1 00:00:15,648 --> 00:00:19,914 This is a story about one of the most inhospitable places on Earth... 2 00:00:20,086 --> 00:00:23,112 ...and animals that have to survive here... 3 00:00:25,892 --> 00:00:27,450 ...they must find food here... 4 00:00:27,627 --> 00:00:32,394 ...and raise their young and protect them from the dangers of the frozen wilderness. 5 00:00:34,701 --> 00:00:38,137 The main danger is others of their own kind - 6 00:00:38,438 --> 00:00:42,306 the main ally the constantly changing sea ice. 7 00:00:49,682 --> 00:00:52,048 They navigate here with heightened senses, 8 00:00:52,218 --> 00:00:55,119 evolved to lead them straight to food. 9 00:00:59,793 --> 00:01:01,055 This is a story, 10 00:01:01,227 --> 00:01:05,459 but it's based on years of research by teams of Arctic scientists. 11 00:01:06,433 --> 00:01:10,199 ln it, we follow the victories and defeats over a single year... 12 00:01:10,370 --> 00:01:13,862 ...on the polar bear battlefield. 13 00:01:38,765 --> 00:01:40,699 This is polar bear country - 14 00:01:40,867 --> 00:01:43,927 a vast frozen sea bordered by stark mountains, 15 00:01:44,104 --> 00:01:47,540 glaciers and barren, snow-covered shores. 16 00:01:49,776 --> 00:01:52,108 lt's a white wilderness at the top of the world, 17 00:01:52,278 --> 00:01:56,112 and you're about to see it as it's never been seen before. 18 00:01:59,185 --> 00:02:01,210 With the help of computer-generated images, 19 00:02:01,387 --> 00:02:03,685 we can see what normally can't be seen 20 00:02:03,857 --> 00:02:06,690 and go anywhere the story takes us... 21 00:02:08,161 --> 00:02:12,461 ...from the vast plain of sea ice where the bears stalk and attack... 22 00:02:15,335 --> 00:02:18,862 ...up to the snowdrifts on the mountain slopes where the birthing dens are hidden, 23 00:02:19,038 --> 00:02:21,472 safe from other polar bears. 24 00:02:26,479 --> 00:02:31,416 lt's a world dominated by ice - ice that changes as the year passes. 25 00:02:31,584 --> 00:02:36,715 And it's those changes that determine where a polar bear goes and what it does. 26 00:02:41,194 --> 00:02:44,391 Solid winter sea ice... melts in the early spring... 27 00:02:44,564 --> 00:02:47,362 to become broken ice floes in the summer. 28 00:02:56,509 --> 00:03:01,344 The ice is where the action is. All the animals here depend on it... 29 00:03:01,514 --> 00:03:06,315 and they live on it or in it or under it. 30 00:03:13,826 --> 00:03:18,126 Where ice, air and water meet there's a place for seals to hide. 31 00:03:18,598 --> 00:03:21,965 And below that is the beluga whale's upside-down world, 32 00:03:22,135 --> 00:03:27,198 where the ice is the ceiling and the whole Arctic ocean is a space to live. 33 00:03:40,086 --> 00:03:41,781 The battlefield's enormous. 34 00:03:41,955 --> 00:03:44,981 lts size makes the polar bear a perpetual nomad, 35 00:03:45,158 --> 00:03:46,955 trekking fifteen miles a day 36 00:03:47,126 --> 00:03:51,688 and up to five thousand a year on ice that's constantly moving. 37 00:03:52,365 --> 00:03:55,630 Our story starts down there in the ice and snow. 38 00:03:55,802 --> 00:04:01,240 lt's spring, and a new life is about to see daylight for the first time... 39 00:04:05,778 --> 00:04:08,338 ...but not until this female tests the air. 40 00:04:08,514 --> 00:04:11,039 She's been holed up for nearly six months... 41 00:04:11,217 --> 00:04:13,879 ...and she doesn't know what's out there now. 42 00:04:14,821 --> 00:04:15,913 There could be danger, 43 00:04:16,089 --> 00:04:19,058 and she has something precious to protect. 44 00:04:19,359 --> 00:04:24,228 When she went into the den last winter, she was fifty per cent heavier and alone. 45 00:04:24,397 --> 00:04:26,126 But she's not alone now - 46 00:04:26,299 --> 00:04:29,791 she has a cub, one cub. 47 00:04:32,171 --> 00:04:35,504 lt's his first experience of the wider world... 48 00:04:36,476 --> 00:04:40,742 ...the first moments away from the warm, dark safety of the den. 49 00:04:41,648 --> 00:04:45,345 He was born in January, just over three months ago. 50 00:04:47,253 --> 00:04:50,188 The world he came into was small and cramped. 51 00:04:50,356 --> 00:04:52,688 He had fur, but his eyes were closed. 52 00:04:52,859 --> 00:04:55,794 He wasn't any bigger than a guinea pig. 53 00:05:06,005 --> 00:05:08,439 Outside, it was the depth of winter 54 00:05:08,608 --> 00:05:11,577 and blizzards were blowing at a hundred miles an hour. 55 00:05:11,744 --> 00:05:15,305 The temperature was minus sixty Celsius. 56 00:05:20,320 --> 00:05:24,814 lnside, though, it was a comfortable two or three degrees above freezing. 57 00:05:24,991 --> 00:05:29,291 Mother's milk like double cream ensured he put on fat rapidly. 58 00:05:33,733 --> 00:05:37,897 For the next couple of years with his mother there'll be little time for play. 59 00:05:38,071 --> 00:05:42,371 He has to learn how to survive as a polar bear. 60 00:05:45,411 --> 00:05:47,242 He and a lot of others. 61 00:05:48,047 --> 00:05:49,446 All along these slopes, 62 00:05:49,615 --> 00:05:53,107 mother bears have been waiting out the winter in their dens... 63 00:05:54,954 --> 00:05:59,288 ...isolated from most dangers at a time when they're vulnerable. 64 00:06:04,464 --> 00:06:07,126 But when travelling to their hunting grounds on the sea ice 65 00:06:07,300 --> 00:06:09,268 they're even more vulnerable. 66 00:06:09,435 --> 00:06:12,336 Here, the biggest danger is other polar bears - 67 00:06:12,505 --> 00:06:17,465 large males, who see cubs as nothing more than potential food. 68 00:06:19,178 --> 00:06:22,375 The mother almost seems to tiptoe... 69 00:06:25,184 --> 00:06:29,086 ...she puts some distance between her cubs and the male. 70 00:06:34,961 --> 00:06:36,826 Polar bears are creatures of habit. 71 00:06:36,996 --> 00:06:40,591 Mothers returning to the same areas to hunt each spring 72 00:06:40,767 --> 00:06:44,328 to a long-awaited breakfast. 73 00:06:44,904 --> 00:06:46,428 And the wait's not over. 74 00:06:46,606 --> 00:06:52,203 Even after they reach the ice, the trek could take them another two hundred miles. 75 00:06:53,312 --> 00:06:56,543 The ice is constantly shifting. 76 00:06:58,017 --> 00:06:59,917 lt cracks and moves. 77 00:07:00,086 --> 00:07:01,451 Huge slabs collide, 78 00:07:01,621 --> 00:07:04,215 and blocks are pushed up to form long pressure ridges 79 00:07:04,390 --> 00:07:07,154 like miniature mountain ranges. 80 00:07:08,561 --> 00:07:11,655 Mother bears know where their prey will be... 81 00:07:13,399 --> 00:07:16,596 ...near lines of weakness next to a pressure ridge. 82 00:07:17,270 --> 00:07:19,830 This mother hasn't eaten since last autumn 83 00:07:20,006 --> 00:07:21,837 but has been producing milk. 84 00:07:22,008 --> 00:07:24,101 So, her supply of fat is almost gone. 85 00:07:24,277 --> 00:07:26,609 She needs to eat soon. 86 00:07:27,413 --> 00:07:30,780 She makes straight for a ridge, sniffing constantly. 87 00:07:32,318 --> 00:07:35,185 Smell is her guiding sense. 88 00:07:35,488 --> 00:07:37,615 Entering the bear's sensory world 89 00:07:37,790 --> 00:07:41,954 we find the most interesting smells are found near the fissures in the ice. 90 00:07:43,162 --> 00:07:45,255 Nothing is left to chance - 91 00:07:45,431 --> 00:07:48,332 she investigates everything. 92 00:07:49,869 --> 00:07:52,167 And this is what she's looking for - 93 00:07:52,338 --> 00:07:53,168 a seal. 94 00:07:53,339 --> 00:07:56,069 At this time of year it's under the solid ice. 95 00:07:56,242 --> 00:07:57,800 The bear could be on top of the seal, 96 00:07:57,977 --> 00:08:01,913 but with ice between them, it might as well be miles away. 97 00:08:02,081 --> 00:08:04,140 She needs a meeting place 98 00:08:04,484 --> 00:08:07,976 and this is it - a tiny breathing hole. 99 00:08:08,554 --> 00:08:09,646 lt's a ringed seal 100 00:08:09,822 --> 00:08:12,985 and like all marine mammals, it needs air to breathe. 101 00:08:13,793 --> 00:08:15,988 lt can stay down for more than twenty minutes, 102 00:08:16,162 --> 00:08:19,529 but eventually it has to get its nose to the air or drown. 103 00:08:19,699 --> 00:08:22,099 So it makes holes in the ice. 104 00:08:23,135 --> 00:08:27,697 Using its sharp claws it scrapes out a hollow on the underside... 105 00:08:27,874 --> 00:08:31,605 ...which ends in a hole no more than an inch across... 106 00:08:35,414 --> 00:08:38,042 lt's just wide enough for a seal's nostrils - 107 00:08:38,217 --> 00:08:41,618 this time, just opposite the bear's nostrils. 108 00:08:42,355 --> 00:08:44,915 lts breath has given it away. 109 00:08:49,362 --> 00:08:52,627 But the seal still manages to escape. 110 00:08:54,400 --> 00:08:55,697 Most attempts end this way, 111 00:08:55,868 --> 00:08:57,995 but the hunt's not over yet. 112 00:08:58,871 --> 00:09:03,240 The seal has several breathing holes, excavated along cracks in the ice. 113 00:09:03,409 --> 00:09:07,846 All the bear has to do is find the hole the seal will be using next... 114 00:09:14,320 --> 00:09:17,949 ...the one leaking the strongest smell. 115 00:09:21,627 --> 00:09:24,892 The seal heads for the hole farthest from the commotion. 116 00:09:37,577 --> 00:09:40,068 The bear tracks along the fissure... 117 00:09:41,047 --> 00:09:44,915 ...sniffing its way from one breathing hole to another. 118 00:09:53,526 --> 00:09:56,393 As the bear gets close to the hole being used... 119 00:09:56,562 --> 00:09:59,156 ...the smell gets stronger. 120 00:09:59,498 --> 00:10:02,558 The seal needs to surface... 121 00:10:04,670 --> 00:10:06,968 ...but the bear is waiting at the last hole. 122 00:10:07,139 --> 00:10:10,540 The seal digs its holes in places where the ice is thin - 123 00:10:10,710 --> 00:10:13,008 thin enough for shadows to show through. 124 00:10:15,214 --> 00:10:17,808 Still, it has to take a chance... 125 00:10:19,785 --> 00:10:22,185 ...and it escapes again... 126 00:10:22,355 --> 00:10:26,223 ...and lives to take another breath. 127 00:10:26,859 --> 00:10:29,760 But there's more here. 128 00:10:31,697 --> 00:10:32,459 lt's April, 129 00:10:32,632 --> 00:10:36,500 and the seals have pupping lairs in the same area. 130 00:10:36,869 --> 00:10:39,235 Seals give birth on the ice or on land, 131 00:10:39,405 --> 00:10:41,498 but ringed seals, early in the season, 132 00:10:41,674 --> 00:10:46,304 have their pups in lairs on the ice but under the snow. 133 00:10:48,414 --> 00:10:50,905 Each lair is a simple chamber... 134 00:10:53,486 --> 00:10:57,252 ...with an escape hole through to the sea. 135 00:10:59,659 --> 00:11:01,524 The lairs, which hold a mother and pup 136 00:11:01,694 --> 00:11:03,559 or pup alone... 137 00:11:03,729 --> 00:11:08,132 ...are on the sheltered side of the same ridges as the breathing holes. 138 00:11:09,502 --> 00:11:10,969 Each mother has a territory, 139 00:11:11,137 --> 00:11:14,300 where she digs a lair and several haul-out chambers... 140 00:11:15,041 --> 00:11:17,839 ...which are used either as emergency boltholes 141 00:11:18,010 --> 00:11:21,207 or decoys to fool polar bears. 142 00:11:22,915 --> 00:11:26,009 But fooling polar bears isn't so easy. 143 00:11:30,156 --> 00:11:32,021 lt's the smells. 144 00:11:33,859 --> 00:11:36,089 They seep out slowly... 145 00:11:36,796 --> 00:11:40,823 percolate up through the ice crystals and drift away downwind... 146 00:11:42,635 --> 00:11:46,002 ...and into the nostrils of polar bears... 147 00:11:48,708 --> 00:11:50,232 ...who walk upwind... 148 00:11:50,409 --> 00:11:53,537 led by the nose to an occupied lair. 149 00:11:58,350 --> 00:12:01,319 Everything the mother does is followed by the cub. 150 00:12:01,487 --> 00:12:05,150 She's hunting. He's learning. 151 00:12:08,360 --> 00:12:10,351 There's nothing obvious in the snow - 152 00:12:10,529 --> 00:12:13,555 no airhole or other giveaway. 153 00:12:19,705 --> 00:12:22,503 As long as the seal doesn't move or breathe hard, 154 00:12:22,675 --> 00:12:26,975 there's a chance the bear will pass her by. 155 00:12:27,179 --> 00:12:30,114 But the cub's onto something. 156 00:12:31,450 --> 00:12:35,409 And now his mother is too. 157 00:12:38,524 --> 00:12:42,620 lt's a lair - and there's breakfast. 158 00:12:42,795 --> 00:12:43,955 Or maybe not. 159 00:12:44,130 --> 00:12:46,121 As the mother bear breaks in... 160 00:12:46,298 --> 00:12:49,358 the mother seal uses her escape hatch... 161 00:12:51,070 --> 00:12:55,336 ...and heads for another of her lairs. 162 00:12:55,608 --> 00:12:59,908 ln yet another is her pup, but maybe she can distract the bear. 163 00:13:04,183 --> 00:13:07,448 The cub continues his own search... 164 00:13:09,955 --> 00:13:14,255 ...while his mother places her entire body into the hole, blocking out light - 165 00:13:14,426 --> 00:13:15,757 it might fool the seal into thinking 166 00:13:15,928 --> 00:13:19,329 the lair is still intact and it might return... 167 00:13:24,503 --> 00:13:26,767 But it doesn't. 168 00:13:29,708 --> 00:13:32,836 She follows her nose to another lair. 169 00:13:43,889 --> 00:13:47,985 She has to check out every trace of seal smell. 170 00:13:53,732 --> 00:13:56,132 Still nothing. 171 00:13:58,704 --> 00:14:01,639 But what's that over there? 172 00:14:06,445 --> 00:14:09,414 The bear locks on to another target. 173 00:14:16,889 --> 00:14:19,221 The slightest sound will warn the seal, 174 00:14:19,391 --> 00:14:22,326 and it'll be down the escape hatch in an instant. 175 00:14:23,295 --> 00:14:25,559 The bear can't see what she's looking for... 176 00:14:25,731 --> 00:14:27,426 but she can smell it all right 177 00:14:27,600 --> 00:14:30,592 and maybe even hear it. 178 00:14:31,103 --> 00:14:32,627 lt is a seal pup - 179 00:14:32,805 --> 00:14:36,901 75% fat - just what polar bears like. 180 00:14:39,245 --> 00:14:43,045 lt's crucial to the bear that every step is soundless... 181 00:14:44,049 --> 00:14:48,008 ...and, to the pup, that it doesn't move at all. 182 00:14:48,888 --> 00:14:51,823 She listens for the slightest sound... 183 00:14:52,091 --> 00:14:55,754 ...and detects a single tiny move. 184 00:14:59,431 --> 00:15:02,525 She breaks through directly over the escape hole. 185 00:15:02,835 --> 00:15:04,462 The pup's cornered. 186 00:15:07,406 --> 00:15:08,771 There's no fight. 187 00:15:08,941 --> 00:15:12,502 She simply grabs the pup's head in her mouth and crushes it. 188 00:15:16,815 --> 00:15:21,479 A baby seal will keep a grown polar bear going for no more than a day. 189 00:15:21,654 --> 00:15:25,920 And normally she'd just eat the energy-rich blubber and leave the meat. 190 00:15:26,091 --> 00:15:28,992 But normally she's not this hungry. 191 00:15:29,161 --> 00:15:31,823 She'll eat the lot. 192 00:15:31,997 --> 00:15:34,830 The cub will soon be having his first taste of seal, 193 00:15:35,000 --> 00:15:38,231 though he'll be on milk for 1 8 months at least. 194 00:15:41,607 --> 00:15:45,338 That is, if he continues to survive the Arctic's many dangers - 195 00:15:45,511 --> 00:15:48,776 and foremost is the weather. 196 00:15:52,718 --> 00:15:56,916 ln the Arctic, the weather can change in a few minutes. 197 00:16:04,430 --> 00:16:05,362 lt may be spring, 198 00:16:05,531 --> 00:16:09,228 but blizzards can still engulf the ice and anything on it. 199 00:16:09,401 --> 00:16:12,097 Polar bears, though, are so warmly dressed that they only need 200 00:16:12,271 --> 00:16:16,833 to find a hollow in the snow, or dig one, and sleep out the storm. 201 00:16:23,082 --> 00:16:26,574 On an adult bear's rump is a thick layer of insulating fat 202 00:16:26,752 --> 00:16:29,277 that tapers out towards its head. 203 00:16:31,957 --> 00:16:33,720 lts fur may look white, 204 00:16:33,892 --> 00:16:36,952 but its skin is black and absorbs heat. 205 00:16:39,431 --> 00:16:41,558 ln fact, the fur isn't white - 206 00:16:41,734 --> 00:16:43,599 it's translucent. 207 00:16:43,769 --> 00:16:46,067 The thick pelt not only helps insulate the bear, 208 00:16:46,238 --> 00:16:49,833 it appears to conduct sunlight to the skin. 209 00:16:54,346 --> 00:16:58,407 The layers of both fur and fat mean that very little heat is lost, 210 00:16:58,584 --> 00:17:01,849 however bad the conditions. 211 00:17:03,789 --> 00:17:06,383 A thermal camera, which detects heat loss, 212 00:17:06,558 --> 00:17:09,584 shows very few hot spots on a polar bear... 213 00:17:10,329 --> 00:17:14,459 ...no more, proportionally, than in the whole landscape. 214 00:17:22,241 --> 00:17:25,733 Even young bears play-fighting on the edge of the ice... 215 00:17:25,911 --> 00:17:29,540 ...are almost invisible to the thermal camera. 216 00:17:32,785 --> 00:17:35,447 For them, this is tremendous exertion... 217 00:17:35,621 --> 00:17:39,648 but they only lose a little heat from the face, shoulders and loins. 218 00:17:39,825 --> 00:17:44,228 All the heat they keep back is what warms them in the worst of the weather. 219 00:17:45,030 --> 00:17:48,056 ln fact, their entire being is built around saving energy 220 00:17:48,233 --> 00:17:50,599 and replenishing it with food. 221 00:17:50,869 --> 00:17:52,860 But as predators they're ungainly - 222 00:17:53,038 --> 00:17:55,097 always ambling, rarely running. 223 00:17:55,274 --> 00:17:58,766 They rely on stealth rather than speed. 224 00:18:05,517 --> 00:18:08,680 Early June brings a change in the bears' sea ice. 225 00:18:08,854 --> 00:18:11,448 lt starts breaking apart. 226 00:18:17,496 --> 00:18:20,988 The wind causes the slabs of ice to move... 227 00:18:21,166 --> 00:18:23,760 ...and where the ice has been flexed by the tide, 228 00:18:23,936 --> 00:18:27,099 leads of clear water appear. 229 00:18:32,277 --> 00:18:34,905 The bears' hunting grounds have changed. 230 00:18:35,080 --> 00:18:38,914 The vast white wilderness is becoming a patchwork quilt. 231 00:18:54,900 --> 00:18:58,063 lt creates long, ice-free highways for marine mammals 232 00:18:58,237 --> 00:19:02,503 from the south who are heading north to feed or breed. 233 00:19:03,909 --> 00:19:06,673 A pod of belugas enters a lead... 234 00:19:07,446 --> 00:19:10,643 ...following the contours of the ice. 235 00:19:13,252 --> 00:19:17,154 Like seals, they have to come to the surface to breathe. 236 00:19:17,322 --> 00:19:19,654 But they can't make little ice holes - 237 00:19:19,825 --> 00:19:22,089 they need some open water. 238 00:19:34,840 --> 00:19:37,001 Things can go wrong, though. 239 00:19:37,176 --> 00:19:38,939 The temperature can drop suddenly, 240 00:19:39,111 --> 00:19:42,877 and ice will reform on the sea's surface. 241 00:19:44,449 --> 00:19:47,816 The leads freeze again... 242 00:19:48,287 --> 00:19:52,656 ...and the whales are trapped under a fast-forming ceiling. 243 00:19:57,162 --> 00:20:00,131 But they need somewhere to breathe... 244 00:20:00,365 --> 00:20:02,697 ...so they keep surfacing at the same spot, 245 00:20:02,868 --> 00:20:05,803 which stops the water there from freezing over. 246 00:20:20,719 --> 00:20:24,712 lt's a frantic fight for air, for life. 247 00:20:29,695 --> 00:20:33,825 The whales have solved their problem, for the time being. 248 00:20:34,833 --> 00:20:38,269 They've created a large breathing hole in the ice... 249 00:20:38,437 --> 00:20:42,396 and now they have to keep it open until the lead thaws again. 250 00:20:50,749 --> 00:20:52,273 Using their echolocation - 251 00:20:52,451 --> 00:20:56,012 their sonar - they search for an escape route. 252 00:20:56,188 --> 00:20:58,588 The whales make sounds that, on bouncing back, 253 00:20:58,757 --> 00:21:01,385 give a picture of the way ahead. 254 00:21:06,865 --> 00:21:10,528 But the only picture they're getting is of a sea of ice. 255 00:21:13,739 --> 00:21:16,503 They're stuck under their breathing hole... 256 00:21:17,309 --> 00:21:21,507 ...and they'll have to keep surfacing to make sure it stays there. 257 00:21:28,487 --> 00:21:32,014 But before they breathe in, they breathe out... 258 00:21:35,127 --> 00:21:39,291 ...and that sends clouds of water and mucous into the air. 259 00:21:41,633 --> 00:21:44,329 The smell is carried on the wind... 260 00:21:48,573 --> 00:21:51,872 ...to the nostrils of a young polar bear... 261 00:21:53,679 --> 00:21:58,082 ...who starts towards the source of the scent. 262 00:21:59,618 --> 00:22:03,645 The whales' troubles have only just begun. 263 00:22:04,323 --> 00:22:08,692 The bear was a mile away when he picked up the tiniest trace of the smell... 264 00:22:08,860 --> 00:22:12,887 ...from a source that not only can't get away... 265 00:22:13,265 --> 00:22:17,031 ...but can't stop producing more. 266 00:22:22,874 --> 00:22:25,434 The bear's walking along a corridor of beluga scent 267 00:22:25,610 --> 00:22:28,773 that gets stronger as he gets closer. 268 00:22:32,417 --> 00:22:34,647 The whales are too busy just breathing to be concerned 269 00:22:34,820 --> 00:22:37,983 about the invitations they're sending out. 270 00:22:39,958 --> 00:22:42,153 And here's another. 271 00:22:45,831 --> 00:22:48,800 The bear can hear the belugas now. 272 00:22:51,436 --> 00:22:56,135 Every time they blow, they give themselves away again. 273 00:22:59,811 --> 00:23:03,406 The bear's nose and ears haven't been lying... 274 00:23:03,715 --> 00:23:06,582 ...because now he can see the whales... 275 00:23:06,918 --> 00:23:09,546 ...and eyesight isn't his strongest sense. 276 00:23:09,721 --> 00:23:12,622 ln fact, it's about the same as a human's. 277 00:23:16,862 --> 00:23:20,593 The bear has definitely found the belugas... 278 00:23:20,766 --> 00:23:25,226 ...and then, in his excitement, he forgets about stealth. 279 00:23:26,872 --> 00:23:30,330 His footsteps reverberate through the ice and the water. 280 00:23:36,715 --> 00:23:39,946 At the best of times, belugas are easily spooked. 281 00:23:40,118 --> 00:23:42,177 Now they're close to panic. 282 00:23:42,587 --> 00:23:44,680 One of them scans the hole. 283 00:23:48,059 --> 00:23:50,857 The bear seems unsure about what to do next. 284 00:23:51,029 --> 00:23:54,328 He's young and has probably never seen belugas before. 285 00:23:57,235 --> 00:24:01,467 lf they're anything like seals, though, they're going to have to surface. 286 00:24:01,640 --> 00:24:05,542 The belugas hold their breath and wait for the bear to go. 287 00:24:05,710 --> 00:24:06,574 He doesn't, of course, 288 00:24:06,745 --> 00:24:09,441 so they have to take a chance. 289 00:24:15,987 --> 00:24:20,185 They know bears - you can tell by the scars. 290 00:24:26,932 --> 00:24:29,230 But this is a bear that has to think. 291 00:24:29,401 --> 00:24:32,666 How do you catch one of these? 292 00:24:43,415 --> 00:24:44,848 He seems to have picked one out 293 00:24:45,016 --> 00:24:48,452 and he'll try to hit it again and again. 294 00:25:09,341 --> 00:25:14,472 Each time he hits the beluga he rips skin and blubber from the back of its head. 295 00:25:15,514 --> 00:25:18,039 The bear's attacks are wearing the beluga down. 296 00:25:18,216 --> 00:25:21,208 lt can't last much longer. 297 00:25:22,921 --> 00:25:27,255 lt's surprising, given all the turmoil, that no other bear has turned up. 298 00:25:27,425 --> 00:25:30,019 Well, now another one has. 299 00:25:30,195 --> 00:25:31,822 And this is no novice. 300 00:25:31,997 --> 00:25:35,364 lt's that male again. 301 00:25:35,567 --> 00:25:38,297 The smaller bear's too busy to notice. 302 00:25:39,271 --> 00:25:41,831 A large bear can stand ten feet tall - 303 00:25:42,007 --> 00:25:45,238 all muscle, claws and teeth. 304 00:25:46,511 --> 00:25:50,106 As the young bear concentrates on his prize... 305 00:25:50,282 --> 00:25:53,649 ...the older bear closes in. 306 00:25:57,088 --> 00:26:00,785 lf it came to it, he could kill the youngster. 307 00:26:02,727 --> 00:26:04,524 The young bear may have killed the whale, 308 00:26:04,696 --> 00:26:07,597 but he still can't get it out. 309 00:26:20,545 --> 00:26:22,240 Finally... 310 00:26:22,414 --> 00:26:23,506 Now he can eat - 311 00:26:23,682 --> 00:26:26,515 although he's not alone. 312 00:26:26,818 --> 00:26:28,718 As the big bear strolls closer, 313 00:26:28,887 --> 00:26:31,720 the gulls settle down to wait for their share. 314 00:26:33,091 --> 00:26:34,649 And here's another opportunist - 315 00:26:34,826 --> 00:26:37,727 an Arctic fox smells blood, too. 316 00:26:42,601 --> 00:26:45,627 And the young bear smells trouble. 317 00:26:52,510 --> 00:26:55,638 The fox sees an opportunity. 318 00:26:57,382 --> 00:27:02,217 The old bear shows the young one the difference in their sizes... 319 00:27:02,387 --> 00:27:06,380 ...while the much smaller animals go straight to the food. 320 00:27:13,999 --> 00:27:16,467 The young bear loses the argument, 321 00:27:16,635 --> 00:27:20,571 but at least he's learned how to land a beluga. 322 00:27:26,011 --> 00:27:29,913 Polar bears are quick to learn from observation and experience. 323 00:27:30,915 --> 00:27:33,907 The fox makes its snatch and grab... 324 00:27:34,085 --> 00:27:37,054 ...and the big bear takes over... 325 00:27:37,422 --> 00:27:40,016 ...along with the other scavengers... 326 00:27:41,059 --> 00:27:42,754 ...while the belugas - minus one - 327 00:27:42,927 --> 00:27:45,794 still wait for the ice to clear. 328 00:27:54,439 --> 00:27:57,738 And, soon enough, it does clear. 329 00:27:58,176 --> 00:28:00,201 Spring is back. 330 00:28:00,378 --> 00:28:02,107 And when the leads open up this time, 331 00:28:02,280 --> 00:28:05,010 it's for the duration of the summer. 332 00:28:18,630 --> 00:28:20,689 The belugas move on... 333 00:28:21,099 --> 00:28:25,001 They're joined by a whole flotilla of ocean migrants... 334 00:28:25,303 --> 00:28:28,431 ...including narwhals, also heading north... 335 00:28:29,340 --> 00:28:33,208 ...and a bunch of resident seals going fishing. 336 00:28:35,080 --> 00:28:37,548 The giants are here, too... 337 00:28:39,684 --> 00:28:41,982 ...bowhead whales... 338 00:29:05,143 --> 00:29:08,840 By mid-June... the snow on the ice has started to thaw, 339 00:29:09,013 --> 00:29:11,982 forming a network of melt-water pools. 340 00:29:15,320 --> 00:29:17,151 As they grow deeper and wider, 341 00:29:17,322 --> 00:29:19,586 the ice gets more slippery. 342 00:29:22,460 --> 00:29:27,955 The thawing by day and freezing by night creates a natural skating rink... 343 00:29:32,470 --> 00:29:34,700 ...but not for polar bears... 344 00:29:35,774 --> 00:29:41,007 ...they have long hairs between the toes that channel water away like car tyres. 345 00:29:45,617 --> 00:29:48,711 And the pads on each sole have tiny bumps and cavities 346 00:29:48,887 --> 00:29:52,015 that stop them from sliding. 347 00:29:55,794 --> 00:29:59,093 And they stay on the ice for as long as they can. 348 00:29:59,264 --> 00:30:04,395 lt's from the ice and only from the ice that they can ambush seals. 349 00:30:04,936 --> 00:30:09,168 And the time left for hunting is rapidly disappearing. 350 00:30:10,475 --> 00:30:15,412 ln early summer in the High Arctic, the sun doesn't set... 351 00:30:17,482 --> 00:30:21,509 ...which means a twenty-four-hour day for hunting... 352 00:30:23,188 --> 00:30:26,555 ...as long as the ice lasts... 353 00:30:33,464 --> 00:30:37,195 ...and it won't last much longer. 354 00:30:41,339 --> 00:30:44,672 Twenty-four hours of sunshine is seeing to that. 355 00:30:46,611 --> 00:30:52,015 The ice platform the bears use for their attacks is slowly disintegrating. 356 00:30:54,352 --> 00:30:58,812 As the weather gets warmer, a polar bear gets hungrier... 357 00:30:59,791 --> 00:31:04,558 ...and its main hunting advantage disappears from under its feet. 358 00:31:07,131 --> 00:31:10,999 There's no possibility of catching seals now... 359 00:31:11,970 --> 00:31:15,906 ...not if a bear loses the ability to surprise one. 360 00:31:16,441 --> 00:31:21,401 Naive seal pups can be caught out, but not on this occasion. 361 00:31:22,113 --> 00:31:25,082 When the tiny ice islands have almost melted away, 362 00:31:25,250 --> 00:31:29,448 a bear can find himself a long swim from the coast. 363 00:31:30,855 --> 00:31:34,586 Of course, there are always other animals he could try for. 364 00:31:34,759 --> 00:31:37,227 Not walruses, though. 365 00:31:39,664 --> 00:31:42,929 They swim too fast and could kill a bear in the water, 366 00:31:43,101 --> 00:31:46,559 though a walrus pup is a consideration. 367 00:31:46,738 --> 00:31:51,869 Not now, but if one hauls out on the shore... 368 00:31:53,778 --> 00:31:56,542 lt's not that polar bears aren't at home in the sea. 369 00:31:56,714 --> 00:32:00,115 Some will swim miles for no obvious reason. 370 00:32:01,319 --> 00:32:03,981 They use their large forepaws to dogpaddle 371 00:32:04,155 --> 00:32:09,320 and trail the hind legs as rudders. 372 00:32:14,065 --> 00:32:17,000 A lot of bears will travel north with the receding ice, 373 00:32:17,168 --> 00:32:21,036 so they can keep hunting from the ice edge... 374 00:32:23,641 --> 00:32:27,270 ...but a bear that's left behind will have to spend the summer on land 375 00:32:27,445 --> 00:32:31,609 and will try to get by mainly on its own body fat. 376 00:32:43,628 --> 00:32:48,895 ln summer, an ice bear becomes a water bear or a land bear. 377 00:33:44,922 --> 00:33:47,891 During summertime the living isn't easy - 378 00:33:48,059 --> 00:33:50,220 polar bears get little to eat. 379 00:33:50,395 --> 00:33:53,887 But not eating for a couple of months requires energy to be conserved, 380 00:33:54,065 --> 00:33:55,692 and that's easy enough. 381 00:33:55,867 --> 00:33:58,700 lt just means doing nothing. 382 00:33:58,970 --> 00:34:00,494 But if starvation looms anyway, 383 00:34:00,671 --> 00:34:03,970 polar bears can be surprisingly adaptable... 384 00:34:04,475 --> 00:34:07,569 ...almost as adaptable as the acknowledged master of the art, 385 00:34:07,745 --> 00:34:11,112 the Arctic fox. 386 00:34:15,720 --> 00:34:18,655 These cliffs are fifteen hundred feet high 387 00:34:18,823 --> 00:34:22,725 and as sheer as if sea ice were turned on its side. 388 00:34:23,327 --> 00:34:27,730 But there's food up there, if a bear can reach it. 389 00:34:32,503 --> 00:34:35,870 Hundreds of thousands of guillemots are nesting on the cliff-face, 390 00:34:36,040 --> 00:34:41,103 but as their chicks mature, there's an increasing danger from gulls. 391 00:34:42,580 --> 00:34:45,481 lt's safer for the fledglings to be out at sea. 392 00:34:45,650 --> 00:34:48,118 The trouble is, they can't fly. 393 00:34:48,286 --> 00:34:50,811 They have to glide - 394 00:34:50,988 --> 00:34:54,446 glide over enemy territory. 395 00:34:54,959 --> 00:34:57,484 Over polar bears... 396 00:34:58,296 --> 00:35:00,264 ...foxes... 397 00:35:00,665 --> 00:35:02,997 ...and gulls... 398 00:35:03,434 --> 00:35:06,835 ...all waiting for them to ditch short of the mark. 399 00:35:23,721 --> 00:35:25,621 A gull may have snatched that one, 400 00:35:25,790 --> 00:35:28,623 but the fox knows there are more coming... 401 00:35:34,866 --> 00:35:37,494 While the bear still seems to be thinking about going up, 402 00:35:37,668 --> 00:35:40,262 the fox is concentrating on what's coming down - 403 00:35:40,438 --> 00:35:43,839 food, straight from the sky. 404 00:35:45,676 --> 00:35:51,171 ln summer, an Arctic fox doesn't need a polar bear in order to get a meal. 405 00:35:54,552 --> 00:35:59,580 As for the bear, better to go back to doing nothing. 406 00:36:03,828 --> 00:36:05,693 When their drifting ice floes have melted, 407 00:36:05,863 --> 00:36:09,458 some bears find themselves trapped on barren islands... 408 00:36:10,201 --> 00:36:12,192 ...but the young bear has landed on the mainland, 409 00:36:12,370 --> 00:36:16,204 where there's at least a chance of finding something to eat. 410 00:36:18,009 --> 00:36:23,538 lt's truly warm now, and the bear's winter insulation could be a real handicap. 411 00:36:24,081 --> 00:36:27,573 Everything about his body is designed to keep heat in, 412 00:36:27,752 --> 00:36:31,518 even when the air temperature reaches thirty degrees. 413 00:36:33,257 --> 00:36:35,191 A polar bear never sweats, 414 00:36:35,359 --> 00:36:38,226 and so one that's too active can overheat. 415 00:36:38,396 --> 00:36:41,160 Heat's lost from the muzzle and inside of the thighs 416 00:36:41,332 --> 00:36:42,822 and there are thin strips of muscle 417 00:36:43,000 --> 00:36:45,935 rich in blood vessels from which heat can escape. 418 00:36:46,404 --> 00:36:51,307 The young bear copes by moving slowly and sleeping as much as possible. 419 00:36:55,746 --> 00:36:57,338 But he still gets hungry, 420 00:36:57,515 --> 00:37:01,110 and there's something interesting down there. 421 00:37:02,420 --> 00:37:04,615 The smell's familiar. 422 00:37:04,789 --> 00:37:08,156 lt's the smell of belugas - hundreds of them. 423 00:37:11,596 --> 00:37:16,397 They come to this shallow estuary to slough off their old skin. 424 00:37:19,670 --> 00:37:22,798 And because river water is a little warmer than seawater, 425 00:37:22,974 --> 00:37:26,808 they bring their newborn calves here. 426 00:37:27,545 --> 00:37:31,072 For belugas, it's like being in a warm communal bath, 427 00:37:31,249 --> 00:37:32,375 but for a bear, 428 00:37:32,550 --> 00:37:36,486 it's more like... beluga stew. 429 00:37:39,023 --> 00:37:42,288 Sometimes a beluga - busy rubbing its skin off on the river gravel - 430 00:37:42,460 --> 00:37:46,521 is caught by the tide and will strand... 431 00:37:50,434 --> 00:37:53,494 ...helpless until the tide returns... 432 00:37:53,671 --> 00:37:56,299 or something worse happens. 433 00:37:58,843 --> 00:38:02,939 lt's the bear or the tide, whichever gets there first. 434 00:38:04,448 --> 00:38:07,849 The beluga still has scratches from the attack at the breathing hole, 435 00:38:08,019 --> 00:38:12,080 but this time it could be far more serious. 436 00:38:21,666 --> 00:38:24,760 The tide is coming in. 437 00:38:28,673 --> 00:38:33,508 lt only takes one footstep in the water for the bear to give himself away. 438 00:39:04,342 --> 00:39:08,108 This was teeming with belugas a minute ago. 439 00:39:09,180 --> 00:39:12,707 But now they're teeming somewhere else. 440 00:39:17,221 --> 00:39:19,155 lt's just another example of how hard 441 00:39:19,323 --> 00:39:24,226 it is for polar bears to hunt without the help of sea ice. 442 00:39:26,163 --> 00:39:29,564 By autumn, starvation is a real possibility. 443 00:39:29,734 --> 00:39:33,670 What little food the bears have found is hardly enough to keep them going. 444 00:39:34,905 --> 00:39:38,033 But not everything that happens is the same every year. 445 00:39:38,209 --> 00:39:40,268 There can be surprises. 446 00:39:41,612 --> 00:39:43,705 This autumn, as luck would have it, 447 00:39:43,881 --> 00:39:46,076 the sea ice is late in forming, 448 00:39:46,250 --> 00:39:50,448 and bears aren't the only ones to feel the consequences of that. 449 00:39:56,627 --> 00:40:01,326 This year's phenomenon starts with a strong smell of seals in the air. 450 00:40:09,340 --> 00:40:12,207 The cause is just over there... 451 00:40:15,813 --> 00:40:18,247 ...at the water's edge. 452 00:40:20,818 --> 00:40:24,777 Walruses - hundreds of them. 453 00:40:28,926 --> 00:40:30,791 They should be out on the ice now, 454 00:40:30,961 --> 00:40:34,556 but like the bears, they're stranded on land. 455 00:40:36,233 --> 00:40:38,360 As hard as they usually are to kill, 456 00:40:38,536 --> 00:40:40,026 they seem vulnerable now, 457 00:40:40,204 --> 00:40:43,537 and bears are coming from miles around... 458 00:40:44,675 --> 00:40:48,475 ...including the intimidating giant. 459 00:40:52,917 --> 00:40:56,114 Blubber, and lots of it... 460 00:40:56,353 --> 00:41:00,187 ...if only it would stand still and not threaten to fight. 461 00:41:04,094 --> 00:41:07,928 Walruses aren't animals that polar bears are used to dealing with. 462 00:41:24,315 --> 00:41:29,548 Somewhere, somehow, there has to be a way into this wall of blubber. 463 00:41:33,757 --> 00:41:36,089 There are pups in there. 464 00:41:39,063 --> 00:41:41,088 There's one. 465 00:41:47,137 --> 00:41:49,367 There's another one. 466 00:41:55,112 --> 00:41:57,603 Another. 467 00:41:58,516 --> 00:42:02,179 But how do you get the pup away from the big ones? 468 00:42:09,727 --> 00:42:13,925 lt's seems to be more than one bear by itself can manage. 469 00:42:15,299 --> 00:42:17,529 But the bear isn't by itself. 470 00:42:17,701 --> 00:42:20,534 Other bears have picked up the scent. 471 00:42:22,873 --> 00:42:25,899 Polar bears are more than just solitary animals - 472 00:42:26,677 --> 00:42:29,737 they actively dislike each other. 473 00:42:29,914 --> 00:42:31,745 But they're all very hungry now, 474 00:42:31,916 --> 00:42:35,613 and there's an awful lot of food cornered here. 475 00:42:36,153 --> 00:42:37,950 They're circling like vultures. 476 00:42:38,122 --> 00:42:39,384 The only trouble is, 477 00:42:39,557 --> 00:42:41,957 these bodies aren't dead. 478 00:42:42,126 --> 00:42:45,118 Even the mother is here with her cub. 479 00:42:46,030 --> 00:42:48,555 The bears have backed the walruses into the water. 480 00:42:48,732 --> 00:42:52,031 But can they organise an assault? 481 00:43:23,601 --> 00:43:27,662 The mass attack, uncoordinated as it is, seems to be working. 482 00:43:27,838 --> 00:43:30,966 The walruses are breaking ranks. 483 00:43:36,213 --> 00:43:40,741 The bears have singled out the young, the old and the unhealthy - 484 00:43:40,918 --> 00:43:44,012 especially the young. 485 00:43:51,362 --> 00:43:54,354 Now they're closing in. 486 00:44:01,005 --> 00:44:03,701 There's the objective... 487 00:44:15,252 --> 00:44:17,220 Confusion among the walruses. 488 00:44:17,388 --> 00:44:19,913 The wall of blubber is breached. 489 00:44:23,060 --> 00:44:25,392 A pup goes. 490 00:44:32,069 --> 00:44:34,435 Another one. 491 00:44:35,139 --> 00:44:36,629 But as soon as a kill is made, 492 00:44:36,807 --> 00:44:41,506 the carcass is dragged away so that other bears won't steal it. 493 00:44:51,388 --> 00:44:54,118 lt's a victory, and it's a massacre. 494 00:44:54,291 --> 00:44:58,751 The beach is covered with walrus meat and bones. 495 00:45:00,864 --> 00:45:03,264 Because there were so many bears, 496 00:45:03,434 --> 00:45:08,064 they're all feasting at a time when they might be expected to starve. 497 00:45:09,506 --> 00:45:13,465 There are even leftovers for late arrivals. 498 00:45:26,757 --> 00:45:31,956 lt's highly unusual for this many polar bears to be gathered in the same place. 499 00:45:36,700 --> 00:45:40,363 For a moment in their lives, they stopped being solitary... 500 00:45:40,537 --> 00:45:44,530 young bears, old bears, males and females... 501 00:45:44,708 --> 00:45:46,733 ...they've all fed alongside each other. 502 00:45:46,910 --> 00:45:48,707 And because there was plenty for everyone, 503 00:45:48,879 --> 00:45:51,780 there were no fights. 504 00:45:52,082 --> 00:45:54,380 And they will all live to see the sea freeze again 505 00:45:54,551 --> 00:45:58,043 and to sniff for seals at their breathing holes. 506 00:45:58,322 --> 00:45:59,414 Now the gathering breaks up, 507 00:45:59,590 --> 00:46:03,754 and each bear goes away to wait for winter, alone. 508 00:46:03,927 --> 00:46:06,725 The surviving walruses are waiting for winter, too. 509 00:46:06,897 --> 00:46:10,128 To avoid another slaughter, they need ice to haul out on, 510 00:46:10,300 --> 00:46:13,565 by leads and patches of open water. 511 00:46:14,371 --> 00:46:18,205 As a few of the remaining walruses bob in the water offshore... 512 00:46:18,375 --> 00:46:22,072 the first snow of winter settles on the beach. 513 00:46:25,015 --> 00:46:26,949 The sea ice will be here soon, 514 00:46:27,117 --> 00:46:31,281 and the young bear bides his time. 515 00:46:31,855 --> 00:46:34,449 He'll be sustained for a while by the walrus massacre 516 00:46:34,625 --> 00:46:36,456 and isn't desperate to eat. 517 00:46:36,627 --> 00:46:39,858 He's just wandering and waiting on the beach. 518 00:46:44,301 --> 00:46:47,168 Then he sees something. 519 00:46:47,971 --> 00:46:49,666 lt's a female polar bear - 520 00:46:49,840 --> 00:46:53,139 one that didn't live to see the sea freeze. 521 00:46:53,744 --> 00:46:56,736 He almost seems to recognise her. 522 00:46:59,483 --> 00:47:01,144 Why did she die? 523 00:47:01,318 --> 00:47:06,847 Was it old age, starvation or was it something else? 524 00:47:12,663 --> 00:47:16,190 Could we be affecting life in the Arctic? 525 00:47:16,366 --> 00:47:19,961 ln some parts the ice forms later every year. 526 00:47:20,137 --> 00:47:24,096 That's because of the worldwide rise in temperatures. 527 00:47:24,274 --> 00:47:26,902 Without ice, a polar bear can't hunt. 528 00:47:27,077 --> 00:47:32,344 Without ice, there can't be polar bears. 529 00:47:34,451 --> 00:47:35,475 lt's October now, 530 00:47:35,652 --> 00:47:38,212 and the sea should freeze over in a few days. 531 00:47:38,388 --> 00:47:41,084 But throughout the Arctic, that's not happening. 532 00:47:41,258 --> 00:47:45,388 What ice there is is retreating and thinning. 533 00:47:51,068 --> 00:47:53,366 But right now, in early winter, 534 00:47:53,537 --> 00:47:57,473 all the polar bears except pregnant females should be out there, 535 00:47:57,641 --> 00:48:00,439 walking on ice. 536 00:48:00,777 --> 00:48:03,041 And eventually the ice does appear. 537 00:48:03,213 --> 00:48:04,805 After a long hard summer 538 00:48:04,982 --> 00:48:07,246 the young bear is back in his element. 539 00:48:07,417 --> 00:48:09,783 He has coped. 540 00:48:12,322 --> 00:48:14,517 But how long will polar bears be able to 541 00:48:14,691 --> 00:48:21,290 when man-made pollution and unnatural heat are seeping into their battlefield?