1 00:00:34,300 --> 00:00:38,240 DAVID ATTENBOROUGH: In winter, at the top of the planet 2 00:00:38,240 --> 00:00:40,920 lies an icy wilderness... 3 00:00:42,040 --> 00:00:45,520 ..not of land but of frozen water. 4 00:00:47,040 --> 00:00:48,760 The Arctic Ocean. 5 00:00:51,280 --> 00:00:55,200 Its surface forms an almost solid platform 6 00:00:55,200 --> 00:00:58,640 that is bigger than the whole of the United States. 7 00:00:58,640 --> 00:01:00,560 WIND HOWLS 8 00:01:03,680 --> 00:01:05,880 Its presence and condition 9 00:01:05,880 --> 00:01:10,600 dominates the lives of all the many and varied animals 10 00:01:10,600 --> 00:01:12,520 that live both on it... 11 00:01:13,560 --> 00:01:15,400 ..and beneath it. 12 00:01:21,920 --> 00:01:24,880 In the coming months, the sun's warmth 13 00:01:24,880 --> 00:01:29,840 will melt much of it and expose the rich waters beneath. 14 00:01:29,840 --> 00:01:32,000 CRACKING 15 00:01:32,000 --> 00:01:36,160 To survive here, life must adapt to this world 16 00:01:36,160 --> 00:01:39,800 that alternates between ice and water. 17 00:01:40,800 --> 00:01:43,000 CRACKING 18 00:01:59,520 --> 00:02:02,320 After three months of winter darkness, 19 00:02:02,320 --> 00:02:06,560 the sun rises across Arctic Norway. 20 00:02:15,240 --> 00:02:19,000 A newly emerged polar bear mother 21 00:02:19,000 --> 00:02:23,120 encourages her cubs to take their first tentative steps 22 00:02:23,120 --> 00:02:24,840 on the sea ice. 23 00:02:33,000 --> 00:02:36,680 Cubs will stay with their mothers for two years, 24 00:02:36,680 --> 00:02:39,960 learning the skills needed to survive out here. 25 00:02:41,520 --> 00:02:43,200 BEAR CALLS 26 00:02:43,200 --> 00:02:46,600 But thereafter, they will be on their own. 27 00:02:50,680 --> 00:02:53,080 Further out on the sea ice... 28 00:02:53,080 --> 00:02:54,800 GRUNTS 29 00:02:54,800 --> 00:02:58,480 ..this young female bear, less than six years old, 30 00:02:58,480 --> 00:03:01,200 is already fully independent. 31 00:03:05,680 --> 00:03:07,960 She's superbly adapted to life 32 00:03:07,960 --> 00:03:10,240 on the frozen ocean, 33 00:03:10,240 --> 00:03:14,240 protected from the cold by thick, insulating fat 34 00:03:14,240 --> 00:03:16,560 and a double layer of fur. 35 00:03:23,600 --> 00:03:28,040 This time of year is the best time for feeding. 36 00:03:31,720 --> 00:03:34,720 The ringed seals on which she depends 37 00:03:34,720 --> 00:03:36,400 feed on fish 38 00:03:36,400 --> 00:03:39,200 and are swimming 40 metres beneath her. 39 00:03:41,480 --> 00:03:43,920 But after ten minutes down there, 40 00:03:43,920 --> 00:03:46,960 they must return to the few gaps in the ice 41 00:03:46,960 --> 00:03:49,360 to take a breath and rest. 42 00:03:53,600 --> 00:03:55,680 She has acute hearing 43 00:03:55,680 --> 00:03:59,040 and one of the most sensitive noses in nature. 44 00:04:04,000 --> 00:04:06,840 She can detect a seal's lair beneath two metres 45 00:04:06,840 --> 00:04:08,640 of snow and ice. 46 00:04:11,520 --> 00:04:13,600 Timing is everything. 47 00:04:34,880 --> 00:04:38,280 Only one in ten attempts is successful. 48 00:04:39,360 --> 00:04:43,800 So for a young bear, each meal is very important. 49 00:04:45,480 --> 00:04:48,680 But a male has picked up the scent of the kill. 50 00:05:03,160 --> 00:05:06,320 Large males pose a real threat... 51 00:05:10,480 --> 00:05:14,040 ..and could inflict fatal injuries in a fight. 52 00:05:20,120 --> 00:05:22,120 But she stands her ground. 53 00:05:35,240 --> 00:05:38,840 Remarkably, rather than fight... 54 00:05:38,840 --> 00:05:41,480 GROWLING 55 00:05:41,480 --> 00:05:43,600 ..they start to play. 56 00:05:55,680 --> 00:05:56,920 And then, 57 00:05:56,920 --> 00:06:00,280 they set off to explore together. 58 00:06:08,480 --> 00:06:11,520 Well fed and still young, 59 00:06:11,520 --> 00:06:15,000 these two seem to be forming a friendship. 60 00:06:24,760 --> 00:06:27,120 She shows off the swimming skills 61 00:06:27,120 --> 00:06:31,680 that enable her to move with ease between water and ice. 62 00:06:42,000 --> 00:06:43,240 GROWLING 63 00:06:55,240 --> 00:06:56,640 She's behind you! 64 00:07:21,760 --> 00:07:24,040 Dancing on ice... 65 00:07:25,920 --> 00:07:29,080 ..apparently, just for the joy of it. 66 00:07:49,680 --> 00:07:53,720 After three hours together, they part company... 67 00:07:55,360 --> 00:07:57,520 GRUNTS 68 00:07:57,520 --> 00:08:02,400 ..and return once again to their solitary lives. 69 00:08:04,800 --> 00:08:07,320 GRUNTS 70 00:08:15,320 --> 00:08:18,520 Polar bears thrive at this time of year 71 00:08:18,520 --> 00:08:23,560 thanks to the huge platform of sea ice on which they can hunt. 72 00:08:28,680 --> 00:08:30,560 The Arctic Ocean lies 73 00:08:30,560 --> 00:08:32,760 across the top of the northern hemisphere 74 00:08:32,760 --> 00:08:34,400 and over the North Pole itself... 75 00:08:36,200 --> 00:08:39,000 ..and is surrounded by three continents - 76 00:08:39,000 --> 00:08:42,760 Europe, North America and Asia. 77 00:08:45,520 --> 00:08:48,360 In winter, the sea ice extends 78 00:08:48,360 --> 00:08:52,000 across an area of over five million square miles. 79 00:08:58,520 --> 00:09:01,320 But off the coast of Arctic Russia, 80 00:09:01,320 --> 00:09:04,400 a tiny pocket of water has been kept open... 81 00:09:13,360 --> 00:09:18,960 ..by the continuous stirring of 30 trapped beluga whales. 82 00:09:30,600 --> 00:09:35,720 These four-metre-long Arctic whales are superbly adapted 83 00:09:35,720 --> 00:09:39,560 for hunting far beneath the surface of the sea ice. 84 00:09:43,280 --> 00:09:45,240 WHALES CALL 85 00:09:45,240 --> 00:09:47,560 Nonetheless, being mammals, 86 00:09:47,560 --> 00:09:50,080 they must return to the surface to breathe 87 00:09:50,080 --> 00:09:52,440 every 15 minutes or so. 88 00:09:57,880 --> 00:10:01,640 But this cold spell is exceptionally severe. 89 00:10:03,160 --> 00:10:06,760 And there's not another breathing hole within 20 miles. 90 00:10:12,480 --> 00:10:16,000 Nearby fish and squid disappeared long ago. 91 00:10:17,600 --> 00:10:21,840 These emaciated whales have been imprisoned by the ice 92 00:10:21,840 --> 00:10:25,520 for five months, and they're now starving. 93 00:10:31,760 --> 00:10:34,440 Their only chance of escape will come 94 00:10:34,440 --> 00:10:36,440 when there is a change in the season. 95 00:10:44,800 --> 00:10:48,080 As spring finally reaches the north of the planet, 96 00:10:48,080 --> 00:10:51,840 air temperatures creep above freezing. 97 00:10:51,840 --> 00:10:54,080 CRACKING 98 00:11:07,320 --> 00:11:11,360 The impenetrable ice ceiling begins to fracture. 99 00:11:14,320 --> 00:11:18,280 Small, life-saving channels open up... 100 00:11:23,520 --> 00:11:26,000 ..bringing freedom. 101 00:11:29,960 --> 00:11:33,880 But spring is a dangerous time for beluga. 102 00:11:34,880 --> 00:11:38,280 As tides and currents pull ice apart, 103 00:11:38,280 --> 00:11:40,800 the beluga find themselves 104 00:11:40,800 --> 00:11:43,200 in a labyrinth of shifting ice floes 105 00:11:43,200 --> 00:11:45,640 that could close their breathing holes 106 00:11:45,640 --> 00:11:48,240 at any point and so drown them. 107 00:11:48,240 --> 00:11:51,000 WHALES CALL 108 00:12:00,440 --> 00:12:03,200 Using their sophisticated sonar, 109 00:12:03,200 --> 00:12:05,960 they try to find a way through the icy maze... 110 00:12:19,480 --> 00:12:23,680 ..and eventually reach a patch of open water. 111 00:12:30,280 --> 00:12:32,800 They're not the only whales here. 112 00:12:39,600 --> 00:12:40,760 Narwhal, 113 00:12:40,760 --> 00:12:45,000 the unicorns of the sea, are closely related to beluga. 114 00:12:51,480 --> 00:12:53,840 In a rarely seen encounter, 115 00:12:53,840 --> 00:12:57,400 these two kinds of whales appear to socialise. 116 00:12:59,520 --> 00:13:02,400 Who knows what's going on between them? 117 00:13:12,040 --> 00:13:14,680 But soon, they set off together 118 00:13:14,680 --> 00:13:17,600 through the shifting fields of ice... 119 00:13:26,360 --> 00:13:29,440 ..a journey of up to 1,000 miles... 120 00:13:32,160 --> 00:13:33,600 WHALE CALLS 121 00:13:33,600 --> 00:13:36,600 ..before they reach ice-free waters, 122 00:13:36,600 --> 00:13:39,240 where they can rear their young. 123 00:13:54,320 --> 00:13:57,160 As the spring sunshine strengthens, 124 00:13:57,160 --> 00:14:00,560 the broken pack ice off the coast of Greenland 125 00:14:00,560 --> 00:14:03,200 becomes a nursery. 126 00:14:09,320 --> 00:14:11,000 A harp seal pup. 127 00:14:13,000 --> 00:14:15,400 Born just a week ago. 128 00:14:17,320 --> 00:14:19,560 He has little fat. 129 00:14:21,160 --> 00:14:22,480 His thick fur 130 00:14:22,480 --> 00:14:25,760 is his only protection from the Arctic chill. 131 00:14:28,840 --> 00:14:32,880 In between dozes, he waits for his mother to return. 132 00:14:37,880 --> 00:14:39,360 MOTHER GRUNTS 133 00:14:41,840 --> 00:14:44,680 She has only one pup a year... 134 00:14:44,680 --> 00:14:46,720 PUP SQUEALS 135 00:14:50,720 --> 00:14:54,240 ..and will produce milk for only 12 days, 136 00:14:54,240 --> 00:14:57,880 one of the shortest nursing periods in nature. 137 00:15:01,720 --> 00:15:03,520 That is just long enough 138 00:15:03,520 --> 00:15:06,640 for him to develop a thick layer of blubber... 139 00:15:08,040 --> 00:15:12,480 ..thanks to his mother's milk, which is 50% fat. 140 00:15:17,600 --> 00:15:20,400 And his mother stays alongside 141 00:15:20,400 --> 00:15:21,960 while he learns 142 00:15:21,960 --> 00:15:24,000 an important survival skill 143 00:15:24,000 --> 00:15:25,480 for any seal... 144 00:15:32,400 --> 00:15:34,200 CALLS 145 00:15:34,200 --> 00:15:35,480 MOTHER GRUNTS 146 00:15:39,080 --> 00:15:40,920 ..how to swim. 147 00:15:43,080 --> 00:15:46,560 He may not be keen to take the plunge. 148 00:15:46,560 --> 00:15:51,280 The saltwater is minus two degrees Celsius, after all. 149 00:16:01,800 --> 00:16:04,840 Pups start with a doggy paddle. 150 00:16:08,720 --> 00:16:11,560 Mum stays reassuringly close. 151 00:16:24,200 --> 00:16:26,560 Still developing his insulating blubber, 152 00:16:26,560 --> 00:16:29,920 a pup is at risk of hypothermia 153 00:16:29,920 --> 00:16:31,880 so needs to rest 154 00:16:31,880 --> 00:16:33,520 and warm up. 155 00:16:39,000 --> 00:16:40,240 Each day, 156 00:16:40,240 --> 00:16:43,080 he puts on another two kilos... 157 00:16:49,000 --> 00:16:50,480 ..and practises swimming 158 00:16:50,480 --> 00:16:52,840 for just a little longer. 159 00:17:07,280 --> 00:17:11,280 Since birth, this pup has tripled in weight, 160 00:17:11,280 --> 00:17:15,520 and he's now at ease in this curious other world. 161 00:17:28,120 --> 00:17:30,600 12 days gone by. 162 00:17:31,840 --> 00:17:35,280 A mother's work is done. 163 00:17:44,280 --> 00:17:48,880 In producing milk, she's lost a third of her body weight. 164 00:17:52,800 --> 00:17:56,600 Now she must return to her feeding grounds. 165 00:18:11,840 --> 00:18:14,080 CALLS OUT 166 00:18:22,840 --> 00:18:26,040 She will never see her pup again. 167 00:18:42,360 --> 00:18:46,640 The next four weeks he spends alone, 168 00:18:46,640 --> 00:18:49,240 sticking close to the ice platform... 169 00:18:51,880 --> 00:18:55,440 ..surviving on his fat reserves 170 00:18:55,440 --> 00:18:59,520 as his downy fleece is replaced by a sleek coat 171 00:18:59,520 --> 00:19:02,000 more suited to swimming. 172 00:19:08,360 --> 00:19:10,360 But temperatures in the Arctic are now 173 00:19:10,360 --> 00:19:12,200 rising faster than ever before... 174 00:19:15,240 --> 00:19:18,880 ..creating storms that break up the ice floes 175 00:19:18,880 --> 00:19:21,120 earlier each spring. 176 00:19:30,880 --> 00:19:34,840 Harp seal pups are being tipped into freezing waters 177 00:19:34,840 --> 00:19:39,000 before they're ready to endure long periods at sea. 178 00:19:48,760 --> 00:19:54,280 In some pupping areas, almost none survive. 179 00:20:19,200 --> 00:20:21,480 As spring turns to summer, 180 00:20:21,480 --> 00:20:26,120 life on the sea ice suddenly begins to proliferate. 181 00:20:28,760 --> 00:20:31,200 The daylight increases, 182 00:20:31,200 --> 00:20:33,440 and algae that had remained dormant 183 00:20:33,440 --> 00:20:36,040 within the ice all winter 184 00:20:36,040 --> 00:20:37,880 begin to bloom. 185 00:20:44,240 --> 00:20:47,240 This upside-down meadow is now cropped 186 00:20:47,240 --> 00:20:48,880 by plankton. 187 00:21:05,320 --> 00:21:08,400 For a little skeleton shrimp 188 00:21:08,400 --> 00:21:12,040 living at the bottom of a towering forest of kelp, 189 00:21:12,040 --> 00:21:14,520 the best way to get a share of the food... 190 00:21:15,680 --> 00:21:17,520 ..is to climb. 191 00:21:21,840 --> 00:21:23,880 If you're only two centimetres long... 192 00:21:25,240 --> 00:21:27,840 ..this is like scaling a skyscraper. 193 00:21:30,600 --> 00:21:34,080 And yet it's not alone. 194 00:21:36,040 --> 00:21:38,360 Hundreds of fellow shrimps 195 00:21:38,360 --> 00:21:41,120 are attempting the same ascent. 196 00:21:46,760 --> 00:21:48,080 A new mother 197 00:21:48,080 --> 00:21:50,520 has parked her brood halfway up. 198 00:21:51,680 --> 00:21:55,360 And she's not about to give way. 199 00:22:08,720 --> 00:22:13,120 This one is a determined commuter. 200 00:22:13,120 --> 00:22:16,040 But the mother's drive to protect her young 201 00:22:16,040 --> 00:22:19,280 is now causing a traffic jam. 202 00:22:27,000 --> 00:22:28,600 At last... 203 00:22:28,600 --> 00:22:31,680 many have made it to the topmost branches 204 00:22:31,680 --> 00:22:33,880 of this underwater forest. 205 00:22:36,320 --> 00:22:39,160 And it's been well worth the effort. 206 00:22:41,200 --> 00:22:42,960 The prize... 207 00:22:42,960 --> 00:22:44,600 is a plankton feast... 208 00:22:49,120 --> 00:22:51,960 ..raining down from above. 209 00:22:57,280 --> 00:23:01,160 By midsummer, Arctic waters are filled 210 00:23:01,160 --> 00:23:02,320 with food... 211 00:23:13,560 --> 00:23:18,120 ..making them into one of the richest of all oceans... 212 00:23:22,360 --> 00:23:26,320 ..feeding billions of microscopic mouths 213 00:23:26,320 --> 00:23:27,520 as well as... 214 00:23:28,640 --> 00:23:30,840 ..the biggest mouth on the planet. 215 00:23:37,480 --> 00:23:39,320 The bowhead whale. 216 00:23:42,720 --> 00:23:45,640 Its four-metre-long baleen plates 217 00:23:45,640 --> 00:23:47,960 enable it to sieve out 218 00:23:47,960 --> 00:23:50,880 up to six tonnes of plankton a day. 219 00:23:53,080 --> 00:23:59,200 And it grows swiftly into an 18-metre, 100-tonne giant. 220 00:24:05,920 --> 00:24:09,320 In summer, the bowheads are so well fed 221 00:24:09,320 --> 00:24:12,000 they head for an annual get-together. 222 00:24:23,800 --> 00:24:26,440 After a year of wear and tear, 223 00:24:26,440 --> 00:24:29,720 their skin needs reconditioning. 224 00:24:31,560 --> 00:24:34,960 WHALES CALL 225 00:24:36,120 --> 00:24:39,200 This is a whale health spa. 226 00:24:48,600 --> 00:24:54,080 Rocks and sand in the shallows are used like pumice stones 227 00:24:54,080 --> 00:24:57,520 with which to rub off dead skin and parasites. 228 00:25:02,440 --> 00:25:05,840 Such places can become very popular. 229 00:25:12,960 --> 00:25:15,400 This bay, off the coast of Russia, 230 00:25:15,400 --> 00:25:20,040 attracts an immense gathering of over 50 bowheads. 231 00:25:25,960 --> 00:25:29,160 They are the longest-lived of all mammals. 232 00:25:37,040 --> 00:25:40,440 Some are 200 years old 233 00:25:40,440 --> 00:25:43,440 and have been coming here for many decades. 234 00:25:46,840 --> 00:25:49,080 Suddenly... 235 00:25:49,080 --> 00:25:52,160 their peace is shattered. 236 00:25:54,840 --> 00:25:59,440 Killer whales have arrived from the south... 237 00:26:01,280 --> 00:26:02,920 ..nine metres long, 238 00:26:02,920 --> 00:26:04,920 weighing nine tonnes... 239 00:26:06,400 --> 00:26:09,400 ..and renowned for their exceptional intelligence. 240 00:26:11,040 --> 00:26:14,920 This particular pack specialises in hunting 241 00:26:14,920 --> 00:26:16,880 bowhead whales. 242 00:26:28,320 --> 00:26:31,160 The bowheads retreat into the shallows... 243 00:26:32,680 --> 00:26:35,000 ..where it will be harder 244 00:26:35,000 --> 00:26:38,040 for killer whales to launch an attack. 245 00:26:42,640 --> 00:26:44,640 But the killers can swim 246 00:26:44,640 --> 00:26:46,520 much faster than the bowheads. 247 00:26:53,920 --> 00:26:56,920 The group tries to close ranks. 248 00:27:01,840 --> 00:27:04,640 But the killers attempt to separate them. 249 00:27:14,160 --> 00:27:16,640 They look for individual signs 250 00:27:16,640 --> 00:27:18,960 of weakness. 251 00:27:29,840 --> 00:27:32,680 In the shallows, the bowheads lash out... 252 00:27:34,720 --> 00:27:37,720 ..with their seven-metre-wide tails. 253 00:27:52,400 --> 00:27:53,840 But in the confusion, 254 00:27:53,840 --> 00:27:55,880 some run aground. 255 00:28:09,960 --> 00:28:13,640 Others try to reach deeper water. 256 00:28:15,520 --> 00:28:18,800 This youngster, half the size of an adult, 257 00:28:18,800 --> 00:28:20,720 is extremely vulnerable. 258 00:28:30,640 --> 00:28:32,240 The killer whales 259 00:28:32,240 --> 00:28:36,280 take turns to ram into its sides... 260 00:28:36,280 --> 00:28:41,000 ..cracking its ribs so that it struggles to breathe. 261 00:29:06,360 --> 00:29:11,760 Then they push the youngster down until, finally... 262 00:29:12,760 --> 00:29:14,720 ..it drowns. 263 00:29:21,760 --> 00:29:23,720 The battle is over. 264 00:29:25,400 --> 00:29:27,840 It lasted an hour. 265 00:29:29,520 --> 00:29:33,760 Yet now the killer whales eat only one part of their prey... 266 00:29:35,440 --> 00:29:38,280 ..the young bowhead's soft, fatty tongue. 267 00:29:52,880 --> 00:29:55,600 Today, more and more bowheads 268 00:29:55,600 --> 00:29:58,840 are falling prey to killer whales 269 00:29:58,840 --> 00:30:00,200 as the warming climate 270 00:30:00,200 --> 00:30:02,800 causes the protective barrier of sea ice 271 00:30:02,800 --> 00:30:05,240 to melt earlier each year. 272 00:30:23,800 --> 00:30:28,440 By midsummer, millions of migratory sea birds, 273 00:30:28,440 --> 00:30:31,480 having flown thousands of miles to get here, 274 00:30:31,480 --> 00:30:34,760 are feeding in the Arctic's rich waters. 275 00:30:35,720 --> 00:30:37,320 BIRDS CALL 276 00:30:39,360 --> 00:30:40,800 Over a million 277 00:30:40,800 --> 00:30:43,680 crested auklets, no bigger than puffins, 278 00:30:43,680 --> 00:30:47,080 now descend on Alaska's Saint Lawrence Island 279 00:30:47,080 --> 00:30:49,800 and are preparing to breed. 280 00:30:54,400 --> 00:30:57,200 To win a mate, a male must try 281 00:30:57,200 --> 00:30:59,040 to stand out from the crowd. 282 00:31:01,320 --> 00:31:04,760 And auditions are already under way. 283 00:31:04,760 --> 00:31:06,000 CHEEPING 284 00:31:06,000 --> 00:31:10,200 Males and females, unusually, look very similar, 285 00:31:10,200 --> 00:31:14,120 each adorned with an Elvis-like crest. 286 00:31:14,120 --> 00:31:17,960 But it's the size of the crest that matters. 287 00:31:22,040 --> 00:31:24,640 And this male's headgear seems to be 288 00:31:24,640 --> 00:31:26,480 no more than adequate. 289 00:31:28,760 --> 00:31:31,600 BIRD SCREECHES 290 00:31:31,600 --> 00:31:34,600 A position on the ground is also important. 291 00:31:39,720 --> 00:31:45,320 One large male wants this particular perch. 292 00:31:54,760 --> 00:31:58,280 And having got it, he breaks into song. 293 00:31:58,280 --> 00:32:00,760 WHOOPING CALL 294 00:32:08,360 --> 00:32:12,520 He now releases a potent tangerine scent 295 00:32:12,520 --> 00:32:14,000 from the back of his neck. 296 00:32:15,040 --> 00:32:17,880 And a mob of fans go wild. 297 00:32:23,680 --> 00:32:25,320 This male, however, 298 00:32:25,320 --> 00:32:27,400 seems to have nothing to offer. 299 00:32:31,880 --> 00:32:33,320 But a gaggle of groupies 300 00:32:33,320 --> 00:32:36,880 can be a dangerous distraction. 301 00:32:40,320 --> 00:32:42,240 An Arctic fox. 302 00:32:48,960 --> 00:32:51,160 BIRDS CALL 303 00:33:08,920 --> 00:33:10,680 It's found an egg. 304 00:33:14,160 --> 00:33:16,240 With the stage cleared, 305 00:33:16,240 --> 00:33:18,360 the highest perch 306 00:33:18,360 --> 00:33:20,040 has become vacant. 307 00:33:40,760 --> 00:33:44,240 This is a moment to shine. 308 00:33:44,240 --> 00:33:47,360 BIRD SCREECHES 309 00:33:55,600 --> 00:33:59,480 His display doesn't go unnoticed. 310 00:34:04,960 --> 00:34:08,840 And his tangerine perfume attracts an admirer. 311 00:34:17,560 --> 00:34:19,840 And not just one. 312 00:34:24,160 --> 00:34:27,280 Now it's down to the females to impress him. 313 00:34:31,280 --> 00:34:34,360 In auklet society, both sexes 314 00:34:34,360 --> 00:34:37,200 have a say when it comes to choosing a mate. 315 00:34:48,520 --> 00:34:53,160 At the height of summer, with 24 hours of sunlight a day, 316 00:34:53,160 --> 00:34:56,640 over half the sea ice melts away. 317 00:34:59,400 --> 00:35:02,360 BIRDS CALL 318 00:35:03,640 --> 00:35:06,000 The beaches of Svalbard 319 00:35:06,000 --> 00:35:10,360 provide safe places to haul out for one of 320 00:35:10,360 --> 00:35:12,400 the Arctic's special residents. 321 00:35:16,840 --> 00:35:18,640 Walruses. 322 00:35:21,400 --> 00:35:26,600 They forage for shellfish for up to 17 hours at a stretch. 323 00:35:31,200 --> 00:35:32,400 Now... 324 00:35:32,400 --> 00:35:34,120 GRUNTS 325 00:35:34,120 --> 00:35:36,160 ..it's time for a rest. 326 00:35:40,520 --> 00:35:44,960 Each adult male weighs more than a tonne. 327 00:35:50,360 --> 00:35:51,960 And heaving oneself over the sand... 328 00:35:54,200 --> 00:35:55,800 ..without the support of water 329 00:35:55,800 --> 00:35:57,760 is very hard work. 330 00:36:04,160 --> 00:36:06,200 This male has a particular 331 00:36:06,200 --> 00:36:08,440 sunbathing spot in mind... 332 00:36:12,080 --> 00:36:13,800 ..right in the middle 333 00:36:13,800 --> 00:36:16,160 of the 50-strong huddle. 334 00:36:16,160 --> 00:36:19,040 GRUNTING 335 00:36:25,720 --> 00:36:27,520 A prod helps in parting the crowd. 336 00:36:41,320 --> 00:36:43,360 Almost in. 337 00:36:53,560 --> 00:36:56,040 At last, he can settle down for a snooze... 338 00:36:57,040 --> 00:36:58,400 ..swaddled on all sides 339 00:36:58,400 --> 00:37:00,840 by the bodies of his neighbours. 340 00:37:02,520 --> 00:37:04,160 GRUNTING 341 00:37:04,160 --> 00:37:07,960 But it's not a peaceful spot. 342 00:37:07,960 --> 00:37:10,560 LOUD GRUNTING 343 00:37:17,520 --> 00:37:21,800 Sleep isn't easy when a fidgety bedfellow 344 00:37:21,800 --> 00:37:23,880 decides that he has an itch 345 00:37:23,880 --> 00:37:26,040 that needs scratching. 346 00:37:27,280 --> 00:37:29,720 This is the time to moult, 347 00:37:29,720 --> 00:37:33,320 to get rid of one's old fur with all its parasites 348 00:37:33,320 --> 00:37:37,920 and expose the healthy new coat beneath. 349 00:37:37,920 --> 00:37:39,440 BUBBLING 350 00:37:50,200 --> 00:37:52,640 These days, Svalbard's summer temperatures 351 00:37:52,640 --> 00:37:56,160 can soar to 22 degrees Celsius. 352 00:38:03,840 --> 00:38:07,040 Flushing red by bringing blood close to the skin 353 00:38:07,040 --> 00:38:09,680 helps them to keep cool. 354 00:38:15,360 --> 00:38:18,840 But some overheating is unavoidable... 355 00:38:20,880 --> 00:38:23,920 ..especially for a big male. 356 00:38:33,640 --> 00:38:35,720 Enough is enough. 357 00:38:42,960 --> 00:38:45,040 Getting up here... 358 00:38:45,040 --> 00:38:46,360 was a slog. 359 00:38:47,480 --> 00:38:51,480 But this male has found a better way of getting down. 360 00:38:52,520 --> 00:38:55,200 Let gravity do the work. 361 00:39:26,800 --> 00:39:30,240 Now, that is cool! 362 00:39:32,200 --> 00:39:34,200 Ahhh! 363 00:39:39,320 --> 00:39:44,360 Everyone is doing it. It saves both time and energy. 364 00:39:49,120 --> 00:39:52,680 But walruses will need all the tricks they can find. 365 00:39:55,960 --> 00:39:59,000 The Arctic is warming, 366 00:39:59,000 --> 00:40:02,720 and these cold-loving animals are facing 367 00:40:02,720 --> 00:40:04,360 a precarious future. 368 00:40:15,200 --> 00:40:19,760 For millennia, the Arctic Ocean has frozen over in the winter 369 00:40:19,760 --> 00:40:21,760 and then gradually melted 370 00:40:21,760 --> 00:40:24,560 throughout the spring and summer. 371 00:40:25,960 --> 00:40:28,240 But in the last 40 years, 372 00:40:28,240 --> 00:40:33,320 the extent of the summer sea ice has declined by 50%. 373 00:40:36,000 --> 00:40:41,840 Some predict that it will be ice-free as early as 2035. 374 00:40:45,920 --> 00:40:47,920 This profound change... 375 00:40:48,960 --> 00:40:50,880 ..is already having an impact 376 00:40:50,880 --> 00:40:54,640 on the Arctic Ocean's highly specialised wildlife. 377 00:41:00,560 --> 00:41:04,280 With less summer sea ice from which to hunt seals, 378 00:41:04,280 --> 00:41:09,320 some polar bears are now travelling up to 400 miles... 379 00:41:09,320 --> 00:41:12,720 swimming continuously for up to ten days 380 00:41:12,720 --> 00:41:14,400 in search of land. 381 00:41:21,800 --> 00:41:24,880 Wrangel Island, off Arctic Russia... 382 00:41:25,960 --> 00:41:30,200 ..the only land for almost 100 miles. 383 00:41:33,480 --> 00:41:37,680 Each summer, more and more polar bears come ashore here. 384 00:41:45,720 --> 00:41:48,120 This newly arrived mother 385 00:41:48,120 --> 00:41:50,920 needs to find food for her family... 386 00:41:50,920 --> 00:41:52,880 CALLS OUT 387 00:41:56,640 --> 00:42:00,720 ..but knows not to approach other adult bears. 388 00:42:04,120 --> 00:42:05,920 A full-grown male 389 00:42:05,920 --> 00:42:08,240 can kill and eat a cub 390 00:42:08,240 --> 00:42:12,280 and will do so if other food is in short supply. 391 00:42:14,360 --> 00:42:18,720 There are over 1,000 bears on this one island. 392 00:42:22,240 --> 00:42:24,960 It's the greatest concentration of polar bears 393 00:42:24,960 --> 00:42:26,880 on the planet. 394 00:42:33,400 --> 00:42:37,200 But there is food to be had on these remote shores. 395 00:42:41,480 --> 00:42:42,920 A walrus colony... 396 00:42:45,160 --> 00:42:46,960 ..2,000 strong. 397 00:42:56,920 --> 00:42:59,560 The walruses panic. 398 00:43:12,560 --> 00:43:15,200 And there are casualties. 399 00:43:31,520 --> 00:43:32,720 GROWLS 400 00:43:36,560 --> 00:43:39,600 Fights break out. 401 00:43:46,320 --> 00:43:50,160 This is no place for a young family. 402 00:43:57,280 --> 00:44:00,440 The mother calls her cubs away. 403 00:44:16,760 --> 00:44:19,160 They must search elsewhere. 404 00:44:38,040 --> 00:44:42,360 Grass is a poor meal for a growing cub. 405 00:44:43,800 --> 00:44:47,320 And starvation in summer is a real threat. 406 00:44:58,520 --> 00:45:01,200 But this opportunity to feed... 407 00:45:02,400 --> 00:45:04,560 ..is one she cannot afford to ignore. 408 00:45:10,160 --> 00:45:12,200 It's time to gamble. 409 00:45:18,080 --> 00:45:19,720 Her cubs follow her. 410 00:45:19,720 --> 00:45:21,760 MOTHER GROWLS 411 00:45:21,760 --> 00:45:23,880 She urges them to stay back. 412 00:45:32,720 --> 00:45:35,280 CUBS CALL OUT 413 00:45:39,240 --> 00:45:41,640 The males are twice her size. 414 00:45:42,960 --> 00:45:45,600 But, preoccupied with feeding, 415 00:45:45,600 --> 00:45:47,880 they tolerate her presence. 416 00:45:53,440 --> 00:45:56,160 The distress calls of her cubs, however... 417 00:45:56,160 --> 00:45:57,280 CUB CALLS OUT 418 00:45:57,280 --> 00:45:58,920 ..attract unwelcome attention. 419 00:46:16,240 --> 00:46:19,640 Their mother rushes to shield them with her body. 420 00:46:27,880 --> 00:46:31,840 But she seems torn between guarding her family 421 00:46:31,840 --> 00:46:33,880 and feeding herself. 422 00:46:49,320 --> 00:46:51,880 Cubs left by themselves 423 00:46:51,880 --> 00:46:55,440 are easy prey for a hungry male bear. 424 00:47:05,360 --> 00:47:10,000 But now her maternal instincts take over. 425 00:47:32,520 --> 00:47:35,480 Faced with a mother's fury... 426 00:47:35,480 --> 00:47:37,880 the dominant male backs down. 427 00:48:01,200 --> 00:48:03,040 Having fought her way in... 428 00:48:04,880 --> 00:48:09,320 ..her cubs can now feed for the first time in weeks. 429 00:48:18,680 --> 00:48:20,520 Polar bears were once 430 00:48:20,520 --> 00:48:24,200 the supreme hunters on the sea ice. 431 00:48:24,200 --> 00:48:27,640 Now, each summer, more and more of them 432 00:48:27,640 --> 00:48:31,280 have to come to land in search of food. 433 00:48:36,200 --> 00:48:39,840 Whether the ice bear survives into the next century 434 00:48:39,840 --> 00:48:44,240 depends on what happens to the sea ice on which they rely. 435 00:48:47,680 --> 00:48:52,600 As with all of the Arctic Ocean's remarkable wildlife, 436 00:48:52,600 --> 00:48:56,080 it's how the climate changes over the coming years 437 00:48:56,080 --> 00:48:58,800 that will determine their future. 438 00:49:15,000 --> 00:49:19,040 In today's unpredictable and changing Arctic, 439 00:49:19,040 --> 00:49:22,880 filming its wildlife is an ever-increasing challenge... 440 00:49:24,920 --> 00:49:27,520 ..none more so than trying to capture the brief time 441 00:49:27,520 --> 00:49:29,960 that a mother harp seal spends 442 00:49:29,960 --> 00:49:32,080 preparing her pup for life at sea. 443 00:49:36,520 --> 00:49:39,360 To find the seal's pupping grounds, 444 00:49:39,360 --> 00:49:42,360 the crew have sailed to a remote area of the Arctic 445 00:49:42,360 --> 00:49:44,680 off the east coast of Greenland. 446 00:49:45,840 --> 00:49:48,080 But here, they quickly discover 447 00:49:48,080 --> 00:49:51,040 that its usually solid platform of sea ice 448 00:49:51,040 --> 00:49:53,920 has broken up into thousands of floes. 449 00:49:55,000 --> 00:49:57,840 It's a surprising sight even for veteran captain 450 00:49:57,840 --> 00:49:59,680 Bjorne Kvernmo. 451 00:50:12,080 --> 00:50:14,840 And with the sea ice so fractured, 452 00:50:14,840 --> 00:50:16,560 there's no sign of any wildlife. 453 00:50:17,920 --> 00:50:21,600 We've been at sea for well over a week now. 454 00:50:21,600 --> 00:50:24,600 We still haven't filmed a thing. 455 00:50:25,880 --> 00:50:29,880 With mother and pup together for just 12 days, it's a race 456 00:50:29,880 --> 00:50:32,040 to find the dense pack ice 457 00:50:32,040 --> 00:50:34,960 on which the breeding seals give birth. 458 00:50:37,400 --> 00:50:41,080 The team head a further 100 miles up the Greenland coast, 459 00:50:41,080 --> 00:50:43,600 to an area no film crew 460 00:50:43,600 --> 00:50:45,360 has ventured into before. 461 00:50:47,560 --> 00:50:50,320 Their gamble pays off. 462 00:50:50,320 --> 00:50:52,240 SQUEAL 463 00:50:53,880 --> 00:50:57,000 Our first harp seal, baby! 464 00:50:57,000 --> 00:51:00,400 From the smaller, more manoeuvrable tender, 465 00:51:00,400 --> 00:51:02,760 cameraman Jamie McPherson 466 00:51:02,760 --> 00:51:04,520 hopes to record the precious time 467 00:51:04,520 --> 00:51:06,280 mother and pup spend together 468 00:51:06,280 --> 00:51:07,680 on the ice. 469 00:51:07,680 --> 00:51:08,720 WHISPERS: I've been filming 470 00:51:08,720 --> 00:51:11,120 probably one of the cutest animals in the world. 471 00:51:11,120 --> 00:51:12,440 And there was suckling, 472 00:51:12,440 --> 00:51:14,440 which is really cool, because it's really funny, 473 00:51:14,440 --> 00:51:16,480 because the baby goes from one nipple to the other nipple 474 00:51:16,480 --> 00:51:18,640 and just goes backwards and forwards. 475 00:51:23,360 --> 00:51:26,640 WHISPERS: That's one of the sweetest things I've ever seen! 476 00:51:26,640 --> 00:51:28,800 Utterly adorable! 477 00:51:30,240 --> 00:51:32,920 With mum now calling it into the water, 478 00:51:32,920 --> 00:51:36,640 this pup may be ready for its very first swim. 479 00:51:36,640 --> 00:51:38,200 PUP CALLS OUT 480 00:51:38,200 --> 00:51:40,800 It's the cue for underwater cameraman 481 00:51:40,800 --> 00:51:42,200 Hugh Miller. 482 00:51:43,440 --> 00:51:45,080 We're going to try something different 483 00:51:45,080 --> 00:51:46,960 and actually get into the water with the seals. 484 00:51:46,960 --> 00:51:50,120 We're definitely in new territory here. 485 00:51:52,280 --> 00:51:54,720 To film this rare moment underwater, 486 00:51:54,720 --> 00:51:56,800 Hugh will need to get a lot closer, 487 00:51:56,800 --> 00:51:58,480 without disturbing them. 488 00:52:00,640 --> 00:52:03,840 But with Arctic waters at minus two degrees Celsius, 489 00:52:03,840 --> 00:52:08,000 even with a protective thermal dry suit, 490 00:52:08,000 --> 00:52:12,560 Hugh only has an hour before he risks developing hypothermia. 491 00:52:15,240 --> 00:52:19,760 It's now a matter of waiting for the pup to take the plunge. 492 00:52:20,800 --> 00:52:23,160 The guys have now been in for about... 493 00:52:26,200 --> 00:52:27,320 ..20 minutes. 494 00:52:28,920 --> 00:52:32,720 I can guarantee you they'll be freezing cold. 495 00:52:34,040 --> 00:52:37,960 Hugh's body temperature is getting dangerously low. 496 00:52:44,080 --> 00:52:46,240 HUGH: Conditions have been... 497 00:52:46,240 --> 00:52:48,160 really hard. 498 00:52:48,160 --> 00:52:49,640 The cold just... 499 00:52:51,520 --> 00:52:53,160 It's been very, very difficult! LAUGHS 500 00:52:54,200 --> 00:52:56,000 DAVID: With less than a week to go 501 00:52:56,000 --> 00:52:59,640 before this mother is likely to leave her pup forever, 502 00:52:59,640 --> 00:53:02,440 Jamie continues to capture their intimate interactions... 503 00:53:07,920 --> 00:53:10,240 ..while Hugh is yet to film a single shot. 504 00:53:12,160 --> 00:53:13,640 To make matters worse, 505 00:53:13,640 --> 00:53:16,280 temperatures fall to 506 00:53:16,280 --> 00:53:18,480 minus 30 degrees centigrade. 507 00:53:19,640 --> 00:53:21,680 And as the wind direction changes, 508 00:53:21,680 --> 00:53:25,440 the floes are forced closer together. 509 00:53:25,440 --> 00:53:28,040 Pack ice has just come in from all around us. 510 00:53:28,040 --> 00:53:29,560 It could flip the boat, 511 00:53:29,560 --> 00:53:32,520 and that would be the end of the shoot. 512 00:53:32,520 --> 00:53:35,240 Hemmed in by blocks 513 00:53:35,240 --> 00:53:37,600 weighing several tonnes, the small skiffs 514 00:53:37,600 --> 00:53:40,640 are at risk of getting crushed. 515 00:53:40,640 --> 00:53:42,960 They radio for help. 516 00:53:42,960 --> 00:53:45,520 But as the mother ship approaches, she shunts 517 00:53:45,520 --> 00:53:47,720 even more ice their way. 518 00:53:52,160 --> 00:53:54,880 So, we've got these big chunks of ice either side of us 519 00:53:54,880 --> 00:53:57,080 and they've got to go somewhere, so... 520 00:53:58,960 --> 00:54:02,000 With help three days away, the crew 521 00:54:02,000 --> 00:54:04,800 can't afford any mistakes. 522 00:54:10,120 --> 00:54:13,320 In the nick of time, a lifeline. 523 00:54:17,720 --> 00:54:19,280 Safely aboard! 524 00:54:20,240 --> 00:54:22,200 That was a bit full-on! 525 00:54:25,880 --> 00:54:29,120 By the next day, the pack ice has drifted apart. 526 00:54:30,160 --> 00:54:32,840 And not a moment too soon. 527 00:54:42,160 --> 00:54:44,240 RACHEL: Awww! 528 00:54:48,240 --> 00:54:50,920 JAMIE WHISPERS: We just saw it go for its first swim. 529 00:54:51,880 --> 00:54:53,000 It was amazing. 530 00:54:53,000 --> 00:54:56,280 It just sort of flops about on the surface. It was very cool. 531 00:54:59,240 --> 00:55:03,480 With the pup finally in the water, Hugh seizes his chance. 532 00:55:05,000 --> 00:55:08,600 But what will the pup make of this curious sea creature? 533 00:55:13,280 --> 00:55:17,960 This pup is playing with - playing with! - the camera. 534 00:55:17,960 --> 00:55:20,520 I can see Hugh's smile from here. 535 00:55:22,200 --> 00:55:24,840 HUGH: Oh, lovely. Wow! 536 00:55:26,480 --> 00:55:28,320 That was great! 537 00:55:28,320 --> 00:55:30,560 Yeah, we saw. That was great! 538 00:55:30,560 --> 00:55:32,360 HUGH: So nice. 539 00:55:35,000 --> 00:55:37,640 Just as Hugh gets his reward, 540 00:55:37,640 --> 00:55:40,880 the Arctic conditions take a turn for the worse. 541 00:55:40,880 --> 00:55:42,320 WIND HOWLS 542 00:55:42,320 --> 00:55:43,920 We've been getting some amazing stuff, 543 00:55:43,920 --> 00:55:47,400 but now the wind's picked up, so we're trying to get out. 544 00:55:49,560 --> 00:55:51,080 With a storm brewing, 545 00:55:51,080 --> 00:55:54,720 not even the mother ship is safe among the ice floes. 546 00:55:54,720 --> 00:55:59,720 The crew have no choice but to leave the seals behind. 547 00:56:07,080 --> 00:56:09,520 It would roll in on a storm? 548 00:56:11,560 --> 00:56:12,960 And they drown? 549 00:56:20,720 --> 00:56:24,960 Today, the combination of reduced Arctic sea ice 550 00:56:24,960 --> 00:56:26,800 and heavy storms 551 00:56:26,800 --> 00:56:30,040 is leading to more and more tragedies like this. 552 00:56:32,760 --> 00:56:34,440 Unless this trend is reversed, 553 00:56:34,440 --> 00:56:38,160 the future for much of the Arctic's unique wildlife 554 00:56:38,160 --> 00:56:40,200 hangs in the balance. 555 00:56:46,480 --> 00:56:47,800 Next time... 556 00:56:49,320 --> 00:56:52,400 ..we explore the unpredictable world 557 00:56:52,400 --> 00:56:54,480 of frozen peaks... 558 00:56:55,800 --> 00:56:57,680 ..to discover the surprising animals 559 00:57:00,920 --> 00:57:01,960 ..that live life... 560 00:57:04,560 --> 00:57:05,640 ..on the edge. 561 00:57:13,360 --> 00:57:16,840 The Open University has produced a poster exploring how animals adapt 562 00:57:16,840 --> 00:57:19,240 to life in the world's coldest environments. 563 00:57:19,240 --> 00:57:24,480 To order your free copy, please call: 564 00:57:26,280 --> 00:57:29,360 Or go to... 565 00:57:31,760 --> 00:57:33,960 ..and follow the links to The Open University.