1 00:00:00,000 --> 00:00:25,051 © anoXmous @ http://thepiratebay.sx/user/Zen_Bud 1 00:00:31,610 --> 00:00:35,780 Both poles of our planet are covered with ice. 2 00:00:36,080 --> 00:00:41,000 They're the largest and most demanding wildernesses of all. 3 00:00:42,750 --> 00:00:47,670 Nowhere else on Earth is seasonal change so extreme. 4 00:00:47,800 --> 00:00:53,220 It causes the ice to advance and retreat every year. 5 00:00:54,260 --> 00:00:58,470 And all life here is governed by that. 6 00:01:17,120 --> 00:01:20,830 When the first polar explorers headed south, 7 00:01:20,950 --> 00:01:26,290 giant cathedrals of ice marked their entry into uncharted territory. 8 00:01:31,460 --> 00:01:33,470 Passing the towering spires, 9 00:01:33,550 --> 00:01:37,260 they must have wondered what unearthly sights lay in store. 10 00:01:42,430 --> 00:01:46,560 As they battled on, the ice became increasingly dominant, 11 00:01:46,690 --> 00:01:52,900 but nothing could have prepared them for the ice world that finally loomed into view. 12 00:01:59,030 --> 00:02:03,620 Terra incognita, ''the unknown land''. 13 00:02:16,130 --> 00:02:18,850 At the southernmost extreme of our planet, 14 00:02:18,930 --> 00:02:24,480 the continent of Antarctica is as large as the United States of America. 15 00:02:31,020 --> 00:02:34,570 Ninety per cent of all the world's ice is found here. 16 00:02:38,320 --> 00:02:44,750 This frozen world is largely deserted until the start of spring. 17 00:02:50,000 --> 00:02:53,960 Adelie penguins in a hurry. 18 00:03:00,640 --> 00:03:02,640 The clock is ticking. 19 00:03:02,720 --> 00:03:09,520 Instead of waiting for the summer melt, the new arrivals hasten south over the frozen sea. 20 00:03:21,820 --> 00:03:26,290 They have come here to breed, but polar summers are so short, 21 00:03:26,410 --> 00:03:30,210 they must be in position before the thaw starts. 22 00:03:35,710 --> 00:03:40,890 As the sea ice retreats, life can journey farther south. 23 00:03:46,930 --> 00:03:53,230 Antarctic waters are so rich that visitors come from far and wide to harvest them. 24 00:04:01,780 --> 00:04:06,910 Vast numbers of chinstrap penguins come ashore to breed. 25 00:04:15,340 --> 00:04:19,510 No bird will lay their eggs directly onto ice 26 00:04:19,630 --> 00:04:22,970 so bare rock is a vital commodity. 27 00:04:23,090 --> 00:04:26,220 The best patches are worth the climb. 28 00:04:31,350 --> 00:04:34,360 The cliff tops are soon stained pink 29 00:04:34,440 --> 00:04:38,530 with the droppings of tens of thousands of nesting penguins. 30 00:04:47,540 --> 00:04:54,670 0nly in a land almost entirely covered in ice could bare rock be reckoned an oasis. 31 00:04:57,300 --> 00:05:01,670 Some will travel into the heart of the continent to find it. 32 00:05:03,680 --> 00:05:09,520 These are nunataks, the exposed peaks of vast mountain ranges 33 00:05:09,640 --> 00:05:12,640 buried in ice over a mile deep. 34 00:05:15,100 --> 00:05:20,110 The eerie silence here is only broken in spring. 35 00:05:27,490 --> 00:05:31,790 The snow petrels have arrived and are courting. 36 00:05:39,090 --> 00:05:44,260 Antarctic petrels now join the most southerly bird colony on Earth. 37 00:05:46,300 --> 00:05:52,230 The birds have flown inland for over 300 miles to reach this breeding site. 38 00:05:57,270 --> 00:06:02,820 0nce their eggs have hatched, they will be forced repeatedly to make the 600-mile round trip 39 00:06:02,940 --> 00:06:05,780 to gather food in the ocean. 40 00:06:07,120 --> 00:06:12,620 First, though, valuable nesting places must be defended from property thieves. 41 00:06:20,170 --> 00:06:25,630 After laying their eggs, the petrels take time out to clean their plumage. 42 00:06:46,990 --> 00:06:51,950 The south polar skua is a formidable opportunist. 43 00:06:55,620 --> 00:06:59,380 But the skuas have not chanced upon the petrels, 44 00:06:59,500 --> 00:07:01,960 they've been waiting for them. 45 00:07:05,670 --> 00:07:09,800 These birds do not need to go to the ocean for their food. 46 00:07:28,240 --> 00:07:32,530 The skuas can survive further south than any other predator 47 00:07:32,660 --> 00:07:36,830 by exploiting the petrels' desperate need for bare rock. 48 00:07:48,010 --> 00:07:53,430 Even at the height of summer, less than three per cent of Antarctica is free of ice, 49 00:07:53,510 --> 00:07:58,600 and nearly all of that exposed rock is found in one place, 50 00:07:58,690 --> 00:08:01,480 the Antarctic Peninsula. 51 00:08:07,740 --> 00:08:11,820 Its long arm extends further north than the rest of the continent, 52 00:08:11,910 --> 00:08:15,830 so spring arrives here first. 53 00:08:29,590 --> 00:08:32,720 The thaw unlocks sheltered bays 54 00:08:32,800 --> 00:08:37,350 that provide refuge from the relentless battering of the Southern 0cean. 55 00:08:42,400 --> 00:08:45,610 In the depths, something stirs. 56 00:09:10,720 --> 00:09:12,720 Humpback whales. 57 00:09:12,800 --> 00:09:17,430 They have travelled over 5,000 miles to reach these waters. 58 00:09:24,770 --> 00:09:27,520 The whales are harvesting krill, 59 00:09:27,770 --> 00:09:32,610 shrimp-like creatures that begin to swarm here as soon as the ice retreats. 60 00:09:47,880 --> 00:09:53,470 Diving into the heart of the swarm, teams of whales spiral round each other 61 00:09:53,550 --> 00:09:55,640 in close coordination. 62 00:09:58,720 --> 00:10:04,640 Now they turn, blasting air from their blowholes, and ascend towards their prey. 63 00:10:06,850 --> 00:10:12,190 The krill becomes concentrated as the spiralling net of bubbles draws inwards. 64 00:10:40,350 --> 00:10:45,520 The team of whales work round the clock for the boom is short-lived. 65 00:10:45,640 --> 00:10:47,690 Summer is already fading 66 00:10:47,810 --> 00:10:51,940 and the whales will soon be forced north as winter returns. 67 00:10:56,490 --> 00:11:01,950 The sun's influence diminishes and the ocean starts to freeze. 68 00:11:02,080 --> 00:11:05,870 The greatest seasonal change on our planet is underway. 69 00:11:12,550 --> 00:11:18,550 The ice grows at an extraordinary rate, advancing two and a half miles a day. 70 00:11:18,680 --> 00:11:23,310 In a matter of weeks, the continent effectively doubles in size. 71 00:11:27,100 --> 00:11:30,310 Life flees from Antarctica. 72 00:11:37,150 --> 00:11:39,570 But one creature is just arriving. 73 00:11:45,080 --> 00:11:50,120 Every winter, emperor penguins leave the comfort of their ocean home 74 00:11:50,210 --> 00:11:52,840 and begin a remarkable journey. 75 00:11:55,260 --> 00:12:00,890 They head towards their breeding grounds, almost 100 miles inland. 76 00:12:24,280 --> 00:12:28,960 Eventually, the emperor penguins reach the place where they were hatched, 77 00:12:29,040 --> 00:12:33,960 an area sheltered by icebergs, trapped in the frozen ocean. 78 00:12:34,840 --> 00:12:37,800 Here they will raise the next generation. 79 00:12:44,930 --> 00:12:48,270 But first, each must find a mate. 80 00:12:51,230 --> 00:12:53,860 The males begin to serenade. 81 00:12:58,570 --> 00:13:04,030 And if a female replies, they pair up, posing like statues. 82 00:13:08,410 --> 00:13:11,710 New couples quickly form a strong bond. 83 00:13:11,790 --> 00:13:15,460 They seem oblivious to the noisy crowd around them. 84 00:13:18,420 --> 00:13:22,930 To cement their relationship, the male steps out with his female. 85 00:13:33,390 --> 00:13:38,070 The brief courtship complete, there isn't a moment to lose. 86 00:13:38,190 --> 00:13:43,700 With so much pressure to perform, any male would struggle to stay on top. 87 00:13:51,830 --> 00:13:56,540 Several weeks later, and it seems that most couplings were successful. 88 00:13:57,920 --> 00:14:01,510 But producing the egg has taken its toll. 89 00:14:02,300 --> 00:14:05,640 The females no longer have the energy to incubate. 90 00:14:08,100 --> 00:14:10,140 The male takes over. 91 00:14:10,390 --> 00:14:13,230 It's still minus 20 degrees centigrade, 92 00:14:13,310 --> 00:14:17,810 so the transfer must be done quickly or else the egg will freeze. 93 00:14:17,900 --> 00:14:23,190 With no bare rock to nest on, the male tucks the egg into a special pouch, 94 00:14:23,320 --> 00:14:26,070 where he can keep it warm. 95 00:14:26,160 --> 00:14:29,780 It requires an extraordinary piece of teamwork. 96 00:14:34,210 --> 00:14:40,000 Driven by hunger, the exhausted females now return to the ocean on their own, 97 00:14:40,090 --> 00:14:45,220 repeating the epic journey they made with the males only a month before. 98 00:14:51,640 --> 00:14:54,730 Now the sun barely appears above the horizon. 99 00:14:56,310 --> 00:15:00,940 As the days shorten, its warmth is withdrawn from the continent. 100 00:15:12,540 --> 00:15:18,170 With the females gone, the colony undergoes a strange transformation. 101 00:15:19,250 --> 00:15:21,630 The males shuffle into groups, 102 00:15:21,710 --> 00:15:25,010 their eggs still tucked away above their feet. 103 00:15:27,930 --> 00:15:33,890 They lock together in tightly-packed huddles as they struggle to keep warm. 104 00:15:37,600 --> 00:15:42,690 Speeding up the action reveals how these huddles constantly shift and change 105 00:15:42,820 --> 00:15:47,860 as each penguin works its way towards the warmer interior. 106 00:15:49,110 --> 00:15:53,280 Crammed into this scrum, the birds are remarkably good-natured. 107 00:15:53,370 --> 00:15:55,120 But they have to be. 108 00:15:55,200 --> 00:16:00,120 If the huddle breaks, even for a moment, precious heat escapes. 109 00:16:19,100 --> 00:16:23,230 It's imperative they reform as quickly as possible, 110 00:16:23,360 --> 00:16:29,360 for only by acting as one can the males withstand the elements and protect their eggs. 111 00:16:35,080 --> 00:16:39,040 But their greatest test lies ahead. 112 00:16:39,160 --> 00:16:43,790 As winter advances, frequent blizzards drive the temperature down. 113 00:16:45,090 --> 00:16:49,130 It's now 60 degrees below zero. 114 00:16:52,010 --> 00:16:57,430 The birds at the edge of the huddle bear the brunt of the 100-mile-an-hour winds 115 00:16:57,520 --> 00:17:02,440 and so provide shelter to those taking their turn in the middle. 116 00:17:10,950 --> 00:17:15,280 Abandoned by the sun, the males are left alone with their eggs 117 00:17:15,370 --> 00:17:19,160 to face the coldest, darkest winter on Earth. 118 00:17:27,250 --> 00:17:33,720 At the northern extreme of our planet, the sun rises for the first time in months, 119 00:17:33,840 --> 00:17:36,550 illuminating a very different ice world. 120 00:17:40,520 --> 00:17:47,480 Unlike Antarctica, the Arctic is a vast frozen sea surrounded by land. 121 00:17:49,690 --> 00:17:53,070 Here winter is coming to an end 122 00:17:53,150 --> 00:17:57,780 but this bleak wilderness remains locked in ice. 123 00:18:05,500 --> 00:18:08,630 Eider ducks break the silence. 124 00:18:08,750 --> 00:18:11,970 They have stayed here, braving the northern winter, 125 00:18:12,050 --> 00:18:15,180 instead of flying south to warmer climes. 126 00:18:19,350 --> 00:18:24,190 Flocks 40,000 strong sweep across the frozen wastes. 127 00:18:38,780 --> 00:18:42,500 They all have the same goal, a polynya, 128 00:18:42,620 --> 00:18:44,710 a permanent hole in the sea ice, 129 00:18:44,830 --> 00:18:48,920 kept open throughout the winter by strong ocean currents. 130 00:18:53,130 --> 00:18:57,800 This unusual duck pond provides an overnight sanctuary 131 00:18:57,930 --> 00:19:02,390 and, when day breaks, a rare chance to feed. 132 00:19:14,570 --> 00:19:21,450 Just 10 metres beneath the ice, the sea floor is carpeted with dense mussel beds. 133 00:19:23,290 --> 00:19:27,580 These can only be reached during a brief lull in the currents. 134 00:19:27,710 --> 00:19:33,210 The ducks must quickly prise the mussels free before the tide starts to turn. 135 00:19:40,510 --> 00:19:43,260 The window of opportunity is short. 136 00:19:43,350 --> 00:19:47,690 As the current begins to build, it's up, up and away. 137 00:19:59,860 --> 00:20:05,580 These permanent holes in the ice provide seafood throughout the winter. 138 00:20:07,500 --> 00:20:09,750 The diners attract others. 139 00:20:16,710 --> 00:20:21,300 In the Arctic, any breach in the icy barrier can be a lifeline. 140 00:20:26,100 --> 00:20:29,690 Musk oxen create their own. 141 00:20:29,980 --> 00:20:34,270 These giants have the strength to smash through the frozen crust 142 00:20:34,360 --> 00:20:38,240 to graze on the vegetation below. 143 00:20:41,570 --> 00:20:45,950 The ice-breakers create an opening for other over-winterers. 144 00:20:47,750 --> 00:20:53,040 Flocks of ptarmigan make unusual grazing companions for the musk oxen, 145 00:20:53,130 --> 00:20:56,250 whose entourage grows throughout the day. 146 00:21:05,100 --> 00:21:09,930 This odd assembly of vegetarians doesn't go unnoticed. 147 00:21:11,270 --> 00:21:13,400 An arctic fox. 148 00:21:18,570 --> 00:21:22,070 The musk oxen have recently given birth. 149 00:21:22,860 --> 00:21:25,450 For the fox, it's a chance to scavenge. 150 00:21:33,750 --> 00:21:38,880 But half a ton of mad hairy cow is not to be trifled with. 151 00:21:48,510 --> 00:21:51,480 The calves are born well before the spring melt, 152 00:21:51,600 --> 00:21:55,860 giving them a head start when summer finally arrives. 153 00:22:00,190 --> 00:22:03,910 It must get to grips with its new ice world, 154 00:22:04,030 --> 00:22:08,080 benign one minute, life-threatening the next. 155 00:22:14,330 --> 00:22:18,590 Even in spring, winds chill to the bone. 156 00:22:21,550 --> 00:22:27,260 The calf must stay close to its mother to avoid getting lost in the sudden blizzard. 157 00:22:36,980 --> 00:22:38,570 Arctic wolves! 158 00:22:43,110 --> 00:22:47,240 In the whiteout, the threat is almost impossible to detect, 159 00:22:47,320 --> 00:22:51,120 but the musk oxen instinctively retreat to higher ground. 160 00:23:07,720 --> 00:23:10,640 Forming a defensive ring around their calves, 161 00:23:10,760 --> 00:23:14,680 the adults present a barricade that few hunters could breach. 162 00:23:17,480 --> 00:23:21,110 But the wolves need not risk injury today. 163 00:23:23,440 --> 00:23:26,450 A calf has been left behind in the panic. 164 00:23:40,130 --> 00:23:44,920 With each passing day, the sun climbs higher in the sky 165 00:23:45,010 --> 00:23:49,390 and its rays strike the Arctic more directly. 166 00:23:49,470 --> 00:23:53,390 It's spring and new life stirs. 167 00:23:58,190 --> 00:24:02,190 The polar bear cubs emerge from the den in which they were born. 168 00:24:02,900 --> 00:24:07,950 Their mother stretches her legs after five months under the snow. 169 00:24:13,410 --> 00:24:17,830 They are just two months old and instinctively follow her lead. 170 00:24:34,560 --> 00:24:41,770 A steep slope makes the best site for a den, but it's a tricky place to take your first steps. 171 00:25:01,710 --> 00:25:07,380 It may look like fun but this is serious training for the task ahead. 172 00:25:07,510 --> 00:25:09,380 There is no food on the slopes 173 00:25:09,510 --> 00:25:12,640 and the family will need to head out across the frozen sea 174 00:25:12,760 --> 00:25:15,350 before the mother's milk runs dry. 175 00:25:22,520 --> 00:25:24,980 Two weeks later, they are ready. 176 00:25:26,770 --> 00:25:30,780 0ut on the sea ice, the female can hunt for seals 177 00:25:30,900 --> 00:25:35,410 but it will take all her mothering skills to keep her cubs safe 178 00:25:35,530 --> 00:25:37,830 in this dangerous world of ice. 179 00:25:53,720 --> 00:25:57,810 The annual melt has begun. 180 00:25:58,770 --> 00:26:02,810 This is a challenging time for the bear family. 181 00:26:02,890 --> 00:26:08,150 0ne out of every two cubs do not survive their first year out on the ice. 182 00:26:19,700 --> 00:26:25,040 As the sun's influence increases, the sea ice seems to take on a life of its own. 183 00:26:34,220 --> 00:26:38,680 Glacial melt waters pour from the land, mingling with the sea 184 00:26:38,810 --> 00:26:40,770 and speeding up the thaw. 185 00:26:46,440 --> 00:26:49,230 The seascape is in constant flux 186 00:26:49,520 --> 00:26:53,360 as broken ice is moved on by winds and currents. 187 00:27:02,790 --> 00:27:07,710 The ice is becoming too weak to support a male polar bear. 188 00:27:16,260 --> 00:27:19,050 He attempts to spread his weight, 189 00:27:19,140 --> 00:27:23,560 but the ice that has supported him all winter is rapidly disintegrating. 190 00:27:26,390 --> 00:27:31,520 Each year, as the climate warms, the Arctic holds less ice. 191 00:27:31,650 --> 00:27:34,740 This is a disaster for polar bears. 192 00:27:34,860 --> 00:27:36,650 Without its solid platform, 193 00:27:36,780 --> 00:27:41,080 they can't hunt the seals they need in order to survive. 194 00:27:44,330 --> 00:27:47,870 This may be a glimpse of the unstable future 195 00:27:47,960 --> 00:27:50,750 faced by this magnificent creature. 196 00:28:24,660 --> 00:28:30,210 As the ice disappears, seabirds return to the high Arctic. 197 00:28:38,680 --> 00:28:42,550 Little auks arrive in their millions. 198 00:28:44,760 --> 00:28:49,140 In some ways, these birds are the penguins of the north. 199 00:28:49,390 --> 00:28:54,730 They seek bare rock on which to lay their eggs and they look rather like penguins, too. 200 00:29:01,530 --> 00:29:06,620 Unlike Antarctica, the Arctic can be reached by land-based predators, 201 00:29:06,740 --> 00:29:10,420 which is why little auks have kept the ability to fly. 202 00:29:15,920 --> 00:29:21,800 They use scree slopes to protect their eggs, burrowing up to a metre beneath the rocks. 203 00:29:29,230 --> 00:29:32,560 At the height of summer, the sun never sets, 204 00:29:32,650 --> 00:29:36,320 but just skims the horizon before rising again. 205 00:29:42,200 --> 00:29:46,780 Migrants return to the Arctic from far and wide. 206 00:29:47,450 --> 00:29:52,620 They've come to make the most of the brief flush of food and to produce their young. 207 00:29:54,710 --> 00:29:58,840 Sandhill cranes have travelled all the way from New Mexico. 208 00:30:05,090 --> 00:30:10,680 Their chicks join the growing band of youngsters exploring the tundra. 209 00:30:18,020 --> 00:30:23,950 For a few months each year, the Arctic becomes ''The land of the midnight sun'' 210 00:30:24,200 --> 00:30:28,990 and 24 hours of daylight allow animals to feed around the clock. 211 00:30:31,040 --> 00:30:36,210 The arctic fox finally has enough food to raise her large family. 212 00:30:52,140 --> 00:30:56,980 If you choose to nest in the open, you must be prepared for a fight. 213 00:31:06,280 --> 00:31:11,620 Arctic skuas will see off any trespassers, even large vegetarians. 214 00:31:58,630 --> 00:32:04,090 The male polar bear's ice world has finally vanished beneath him. 215 00:32:16,430 --> 00:32:21,360 While the female is still kept on land by her dependent cubs, 216 00:32:21,480 --> 00:32:24,940 the male can take to the sea in search of food. 217 00:32:25,240 --> 00:32:28,820 Ducking and diving, he hopes to ambush seals 218 00:32:28,950 --> 00:32:32,280 resting on the remaining fragments of ice. 219 00:32:59,440 --> 00:33:05,530 In these new surroundings, he is a surprisingly adept swimmer. 220 00:33:15,990 --> 00:33:18,830 0nce an extremely rare sight, 221 00:33:18,960 --> 00:33:23,710 polar bears have recently been seen over 60 miles from the shore. 222 00:33:37,930 --> 00:33:42,020 There is now no turning back for this bear. 223 00:33:42,150 --> 00:33:45,860 He is forced to head out into deeper water. 224 00:33:53,910 --> 00:33:58,790 His giant front paws help him to fight the ocean currents. 225 00:34:20,310 --> 00:34:25,360 He seems at home in the sea, but he cannot swim indefinitely. 226 00:34:29,030 --> 00:34:34,700 He will drown if he doesn't find land somewhere in this vast ocean. 227 00:35:02,810 --> 00:35:07,360 Walruses are now gathering on low-lying islands. 228 00:35:07,440 --> 00:35:12,070 They gave birth on the sea ice, but with this platform now gone, 229 00:35:12,150 --> 00:35:15,910 they need a new place to haul out and nurse their young. 230 00:35:18,660 --> 00:35:23,830 After several days at sea, the male bear finally makes landfall, 231 00:35:24,000 --> 00:35:28,130 drawn by the pungent smells emanating from the island. 232 00:35:36,590 --> 00:35:41,430 By the end of the summer, the bear has lost half his weight. 233 00:35:41,560 --> 00:35:46,690 With the ice long gone, he is forced onto land in search of food. 234 00:35:56,320 --> 00:36:00,070 There will be no easy meals on this island. 235 00:36:00,160 --> 00:36:03,450 Walruses are the largest seals in the world. 236 00:36:03,540 --> 00:36:08,580 They weigh over a ton and are armed with tusks a metre long. 237 00:36:11,590 --> 00:36:16,260 Exhausted from his swim, the bear must regain his strength. 238 00:36:23,560 --> 00:36:27,690 The next day, a sea fog shrouds the island. 239 00:36:27,770 --> 00:36:30,770 The walruses sense that they are in danger. 240 00:36:33,900 --> 00:36:38,110 Using the fog as cover, the bear approaches the herd. 241 00:36:43,490 --> 00:36:46,290 The adults close ranks around their young, 242 00:36:46,410 --> 00:36:49,790 presenting a wall of blubber and hide. 243 00:36:57,470 --> 00:37:02,180 He tests the barrier, but it stands firm. 244 00:37:03,810 --> 00:37:08,810 It appears that the world's largest land carnivore has met his match. 245 00:37:16,860 --> 00:37:20,280 There must be a chink in the armour somewhere. 246 00:37:23,830 --> 00:37:25,200 Not here! 247 00:37:34,210 --> 00:37:39,670 This female walrus is shielding her pup, if he can just prise her off... 248 00:37:47,060 --> 00:37:51,690 The bear's claws and teeth can't penetrate her thick hide. 249 00:38:00,610 --> 00:38:04,870 With the herd retreating to water, the bear must move quickly. 250 00:38:10,540 --> 00:38:14,080 Having failed with one, he heads straight for another. 251 00:38:31,980 --> 00:38:36,560 The chance of his first meal in months is slipping away. 252 00:38:43,740 --> 00:38:46,070 He seems increasingly desperate. 253 00:38:52,080 --> 00:38:53,580 It's now or never. 254 00:38:54,960 --> 00:38:58,880 He must avoid the stabbing tusks if he is to win. 255 00:39:06,090 --> 00:39:09,220 The flailing walrus is immensely powerful 256 00:39:09,350 --> 00:39:14,020 and drags the bear away from the shallows towards the safety of the herd. 257 00:39:30,120 --> 00:39:32,200 It slips from his grasp. 258 00:39:41,210 --> 00:39:43,550 0nly at the height of summer, 259 00:39:43,630 --> 00:39:49,350 when bears are on the verge of starvation, will they risk attacking such dangerous prey. 260 00:39:54,230 --> 00:39:57,440 It was a gamble that this bear took and lost. 261 00:40:01,150 --> 00:40:07,570 The stab wounds he received from the walrus are so severe that he can barely walk. 262 00:40:12,740 --> 00:40:15,580 The walruses are calm again, 263 00:40:15,660 --> 00:40:21,420 seemingly aware that the injured bear no longer poses a threat to them or their young. 264 00:40:38,020 --> 00:40:42,520 Unable to feed, this bear will not survive. 265 00:40:55,290 --> 00:41:01,750 If the global climate continues to warm, and the Arctic ice melts sooner each year, 266 00:41:01,830 --> 00:41:05,840 it is certain that more bears will share this fate. 267 00:41:28,440 --> 00:41:35,080 At the southern end of our planet, fiery ribbons are illuminating the winter skies. 268 00:41:35,160 --> 00:41:37,540 The aurora australis. 269 00:41:41,210 --> 00:41:45,460 This light brings no warmth to the male penguins, 270 00:41:45,590 --> 00:41:50,340 who are still huddling, defying the coldest conditions on the planet. 271 00:42:04,690 --> 00:42:07,780 Their ordeal is drawing to a close. 272 00:42:16,030 --> 00:42:22,330 Thirty days after it last set, the sun rises once more on Antarctica. 273 00:42:45,440 --> 00:42:49,820 Their appalling trials have all been for this. 274 00:43:06,170 --> 00:43:10,420 Each father has just one meal left inside him. 275 00:43:11,840 --> 00:43:14,880 He has been saving it all winter. 276 00:43:15,640 --> 00:43:21,470 This single feed will sustain the chicks for a few more days, 277 00:43:21,560 --> 00:43:24,640 but the males have not eaten for nearly four months. 278 00:43:24,730 --> 00:43:29,150 If they do not eat soon, they and their chicks will die. 279 00:43:39,950 --> 00:43:43,500 But there is hope on the horizon. 280 00:43:55,050 --> 00:44:00,310 The females are returning and their bellies are full with fish. 281 00:44:07,150 --> 00:44:11,270 As they approach, waves of excitement ripple through the huddle. 282 00:44:20,120 --> 00:44:27,370 Each female calls to her mate and he, recognising her song, trumpets back. 283 00:44:30,380 --> 00:44:32,840 Reunited at last. 284 00:44:36,470 --> 00:44:39,550 The mother sees her chick for the first time. 285 00:44:44,140 --> 00:44:47,140 She's keen to start parenting, 286 00:44:47,270 --> 00:44:52,520 but the father needs persuading to surrender the chick he has been caring for all winter. 287 00:44:57,450 --> 00:45:00,320 He must now put his chick at risk. 288 00:45:00,410 --> 00:45:03,660 In these temperatures it could freeze in seconds. 289 00:45:07,830 --> 00:45:10,210 The male will have to let go. 290 00:45:17,300 --> 00:45:21,220 Eventually, the transfer to the mother is safely made. 291 00:45:36,780 --> 00:45:40,990 The chicks grow quickly on a diet of fish and squid. 292 00:45:55,500 --> 00:46:00,630 Soon they are keen to explore, but always with mother in tow. 293 00:46:03,300 --> 00:46:08,730 This chick is less fortunate, its mother has not returned to claim it. 294 00:46:11,350 --> 00:46:14,360 Another orphan is searching for a new family, 295 00:46:14,440 --> 00:46:17,980 but this female already has a chick of her own. 296 00:46:26,780 --> 00:46:29,410 Some orphans receive too much mothering 297 00:46:29,500 --> 00:46:33,000 from penguins whose own chicks have not survived. 298 00:46:33,080 --> 00:46:37,380 The urge to parent is so strong that they will compete with one another 299 00:46:37,460 --> 00:46:39,630 to adopt any chick they find. 300 00:46:44,970 --> 00:46:51,480 Many of these squabbles end in tragedy as the poor chick is trampled to death. 301 00:47:03,820 --> 00:47:08,740 Those chicks that do have parents quickly learn survival skills. 302 00:47:10,950 --> 00:47:14,170 Even in spring, they must huddle together for warmth, 303 00:47:14,250 --> 00:47:18,040 just as their fathers did in the depths of winter. 304 00:47:21,970 --> 00:47:24,840 A group of chicks has got lost in the blizzard. 305 00:47:32,140 --> 00:47:36,060 Cold and disorientated, they search for the colony. 306 00:47:43,150 --> 00:47:48,200 It will not be long before the storm claims its first victims. 307 00:48:07,140 --> 00:48:12,310 By early summer, the chicks are surprisingly well-developed 308 00:48:12,430 --> 00:48:16,100 and now look ready to take on the world. 309 00:48:17,600 --> 00:48:22,480 Those that survive their first year have the best possible start in life 310 00:48:22,570 --> 00:48:27,240 thanks to the extraordinary hardships endured by their parents. 311 00:48:28,240 --> 00:48:33,910 Parents who battled with the Antarctic winter and won. 312 00:48:43,670 --> 00:48:49,010 In the Arctic, the two polar bear cubs are now independent of their mother 313 00:48:49,090 --> 00:48:52,970 and they briefly reunite where their home ranges overlap. 314 00:49:00,610 --> 00:49:03,730 Their time together will be fleeting. 315 00:49:03,860 --> 00:49:10,700 Most of their lives are now spent alone, wandering the vast tracts of frozen ocean. 316 00:49:40,190 --> 00:49:44,940 Following their mother has prepared them for life at the pole, 317 00:49:45,020 --> 00:49:49,030 an ever-changing land ruled by ice. 318 00:49:51,200 --> 00:49:53,370 Whether they are ready for the bigger changes 319 00:49:53,450 --> 00:49:58,960 that have begun to shape the ice worlds of our planet remains to be seen. 293 00:50:19,164 --> 00:50:34,164 © anoXmous @ http://thepiratebay.sx/user/Zen_Bud