1 00:00:42,567 --> 00:00:47,357 There can be few places on earth as bleak, cold, hostile to life... 2 00:00:47,527 --> 00:00:49,677 as these Arctic snowfields. 3 00:00:49,847 --> 00:00:53,965 But for one animal, the polar bear, this is heaven. 4 00:00:58,447 --> 00:01:02,998 We tend to think as polar bears as wandering across these snowfields... 5 00:01:03,167 --> 00:01:04,441 hunting for seals... 6 00:01:04,607 --> 00:01:08,725 but in fact some bears spend their winter actually under the snow... 7 00:01:10,447 --> 00:01:12,802 and when the summer comes and the ice melts... 8 00:01:12,967 --> 00:01:17,677 they are as likely to be swimming in the water as on the ice. 9 00:01:18,247 --> 00:01:20,602 So here, for the first time... 10 00:01:20,767 --> 00:01:25,318 is a full picture of that most impressive, formidable of hunters: 11 00:01:25,567 --> 00:01:27,478 the polar bear. 12 00:01:30,727 --> 00:01:33,036 After four months of winter darkness... 13 00:01:33,207 --> 00:01:36,005 light returns to the High Arctic once more... 14 00:01:36,167 --> 00:01:39,637 and reveals a world frozen and still. 15 00:01:42,807 --> 00:01:44,445 The Arctic is an ocean... 16 00:01:44,607 --> 00:01:47,599 sealed by ice and bordered by land. 17 00:01:47,767 --> 00:01:50,076 But this is not a world of permanent winter... 18 00:01:50,247 --> 00:01:52,477 and each season brings great changes... 19 00:01:52,647 --> 00:01:55,161 to which polar bears must adapt. 20 00:01:57,927 --> 00:02:00,395 High on the slopes of the Arctic mountains... 21 00:02:00,767 --> 00:02:03,406 life begins to stir. 22 00:02:21,247 --> 00:02:22,521 It's April... 23 00:02:22,687 --> 00:02:25,645 and this bear has been under the snow in her den... 24 00:02:25,807 --> 00:02:29,402 all winter. But she's not alone. 25 00:02:44,047 --> 00:02:47,642 Born in December, and now about four months old... 26 00:02:47,807 --> 00:02:51,038 her cubs are ready to face the outside world. 27 00:02:56,687 --> 00:03:00,441 Their woolly fur helps to insulate them from the bitter cold. 28 00:03:00,607 --> 00:03:02,518 The temperature here regularly drops... 29 00:03:02,687 --> 00:03:05,565 to a nippy minus thirty five. 30 00:03:17,447 --> 00:03:21,679 Throughout the winter, other bears have remained out... 31 00:03:22,007 --> 00:03:23,042 on the frozen sea ice, hunting. 32 00:03:23,207 --> 00:03:26,165 But winter is a long, lean time for them... 33 00:03:26,327 --> 00:03:28,887 as seals can be hard to find. 34 00:03:30,367 --> 00:03:35,122 In peak condition, a male bear can weigh as much as ten men. 35 00:03:35,567 --> 00:03:40,402 But this bear has just endured a winter and its weight is very low. 36 00:03:43,327 --> 00:03:46,399 Ringed seals, the smallest of the Arctic seals... 37 00:03:46,567 --> 00:03:48,603 are they favoured prey. 38 00:03:49,527 --> 00:03:52,564 But adult seals are experienced and very wary... 39 00:03:52,727 --> 00:03:57,562 at the slightest sign of danger, they disappear into another world. 40 00:04:10,447 --> 00:04:13,007 More at home in the water than on the ice... 41 00:04:13,167 --> 00:04:16,876 they have access to a number of well spaced breathing holes... 42 00:04:17,047 --> 00:04:20,517 and so can easily outmanoeuvre a hunting bear. 43 00:04:38,287 --> 00:04:41,040 But what bears are really after in spring... 44 00:04:41,207 --> 00:04:43,641 are this year's seal pups. 45 00:04:43,807 --> 00:04:46,196 Never having encountered a polar bear before... 46 00:04:46,367 --> 00:04:48,597 they seem unaware of the danger. 47 00:05:44,207 --> 00:05:47,483 This bear hasn't got it quite right yet. 48 00:05:55,487 --> 00:05:59,036 Yet more hungry bears will soon appear in the surrounding hills... 49 00:05:59,207 --> 00:06:03,280 as emerging families prepare for life on the sea ice. 50 00:06:08,447 --> 00:06:11,086 Having been confined to their den since birth... 51 00:06:11,247 --> 00:06:14,956 it's important for cubs to exercise and gain strength. 52 00:06:15,287 --> 00:06:17,562 For once they leave the safety of their den... 53 00:06:17,727 --> 00:06:21,925 they will find little relief from the trials of life ahead of them. 54 00:06:47,407 --> 00:06:50,843 This female has had nothing to eat for five months... 55 00:06:51,007 --> 00:06:53,726 and her body weight has dropped by half. 56 00:06:53,887 --> 00:06:56,355 But she still has a difficult time ahead... 57 00:06:56,527 --> 00:06:59,360 because she can't go down to the sea ice to hunt... 58 00:06:59,527 --> 00:07:03,076 until her cubs are stronger and more co-ordinated. 59 00:07:35,327 --> 00:07:38,922 It takes time for the cubs to acclimatise to the temperatures... 60 00:07:39,087 --> 00:07:40,406 outside their den. 61 00:07:40,567 --> 00:07:42,444 And although they have thick fur... 62 00:07:42,607 --> 00:07:45,679 they have little insulation from fat at this age... 63 00:07:45,847 --> 00:07:48,839 and so depend on the richness and energy of their mother's milk... 64 00:07:49,007 --> 00:07:51,043 to keep them warm. 65 00:08:15,447 --> 00:08:19,759 Females without cubs have spent the winter out on the sea ice. 66 00:08:20,207 --> 00:08:23,358 Free from the responsibilities of maternal care... 67 00:08:23,527 --> 00:08:27,122 they have meet other demands: males. 68 00:08:33,287 --> 00:08:35,596 Competition for females is high. 69 00:08:35,767 --> 00:08:37,723 This large, scarred male... 70 00:08:37,887 --> 00:08:40,720 will try to keep the small female away from his rivals... 71 00:08:40,887 --> 00:08:43,401 by herding her into remote areas. 72 00:08:43,607 --> 00:08:47,043 That way he gets exclusive access to her. 73 00:08:47,207 --> 00:08:52,076 The scars on his head and neck are evidence of fights with former rivals. 74 00:09:08,607 --> 00:09:14,318 When the cubs are strong enough, and driven by her need for food... 75 00:09:14,487 --> 00:09:19,038 this mother leads her cubs away from the den for the last time. 76 00:09:27,287 --> 00:09:30,563 They are about to enter a much more dangerous world... 77 00:09:30,727 --> 00:09:32,877 down on the sea ice. 78 00:09:36,607 --> 00:09:39,326 Because ice conditions vary from year to year... 79 00:09:39,487 --> 00:09:41,796 seal distribution is unpredictable... 80 00:09:41,967 --> 00:09:45,198 so bears may have to range over thousands of kilometres... 81 00:09:45,367 --> 00:09:47,801 in search of the best hunting grounds. 82 00:09:53,487 --> 00:09:55,523 They hunt along pressure ridges... 83 00:09:55,687 --> 00:09:58,804 which form as ice sheets collide with each other. 84 00:09:58,967 --> 00:10:01,765 It is under the snow drifts in the lee of these ridges... 85 00:10:01,927 --> 00:10:05,283 that ringed seals give birth to their pups. 86 00:10:05,447 --> 00:10:07,597 There may be a number of chambers to the lair... 87 00:10:07,767 --> 00:10:11,203 but there is usually only one access to the sea beneath. 88 00:10:11,767 --> 00:10:14,964 Under the snow, the pup is protected from bad weather... 89 00:10:15,127 --> 00:10:17,038 and is out of sight. 90 00:10:24,167 --> 00:10:27,955 But bears have an astonishingly acute sense of smell... 91 00:10:28,287 --> 00:10:31,484 and can detect the presence of a seal, deep within the snow... 92 00:10:31,647 --> 00:10:34,400 at a distance of a kilometre or more. 93 00:10:39,167 --> 00:10:42,796 Even so, the bear must pinpoint the exact position... 94 00:10:42,967 --> 00:10:44,878 of the seal beneath him. 95 00:10:47,567 --> 00:10:51,480 And the slightest crunch of snow could give him away. 96 00:12:03,407 --> 00:12:05,602 This time the seal got away... 97 00:12:05,767 --> 00:12:08,600 only about one in twenty hunts are successful... 98 00:12:08,767 --> 00:12:12,123 so the odds seem to be in the seal's favour. 99 00:12:12,287 --> 00:12:15,120 But with so many hungry bears prowling the ice... 100 00:12:15,287 --> 00:12:18,279 a pup's future is far from secure. 101 00:12:23,327 --> 00:12:26,478 Hunting requires skill and patience. 102 00:12:26,807 --> 00:12:29,196 It's hard enough for a lone bear... 103 00:12:29,367 --> 00:12:33,963 but a female encumbered by cubs, will be even less successful. 104 00:12:35,567 --> 00:12:37,956 If she doesn't manage to catch enough seals... 105 00:12:38,127 --> 00:12:42,439 she stops producing milk and her cubs soon starve. 106 00:12:48,367 --> 00:12:50,597 So far this family is doing well. 107 00:12:50,767 --> 00:12:55,204 The mother has found enough food to keep both cubs alive. 108 00:12:58,607 --> 00:13:01,246 But getting enough food is not the only problem... 109 00:13:01,407 --> 00:13:04,205 facing a female with dependent cubs. 110 00:13:18,607 --> 00:13:22,805 Given the chance, a large male might kill the cubs. 111 00:13:25,327 --> 00:13:28,842 Their mother would then become sexually receptive again... 112 00:13:29,007 --> 00:13:30,759 so he could mate with her and ensure... 113 00:13:30,927 --> 00:13:33,760 the next generation carries his genes. 114 00:13:40,247 --> 00:13:45,116 She's very protective and the cubs aren't allowed to stray far from her. 115 00:13:49,567 --> 00:13:52,923 At three times her weight, a 600 kilogram... 116 00:13:53,087 --> 00:13:57,922 male is a fearsome opponent, and she avoids any chance of an encounter. 117 00:14:03,767 --> 00:14:05,962 Svalbard. A group of islands... 118 00:14:06,127 --> 00:14:09,119 700 miles north of Norway. 119 00:14:09,287 --> 00:14:13,041 In April bears converge in prime seal habitat... 120 00:14:13,207 --> 00:14:16,517 where they can be sure of finding unwary seal pups. 121 00:14:27,807 --> 00:14:29,957 These cubs are a year and a half old... 122 00:14:30,127 --> 00:14:32,641 and now rely largely on meat. 123 00:14:32,807 --> 00:14:35,799 Their increasing size puts more and more pressure on their mother... 124 00:14:35,967 --> 00:14:38,959 to provide enough food for the three of them. 125 00:14:46,847 --> 00:14:49,919 Bears tend to wolf down a fresh kill... 126 00:14:50,087 --> 00:14:53,762 because it's very likely to be stolen from them by larger bears... 127 00:14:53,927 --> 00:14:56,122 even their own mother. 128 00:15:23,647 --> 00:15:25,365 Cubs have a great deal to learn... 129 00:15:25,527 --> 00:15:28,041 before they can survive alone in the Arctic. 130 00:15:28,207 --> 00:15:33,520 If there's food, a mother will stay with them for 2 and a half years. 131 00:15:47,607 --> 00:15:50,519 Like most animals, adult polar bears... 132 00:15:50,687 --> 00:15:53,155 do not waste hard-earned energy... 133 00:15:53,327 --> 00:15:55,761 but for the cubs play continues to be... 134 00:15:55,927 --> 00:15:58,566 a vital part of their training. 135 00:16:08,527 --> 00:16:11,280 It's only by continuing to be inquisitive... 136 00:16:11,447 --> 00:16:14,917 that they learn how to adapt to new situations. 137 00:16:17,167 --> 00:16:20,876 But they still don't have the skills to hunt successfully for themselves. 138 00:16:21,047 --> 00:16:24,483 And this keeps them totally dependent on their mother. 139 00:16:39,247 --> 00:16:43,035 They start to imitate her hunting techniques at an early age... 140 00:16:43,287 --> 00:16:46,404 but they are simply not heavy enough to break through... 141 00:16:46,567 --> 00:16:49,001 into the lair of a seal pup. 142 00:18:05,327 --> 00:18:07,966 The only other mammal to be found on the sea ice... 143 00:18:08,127 --> 00:18:09,879 is the Arctic fox. 144 00:18:10,047 --> 00:18:15,201 In some places its life is intricately bound to that of the polar bear. 145 00:18:27,887 --> 00:18:30,924 Arctic foxes are the jackals of the north. 146 00:18:31,087 --> 00:18:33,476 Although they will hunt seal pups for themselves... 147 00:18:33,647 --> 00:18:36,923 they can only kill pups less than a week old. 148 00:18:37,087 --> 00:18:42,115 So scavenging is important. Foxes will follow bears far onto the ice... 149 00:18:42,287 --> 00:18:44,926 to feed on the remains of their kills. 150 00:18:45,087 --> 00:18:48,841 Away from land, foxes are totally dependent on bears... 151 00:18:49,007 --> 00:18:50,725 for their survival. 152 00:18:55,887 --> 00:18:58,765 Gulls also home in on the feast. 153 00:19:14,367 --> 00:19:17,916 Nothing from a polar bear kill is wasted. 154 00:19:29,007 --> 00:19:31,077 Keeping fur in good condition... 155 00:19:31,247 --> 00:19:34,284 is as crucial for foxes as it is for bears. 156 00:19:34,447 --> 00:19:37,200 Fox fur is very fine and very dense. 157 00:19:37,367 --> 00:19:41,963 And like bear fur each hair is hollow which maximises insulation. 158 00:20:01,567 --> 00:20:04,081 Such bounty is too good to waste. 159 00:20:04,247 --> 00:20:06,761 This canny fox will hide its prize... 160 00:20:06,927 --> 00:20:09,885 as an insurance against harder times. 161 00:20:18,807 --> 00:20:22,083 No bear is above scavenging from another's kill. 162 00:20:22,247 --> 00:20:24,442 This family has travelled for many miles... 163 00:20:24,607 --> 00:20:27,326 drawn by the smell of a dead seal. 164 00:20:42,527 --> 00:20:47,282 Abandoned carcasses will have been stripped of their energy-rich fat... 165 00:20:47,447 --> 00:20:49,961 as all bears eat this first... 166 00:20:50,127 --> 00:20:52,766 in case an intruder arrives early and steals the kill. 167 00:20:52,927 --> 00:20:55,077 But there is still a lot of meat on the bones... 168 00:20:55,247 --> 00:20:57,397 invaluable food for younger bears... 169 00:20:57,567 --> 00:20:59,523 who are not yet proficient hunters... 170 00:20:59,687 --> 00:21:01,996 or for a family whose cubs are still growing... 171 00:21:02,167 --> 00:21:04,237 and in need of protein. 172 00:21:09,447 --> 00:21:12,644 This seal was killed by a large male bear... 173 00:21:12,807 --> 00:21:14,923 who once threatened these cubs. 174 00:21:15,087 --> 00:21:17,681 Now he has unwittingly provided them with food... 175 00:21:17,847 --> 00:21:20,645 and increased their chances of survival. 176 00:21:52,167 --> 00:21:54,806 It's June. As summer progresses... 177 00:21:54,967 --> 00:21:57,686 the Arctic ice begins to loosen its grip... 178 00:21:57,847 --> 00:22:01,396 and the polar bear's world is transformed. 179 00:22:04,927 --> 00:22:07,521 Seals begin to have an easier time of it. 180 00:22:07,687 --> 00:22:10,281 There is more open water for them to retreat to. 181 00:22:11,047 --> 00:22:14,278 The pups themselves have also become more wary. 182 00:22:23,767 --> 00:22:27,123 The bearded seal is a huge animal. 183 00:22:27,327 --> 00:22:29,966 It prefers to lie on drifting ice floes. 184 00:22:30,127 --> 00:22:32,561 So when the solid ice sheets begin to break up... 185 00:22:32,727 --> 00:22:36,003 these seals can be found closer to land. 186 00:22:37,487 --> 00:22:39,159 Weighing as much as a bear... 187 00:22:39,327 --> 00:22:41,761 and five times as much as a ringed seal... 188 00:22:41,927 --> 00:22:46,682 a bearded seal is a valuable prize: if caught. 189 00:22:50,127 --> 00:22:52,766 Bears have very individual characters. 190 00:22:52,927 --> 00:22:55,361 They learn the essentials of hunting from their mother... 191 00:22:55,527 --> 00:22:57,597 but then each develops its own solution... 192 00:22:57,767 --> 00:22:59,325 to the problems of survival... 193 00:22:59,487 --> 00:23:02,285 based on its own, unique experiences. 194 00:23:05,047 --> 00:23:07,766 This young bear, now hunting on its own... 195 00:23:07,927 --> 00:23:11,078 uses melt channels and the cover offered by ice... 196 00:23:11,247 --> 00:23:13,761 to sneak up on its intended victim. 197 00:24:13,887 --> 00:24:18,358 Small ice floes conceal its approach as it gets closer. 198 00:24:35,647 --> 00:24:38,559 Once again the bear goes hungry. 199 00:24:41,447 --> 00:24:44,917 Its first year alone will be the hardest. 200 00:24:52,687 --> 00:24:56,043 With 24 hours of sunlight, the temperature rises... 201 00:24:56,207 --> 00:24:59,836 and the bears' hunting platform fast disappears. 202 00:25:27,367 --> 00:25:31,758 But for others the release of water offers new opportunities... 203 00:25:32,207 --> 00:25:37,520 a developing bloom of planktonic life attracts millions of birds. 204 00:25:37,727 --> 00:25:42,084 Here, over the short summer, they feed and raise their chicks. 205 00:25:45,167 --> 00:25:47,044 For most animals and birds... 206 00:25:47,207 --> 00:25:49,243 summer is a time of plenty... 207 00:25:49,407 --> 00:25:53,036 but bears now enter the most difficult period of the year. 208 00:25:53,207 --> 00:25:54,765 There is little left of the ice... 209 00:25:54,927 --> 00:25:58,363 and so stalking seals is virtually impossible. 210 00:26:09,087 --> 00:26:12,397 They are still, for the most part, solitary creatures... 211 00:26:12,567 --> 00:26:15,365 and they continue to give each other a wide berth. 212 00:26:36,127 --> 00:26:39,676 Open water is no obstacle to them. 213 00:27:00,727 --> 00:27:04,402 Their fur is ideal, not only to keep them warm in winter... 214 00:27:04,567 --> 00:27:07,718 but now in summer, to shed water. 215 00:27:27,127 --> 00:27:29,163 As ice floes melt away... 216 00:27:29,327 --> 00:27:32,046 bears are forced to head for land. 217 00:27:34,407 --> 00:27:37,080 They can spend many hours in this freezing ocean... 218 00:27:37,247 --> 00:27:41,877 and have been known to swim a 100 miles or more to reach shore. 219 00:28:06,567 --> 00:28:10,242 The polar bear, as these unique pictures reveal... 220 00:28:10,407 --> 00:28:14,195 might just as appropriately be called the 'sea-bear'. 221 00:28:16,047 --> 00:28:20,802 It is a superbly competent swimmer and has partially webbed feet... 222 00:28:20,967 --> 00:28:22,685 for efficient paddling. 223 00:31:00,967 --> 00:31:04,357 In more southern areas, the ice disappears altogether... 224 00:31:04,527 --> 00:31:08,042 and bears spend the next five months on land. 225 00:31:08,327 --> 00:31:10,477 Here food is scarce. 226 00:31:10,647 --> 00:31:14,356 But they have one adaptation that is the most astounding of all... 227 00:31:14,527 --> 00:31:17,963 they can reduce their metabolism to extremely low levels... 228 00:31:18,127 --> 00:31:22,837 and save energy, whilst still able to remain active and hunt. 229 00:31:23,007 --> 00:31:28,365 This is how they could cope with their intermittent success at hunting seals. 230 00:31:28,647 --> 00:31:32,560 And how they will cope with little food in the months to come. 231 00:31:39,767 --> 00:31:42,884 Akpatok, a remote Canadian island... 232 00:31:43,047 --> 00:31:45,959 whose towering cliffs offer ideal nesting ledges... 233 00:31:46,127 --> 00:31:49,324 for hundreds of thousands of guillemots. 234 00:32:13,607 --> 00:32:15,165 By nesting on cliffs... 235 00:32:15,327 --> 00:32:18,444 these birds gain some protection from likely predators... 236 00:32:18,607 --> 00:32:23,203 foxes and bears, who also use the island as a summer retreat. 237 00:32:31,527 --> 00:32:33,916 The only food accessible to bears... 238 00:32:34,087 --> 00:32:37,397 are the rotting carcasses at the bottom of the cliff. 239 00:33:25,367 --> 00:33:30,646 The sight and smell of food so close is a strong lure. 240 00:33:55,367 --> 00:33:59,360 Unable to reach the birds, this bear opts for vegetation... 241 00:33:59,527 --> 00:34:02,121 which flourishes here because of the rich guano. 242 00:34:04,967 --> 00:34:07,879 Polar bears are closely related to brown bears... 243 00:34:08,047 --> 00:34:10,959 and, like them, are able to digest plants. 244 00:34:11,767 --> 00:34:15,077 Such meagre meals are probably not about energy intake... 245 00:34:15,247 --> 00:34:18,956 it's more likely that vegetation provides vitamins and minerals... 246 00:34:19,127 --> 00:34:21,800 absent from their seal diet. 247 00:34:39,407 --> 00:34:44,197 It's September, and all around the Arctic the ice has retreated. 248 00:35:01,047 --> 00:35:04,278 Here on Wrangel Island, north of Siberia... 249 00:35:04,447 --> 00:35:08,565 walruses can be found hauled out on the beach in late summer. 250 00:35:08,967 --> 00:35:12,482 One year in ten, the ice melts so far north... 251 00:35:12,647 --> 00:35:16,401 that walruses become stranded on this sandy spit. 252 00:35:25,607 --> 00:35:29,839 Bears also get left behind by the retreating ice. 253 00:35:39,687 --> 00:35:43,475 A bounty such as this offers relief from hunger. 254 00:36:25,807 --> 00:36:29,880 A mature walrus is so big and has such thick skin... 255 00:36:30,047 --> 00:36:32,766 that a bear is seldom able to take one. 256 00:36:34,807 --> 00:36:37,116 But a young animal is easier prey... 257 00:36:37,287 --> 00:36:39,357 once it has been separated from the group. 258 00:37:00,407 --> 00:37:02,523 Wrangel Island bears are lucky to have... 259 00:37:02,687 --> 00:37:06,839 such rich pickings in this otherwise lean period. 260 00:37:18,127 --> 00:37:20,243 Though solitary for most of the year... 261 00:37:20,407 --> 00:37:23,479 at this time these bears tolerate company. 262 00:37:23,647 --> 00:37:26,559 It's extremely rare to see so many bears of all ages... 263 00:37:26,727 --> 00:37:28,638 and both sexes together. 264 00:37:28,807 --> 00:37:32,766 But, on a full stomach and with so much more food close to hand... 265 00:37:32,927 --> 00:37:36,044 there is little to be gained by being aggressive. 266 00:37:44,047 --> 00:37:46,925 Churchill, on the shores of Hudson Bay, in Canada... 267 00:37:47,087 --> 00:37:49,760 it's on the same latitude as Scotland... 268 00:37:49,927 --> 00:37:54,045 and it's home to the most southerly population of polar bears. 269 00:37:58,247 --> 00:38:01,717 Here bears undergo one of the most extreme fasts... 270 00:38:01,887 --> 00:38:03,764 known for any mammal. 271 00:38:03,927 --> 00:38:07,886 It's now October, and apart from seaweed and a few berries... 272 00:38:08,047 --> 00:38:12,484 they've hardly eaten at all, since the ice melted away in July. 273 00:38:16,127 --> 00:38:18,482 It's probably not even worth wasting their energy... 274 00:38:18,647 --> 00:38:21,639 Iooking for such insignificant meals. 275 00:38:35,407 --> 00:38:38,001 Bears risk overheating at this time... 276 00:38:38,167 --> 00:38:41,716 as they are better adapted to keeping warm on the ice. 277 00:38:44,847 --> 00:38:48,317 The best way to conserve their dwindling energy reserves... 278 00:38:48,487 --> 00:38:49,636 and to keep cool... 279 00:38:49,807 --> 00:38:53,686 is simply to remain inactive, or to take a dip. 280 00:38:59,207 --> 00:39:02,483 Year after year the same bears appear in Churchill. 281 00:39:02,647 --> 00:39:05,764 So it seems that though bears may wander over vast areas... 282 00:39:05,927 --> 00:39:07,406 when out on the sea ice... 283 00:39:07,567 --> 00:39:09,125 their navigation is good... 284 00:39:09,287 --> 00:39:12,518 and they stay within a familiar home range. 285 00:39:18,847 --> 00:39:20,439 Respite from the gruelling heat... 286 00:39:20,607 --> 00:39:23,326 comes with the first storms of winter. 287 00:39:23,487 --> 00:39:26,843 But relief from hunger is still a long way off. 288 00:39:27,127 --> 00:39:30,005 For although the fresh water lakes freeze over quickly... 289 00:39:30,167 --> 00:39:32,476 the sea takes a great deal longer. 290 00:39:32,807 --> 00:39:35,241 And that is where the seals are. 291 00:39:38,327 --> 00:39:41,717 Males stay close to shore during the summer and autumn. 292 00:39:41,887 --> 00:39:46,278 And even though they are hungry, in Churchill they tolerate each other. 293 00:39:46,847 --> 00:39:51,716 Indeed these bears go beyond tolerance and actually socialise. 294 00:39:53,367 --> 00:39:56,882 And why not, at this time there is nothing to compete over... 295 00:39:57,047 --> 00:39:59,720 no food and no females. 296 00:40:03,207 --> 00:40:06,677 When it's cooler and overheating is no longer a risk... 297 00:40:06,847 --> 00:40:10,601 male bears sometimes engage in play fighting. 298 00:40:28,727 --> 00:40:32,242 Females and cubs have spent the summer further inland... 299 00:40:32,407 --> 00:40:35,126 avoiding the danger of hungry males. 300 00:40:35,447 --> 00:40:37,597 Now, with the approach of winter... 301 00:40:37,767 --> 00:40:41,840 they move back to the coast in anticipation of the sea freezing over. 302 00:40:42,367 --> 00:40:46,519 But they still remain cautious, and are wary of other bears. 303 00:41:08,127 --> 00:41:11,085 Play fighting between males is harmless. 304 00:41:11,247 --> 00:41:14,284 It's one way to establish who is who in the pecking order... 305 00:41:14,447 --> 00:41:16,915 and to assess your future opponents. 306 00:41:17,287 --> 00:41:18,686 For come spring... 307 00:41:18,847 --> 00:41:21,281 when competition for females is high... 308 00:41:21,447 --> 00:41:25,281 the fights are for real and are extremely aggressive. 309 00:41:25,607 --> 00:41:27,245 It's better to find out in rehearsal... 310 00:41:27,407 --> 00:41:30,558 that you don't have a hope of beating a particular rival... 311 00:41:30,727 --> 00:41:33,799 than to suffer serious injury later on. 312 00:41:48,007 --> 00:41:50,043 It's now early November... 313 00:41:50,207 --> 00:41:53,643 and the long awaited freeze up is slowly happening. 314 00:41:54,007 --> 00:41:56,521 But until the ice can support the bears... 315 00:41:56,687 --> 00:41:59,918 they continue to bide their time on land. 316 00:43:04,807 --> 00:43:07,367 By mid November day length is short... 317 00:43:07,527 --> 00:43:11,156 and the sea ice is now strong enough to support the bears. 318 00:43:23,927 --> 00:43:25,565 High among the mountains... 319 00:43:25,727 --> 00:43:28,321 pregnant females dig shallow dens... 320 00:43:28,487 --> 00:43:31,081 and wait for the snow to cover them. 321 00:43:31,247 --> 00:43:33,203 Up here they are safe from other bears... 322 00:43:33,367 --> 00:43:36,200 who would kill them to satisfy their hunger. 323 00:43:50,447 --> 00:43:55,043 All other bears walk out onto the newly frozen sea. 324 00:43:56,527 --> 00:43:59,121 Having lost up to a third of their body weight... 325 00:43:59,287 --> 00:44:01,642 and weakened by their long fast... 326 00:44:01,807 --> 00:44:05,482 they begin their search for ringed seals once more. 327 00:44:40,487 --> 00:44:43,479 The Northern Lights play in the winter sky... 328 00:44:43,647 --> 00:44:45,319 whilst below in the mountains... 329 00:44:45,487 --> 00:44:48,718 and by now well covered by a deep layer of snow... 330 00:44:48,887 --> 00:44:52,926 this pregnant female settles down for the next four months. 331 00:45:23,767 --> 00:45:26,759 Her cub is born, helpless and blind... 332 00:45:26,967 --> 00:45:30,164 after only sixty days in the womb. 333 00:45:30,647 --> 00:45:33,366 Deep under the protective covering of snow... 334 00:45:33,527 --> 00:45:35,961 and tucked into its mother's thick fur... 335 00:45:36,127 --> 00:45:41,121 the cub stays warm, despite the appalling conditions outside... 336 00:45:41,407 --> 00:45:44,922 where temperatures drop to below minus 50 degrees. 337 00:46:27,207 --> 00:46:31,041 It's only by having such tiny and immature cubs... 338 00:46:31,207 --> 00:46:35,280 that a female's body can cope with the continuing lack of food. 339 00:46:35,447 --> 00:46:37,756 So, unlike most mammals... 340 00:46:37,927 --> 00:46:40,680 much of the infant's growth goes on outside... 341 00:46:40,847 --> 00:46:43,202 rather than inside, the mother's body. 342 00:47:41,647 --> 00:47:44,445 In a few months, this cub will emerge... 343 00:47:44,607 --> 00:47:47,679 to face an unfamiliar world outside. 344 00:47:51,887 --> 00:47:54,196 In time it will learn the skills... 345 00:47:54,367 --> 00:47:56,642 necessary to hunt and survive in a place... 346 00:47:56,807 --> 00:47:59,640 which is forever changing with the seasons. 347 00:47:59,967 --> 00:48:03,198 Only by adapting to the challenges ahead... 348 00:48:03,447 --> 00:48:07,042 will it survive to continue its own line.