1 00:00:21,720 --> 00:00:23,360 200 million years ago, 2 00:00:23,360 --> 00:00:25,200 our planet looked very different 3 00:00:25,200 --> 00:00:26,800 from what it does today. 4 00:00:26,800 --> 00:00:29,280 It was entirely covered by sea, 5 00:00:29,280 --> 00:00:33,920 which surrounded one single supercontinent we call Pangea. 6 00:00:36,160 --> 00:00:38,800 And then Pangea began to break up. 7 00:00:40,960 --> 00:00:43,440 Life was cast adrift 8 00:00:43,440 --> 00:00:45,120 on fragments of land. 9 00:00:47,560 --> 00:00:51,960 And these fragments eventually became our seven continents. 10 00:00:54,680 --> 00:00:58,120 We will see how life developed on each continent, 11 00:00:58,120 --> 00:01:02,160 giving rise to the extraordinary and wonderful diversity 12 00:01:02,160 --> 00:01:03,440 that we see today. 13 00:01:05,080 --> 00:01:10,440 We'll venture through the frozen wilderness of Antarctica, 14 00:01:10,440 --> 00:01:13,160 where life thrives against the odds. 15 00:01:15,760 --> 00:01:19,320 And to the riches of South America, 16 00:01:19,320 --> 00:01:20,840 full of the unexpected. 17 00:01:25,200 --> 00:01:27,200 From the wilds of Africa. 18 00:01:30,160 --> 00:01:34,280 To the vast expanses of North America 19 00:01:34,280 --> 00:01:36,680 and the searing heat of Australia. 20 00:01:39,560 --> 00:01:44,400 We'll explore the remote reaches of Asia, 21 00:01:44,400 --> 00:01:46,440 home to rarely seen creatures. 22 00:01:49,120 --> 00:01:53,240 And Europe, a world transformed by humanity. 23 00:01:58,840 --> 00:02:01,280 And we'll discover how this may be 24 00:02:01,280 --> 00:02:04,760 the most critical moment for life on Earth 25 00:02:04,760 --> 00:02:06,280 since the continents formed. 26 00:02:08,000 --> 00:02:10,840 We are changing the world so rapidly, 27 00:02:10,840 --> 00:02:15,280 that wildlife is now facing some of its greatest challenges yet. 28 00:02:19,200 --> 00:02:22,200 Never has it been a more important time 29 00:02:22,200 --> 00:02:25,440 to reveal the precious diversity of life 30 00:02:25,440 --> 00:02:27,280 on our seven continents. 31 00:02:51,080 --> 00:02:54,480 This is Seven Worlds, One Planet. 32 00:03:21,400 --> 00:03:24,600 Of all the continents, 33 00:03:24,600 --> 00:03:28,800 one was first sighted by humans just 200 years ago. 34 00:03:32,920 --> 00:03:34,240 And only now 35 00:03:34,240 --> 00:03:36,520 are we beginning to understand 36 00:03:36,520 --> 00:03:38,640 what it takes to survive here. 37 00:03:44,840 --> 00:03:47,480 It's the most hostile of them all. 38 00:04:01,920 --> 00:04:05,600 98% of mainland Antarctica, 39 00:04:05,600 --> 00:04:09,440 an area one-and-a-half times the size of the United States, 40 00:04:09,440 --> 00:04:12,920 is covered in ice 41 00:04:12,920 --> 00:04:15,720 on which virtually nothing can live. 42 00:04:23,080 --> 00:04:26,920 So life is dependent on the ocean that surrounds it. 43 00:04:29,560 --> 00:04:31,480 But even the ocean freezes. 44 00:04:34,920 --> 00:04:38,680 Only one mammal can live this far south. 45 00:04:42,120 --> 00:04:43,920 The Weddell seal. 46 00:04:43,920 --> 00:04:45,360 SEAL BARKS 47 00:04:46,640 --> 00:04:49,520 She has to keep her breathing hole open 48 00:04:49,520 --> 00:04:52,680 by grinding back the ice with her teeth. 49 00:05:05,920 --> 00:05:07,920 Out here on the sea ice, 50 00:05:07,920 --> 00:05:12,240 all these seals are far from the predators of the open ocean. 51 00:05:13,840 --> 00:05:17,880 So, this is the safest place for her to give birth. 52 00:05:20,360 --> 00:05:23,600 Leaving the warmth of the womb and landing on ice 53 00:05:23,600 --> 00:05:28,080 is the sharpest drop in temperature any animal ever faces. 54 00:05:37,640 --> 00:05:42,280 But her pup can't swim for the first ten days of its life. 55 00:05:47,400 --> 00:05:49,360 It's trapped here 56 00:05:49,360 --> 00:05:50,600 out on the ice. 57 00:06:00,680 --> 00:06:02,320 SEAL PUP MEWS 58 00:06:11,640 --> 00:06:13,680 She shields her pup from the wind. 59 00:06:16,280 --> 00:06:19,960 Although in spring, temperatures can drop 60 00:06:19,960 --> 00:06:22,520 to minus 40 degrees Celsius, 61 00:06:22,520 --> 00:06:24,720 and blizzards can rage for days. 62 00:06:48,440 --> 00:06:51,840 Three days on, and the storm is still raging. 63 00:06:54,000 --> 00:06:56,800 She now faces the hardest of decisions. 64 00:07:03,200 --> 00:07:04,720 Does she stay with her pup? 65 00:07:04,720 --> 00:07:05,840 PUP MEWS 66 00:07:08,400 --> 00:07:09,560 PUP MEWS 67 00:07:11,320 --> 00:07:13,040 Or shelter in the water? 68 00:07:36,160 --> 00:07:39,680 Now, her pup's best chance of survival 69 00:07:39,680 --> 00:07:42,400 is for the storm to pass quickly. 70 00:08:05,880 --> 00:08:07,960 Some pups didn't make it. 71 00:08:13,600 --> 00:08:15,000 SEAL BARKS 72 00:08:18,040 --> 00:08:20,520 PUP MEWS 73 00:08:20,520 --> 00:08:21,520 An answer. 74 00:08:22,560 --> 00:08:23,960 SEAL BARKS 75 00:08:37,400 --> 00:08:41,640 If this pup now joins its mother in the water, 76 00:08:41,640 --> 00:08:43,280 it will be safe 77 00:08:43,280 --> 00:08:44,880 from any future storm. 78 00:08:53,400 --> 00:08:56,560 It's minus two degrees Celsius, 79 00:08:56,560 --> 00:08:59,040 but being in water is warmer 80 00:08:59,040 --> 00:09:00,720 than lying on the ice 81 00:09:00,720 --> 00:09:02,160 in the howling wind. 82 00:09:07,040 --> 00:09:11,480 Its chances of surviving here are now extremely good. 83 00:09:23,320 --> 00:09:28,560 Only a few hardy animals can live all year round as far south as this. 84 00:09:31,600 --> 00:09:33,000 Further from the pole, 85 00:09:33,000 --> 00:09:34,800 on the fringes of the continent, 86 00:09:34,800 --> 00:09:37,680 lie islands that are free of sea ice. 87 00:09:43,440 --> 00:09:46,240 Here, there are other challenges. 88 00:09:51,800 --> 00:09:54,400 St Andrews Bay on South Georgia 89 00:09:54,400 --> 00:09:57,600 is packed with half a million king penguins. 90 00:10:06,160 --> 00:10:09,160 In spring, the chicks are left for days, 91 00:10:09,160 --> 00:10:11,480 while their parents are away 92 00:10:11,480 --> 00:10:13,320 collecting food for them. 93 00:10:15,480 --> 00:10:18,560 There is a simple arrangement. 94 00:10:18,560 --> 00:10:21,680 The chicks must stay exactly where their parents left them 95 00:10:21,680 --> 00:10:23,960 to be sure of being found again. 96 00:10:30,520 --> 00:10:33,000 CHICK CHIRPS 97 00:10:35,400 --> 00:10:38,760 But this chick has decided to look around. 98 00:10:47,920 --> 00:10:50,440 There is a lot to be investigated. 99 00:10:57,800 --> 00:11:00,880 CHICKS CHIRP 100 00:11:34,480 --> 00:11:36,560 But it must not stray too far 101 00:11:36,560 --> 00:11:38,360 from its meeting place. 102 00:11:42,800 --> 00:11:44,240 This parent has returned 103 00:11:44,240 --> 00:11:45,560 with food in its crop. 104 00:11:47,120 --> 00:11:49,720 But its chick isn't where it left it. 105 00:11:53,560 --> 00:11:54,800 It's hard to stay put 106 00:11:54,800 --> 00:11:56,960 when there's so much to play with. 107 00:12:01,240 --> 00:12:03,120 Elephant seals are here, too. 108 00:12:07,000 --> 00:12:08,320 Very mysterious. 109 00:12:08,320 --> 00:12:09,440 SEAL BARKS 110 00:12:09,440 --> 00:12:10,440 CHICKS CHIRP 111 00:12:10,440 --> 00:12:12,680 SEAL BARKS LOUDLY 112 00:12:34,280 --> 00:12:36,640 Finding it in the crowd of youngsters 113 00:12:36,640 --> 00:12:38,320 is not going to be easy. 114 00:12:39,800 --> 00:12:42,160 They must recognise each other by their calls. 115 00:12:45,240 --> 00:12:47,360 CHICK CHIRPS 116 00:12:48,480 --> 00:12:51,320 But to hear these in such a noisy colony, 117 00:12:51,320 --> 00:12:53,760 then they must be within 15 metres of each other. 118 00:12:53,760 --> 00:12:56,760 CHICKS AND PARENTS CALL THROUGHOUT 119 00:13:24,400 --> 00:13:25,800 Reunited. 120 00:13:37,000 --> 00:13:41,560 St Andrews Beach is one of the most crowded on the planet, 121 00:13:41,560 --> 00:13:44,720 and so holding a territory here is a constant battle. 122 00:13:49,600 --> 00:13:52,040 This bull elephant seal holds 123 00:13:52,040 --> 00:13:55,480 the mating rights to 60 females. 124 00:13:59,600 --> 00:14:03,480 For two months, he's guarded this stretch of beach. 125 00:14:05,000 --> 00:14:06,240 Unable to feed, 126 00:14:06,240 --> 00:14:09,360 he's losing ten kilos a day, 127 00:14:09,360 --> 00:14:11,560 and he's exhausted. 128 00:14:15,480 --> 00:14:17,800 But other bulls are lying around, 129 00:14:17,800 --> 00:14:19,440 waiting their chance. 130 00:14:46,440 --> 00:14:53,320 SEAL BARKS LOUDLY 131 00:15:28,760 --> 00:15:31,360 Blubber, 15 centimetres thick, 132 00:15:31,360 --> 00:15:34,000 is protection against the cold, 133 00:15:34,000 --> 00:15:35,600 but not from the impact 134 00:15:35,600 --> 00:15:37,440 of a four-tonne opponent. 135 00:16:06,680 --> 00:16:08,080 He holds his ground 136 00:16:08,080 --> 00:16:10,080 and forces the intruder 137 00:16:10,080 --> 00:16:11,280 back out to sea. 138 00:16:20,520 --> 00:16:23,160 Life in the Antarctic is harsh indeed. 139 00:16:24,400 --> 00:16:26,600 But all these creatures come here 140 00:16:26,600 --> 00:16:28,360 because the Southern Ocean 141 00:16:28,360 --> 00:16:30,240 is one of the richest on Earth. 142 00:16:33,920 --> 00:16:35,760 When, 30 million years ago, 143 00:16:35,760 --> 00:16:37,600 the continent broke away 144 00:16:37,600 --> 00:16:40,440 from South America and drifted south, 145 00:16:40,440 --> 00:16:43,120 currents began to swirl right around it. 146 00:16:49,560 --> 00:16:51,160 They are now the strongest 147 00:16:51,160 --> 00:16:53,000 of any currents on the planet. 148 00:16:59,520 --> 00:17:02,160 They sweep up nutrients from the depths, 149 00:17:02,160 --> 00:17:05,400 and so create one of the richest feeding grounds 150 00:17:05,400 --> 00:17:07,360 in all the world's oceans. 151 00:17:11,840 --> 00:17:13,280 And some of the creatures 152 00:17:13,280 --> 00:17:14,560 that come here to feast 153 00:17:14,560 --> 00:17:17,320 do so in a most sophisticated way. 154 00:17:36,880 --> 00:17:38,520 Humpback whales. 155 00:17:42,760 --> 00:17:45,000 It's summer, and they've come here 156 00:17:45,000 --> 00:17:46,240 for a banquet. 157 00:18:02,680 --> 00:18:04,520 The cold waters contain 158 00:18:04,520 --> 00:18:06,760 great shoals of krill. 159 00:18:09,200 --> 00:18:13,400 It's estimated that there are 400 trillion of them 160 00:18:13,400 --> 00:18:16,760 and that their combined weight is greater than that of any other 161 00:18:16,760 --> 00:18:18,920 animal species on the planet. 162 00:18:23,360 --> 00:18:27,080 To collect them, the humpbacks blow curtains of bubbles, 163 00:18:27,080 --> 00:18:29,680 which the krill won't cross. 164 00:18:37,040 --> 00:18:42,400 The whales then rise, spiralling inwards, to concentrate the swarm. 165 00:18:55,680 --> 00:18:59,600 Summer in Antarctica is a time of plenty, 166 00:18:59,600 --> 00:19:03,200 when most humpbacks are able to put on the reserves they need 167 00:19:03,200 --> 00:19:05,480 for the whole year. 168 00:19:08,520 --> 00:19:12,760 But the wildlife in these waters faces an uncertain future. 169 00:19:17,840 --> 00:19:20,480 The Southern Ocean is warming. 170 00:19:26,680 --> 00:19:31,080 90% of the world's ice lies in Antarctica 171 00:19:31,080 --> 00:19:33,880 and, in some parts, the rate at which it's melting 172 00:19:33,880 --> 00:19:36,520 is doubling every decade. 173 00:19:39,160 --> 00:19:41,600 Sea levels are rising. 174 00:19:43,280 --> 00:19:46,280 But there is a more immediate threat. 175 00:19:48,800 --> 00:19:53,240 The warming of the coldest region on Earth is having a profound effect 176 00:19:53,240 --> 00:19:55,480 on global weather patterns. 177 00:19:57,080 --> 00:20:02,080 And this change in the climate is already being felt right here. 178 00:20:06,800 --> 00:20:10,840 This grey-headed albatross chick is four weeks old. 179 00:20:13,520 --> 00:20:17,840 So far, it has been sheltered from the gales by its parents, 180 00:20:17,840 --> 00:20:21,200 who take turns to collect food for it out at sea. 181 00:20:27,320 --> 00:20:31,760 It is the only chick that they will have in two years. 182 00:20:31,760 --> 00:20:33,800 ALBATROSS CHICK SQUEAKS 183 00:20:39,720 --> 00:20:43,600 The delicate touching of beaks strengthens their bond. 184 00:20:49,880 --> 00:20:52,480 BEAKS CLICK 185 00:21:03,480 --> 00:21:07,200 But these tender moments cannot last forever. 186 00:21:12,600 --> 00:21:16,480 As a chick grows, so does its appetite. 187 00:21:16,480 --> 00:21:20,920 So one parent has to leave to find food before the other returns. 188 00:21:25,000 --> 00:21:29,760 Parting is a big step and they take time over it. 189 00:21:29,760 --> 00:21:31,960 ALBATROSS CHICK SQUEAKS 190 00:22:06,400 --> 00:22:10,640 For the first time in its life, this chick is alone. 191 00:22:20,200 --> 00:22:24,400 The Antarctic is the windiest continent, 192 00:22:24,400 --> 00:22:28,400 and in recent years, climate change has brought storms 193 00:22:28,400 --> 00:22:31,400 that are more frequent and even more powerful. 194 00:22:41,040 --> 00:22:44,800 Winds now regularly reach 70mph. 195 00:22:52,040 --> 00:22:56,000 But the albatross chicks must try to stay on their nests. 196 00:23:49,800 --> 00:23:52,560 Surviving the storm is one thing... 197 00:23:54,440 --> 00:23:58,360 ..but now, off the nest in these freezing temperatures, 198 00:23:58,360 --> 00:24:01,360 this chick has just hours to live. 199 00:24:13,280 --> 00:24:16,680 The brutal conditions have taken their toll. 200 00:24:20,680 --> 00:24:24,040 Some chicks have already succumbed to exposure. 201 00:24:35,440 --> 00:24:40,560 The bond is so strong, it can be hard for a father to let go. 202 00:24:45,520 --> 00:24:48,680 The albatross population here has more than halved 203 00:24:48,680 --> 00:24:51,280 in the last 15 years. 204 00:24:54,840 --> 00:24:58,320 These albatross are facing extinction. 205 00:25:00,320 --> 00:25:03,560 They simply cannot keep pace with the changes 206 00:25:03,560 --> 00:25:06,200 affecting their world. 207 00:25:27,360 --> 00:25:30,840 More parents are returning to the colony. 208 00:25:41,320 --> 00:25:43,960 Something is not right. 209 00:25:47,040 --> 00:25:49,840 The nest should not be empty. 210 00:26:00,080 --> 00:26:04,120 The chick is actually right below its parent, 211 00:26:04,120 --> 00:26:08,600 but because it's not on the nest, the parent doesn't recognise it. 212 00:26:11,000 --> 00:26:13,320 ALBATROSS CHICK SQUEAKS 213 00:26:18,240 --> 00:26:20,560 And doesn't help it. 214 00:26:25,240 --> 00:26:30,280 Strangely, perhaps, these albatross do not recognise their chicks 215 00:26:30,280 --> 00:26:33,040 by sight, sound or smell. 216 00:26:34,600 --> 00:26:38,240 They identify them by finding them on the nest. 217 00:26:41,880 --> 00:26:45,680 So, these violent storms have created a problem 218 00:26:45,680 --> 00:26:49,280 that the albatross are not equipped to solve. 219 00:26:55,360 --> 00:26:57,600 ALBATROSS CHICK SQUAWKS 220 00:26:57,600 --> 00:27:02,160 If it is to survive, the chick will have to get back on the nest 221 00:27:02,160 --> 00:27:04,840 by itself. 222 00:28:02,320 --> 00:28:04,560 The chick has made it. 223 00:28:06,920 --> 00:28:10,320 The bond is re-established immediately 224 00:28:10,320 --> 00:28:14,560 and its parent, once again, provides the warmth that the chick 225 00:28:14,560 --> 00:28:16,840 so desperately needs. 226 00:28:16,840 --> 00:28:18,840 ALBATROSS CHICK SQUEAKS 227 00:28:24,880 --> 00:28:27,880 It's safe...for now. 228 00:28:49,040 --> 00:28:53,080 Nowhere in Antarctica is survival easy. 229 00:28:55,360 --> 00:28:59,200 Gentoo penguins travel up to 50 miles every day 230 00:28:59,200 --> 00:29:01,560 to find food. 231 00:29:01,560 --> 00:29:04,280 And they're now returning to their chicks. 232 00:29:06,280 --> 00:29:08,920 They are the fastest penguin in the sea 233 00:29:08,920 --> 00:29:11,760 and can swim at 22mph. 234 00:29:14,760 --> 00:29:18,000 But other animals can swim much faster. 235 00:29:27,320 --> 00:29:29,720 Orca. 236 00:29:42,480 --> 00:29:45,920 This penguin must rely on its agility. 237 00:29:55,000 --> 00:29:57,160 PENGUIN WHINES 238 00:30:20,400 --> 00:30:22,280 PENGUIN WHINES 239 00:30:34,880 --> 00:30:37,080 PENGUIN WHINES 240 00:30:43,800 --> 00:30:45,840 PENGUIN WHINES 241 00:31:07,400 --> 00:31:12,240 With four orcas chasing it, the penguin stood little chance. 242 00:31:32,560 --> 00:31:35,120 PENGUINS CHIRP 243 00:31:40,280 --> 00:31:44,320 Most gentoo parents do make it back to the colony. 244 00:31:48,120 --> 00:31:51,560 Today, it's been a good hunt for krill. 245 00:31:54,680 --> 00:31:57,200 Perhaps too good. 246 00:31:59,840 --> 00:32:03,800 The chicks grow and it seems that the Mohawk style 247 00:32:03,800 --> 00:32:05,840 is back in fashion. 248 00:32:08,120 --> 00:32:10,320 It's just a phase. 249 00:32:10,320 --> 00:32:12,360 He'll grow out of it. 250 00:32:15,240 --> 00:32:19,320 He'll soon lose these remaining down feathers and be ready to leave 251 00:32:19,320 --> 00:32:22,320 the colony and collect food for himself. 252 00:32:23,400 --> 00:32:28,640 But doing so is becoming harder because of climate change. 253 00:32:35,200 --> 00:32:38,440 Glaciers in the region are now calving faster 254 00:32:38,440 --> 00:32:41,840 than they have done since records began. 255 00:32:48,720 --> 00:32:52,320 And this brash ice now fills the bays. 256 00:33:02,960 --> 00:33:05,040 It's autumn. 257 00:33:07,240 --> 00:33:11,680 The chicks have lost their down feathers and they're hungry. 258 00:33:13,000 --> 00:33:16,560 They must go to sea for the first time. 259 00:33:16,560 --> 00:33:18,160 PENGUINS SQUEAK 260 00:33:20,000 --> 00:33:24,040 But now there's a risk of being crushed between blocks of ice. 261 00:33:30,000 --> 00:33:33,160 They have to get to the distant icebergs... 262 00:33:35,920 --> 00:33:39,480 ..and so reach the open ocean that lies beyond. 263 00:33:43,160 --> 00:33:46,000 And that is easier said than done. 264 00:33:55,520 --> 00:33:57,800 A leopard seal... 265 00:33:59,160 --> 00:34:01,320 ..their main predator. 266 00:34:02,640 --> 00:34:05,600 It's a giant, three metres long. 267 00:34:07,960 --> 00:34:12,000 These icy conditions help it to hunt. 268 00:34:17,920 --> 00:34:20,240 PENGUIN TRILLS 269 00:34:20,240 --> 00:34:23,560 The penguins can neither walk nor swim. 270 00:34:33,560 --> 00:34:37,600 They have no way of telling where the seal will strike. 271 00:34:37,600 --> 00:34:39,560 PENGUIN SQUEAKS 272 00:34:57,280 --> 00:34:59,760 PENGUIN SQUEAKS 273 00:35:14,800 --> 00:35:17,640 These are easy pickings. 274 00:35:25,640 --> 00:35:27,760 LEOPARD SEAL GROWLS 275 00:35:29,400 --> 00:35:32,240 For some, it's time to retreat. 276 00:36:08,240 --> 00:36:11,240 But now, it's back to square one. 277 00:36:15,560 --> 00:36:20,720 There's no alternative but to run the gauntlet once again. 278 00:36:32,240 --> 00:36:34,600 PENGUIN BRAYS 279 00:36:46,040 --> 00:36:48,000 PENGUIN BRAYS 280 00:36:54,280 --> 00:36:58,080 The seal seems to be toying with this penguin. 281 00:37:01,160 --> 00:37:03,920 But safety is in sight. 282 00:37:20,720 --> 00:37:23,600 The ice floe is near the open ocean. 283 00:37:27,200 --> 00:37:30,160 But this penguin is exhausted. 284 00:37:54,440 --> 00:37:56,440 PENGUIN BRAYS 285 00:37:56,440 --> 00:37:58,240 SEAL GROWLS 286 00:38:01,840 --> 00:38:03,560 PENGUIN BRAYS 287 00:38:03,560 --> 00:38:06,200 SEAL GROWLS 288 00:38:09,960 --> 00:38:12,920 Perhaps it's not worth it, after all. 289 00:38:38,280 --> 00:38:40,680 Winter is coming. 290 00:38:44,640 --> 00:38:48,880 Antarctica now undergoes a major transformation. 291 00:38:51,560 --> 00:38:56,400 Every day, 40,000 more square miles of sea freeze over. 292 00:38:59,240 --> 00:39:03,280 By the end of winter, the continent has doubled in size. 293 00:39:06,000 --> 00:39:10,080 This is by far the largest desert in the world. 294 00:39:13,640 --> 00:39:15,800 WIND HOWLS 295 00:39:27,880 --> 00:39:32,320 But the frozen surface of the sea hides a great secret. 296 00:39:40,880 --> 00:39:44,760 It may be hostile above the ice, but below it, 297 00:39:44,760 --> 00:39:48,480 conditions are so stable that life over millennia 298 00:39:48,480 --> 00:39:51,080 has had time to diversify. 299 00:39:55,960 --> 00:39:59,480 Creatures here grow to a great size. 300 00:39:59,480 --> 00:40:02,880 Predatory nemertean worms are three metres long. 301 00:40:06,920 --> 00:40:10,720 These dramas only become visible when speeded up. 302 00:40:15,560 --> 00:40:19,280 We're only just beginning to discover the details of the lives 303 00:40:19,280 --> 00:40:21,880 of such strange creatures. 304 00:40:26,840 --> 00:40:29,680 Nudibranchs are hermaphrodites. 305 00:40:32,560 --> 00:40:37,960 Each individual possesses both male and female reproductive organs. 306 00:40:37,960 --> 00:40:41,000 So, to mate, one nudibranch just needs to find 307 00:40:41,000 --> 00:40:43,280 another nudibranch. 308 00:40:43,280 --> 00:40:45,680 And any one will do. 309 00:40:47,880 --> 00:40:52,360 But nonetheless, this is a challenge when their tiny eyes can barely see. 310 00:41:05,760 --> 00:41:08,360 Some do get lucky. 311 00:41:16,560 --> 00:41:21,000 They're fertilising each other and both will produce young. 312 00:41:28,360 --> 00:41:32,120 When it's hard to find a partner, it pays not to have to worry 313 00:41:32,120 --> 00:41:34,440 about your gender. 314 00:41:44,400 --> 00:41:49,360 Sea anemones may look like plants, but, actually, are animals 315 00:41:49,360 --> 00:41:53,120 and feed by catching edible particles that drift within reach 316 00:41:53,120 --> 00:41:55,320 of their tentacles. 317 00:41:58,400 --> 00:42:03,320 But being rooted to the sea floor makes them vulnerable to predators. 318 00:42:06,760 --> 00:42:11,800 An ocean-going jellyfish, a metre or so across, searching for food. 319 00:42:26,000 --> 00:42:28,560 The jellyfish senses prey. 320 00:42:50,320 --> 00:42:54,040 But it's the sea anemones that have made the catch 321 00:42:54,040 --> 00:42:56,760 and they've grabbed a monster. 322 00:43:08,440 --> 00:43:11,880 A rare feast for these stationary predators. 323 00:43:17,480 --> 00:43:21,480 They devour their catch over the next four days. 324 00:43:34,240 --> 00:43:39,080 Life here under the ice has remained unchanged for millennia. 325 00:43:40,480 --> 00:43:45,000 But in the last 200 years, much of Antarctica's wildlife 326 00:43:45,000 --> 00:43:48,080 has had to face new predators... 327 00:43:51,720 --> 00:43:53,720 ..human beings. 328 00:43:53,720 --> 00:43:54,920 BELL RINGS 329 00:43:56,520 --> 00:44:00,920 We devised new hunting techniques and used them so mercilessly 330 00:44:00,920 --> 00:44:04,320 that we almost exterminated the great whales. 331 00:44:07,480 --> 00:44:11,280 These whaling stations on South Georgia were at the centre 332 00:44:11,280 --> 00:44:13,560 of this industry. 333 00:44:23,840 --> 00:44:27,480 More than one-and-a-half million whales were slaughtered 334 00:44:27,480 --> 00:44:30,120 in Antarctic waters. 335 00:44:33,200 --> 00:44:36,560 The blubber was stripped from their massive bodies 336 00:44:36,560 --> 00:44:41,280 and boiled down in vats to make margarine and soap. 337 00:44:44,400 --> 00:44:48,320 And the largest animal ever recorded, 338 00:44:48,320 --> 00:44:54,120 a 33-metre blue whale, perhaps over 100 years old, 339 00:44:54,120 --> 00:44:58,040 was butchered on this ramp in just two hours. 340 00:45:06,920 --> 00:45:11,520 This reckless slaughter marked a new low in our relationship 341 00:45:11,520 --> 00:45:14,240 with the natural world. 342 00:45:43,280 --> 00:45:46,480 Southern right whales were hit the hardest. 343 00:45:50,280 --> 00:45:53,320 They were so trusting and inquisitive 344 00:45:53,320 --> 00:45:56,600 that they swam right up to the whalers' boats. 345 00:45:58,920 --> 00:46:02,640 And the whalers called them right whales 346 00:46:02,640 --> 00:46:05,960 because they were the right whales to hunt. 347 00:46:07,560 --> 00:46:09,240 WHALE CALL 348 00:46:11,880 --> 00:46:13,520 WHALE CALL 349 00:46:14,960 --> 00:46:18,760 Mothers with calves were targeted first. 350 00:46:21,680 --> 00:46:26,160 To give birth, females came to the same sheltered bays 351 00:46:26,160 --> 00:46:29,920 and would not leave their calves alone at the surface. 352 00:46:31,440 --> 00:46:36,520 In just decades, a population of 35,000 353 00:46:36,520 --> 00:46:41,360 was so reduced that only 35 of the females survived. 354 00:46:45,800 --> 00:46:48,560 But times have changed. 355 00:46:48,560 --> 00:46:54,160 A ban on the commercial hunting of whales, introduced in 1986, 356 00:46:54,160 --> 00:46:58,600 has stopped all but Japan, Norway and Iceland. 357 00:47:03,160 --> 00:47:06,480 Our relationship to these remarkable creatures 358 00:47:06,480 --> 00:47:09,040 has undergone a huge shift. 359 00:47:11,840 --> 00:47:15,680 Scientists are now learning a great deal about these whales. 360 00:47:19,960 --> 00:47:23,160 But we still don't know how long they live. 361 00:47:26,560 --> 00:47:30,080 It's thought that some individuals alive today 362 00:47:30,080 --> 00:47:33,360 were around at the time of the mass slaughter. 363 00:47:34,680 --> 00:47:38,040 Yet these 60-tonne whales remain gentle 364 00:47:38,040 --> 00:47:40,880 and inquisitive around humans. 365 00:47:48,920 --> 00:47:52,000 By putting a stop to commercial hunting, 366 00:47:52,000 --> 00:47:56,360 this population of whales has now grown to over 2,000. 367 00:48:19,320 --> 00:48:24,720 The recovery of life in Antarctic waters may have a significance 368 00:48:24,720 --> 00:48:28,280 that extends far beyond the reaches of the continent 369 00:48:28,280 --> 00:48:30,720 and will affect us all. 370 00:48:34,720 --> 00:48:38,160 Just off the coast of Elephant Island, 371 00:48:38,160 --> 00:48:41,440 we have recently witnessed what might be 372 00:48:41,440 --> 00:48:44,280 the greatest feeding spectacle on Earth. 373 00:48:48,720 --> 00:48:53,160 On the horizon, over 150 whales have gathered 374 00:48:53,160 --> 00:48:56,000 to feast on krill. 375 00:49:04,720 --> 00:49:09,360 This is the largest congregation of great whales ever filmed. 376 00:49:22,200 --> 00:49:26,360 These are mostly fin whales, up to 26 metres long. 377 00:49:29,480 --> 00:49:32,600 Humpback whales are dwarfed in comparison. 378 00:49:36,280 --> 00:49:40,040 Thousands of animals from all over Antarctic waters 379 00:49:40,040 --> 00:49:42,680 are making their way here. 380 00:49:54,560 --> 00:49:59,160 These seas are, once again, beginning to brim with life. 381 00:50:03,640 --> 00:50:07,800 And scientists have discovered that the Southern Ocean, 382 00:50:07,800 --> 00:50:11,520 and the life within it, soaks up more than twice as much 383 00:50:11,520 --> 00:50:15,760 carbon from the atmosphere as the Amazon rainforest. 384 00:50:25,160 --> 00:50:29,680 By protecting Antarctica, we don't just protect the life here... 385 00:50:30,920 --> 00:50:34,600 ..we are helping to restore the natural balance 386 00:50:34,600 --> 00:50:37,240 of the entire planet. 387 00:51:00,360 --> 00:51:04,160 St Andrews Bay provides one of the most spectacular sights 388 00:51:04,160 --> 00:51:06,680 in the whole of the Antarctic. 389 00:51:06,680 --> 00:51:09,440 But to get there, the team will have to cross 390 00:51:09,440 --> 00:51:13,920 the roughest seas in the world, and nerves are starting to show. 391 00:51:13,920 --> 00:51:15,960 The wind is picking up already! 392 00:51:15,960 --> 00:51:17,440 THEY LAUGH 393 00:51:18,840 --> 00:51:22,880 It'll take ten days at sea to reach this remote location. 394 00:51:24,520 --> 00:51:28,360 And it's not long before they start to feel a bit green. 395 00:51:32,040 --> 00:51:34,280 There's some big waves coming now. 396 00:51:34,280 --> 00:51:39,760 With these conditions lasting days, all who can take shifts at the helm. 397 00:51:41,560 --> 00:51:45,040 And you get given a talk, to say if you fall in the water here, 398 00:51:45,040 --> 00:51:48,520 there's nothing anyone can do - they can't save you. 399 00:51:48,520 --> 00:51:52,120 It's so cold, you'll die in under a couple of minutes. 400 00:51:52,120 --> 00:51:53,920 Wow! 401 00:51:58,280 --> 00:52:02,280 Below deck, Rolf hasn't yet found his sea legs. 402 00:52:02,280 --> 00:52:04,320 HE RETCHES VIOLENTLY 403 00:52:04,320 --> 00:52:06,160 Oh! 404 00:52:06,160 --> 00:52:09,440 For me, this is like punishment or prisoner-ship or whatever. 405 00:52:09,440 --> 00:52:13,280 I mean, I can't understand at all how people do this voluntarily, 406 00:52:13,280 --> 00:52:17,120 people dream of being on a boat or sailing or anything. 407 00:52:17,120 --> 00:52:18,680 Look at that. 408 00:52:18,680 --> 00:52:20,760 I mean, look how much the boat is moving. 409 00:52:20,760 --> 00:52:23,800 I feel like in a washing machine. 410 00:52:23,800 --> 00:52:27,280 The island of South Georgia finally appears. 411 00:52:31,360 --> 00:52:34,800 It's a relief to step onto solid land. 412 00:52:38,880 --> 00:52:41,680 Yeah, the seasickness is already forgotten, to be honest! 413 00:52:41,680 --> 00:52:43,520 But it's all forgotten. 414 00:52:44,520 --> 00:52:47,800 It's just out of this world. 415 00:52:47,800 --> 00:52:50,480 It's so wonderful that these places still exist. 416 00:52:56,360 --> 00:52:59,960 They will spend the next three weeks in St Andrews Bay. 417 00:53:01,840 --> 00:53:06,480 Rolf is here to film the king penguins in this enormous colony. 418 00:53:08,080 --> 00:53:13,160 And Mark must capture the elephant seals' intense mating season. 419 00:53:13,160 --> 00:53:15,400 SEAL SNORTS 420 00:53:17,080 --> 00:53:20,720 On such a crowded beach, fights can break out anywhere. 421 00:53:20,720 --> 00:53:22,520 SEAL SNORTS 422 00:53:26,000 --> 00:53:29,240 Males are up to six metres long and they are pumped 423 00:53:29,240 --> 00:53:31,240 full of testosterone. 424 00:53:33,360 --> 00:53:38,720 The bulls take little notice of the crew and will stop at nothing. 425 00:53:38,720 --> 00:53:40,680 Oh, my God! 426 00:54:05,640 --> 00:54:08,200 That went from nothing to being nearly steam-rollered 427 00:54:08,200 --> 00:54:10,680 by four huge males. 428 00:54:17,080 --> 00:54:22,040 Beyond the chaos of the beach, Rolf has king penguins in front of him, 429 00:54:22,040 --> 00:54:25,120 and, thankfully, he's smiling again. 430 00:54:25,120 --> 00:54:27,680 I would really call them the gentleman penguins 431 00:54:27,680 --> 00:54:30,640 because they are very polite, they're charming, 432 00:54:30,640 --> 00:54:32,440 they have humour. 433 00:54:32,440 --> 00:54:35,760 There's so many funny, lovely moments. 434 00:54:35,760 --> 00:54:39,440 I absolutely adore these penguins for that! 435 00:54:39,440 --> 00:54:43,840 But as weeks go by, the reality of living amongst penguins 436 00:54:43,840 --> 00:54:46,080 comes to the fore. 437 00:54:47,400 --> 00:54:52,080 Every morning, I think, "Wow, it's stinky!" 438 00:54:52,080 --> 00:54:56,560 But then I realise, these smells come out of my shoes 439 00:54:56,560 --> 00:54:58,800 and it's myself. 440 00:54:58,800 --> 00:55:00,240 Oh! 441 00:55:06,480 --> 00:55:11,200 Back on the beach, the team is using a stabilised camera rig. 442 00:55:12,360 --> 00:55:14,840 They can now react faster to fights. 443 00:55:16,000 --> 00:55:18,320 So far in the shoot, we've seen a lot of quick fights, 444 00:55:18,320 --> 00:55:20,520 but we haven't seen some extended fights, 445 00:55:20,520 --> 00:55:24,200 where you see one bull paired 446 00:55:24,200 --> 00:55:26,280 equally against another bull. 447 00:55:27,760 --> 00:55:29,680 These sights are rare. 448 00:55:29,680 --> 00:55:31,880 The team will need to be at the ready. 449 00:55:31,880 --> 00:55:34,040 Mark, Mark, Mark! 450 00:55:34,040 --> 00:55:36,200 Let's get running. 451 00:55:40,640 --> 00:55:42,680 Oh, hello! 452 00:55:59,960 --> 00:56:02,280 These are two huge, evenly matched boys. 453 00:56:02,280 --> 00:56:03,640 I know. 454 00:56:03,640 --> 00:56:06,280 Wow, I never thought we'd be this close to it. I know, nor did I. 455 00:56:06,280 --> 00:56:08,880 This is really tense, we've just got to watch out. 456 00:56:14,240 --> 00:56:16,200 We got there. 457 00:56:19,480 --> 00:56:22,120 I never thought I'd see it that close 458 00:56:22,120 --> 00:56:25,240 and be able to move around it, as this kind of 459 00:56:25,240 --> 00:56:27,480 aggressive ballet is happening. 460 00:56:27,480 --> 00:56:28,840 Oh! 461 00:56:30,160 --> 00:56:32,240 And it does make you quite tense. 462 00:56:34,120 --> 00:56:38,520 The shoot is going well, but the crew are noticing worrying signs. 463 00:56:40,760 --> 00:56:43,240 It's a really hot day today. 464 00:56:44,680 --> 00:56:48,280 30 years ago, the front of that glacier 465 00:56:48,280 --> 00:56:50,920 was right down on the beach. 466 00:56:50,920 --> 00:56:54,000 It's retreated a huge amount. 467 00:56:54,000 --> 00:56:57,840 I don't really know what climate change is going to mean 468 00:56:57,840 --> 00:57:01,120 for all the wildlife that's living here. 469 00:57:01,120 --> 00:57:04,480 Parts of the Antarctic are warming five times faster 470 00:57:04,480 --> 00:57:06,760 than the rest of the world. 471 00:57:08,160 --> 00:57:11,920 If this trend continues, it will threaten the very existence 472 00:57:11,920 --> 00:57:14,240 of these polar creatures. 473 00:57:17,160 --> 00:57:20,960 On the last day of filming, the team can't help but reflect 474 00:57:20,960 --> 00:57:24,120 on the future of the wildlife here. 475 00:57:24,120 --> 00:57:27,680 For me, it's emotional because I know this might have been 476 00:57:27,680 --> 00:57:30,000 a once-in-a-lifetime experience. 477 00:57:31,200 --> 00:57:34,760 I will definitely take big memories with me and I will be sad. 478 00:57:36,920 --> 00:57:39,760 It's a really special place, you know? So... 479 00:57:41,520 --> 00:57:43,600 I don't know. 480 00:57:46,200 --> 00:57:49,840 I just hope we can keep these places. 481 00:57:51,040 --> 00:57:53,120 And protect them. 482 00:58:09,160 --> 00:58:11,400 Next time... 483 00:58:11,400 --> 00:58:13,960 ..the largest continent on Earth. 484 00:58:17,440 --> 00:58:20,200 A world of extremes... 485 00:58:20,200 --> 00:58:23,920 ..where rarely seen animals roam the land... 486 00:58:30,680 --> 00:58:32,880 ..Asia.