there, the big old bulls like that one 262 00:25:31,960 --> 00:25:36,556 must suppress the feelings of antagonism they felt only a few months ago 263 00:25:36,732 --> 00:25:41,328 and lie close together with their fellows in the interests of keeping warm. 264 00:25:48,143 --> 00:25:50,611 These are the biggest of all seals. 265 00:25:50,813 --> 00:25:56,183 The huge adult males develop a bladder on top of their noses, like a kind of trunk. 266 00:26:01,123 --> 00:26:05,651 But they also justify their name of sea elephant by their immense size. 267 00:26:06,028 --> 00:26:10,192 The bulls may grow to 20 feet long and weigh three tons. 268 00:26:19,341 --> 00:26:23,903 If you wanted to pick a creature to symbolise the frozen Antarctic wastes, 269 00:26:24,079 --> 00:26:27,173 you might well choose a creature like this. 270 00:26:27,349 --> 00:26:30,910 These are macaroni penguins on the island of South Georgia, 271 00:26:31,086 --> 00:26:34,783 halfway between the tip of South America and the Antarctic. 272 00:26:35,190 --> 00:26:41,254 But it seems the original penguins evolved in relatively warm climates. 273 00:26:41,430 --> 00:26:45,457 Even today, there are species of penguins that live on the equator, 274 00:26:45,634 --> 00:26:47,226 in the Galapagos islands. 275 00:26:47,569 --> 00:26:51,835 So this dense coat of feathers with a layer of fat beneath it 276 00:26:52,007 --> 00:26:56,444 was probably developed to keep them warm in the seas anywhere, 277 00:26:56,612 --> 00:27:00,378 but it serves them just as well in the freezing Antarctic winds, 278 00:27:00,549 --> 00:27:03,950 standing on land or on a surging iceberg. 279 00:27:22,738 --> 00:27:25,400 And they are superb swimmers. 280 00:27:27,443 --> 00:27:29,877 Swift and agile through water, 281 00:27:30,045 --> 00:27:33,481 they come in to land through breakers that would smash any boat 282 00:27:33,649 --> 00:27:36,482 with the resilience of rubber balls. 283 00:27:46,228 --> 00:27:49,720 These chinstrap penguins are only a couple of feet high. 284 00:27:49,898 --> 00:27:52,458 King penguins are half as tall again. 285 00:27:52,734 --> 00:27:56,170 Large size can be an advantage in cold climates. 286 00:27:56,438 --> 00:28:01,273 The bigger a body, the smaller the surface area of its skin relative to its volum 287 00:28:01,510 --> 00:28:05,446 So big penguins retain heat better than small ones. 288 00:28:05,814 --> 00:28:09,181 But their great size causes problems in breeding. 289 00:28:09,384 --> 00:28:12,512 They lay just one egg, which they keep warm 290 00:28:12,688 --> 00:28:17,148 by the rather inconvenient method of holding it on top of their feet, 291 00:28:17,426 --> 00:28:22,420 covered by a fold of feathered skin, for eight long weeks. 292 00:28:22,764 --> 00:28:28,031 When it does hatch, the chick takes so long to mature 293 00:28:28,203 --> 00:28:31,195 that they have to feed it for a further ten months 294 00:28:32,274 --> 00:28:35,368 These king penguins aren't the biggest of all penguins. 295 00:28:35,611 --> 00:28:39,547 They have a cousin, living farther south, which grows even bigger. 296 00:28:39,781 --> 00:28:43,046 It, too, has fearsome problems in raising its chic 297 00:28:43,218 --> 00:28:46,654 and it solves them in the most dramatic way imaginable. 298 00:28:47,222 --> 00:28:51,659 They lay their eggs not in spring, but at the end of summer. 299 00:28:52,027 --> 00:28:55,394 Their breeding grounds are on the permanent sea ice near the coast. 300 00:28:55,631 --> 00:29:02,537 The females return to the sea to feed, leaving the males with the eggs. 301 00:29:02,804 --> 00:29:05,830 They shuffle back and forth, each with an egg on his feet, 302 00:29:06,008 --> 00:29:08,203 held carefully above the ice. 303 00:29:15,584 --> 00:29:18,883 The gales intensify as the winter advances 304 00:29:19,054 --> 00:29:20,851 and the sun sinks lower. 305 00:29:22,658 --> 00:29:25,821 In the skies above, the aurora plays. 306 00:29:26,562 --> 00:29:30,259 The male emperors stoically sit out the months of winter darkness. 307 00:29:30,666 --> 00:29:35,069 The sea ice can offer them no nest. Not even a scree for a few pebbles. 308 00:29:35,237 --> 00:29:40,072 They have nothing to eat, and nothing to do except protect the precious egg 309 00:29:40,242 --> 00:29:44,178 and prevent it from freezing while the chick slowly forms inside it. 310 00:29:44,580 --> 00:29:49,574 As the gales intensify, the males huddle together to give one another shelter. 311 00:29:50,586 --> 00:29:55,455 Then, 65 days after it was laid, the chick begins to hatch. 312 00:30:13,475 --> 00:30:15,670 The newly-emerged chicks are hungry. 313 00:30:15,911 --> 00:30:21,315 All the male can provide is a little secretion from his throat and long-empty stomach. 314 00:30:21,783 --> 00:30:23,080 He's close to starving himself, 315 00:30:23,251 --> 00:30:26,948 having been sustained only by the layer of fat beneath his skin. 316 00:30:27,222 --> 00:30:29,588 He's lost a third of his weight. 317 00:30:32,361 --> 00:30:35,660 But soon after, the female reappears with a full stomach 318 00:30:35,897 --> 00:30:40,334 and takes the chick onto her feet for its first proper feed. 319 00:30:41,336 --> 00:30:46,035 Now the parents will take turns to trek to the sea and back, 320 00:30:46,208 --> 00:30:48,073 bringing food for their youngsters. 321 00:30:48,744 --> 00:30:53,443 But now, at the end of winter, the ice has extended far out to sea, 322 00:30:53,615 --> 00:30:57,984 and the penguins may have to walk 50 miles to reach open water. 323 00:30:59,054 --> 00:31:02,217 The adults have a powerful urge to cherish a chick. 324 00:31:02,591 --> 00:31:05,719 Those that have lost one will try and adopt any that wanders by 325 00:31:05,894 --> 00:31:08,590 or incubate pieces of ice. 326 00:31:20,742 --> 00:31:22,937 Repeatedly, the parent in charge 327 00:31:23,111 --> 00:31:26,012 manages to find something from the pit of its stomach 328 00:31:26,181 --> 00:31:28,342 to feed the ever-hungry chick. 329 00:31:33,355 --> 00:31:36,552 Until the chicks lose their down and get their adult plumage, 330 00:31:36,725 --> 00:31:40,058 they can't swim and so can't feed for themselves. 331 00:31:40,595 --> 00:31:46,033 But being so big, they, like the king penguins, take a long time to grow to full size, 332 00:31:46,201 --> 00:31:51,901 and so their parents must make the long march to the sea to collect food for them. 333 00:31:53,742 --> 00:31:57,678 Though the winter is almost over, there is still bad weather. 334 00:31:57,879 --> 00:31:59,346 Blizzards rage over the ice, 335 00:31:59,514 --> 00:32:05,749 and the young huddle together in groups of their own amongst the parent birds. 336 00:32:10,525 --> 00:32:14,120 Many of the youngsters lack the strength to withstand the cold. 337 00:32:14,429 --> 00:32:15,555 Many die. 338 00:32:16,965 --> 00:32:22,562 As the sun rises higher each day, the adults suffer in a different fashion. 339 00:32:22,938 --> 00:32:26,806 On sunny days they get too hot in their insulating blanket of feathers, 340 00:32:26,975 --> 00:32:30,035 and eat snow in order to cool themselves. 341 00:32:32,347 --> 00:32:35,407 The chicks still have their downy feathers and can't swim. 342 00:32:35,584 --> 00:32:39,918 But ten months on from laying, the chicks fledge, 343 00:32:40,088 --> 00:32:44,582 and over the next few weeks, they all walk down to the sea, 344 00:32:44,760 --> 00:32:49,288 which now, with the spring break-up of the ice, is close at hand. 345 00:32:51,833 --> 00:32:55,633 Now, at last, the adults can feed entirely for themselves. 346 00:32:56,104 --> 00:32:58,664 They've got two months in which to restore their weight 347 00:32:58,840 --> 00:33:01,968 before they start the whole process over again. 348 00:33:06,815 --> 00:33:09,340 These birds, at first sight so penguin-like, 349 00:33:09,518 --> 00:33:12,453 live not near the south pole, but the north. 350 00:33:12,888 --> 00:33:16,790 They're not penguins but guillemots, members of the auk family. 351 00:33:17,392 --> 00:33:20,987 All auks, like penguins, are excellent underwater swimmers. 352 00:33:21,196 --> 00:33:23,756 They use their wings like flippers, 353 00:33:24,065 --> 00:33:27,193 but they have not become such specialised swimmers as the penguins, 354 00:33:27,369 --> 00:33:28,859 for they can still fly. 355 00:33:29,771 --> 00:33:33,002 These are the guillemots' smaller cousins, the little auk. 356 00:33:51,359 --> 00:33:55,921 Auks and penguins, similar though they are, are not closely related. 357 00:33:56,097 --> 00:33:59,931 They've come to resemble one another by adopting a similar lifestyle 358 00:34:00,101 --> 00:34:02,126 at opposite ends of the earth. 359 00:34:05,440 --> 00:34:09,501 Unlike Antarctica, that isolated continent surrounded by sea, 360 00:34:09,678 --> 00:34:14,638 the Arctic is connected by land to more temperate regions. 361 00:34:14,950 --> 00:34:19,785 So the land animals of Europe and North America have been able to colonise it 362 00:34:19,955 --> 00:34:23,083 and adapt to its particular demands. 363 00:34:25,560 --> 00:34:27,528 Foxes have moved up here. 364 00:34:27,863 --> 00:34:33,597 The Arctic fox's coat is lighter than its southern cousin, and in winter turns whit 365 00:34:34,135 --> 00:34:39,095 On land, it feeds on small rodents, and on ice floes, perhaps the odd bird. 366 00:34:39,474 --> 00:34:42,841 It's just as well the little auks have kept their powers of flight. 367 00:34:58,793 --> 00:35:05,130 The ice floes are also the hunting ground of one of the biggest of all carnivores. 368 00:35:12,741 --> 00:35:14,231 The polar bear. 369 00:35:15,176 --> 00:35:18,270 This one has killed a bearded seal. 370 00:35:30,525 --> 00:35:35,428 A young bear is eager to take a share of the kill, but must be cautious. 371 00:35:35,697 --> 00:35:38,791 Adults sometimes kill youngsters in squabbles. 372 00:36:11,900 --> 00:36:17,736 The polar bear is clearly a close relative of the bears that live in Europe and America. 373 00:36:18,206 --> 00:36:23,940 Its whiteness is an obvious adaptation to the snow and ice, but so is its huge size. 374 00:36:24,412 --> 00:36:31,318 The principle of a big body retaining more heat applies to bears as much as penguins, 375 00:36:31,553 --> 00:36:36,991 and polar bears are very much bigger than their cousins in temperate lands farther south. 376 00:36:54,609 --> 00:37:00,309 Polar bears, if forced to, will eat all kinds of t but their preferred food is flesh, 377 00:37:00,482 --> 00:37:02,279 particularly that of seals. 378 00:37:02,650 --> 00:37:06,518 They especially like the blubber just below the seal's skin, 379 00:37:06,721 --> 00:37:10,179 and often leave the meat for the scavenging gulls and foxes. 380 00:37:37,786 --> 00:37:42,519 Among the glaucous gulls is the much rarer and pure-white ivory gull. 381 00:37:52,067 --> 00:37:57,733 The polar bear's white coat and great size are not its only adaptations to Arctic life. 382 00:37:57,972 --> 00:38:01,499 It grips the ice with long, sharp claws 383 00:38:01,676 --> 00:38:07,273 and thick hair on the soles, which also makes them excellent paddles, 384 00:38:07,582 --> 00:38:11,678 for the polar bear spends a lot of time swimming during the summer. 385 00:38:54,295 --> 00:38:56,729 Ringed seals are much hunted by polar bears, 386 00:38:56,898 --> 00:39:01,301 and when on the ice, must be constantly on the alert. 387 00:39:05,373 --> 00:39:09,002 They need ice holes through which to leave the water, 388 00:39:09,177 --> 00:39:12,078 or at least stick up their heads to breathe. 389 00:39:17,852 --> 00:39:22,880 A polar bear will wait for many hours, motionless, beside such a hole. 390 00:39:27,462 --> 00:39:31,990 They also stalk seals that are rash enough to lie out on the ice. 391 00:39:47,715 --> 00:39:53,278 The polar bear has lost, but about once in every five hunting days, it does kill, 392 00:39:53,488 --> 00:39:54,978 and that is enough. 393 00:40:03,031 --> 00:40:08,663 The most powerful effective hunter of all, however, on the northern ice, is man. 394 00:40:12,440 --> 00:40:15,637 Eskimo, or Inuit, as they prefer to call themselves, 395 00:40:15,810 --> 00:40:18,836 came up to the Arctic in very early times. 396 00:40:19,147 --> 00:40:22,776 Superb hunters, they could live for many months in winter 397 00:40:22,951 --> 00:40:25,715 on nothing whatever but raw meat. 398 00:40:38,466 --> 00:40:43,904 They were so skilled at living on the ice that with only a knife of bone 399 00:40:44,072 --> 00:40:48,099 they could make a waterproof house from snow in an hour or so. 400 00:41:01,022 --> 00:41:03,547 A slab of sea ice made a window. 401 00:41:23,811 --> 00:41:27,770 Inside, the igloo was lit with lamps fed by seal blubber. 402 00:41:28,082 --> 00:41:29,982 Heat from the flame and from their bodies 403 00:41:30,151 --> 00:41:35,555 could raise the temperature enough for them to remove their heavy clothing and relax. 404 00:41:49,737 --> 00:41:53,332 It was a life of extraordinary rigour and privatio 405 00:41:53,775 --> 00:41:56,369 These pictures were taken 20 years ago. 406 00:41:56,644 --> 00:41:59,340 No Eskimo lives in this way today. 407 00:42:01,282 --> 00:42:03,477 The poles have not always been so cold. 408 00:42:03,718 --> 00:42:08,417 One explanation of why they've become so is the warming effect of ocean currents. 409 00:42:08,656 --> 00:42:12,615 If they can circulate the waters of the polar seas down towards the equator, 410 00:42:12,794 --> 00:42:14,887 they would keep them relatively warm. 411 00:42:15,129 --> 00:42:20,499 And maybe they did so 100 million years ago, when the continents were arranged like this. 412 00:42:21,202 --> 00:42:25,400 But the continents have shifted, the polar seas become more enclosed 413 00:42:25,573 --> 00:42:28,007 and any such currents interrupted. 414 00:42:30,611 --> 00:42:33,171 Meanwhile, during the same period, 415 00:42:33,348 --> 00:42:38,376 the Antarctic continent drifted south until it came to rest over the south pole. 416 00:42:38,653 --> 00:42:43,454 Now ocean currents could not keep that part of the world warm either, 417 00:42:43,624 --> 00:42:45,524 and so an ice cap formed. 418 00:42:46,227 --> 00:42:51,790 The whiteness reflected 90% of the heat in the already feeble rays of the sun. 419 00:42:52,033 --> 00:42:56,527 So ice now covers all of Antarctica and the seas of the north pole. 420 00:42:57,071 --> 00:43:00,234 Over the past million years there have been other variations, 421 00:43:00,408 --> 00:43:03,206 due to the sun's varying strength, 422 00:43:03,378 --> 00:43:05,972 and the ice cover has waxed and waned. 423 00:43:06,314 --> 00:43:09,715 Now we're in one of the warmer phases, 424 00:43:09,884 --> 00:43:13,684 but even so, Antarctica is still buried beneath ice a mile thick, 425 00:43:13,855 --> 00:43:20,283 and in the north, ice and snow extend for 1,000 miles away from the pole. 426 00:43:42,083 --> 00:43:45,541 As you come down the mountain or away from the pole, 427 00:43:45,720 --> 00:43:51,249 the land becomes warm enough to prevent it being covered by ice and snow all year. 428 00:43:51,559 --> 00:43:55,757 Beyond, the country is bleak enough: Boulders and gravel, 429 00:43:55,930 --> 00:44:00,958 rocks that have been ground to fragments by the glaciers and pushed in front of them. 430 00:44:02,136 --> 00:44:07,335 This is the tundra, a land full of strange shapes and patterns. 431 00:44:07,775 --> 00:44:11,541 Fine muds and sands retain more moisture than coarse gravel, 432 00:44:11,712 --> 00:44:14,442 so when they freeze, they expand more 433 00:44:14,615 --> 00:44:19,609 and push the gravel outwards to produce these geometric shapes. 434 00:44:20,021 --> 00:44:23,513 A foot down, the soil is still frozen, permafrost, 435 00:44:23,691 --> 00:44:26,489 so the summer melt water can't soak away 436 00:44:26,661 --> 00:44:31,997 and the land is covered with bogs and ponds that lie within the polygonal ridges, 437 00:44:32,166 --> 00:44:36,125 so that the land looks almost as though it's been cultivated by man. 438 00:44:39,841 --> 00:44:44,642 In places, the underground ice pushes upwards into a mountain called a pingo. 439 00:44:45,546 --> 00:44:49,983 It looks like a small volcano, but instead of hot lava in its heart, 440 00:44:50,151 --> 00:44:52,585 it has cold, blue ice. 441 00:45:04,031 --> 00:45:08,730 Although the ice relaxes its grip for only a few weeks in summer, 442 00:45:08,903 --> 00:45:13,863 a surprising number of plants and animals manage to find a permanent home here. 443 00:45:18,145 --> 00:45:20,613 Small flowering plants keep low, 444 00:45:20,781 --> 00:45:26,083 for close to the ground there is little wind and the sun's rays can be quite warm. 445 00:45:33,661 --> 00:45:37,620 One kind of tree manages to live up here in large numbers 446 00:45:37,798 --> 00:45:40,460 by adopting exactly the same policy. 447 00:45:41,702 --> 00:45:44,432 This is the Arctic willow and it lies flat. 448 00:45:44,605 --> 00:45:47,301 It grows extremely slowly in these cold temperatures, 449 00:45:47,475 --> 00:45:52,811 and this one may be a century or so old. 450 00:45:53,948 --> 00:45:56,075 In shallow burrows in the topsoil 451 00:45:56,250 --> 00:46:01,347 live the harvesters of this meagre crop of leaves and grass: Lemmings. 452 00:46:04,892 --> 00:46:08,760 In summer, when there's food about, they breed with great speed. 453 00:46:08,996 --> 00:46:15,196 One female produces five or six babies in a litter, four or five times in a single season 454 00:46:15,469 --> 00:46:18,836 So in a few months she may produce 30 young. 455 00:46:19,106 --> 00:46:23,475 The babies grow so quickly that the first to be born in the spring 456 00:46:23,644 --> 00:46:26,772 can themselves produce young before the winter returns. 457 00:46:33,521 --> 00:46:37,252 In summer, all the tundra plants put out their leaves 458 00:46:37,425 --> 00:46:38,915 and there's lots to eat. 459 00:46:46,534 --> 00:46:49,697 The swarming hordes of lemmings attract hunters: 460 00:46:52,273 --> 00:46:53,706 Snowy owls. 461 00:47:06,721 --> 00:47:10,088 During the summer, lemmings are the owl's main food. 462 00:47:29,276 --> 00:47:34,145 Abundant though the lemmings are, the hunting has been poor for this owl. 463 00:47:34,348 --> 00:47:39,115 She may have laid as many as eight eggs, but only one chick has survived. 464 00:47:54,702 --> 00:47:58,832 As the days lengthen, herds of caribou migrate up from the south. 465 00:47:59,473 --> 00:48:05,070 Their calves were born early in the season and the herd moves up to 15 miles a day 466 00:48:05,446 --> 00:48:10,179 They have to keep traveling in order to find enough food to sustain them all. 467 00:48:39,180 --> 00:48:41,410 They follow the same route each year. 468 00:48:41,582 --> 00:48:44,415 In places, paths are worn 18 inches deep 469 00:48:44,585 --> 00:48:48,043 where the animals have passed, century after century. 470 00:48:54,161 --> 00:48:56,026 Snow geese fly up, too. 471 00:48:56,330 --> 00:49:00,357 They've come from as far away as Mexico, 3,000 miles distant, 472 00:49:00,534 --> 00:49:04,903 to claim a share in summer's brief crop and to breed. 473 00:49:14,014 --> 00:49:15,879 They exist in two forms: 474 00:49:16,050 --> 00:49:20,111 Ones with dark feathers on the body, as well as pure-white ones. 475 00:49:20,488 --> 00:49:24,015 But they're all the same species, and mixed couples are common. 476 00:49:28,095 --> 00:49:31,223 Soon the tundra is thick with their nests. 477 00:49:34,168 --> 00:49:38,434 Ptarmigan, now in their dark summer plumage, feed on the willow scrub. 478 00:49:45,746 --> 00:49:49,375 The caribou take not only willow, but grasses and lichen. 479 00:50:01,629 --> 00:50:05,861 The first snow geese to arrive already have goslings, 480 00:50:06,033 --> 00:50:07,796 and are foraging as a family. 481 00:50:16,577 --> 00:50:18,636 Later arrivals are still on the nest, 482 00:50:18,813 --> 00:50:22,340 and can't leave until the last egg has hatched. 483 00:50:22,817 --> 00:50:25,843 While there, the first goslings to emerge and their parents 484 00:50:26,020 --> 00:50:30,787 are plagued by hordes of voracious blood-hungry mosquitoes. 485 00:50:45,573 --> 00:50:49,441 From the warming pools, more and more mosquitoes hatch. 486 00:50:55,950 --> 00:51:00,410 They provide food for the red-necked phalarope, and there are plenty to gather. 487 00:51:00,588 --> 00:51:05,821 A square yard of fresh water here can produce 100,000 insects in a season. 488 00:51:06,894 --> 00:51:08,486 Now the blackfly larvae, 489 00:51:08,662 --> 00:51:12,223 which as eggs were attached to stones in the shallow pools, 490 00:51:12,399 --> 00:51:14,663 are also beginning to emerge. 491 00:51:36,056 --> 00:51:42,655 Activity now is intense, for it is light for almost the whole 24 hours of the day. 492 00:51:45,266 --> 00:51:49,100 But by late August, the snow geese sense the imminence of winter 493 00:51:49,270 --> 00:51:51,465 and start to head southwards again. 494 00:52:01,348 --> 00:52:03,873 The caribou, too, end their grazing, 495 00:52:04,051 --> 00:52:07,043 and start to plod back across the tundra. 496 00:52:07,655 --> 00:52:09,520 As they go, they continue to feed, 497 00:52:09,690 --> 00:52:14,252 building up the reserves of fat they will need to sustain themselves through the winter. 498 00:52:34,181 --> 00:52:39,050 As the weather gets colder and colder, the need for shelter becomes more urgent 499 00:52:39,320 --> 00:52:42,221 and the herds may cover 25 miles in a day. 500 00:53:03,077 --> 00:53:08,481 And then, at last, the returning travellers reach the first tall tree 501 00:53:08,849 --> 00:53:11,249 It's the start of the great coniferous forest 502 00:53:11,418 --> 00:53:14,945 that lies south of the tundra right round the globe. 503 00:53:15,656 --> 00:53:18,853 The snow geese will fly on for thousands of miles, 504 00:53:19,026 --> 00:53:22,427 but the caribou have reached their wintering grounds. 505 00:53:22,930 --> 00:53:24,898 The forest is a sanctuary 506 00:53:25,065 --> 00:53:28,364 which will protect them from the bitter winter col 507 00:53:28,736 --> 00:53:32,672 and it's here that we shall be coming in the next programme. 508 00:53:32,722 --> 00:53:37,272 Repair and Synchronization by Easy Subtitles Synchronizer 1.0.0.0 49569

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