1 00:00:26,840 --> 00:00:28,920 DAVID ATTENBOROUGH: A Perfect Planet. 2 00:00:38,200 --> 00:00:42,760 There is a nuclear reactor 93 million miles away. 3 00:00:47,280 --> 00:00:49,280 We call it the Sun. 4 00:00:51,560 --> 00:00:54,760 Its rays, travelling through space, 5 00:00:54,760 --> 00:00:57,920 reach the Earth in just eight minutes... 6 00:01:00,240 --> 00:01:03,960 ..and give power to life throughout the planet. 7 00:01:09,400 --> 00:01:12,600 Its daily and yearly rhythms 8 00:01:12,600 --> 00:01:16,560 shape the existence of every creature on Earth... 9 00:01:20,320 --> 00:01:24,640 ..and has done so for over three billion years. 10 00:01:35,800 --> 00:01:37,480 In the beginning... 11 00:01:39,040 --> 00:01:41,320 ..there was light. 12 00:01:56,360 --> 00:02:00,560 Surprisingly, perhaps, almost every part of the Earth's surface 13 00:02:00,560 --> 00:02:05,120 receives the same quantity of sunlight each year... 14 00:02:06,600 --> 00:02:10,000 ..4,380 hours of it. 15 00:02:12,800 --> 00:02:15,680 But it's delivered in varying amounts 16 00:02:15,680 --> 00:02:18,040 at different times of the year, 17 00:02:18,040 --> 00:02:20,240 depending on where you are. 18 00:02:25,120 --> 00:02:28,920 It's only here in the tropics, close to the equator, 19 00:02:28,920 --> 00:02:32,880 that there are 12 hours of guaranteed daily sunlight 20 00:02:32,880 --> 00:02:34,080 the year round. 21 00:02:38,560 --> 00:02:43,240 And, here, that has created a great richness of life - 22 00:02:43,240 --> 00:02:45,040 the tropical forest. 23 00:02:48,520 --> 00:02:53,600 Each leaf is a natural solar panel which collects the sun's energy 24 00:02:53,600 --> 00:02:56,880 and fuels a multitude of plants. 25 00:02:58,960 --> 00:03:02,440 And, in Southeast Asia, gibbons live here. 26 00:03:06,080 --> 00:03:09,400 WHOOPING 27 00:03:09,400 --> 00:03:10,840 BIRD CALLS 28 00:03:10,840 --> 00:03:13,800 A five-year-old female... 29 00:03:15,440 --> 00:03:18,840 ..and her lifelong partner are on a mission. 30 00:03:24,520 --> 00:03:27,640 Every morning, they head out across their territory 31 00:03:27,640 --> 00:03:29,040 to look for ripe fruit. 32 00:03:36,760 --> 00:03:40,960 There is one kind of tree here that they need more than any other. 33 00:03:46,000 --> 00:03:47,200 The fig tree. 34 00:03:52,800 --> 00:03:57,600 These are the only plants in the entire forest that produce fruit 35 00:03:57,600 --> 00:03:59,920 all year round. 36 00:03:59,920 --> 00:04:03,200 Their flowers grow in dense clusters 37 00:04:03,200 --> 00:04:06,680 inside undeveloped figs, 38 00:04:06,680 --> 00:04:09,480 but these have not yet been pollinated 39 00:04:09,480 --> 00:04:11,600 and are not yet edible. 40 00:04:11,600 --> 00:04:14,480 The gibbons will have to wait. 41 00:04:19,000 --> 00:04:23,080 To produce ripe fruit, the fig still needs two things... 42 00:04:24,240 --> 00:04:26,920 ..a large dose of sunlight 43 00:04:26,920 --> 00:04:30,560 and some of the smallest creatures in the forest. 44 00:04:33,480 --> 00:04:36,200 Tiny fig wasps. 45 00:04:36,200 --> 00:04:39,120 They're only 2mm long. 46 00:04:41,240 --> 00:04:45,600 The figs have a unique partnership with these insects. 47 00:04:47,920 --> 00:04:51,960 A female wasp has the space of just a single day 48 00:04:51,960 --> 00:04:56,600 when the fig will allow her to burrow into the undeveloped fruit. 49 00:04:57,960 --> 00:05:01,800 It's such a tight squeeze that her wings are ripped off. 50 00:05:04,160 --> 00:05:07,640 But she's not going to use them again. 51 00:05:10,680 --> 00:05:13,960 Once inside, she makes her way to the tiny, 52 00:05:13,960 --> 00:05:16,720 tightly packed internal flowers. 53 00:05:20,320 --> 00:05:23,720 And, here within, she lays hundreds of eggs. 54 00:05:26,200 --> 00:05:30,560 She then carefully unpacks fig pollen from her abdomen... 55 00:05:32,960 --> 00:05:36,360 ..and with it fertilises the tiny flowers. 56 00:05:38,800 --> 00:05:40,440 When she's finished laying, 57 00:05:40,440 --> 00:05:42,920 she dies... 58 00:05:42,920 --> 00:05:45,440 ..inside the unripe fig 59 00:05:45,440 --> 00:05:48,440 alongside her eggs. 60 00:05:50,440 --> 00:05:53,960 The sunlight now slowly ripens the figs 61 00:05:53,960 --> 00:05:57,280 and helps the young wasps inside to develop. 62 00:06:00,000 --> 00:06:04,680 After just five weeks, the eggs start to hatch. 63 00:06:05,880 --> 00:06:09,960 The first to emerge are the golden, wingless males. 64 00:06:13,120 --> 00:06:16,440 Things now become stranger than fiction. 65 00:06:19,880 --> 00:06:24,760 These males start to mate with their unhatched sisters. 66 00:06:27,280 --> 00:06:31,400 To reach them, they use a telescopic penis 67 00:06:31,400 --> 00:06:33,560 that's twice their body length. 68 00:06:43,040 --> 00:06:47,280 While their now-pregnant sisters are beginning to hatch, 69 00:06:47,280 --> 00:06:52,320 the males themselves burrow their way to the outside world. 70 00:07:08,600 --> 00:07:12,400 The brothers' final act is a chivalrous one. 71 00:07:17,040 --> 00:07:22,320 They sacrifice themselves to marauding ants. 72 00:07:26,760 --> 00:07:28,640 They're serving as decoys 73 00:07:28,640 --> 00:07:31,400 so their sisters can take to the skies. 74 00:07:36,120 --> 00:07:40,240 The young females, loaded with pollen, live for just 48 hours, 75 00:07:40,240 --> 00:07:45,640 in which time they must find another fig tree at just the right stage 76 00:07:45,640 --> 00:07:50,120 into which they themselves can burrow, as their mothers did. 77 00:07:54,160 --> 00:07:58,320 With the sun's helping hand, the figs are now ready to eat. 78 00:08:07,200 --> 00:08:10,680 The gibbons know all the fig trees in their territory. 79 00:08:12,240 --> 00:08:15,680 And each day they travel up to two miles 80 00:08:15,680 --> 00:08:19,440 to find one with fruit that's ready to eat. 81 00:08:28,240 --> 00:08:31,240 Ripe figs at last... 82 00:08:32,480 --> 00:08:36,280 ..a major part of their diet and available the year round. 83 00:08:40,640 --> 00:08:43,840 Thousands of animals rely on fig trees. 84 00:08:48,360 --> 00:08:54,280 This abundance is only possible in a world without seasons 85 00:08:54,280 --> 00:08:57,080 and constant daily sunlight. 86 00:09:04,880 --> 00:09:08,360 But this 12-hour cycle of light and darkness 87 00:09:08,360 --> 00:09:11,040 only happens close to the equator. 88 00:09:13,120 --> 00:09:17,000 Elsewhere, the amount of sunlight fluctuates across the year. 89 00:09:19,120 --> 00:09:24,160 That is because the Earth does not spin in an upright way. 90 00:09:24,160 --> 00:09:27,200 Its axis is on a tilt. 91 00:09:27,200 --> 00:09:29,880 23.5 degrees. 92 00:09:31,280 --> 00:09:35,200 So as the Earth makes its annual orbit around the Sun, 93 00:09:35,200 --> 00:09:37,920 keep your eye on the North Pole. 94 00:09:39,840 --> 00:09:43,960 For the first half of the year, it's angled away from the Sun, 95 00:09:43,960 --> 00:09:48,080 bringing darkness and winter to the northern hemisphere. 96 00:09:48,080 --> 00:09:50,320 For the second part of the year, 97 00:09:50,320 --> 00:09:54,600 the North Pole swings towards the Sun, bringing summer. 98 00:09:57,640 --> 00:10:00,560 The Earth's tilt gives us the seasons. 99 00:10:04,120 --> 00:10:05,760 And life has adapted 100 00:10:05,760 --> 00:10:09,960 to deal with even the most extreme changes in light. 101 00:10:11,520 --> 00:10:13,400 The High Arctic. 102 00:10:13,400 --> 00:10:16,760 After six months of being angled towards the Sun, 103 00:10:16,760 --> 00:10:20,840 it begins six months of freezing darkness. 104 00:10:27,000 --> 00:10:29,840 This is Ellesmere Island, 105 00:10:29,840 --> 00:10:32,360 the closest land to the North Pole. 106 00:10:34,000 --> 00:10:38,080 It's winter, and for the last four, long months, 107 00:10:38,080 --> 00:10:41,800 the only light here has come from the Moon. 108 00:10:44,200 --> 00:10:47,920 Few creatures can survive this sustained darkness. 109 00:10:49,160 --> 00:10:54,280 They have become specialists in living for months without sunlight. 110 00:10:54,280 --> 00:10:56,760 WIND HOWLS 111 00:10:58,880 --> 00:11:00,600 Muskox. 112 00:11:00,600 --> 00:11:03,080 Remnants of the last Ice Age. 113 00:11:07,840 --> 00:11:11,720 Having grazed all summer, they've built up fat reserves 114 00:11:11,720 --> 00:11:15,240 that will enable them to survive the brutal cold of winter. 115 00:11:17,800 --> 00:11:23,360 And this makes them a prime target for other sub-zero specialists. 116 00:11:31,760 --> 00:11:34,080 GROWLING 117 00:11:34,080 --> 00:11:36,360 Arctic wolves. 118 00:11:39,000 --> 00:11:43,480 The Moon provides just enough light for them to see. 119 00:11:47,680 --> 00:11:49,600 SHE SNIFFS 120 00:11:52,000 --> 00:11:55,520 This alpha female leads the hunt. 121 00:12:01,680 --> 00:12:03,720 Target in sight. 122 00:12:05,080 --> 00:12:10,160 If her pack is to survive, they need to make a large kill 123 00:12:10,160 --> 00:12:13,280 at least once every three weeks. 124 00:12:24,760 --> 00:12:28,760 The alpha female signals the start of the attack. 125 00:12:41,280 --> 00:12:45,800 They run at the muskox and the herd panics. 126 00:12:58,960 --> 00:13:01,680 The muskox close ranks. 127 00:13:05,480 --> 00:13:08,480 The wolves look for weakness. 128 00:13:10,200 --> 00:13:12,280 MUSKOX ROARS 129 00:13:17,080 --> 00:13:19,600 IT ROARS FIERCELY 130 00:13:19,600 --> 00:13:21,000 WOLVES WHINE 131 00:13:23,680 --> 00:13:27,680 Charging risks isolation from the crowd. 132 00:13:27,680 --> 00:13:29,480 ROARING 133 00:13:33,760 --> 00:13:36,800 And that is just what the wolf pack wants. 134 00:13:36,800 --> 00:13:39,240 ROARING 135 00:13:54,720 --> 00:13:57,040 The wolves can sense victory. 136 00:14:12,760 --> 00:14:15,160 But the herd comes to the rescue. 137 00:14:23,520 --> 00:14:27,120 And, once again, they close ranks. 138 00:14:30,560 --> 00:14:35,240 Most winter hunts end in failure for the wolves. 139 00:14:35,240 --> 00:14:37,120 MUSKOX ROARS, WOLVES WHINE 140 00:14:46,640 --> 00:14:49,600 As the long polar nights drag on, 141 00:14:49,600 --> 00:14:54,720 the hungry wolves turn to their only other source of food... 142 00:14:57,880 --> 00:15:00,360 ..arctic hares. 143 00:15:08,560 --> 00:15:12,520 They've gathered together in their hundreds for safety. 144 00:15:30,000 --> 00:15:32,760 Trying to catch one hare among hundreds 145 00:15:32,760 --> 00:15:35,000 is harder than you might think. 146 00:15:41,120 --> 00:15:45,360 Even if they do catch one, it's not much of a meal. 147 00:15:56,240 --> 00:16:00,280 Sometimes you just have to admit defeat. 148 00:16:06,240 --> 00:16:09,160 WOLF GROWLS 149 00:16:10,960 --> 00:16:14,520 But life is about to get better for the wolves. 150 00:16:26,560 --> 00:16:32,920 For the first time in six months, the sun rises above the horizon. 151 00:16:42,320 --> 00:16:48,560 Its appearance marks the beginning of half a year of continuous light. 152 00:16:50,800 --> 00:16:55,720 The sun's warmth will allow the muskox to give birth, 153 00:16:55,720 --> 00:17:00,880 and that will provide easier hunting for the wolves. 154 00:17:13,160 --> 00:17:15,360 It's early spring, 155 00:17:15,360 --> 00:17:19,800 and much of North America is still locked in ice. 156 00:17:23,120 --> 00:17:26,040 As our tilted planet orbits the Sun, 157 00:17:26,040 --> 00:17:29,680 the northern hemisphere receives increasing sunlight... 158 00:17:32,760 --> 00:17:37,200 ..and wakens an animal with an almost supernatural ability. 159 00:17:45,840 --> 00:17:48,520 It is frozen solid, 160 00:17:48,520 --> 00:17:50,440 like a block of ice, 161 00:17:50,440 --> 00:17:53,400 and has been all winter. 162 00:17:56,600 --> 00:17:58,480 An ordinary-looking frog... 163 00:18:00,400 --> 00:18:02,920 ..but an extraordinary one. 164 00:18:04,000 --> 00:18:05,800 A wood frog. 165 00:18:06,920 --> 00:18:09,720 Its heart has stopped beating completely. 166 00:18:15,360 --> 00:18:17,520 But, as the sun's power increases, 167 00:18:17,520 --> 00:18:20,800 almost miraculously, it begins to change. 168 00:18:29,920 --> 00:18:32,120 Its frozen blood is melting 169 00:18:32,120 --> 00:18:35,360 and begins to flow through its veins... 170 00:18:38,040 --> 00:18:41,720 ..as its heart begins to beat again. 171 00:18:41,720 --> 00:18:45,160 HEARTBEAT 172 00:18:49,000 --> 00:18:52,280 The wood frog is cryogenic. 173 00:18:55,160 --> 00:18:57,600 In just 12 hours, 174 00:18:57,600 --> 00:19:02,040 it thaws and comes back to life, as if by magic. 175 00:19:07,000 --> 00:19:08,920 This defrosting ability 176 00:19:08,920 --> 00:19:12,880 means it's ready for the moment when, at last, 177 00:19:12,880 --> 00:19:15,400 spring arrives. 178 00:19:18,880 --> 00:19:21,320 All across the northern hemisphere, 179 00:19:21,320 --> 00:19:24,440 the sun's warmth is bringing dramatic change. 180 00:19:48,200 --> 00:19:52,080 As the sun rises higher and spring takes hold, 181 00:19:52,080 --> 00:19:56,000 the warming air reaches the ground and the rocks beneath. 182 00:20:01,160 --> 00:20:05,240 Here, thousands of animals begin to stir. 183 00:20:09,240 --> 00:20:10,920 Garter snakes, 184 00:20:10,920 --> 00:20:14,640 one of Canada's most northerly reptiles. 185 00:20:16,880 --> 00:20:19,360 After six months of hibernation, 186 00:20:19,360 --> 00:20:22,080 the males are the first to emerge. 187 00:20:23,200 --> 00:20:26,280 They haven't eaten for months. 188 00:20:26,280 --> 00:20:31,440 Even so, it's not food that is on their minds, it's something else... 189 00:20:33,360 --> 00:20:35,880 ..females. 190 00:20:35,880 --> 00:20:39,600 But they stand no chance of doing anything about that 191 00:20:39,600 --> 00:20:42,520 until they've charged their batteries. 192 00:20:49,000 --> 00:20:53,320 Snakes are cold-blooded and they need to absorb the sun's heat 193 00:20:53,320 --> 00:20:55,920 before they're able to move quickly. 194 00:21:02,280 --> 00:21:06,040 After a few hours, the males are raring to go. 195 00:21:09,880 --> 00:21:12,280 20,000 snakes, 196 00:21:12,280 --> 00:21:14,800 the largest emergence of reptiles 197 00:21:14,800 --> 00:21:17,320 anywhere on Earth. 198 00:21:31,520 --> 00:21:34,800 Now a few females appear. 199 00:21:38,360 --> 00:21:40,960 They're much bigger than the males... 200 00:21:43,080 --> 00:21:45,840 ..and warming will take them longer. 201 00:21:47,040 --> 00:21:49,200 She releases a scent, a pheromone, 202 00:21:49,200 --> 00:21:52,280 that attracts the males. 203 00:21:52,280 --> 00:21:55,440 They outnumber her 100 to one. 204 00:21:59,360 --> 00:22:04,560 To speed her own return to activity, she will absorb heat from them. 205 00:22:11,840 --> 00:22:14,880 Intoxicated by her scent, the males compete for her, 206 00:22:14,880 --> 00:22:18,160 wrapping themselves around her. 207 00:22:35,600 --> 00:22:38,880 She now has hundreds of males on top of her, 208 00:22:38,880 --> 00:22:41,280 making mating near impossible. 209 00:22:42,640 --> 00:22:46,680 But she has a way of weeding out the men from the boys. 210 00:22:49,160 --> 00:22:53,800 She'll make a daring ascent of the nearby cliff. 211 00:22:56,640 --> 00:23:01,240 She barges her way through the crowd to get to the rock face. 212 00:23:12,320 --> 00:23:17,280 As she climbs, only the strongest, fittest males can keep up with her. 213 00:23:52,560 --> 00:23:54,760 She's made it to the top. 214 00:23:54,760 --> 00:23:59,840 Only a few of her suitors have managed to rise to the occasion, 215 00:23:59,840 --> 00:24:02,960 and she may reward them all. 216 00:24:08,680 --> 00:24:12,200 This entire mating jamboree only lasts 217 00:24:12,200 --> 00:24:15,720 for one short week in the year. 218 00:24:21,800 --> 00:24:26,280 And when it's over, they all move off into the forest. 219 00:24:28,640 --> 00:24:33,800 There, they disperse to lead solitary lives searching for food 220 00:24:33,800 --> 00:24:39,640 until winter drives them back to the shelter of the rocks below ground. 221 00:24:48,400 --> 00:24:52,360 It's June, halfway through the Earth's annual journey 222 00:24:52,360 --> 00:24:57,600 around the sun, and summer has arrived in the northern hemisphere. 223 00:25:01,840 --> 00:25:06,760 Karak Lake, in Canada, north of the Arctic Circle. 224 00:25:08,600 --> 00:25:10,600 The summer will be brief, 225 00:25:10,600 --> 00:25:14,080 but there is sunlight for 24 hours every day. 226 00:25:17,000 --> 00:25:22,000 So the next few months are vital for every living thing here. 227 00:25:27,520 --> 00:25:30,680 And this arctic fox knows it. 228 00:25:34,040 --> 00:25:35,680 CUBS SQUEAK 229 00:25:37,400 --> 00:25:43,320 Winter has been hard for her, and now with a new family to support, 230 00:25:43,320 --> 00:25:47,320 she must make the most of the summer's abundance. 231 00:25:51,960 --> 00:25:56,400 Her three-week-old pups have just emerged from the den. 232 00:26:02,760 --> 00:26:04,800 CUBS SQUEAL 233 00:26:07,680 --> 00:26:10,120 Each of these little bundles of fur 234 00:26:10,120 --> 00:26:14,920 needs nearly 300 calories of food every day. 235 00:26:17,240 --> 00:26:19,400 A tall order for Mum. 236 00:26:20,400 --> 00:26:22,000 GEESE HONK 237 00:26:22,000 --> 00:26:25,040 But a solution for her problem is just arriving. 238 00:26:28,200 --> 00:26:30,000 Snow geese. 239 00:26:30,000 --> 00:26:34,680 They have flown over a thousand miles from the United States, 240 00:26:34,680 --> 00:26:39,280 timing their arrival to coincide with the end of the snow. 241 00:26:39,280 --> 00:26:43,000 GEESE HONK 242 00:26:51,760 --> 00:26:55,160 More than half a million will spend the summer here, 243 00:26:55,160 --> 00:26:57,480 nesting and feeding on the grass. 244 00:26:59,360 --> 00:27:02,320 There's fierce competition between couples 245 00:27:02,320 --> 00:27:04,400 for the safest nesting sites. 246 00:27:13,160 --> 00:27:17,840 The losers will have to nest on the outskirts of the colony... 247 00:27:17,840 --> 00:27:21,440 ..the first part to be raided by the foxes. 248 00:27:38,080 --> 00:27:42,360 Mother is after eggs... 249 00:27:42,360 --> 00:27:45,680 ..but getting them is not going to be easy. 250 00:27:53,240 --> 00:27:56,960 GEESE HONK 251 00:28:05,560 --> 00:28:10,120 The geese will risk their lives to protect their eggs. 252 00:28:10,120 --> 00:28:14,720 If they lose them, they can't produce another clutch this season. 253 00:28:20,120 --> 00:28:22,520 The fox wins. 254 00:28:24,480 --> 00:28:27,600 GEESE CALL 255 00:28:31,000 --> 00:28:34,320 She gives the first eggs to her young pups... 256 00:28:38,560 --> 00:28:41,360 ..and then heads back for more. 257 00:28:53,480 --> 00:28:56,640 GEESE HONK 258 00:29:05,360 --> 00:29:08,720 Some of the eggs she stashes away. 259 00:29:11,880 --> 00:29:15,480 They will be food to help her through the coming winter. 260 00:29:15,480 --> 00:29:17,760 GOOSE HONKS 261 00:29:34,080 --> 00:29:40,040 In just three weeks, she will steal over 800 eggs from the geese. 262 00:29:51,200 --> 00:29:54,240 But eating a big egg is not easy 263 00:29:54,240 --> 00:29:56,640 if one is rather small. 264 00:30:00,040 --> 00:30:04,720 It's a technique the pups haven't quite yet cracked. 265 00:30:05,960 --> 00:30:09,000 Mum shows how it's done. 266 00:30:18,520 --> 00:30:21,240 GOSLING CHEEPS 267 00:30:21,240 --> 00:30:25,400 Goslings are now hatching all across the colony. 268 00:30:27,520 --> 00:30:30,080 And they will need all the food they can get 269 00:30:30,080 --> 00:30:33,520 to build up their fat before their journey south. 270 00:30:36,240 --> 00:30:38,280 Now that the chicks have hatched, 271 00:30:38,280 --> 00:30:41,160 they can all find safety on the water. 272 00:30:49,160 --> 00:30:50,720 CUBS SQUEAL 273 00:30:50,720 --> 00:30:55,440 In these brief sunlit months, there's time for the cubs to play. 274 00:30:58,320 --> 00:31:01,240 But there is no playtime for Mum. 275 00:31:15,080 --> 00:31:17,960 But the Arctic is warming, 276 00:31:17,960 --> 00:31:21,440 and the timing of the seasons and the migration of the geese 277 00:31:21,440 --> 00:31:23,600 is becoming unpredictable. 278 00:31:31,280 --> 00:31:34,440 Although the sun stays above the horizon continuously 279 00:31:34,440 --> 00:31:37,080 throughout the Arctic summer, 280 00:31:37,080 --> 00:31:40,480 its rays are comparatively feeble. 281 00:31:43,440 --> 00:31:47,000 Closer to the equator, in our planet's deserts, 282 00:31:47,000 --> 00:31:49,440 cloud cover is rare. 283 00:32:02,240 --> 00:32:05,560 The sun here is not a friend... 284 00:32:05,560 --> 00:32:07,640 ..but an enemy. 285 00:32:13,840 --> 00:32:17,000 WIND GUSTS 286 00:32:17,000 --> 00:32:18,760 Africa. 287 00:32:19,760 --> 00:32:21,920 The Sahara. 288 00:32:25,680 --> 00:32:28,480 Few creatures can live here. 289 00:32:32,400 --> 00:32:36,040 Get caught out in the open at the wrong time of day 290 00:32:36,040 --> 00:32:38,480 and it's game over. 291 00:32:38,480 --> 00:32:40,800 WIND GUSTS 292 00:32:44,440 --> 00:32:47,240 By 10:00 in the morning, the temperature on the surface 293 00:32:47,240 --> 00:32:50,680 of the sand is pushing 60 degrees Celsius. 294 00:32:52,040 --> 00:32:56,160 Even the toughest will soon have to take cover. 295 00:33:00,400 --> 00:33:03,480 But one creature is waiting underground 296 00:33:03,480 --> 00:33:06,400 for the sun to get even hotter. 297 00:33:12,480 --> 00:33:14,800 Temperatures are now so high 298 00:33:14,800 --> 00:33:17,880 that everything else has to shelter. 299 00:33:24,080 --> 00:33:29,560 The desert now belongs to the Earth's greatest solar specialist... 300 00:33:30,960 --> 00:33:34,240 ..the Saharan silver ant. 301 00:33:36,360 --> 00:33:39,840 At midday, when the sun is at its fiercest, 302 00:33:39,840 --> 00:33:44,120 they emerge to look for creatures killed by the scorching heat. 303 00:33:46,040 --> 00:33:49,960 They're one of the fastest insects on Earth, and they need to be, 304 00:33:49,960 --> 00:33:53,760 with just five minutes to find food before the heat kills them. 305 00:33:57,960 --> 00:34:00,920 Getting lost would mean certain death, 306 00:34:00,920 --> 00:34:03,600 so every few seconds they spin round, 307 00:34:03,600 --> 00:34:06,040 taking a bearing from the sun. 308 00:34:14,680 --> 00:34:19,200 When others are frying, these ants have solar tech 309 00:34:19,200 --> 00:34:22,400 to stop them from overheating... 310 00:34:26,720 --> 00:34:29,840 ..special glassy hairs and shining bodies 311 00:34:29,840 --> 00:34:32,840 that reflect the sun's lethal rays. 312 00:34:35,240 --> 00:34:37,840 It buys them precious time. 313 00:34:45,360 --> 00:34:48,360 To get their prize back as quickly as possible 314 00:34:48,360 --> 00:34:51,960 to their underground den demands teamwork. 315 00:34:59,400 --> 00:35:02,560 But shelter is a long way away. 316 00:35:04,800 --> 00:35:07,800 Any technique will do. 317 00:35:07,800 --> 00:35:10,240 The push and slide. 318 00:35:13,240 --> 00:35:15,200 The spin. 319 00:35:18,040 --> 00:35:20,720 Even dune surfing. 320 00:35:31,640 --> 00:35:34,840 The nest is still 70 metres away. 321 00:35:45,360 --> 00:35:48,640 Some are already collapsing in the heat. 322 00:35:51,000 --> 00:35:54,360 Reinforcements are needed urgently. 323 00:35:56,440 --> 00:36:00,880 Now the heat whips up violent gusts of hot desert air. 324 00:36:04,120 --> 00:36:06,640 For an ant, these are hurricanes. 325 00:36:12,280 --> 00:36:14,520 WIND HOWLS 326 00:36:27,160 --> 00:36:30,920 They must get their prize underground as soon as possible, 327 00:36:30,920 --> 00:36:35,520 and blown sand has blocked the entrance to their den. 328 00:36:35,520 --> 00:36:38,920 Any longer out here and they will be toast. 329 00:36:45,080 --> 00:36:47,840 One final effort. 330 00:37:01,360 --> 00:37:04,280 The last of the team race home. 331 00:37:08,000 --> 00:37:11,240 Shade, at last. 332 00:37:18,840 --> 00:37:22,360 Much of the land on our planet could become as scorched 333 00:37:22,360 --> 00:37:26,040 and lifeless as this if we allow our activities 334 00:37:26,040 --> 00:37:29,080 to continue to change the atmosphere. 335 00:37:33,280 --> 00:37:38,200 The Sahara alone has expanded by an area twice the size of France 336 00:37:38,200 --> 00:37:41,240 in just the last hundred years... 337 00:37:41,240 --> 00:37:44,160 WIND GUSTS 338 00:37:44,160 --> 00:37:49,920 ..part of a global desert invasion that threatens a third of all land. 339 00:37:54,800 --> 00:37:58,000 The sun can certainly be a lethal threat, 340 00:37:58,000 --> 00:38:00,080 but it could also be our saviour. 341 00:38:01,080 --> 00:38:04,680 The solar energy that strikes our planet in just an hour 342 00:38:04,680 --> 00:38:09,080 contains more power than that used by all of humanity 343 00:38:09,080 --> 00:38:11,680 in an entire year. 344 00:38:20,720 --> 00:38:24,280 By October, as the Earth completes its annual journey 345 00:38:24,280 --> 00:38:28,600 around the sun, day lengths in the northern hemisphere 346 00:38:28,600 --> 00:38:31,240 are shortening once again. 347 00:38:34,800 --> 00:38:38,680 The sun's power is diminishing. 348 00:38:38,680 --> 00:38:43,840 Trees are beginning to shut down their solar panels. 349 00:38:43,840 --> 00:38:48,240 The green chlorophyll with which they collected the sun's energy 350 00:38:48,240 --> 00:38:51,960 is broken down chemically and reabsorbed. 351 00:39:00,200 --> 00:39:04,680 And the forests turn from emerald to gold. 352 00:39:06,720 --> 00:39:08,840 It's autumn. 353 00:39:12,080 --> 00:39:17,440 Once again, the living world away from the tropics is transformed. 354 00:39:20,200 --> 00:39:23,120 Plants stop growing 355 00:39:23,120 --> 00:39:27,400 and many animals begin to prepare for tough times ahead. 356 00:39:36,360 --> 00:39:39,560 The forests of central China... 357 00:39:41,200 --> 00:39:45,200 ..home to the golden snub-nosed monkey. 358 00:39:49,280 --> 00:39:52,760 They will not survive the fast-approaching winter 359 00:39:52,760 --> 00:39:56,320 unless they stock up on calorie-rich food. 360 00:39:58,760 --> 00:40:04,760 Top of their autumn menu - pine cones, 361 00:40:04,760 --> 00:40:09,240 They grew during the summer sunlight and are rich in fats. 362 00:40:14,000 --> 00:40:16,080 Few are now left, 363 00:40:16,080 --> 00:40:19,000 and time to gather them is running out. 364 00:40:25,520 --> 00:40:28,640 Dominant males patrol the troop, 365 00:40:28,640 --> 00:40:31,240 making sure they get the pick of the crop. 366 00:40:31,240 --> 00:40:34,000 MONKEYS SCREECH 367 00:40:34,000 --> 00:40:36,760 As the number of pine cones dwindles, 368 00:40:36,760 --> 00:40:39,720 tensions between rival families increase. 369 00:40:39,720 --> 00:40:43,080 AGGRESSIVE SCREECHING 370 00:40:47,920 --> 00:40:53,760 Mere threats between two males may not be enough to settle disputes. 371 00:40:58,200 --> 00:41:00,600 MONKEYS SCREECH 372 00:41:00,600 --> 00:41:03,200 Conflict is in the air. 373 00:41:04,640 --> 00:41:06,720 There's going to be a fight. 374 00:41:36,760 --> 00:41:39,200 MONKEY SCREECHES 375 00:41:39,200 --> 00:41:41,400 Vital food is at stake, 376 00:41:41,400 --> 00:41:44,240 so every pine cone is worth fighting for. 377 00:42:08,000 --> 00:42:09,040 MONKEY SCREECHES 378 00:42:10,280 --> 00:42:15,440 The victor and his family enjoy the spoils of war. 379 00:42:18,920 --> 00:42:22,680 The losers get no more than a few dead leaves 380 00:42:22,680 --> 00:42:26,920 and will have fewer energy reserves for the coming winter. 381 00:42:31,080 --> 00:42:33,560 The sun's power dims. 382 00:42:34,920 --> 00:42:37,320 Temperatures drop. 383 00:42:42,360 --> 00:42:44,960 Everything slows down. 384 00:42:47,640 --> 00:42:51,640 Ahead lies months of crippling cold. 385 00:42:51,640 --> 00:42:53,320 MONKEY WHINES 386 00:43:10,440 --> 00:43:14,400 Most of the life on Earth away from the tropics 387 00:43:14,400 --> 00:43:18,520 has managed to adapt to the changing seasons, 388 00:43:18,520 --> 00:43:21,360 but there are some creatures that have found a way 389 00:43:21,360 --> 00:43:24,680 to avoid the cold of winter altogether. 390 00:43:26,240 --> 00:43:29,160 Snares Island, New Zealand, 391 00:43:29,160 --> 00:43:31,560 deep in the southern hemisphere. 392 00:43:31,560 --> 00:43:33,720 CAWING 393 00:43:33,720 --> 00:43:37,720 Here, sooty shearwaters have been nesting throughout the long summer 394 00:43:37,720 --> 00:43:40,480 and gorging themselves on fish. 395 00:43:42,000 --> 00:43:46,200 As a result, they've piled on quite a few pounds. 396 00:43:48,680 --> 00:43:53,040 But the sun is now fading, and the southern winter is approaching. 397 00:43:54,240 --> 00:43:57,240 No time to hang around. 398 00:43:57,240 --> 00:43:59,360 SHEARWATERS CAW 399 00:44:05,680 --> 00:44:07,800 When you're a touch tubby, 400 00:44:07,800 --> 00:44:10,400 launching into the air... 401 00:44:10,400 --> 00:44:12,280 ..is a leap of faith. 402 00:44:15,280 --> 00:44:19,280 They won't see land again for four weeks. 403 00:44:23,840 --> 00:44:27,240 Setting off across the Pacific, they're starting on 404 00:44:27,240 --> 00:44:31,720 one of the longest journeys made by any living thing. 405 00:44:33,720 --> 00:44:38,480 Their aim - to avoid the consequences of the Earth's tilt 406 00:44:38,480 --> 00:44:42,760 and follow the sun's warmth as it dwindles in the south 407 00:44:42,760 --> 00:44:45,240 and increases in the north. 408 00:44:57,240 --> 00:45:01,120 For those who survive the 10,000-mile marathon, 409 00:45:01,120 --> 00:45:03,800 there will be a great prize. 410 00:45:08,200 --> 00:45:12,200 The reward for travelling from one end of the planet to the other 411 00:45:12,200 --> 00:45:15,840 is long summer days the year round. 412 00:45:18,520 --> 00:45:20,920 This is their destination... 413 00:45:22,600 --> 00:45:25,240 ..Alaska's Aleutian Islands. 414 00:45:28,840 --> 00:45:32,400 While the south of our planet is slipping into autumn... 415 00:45:34,160 --> 00:45:37,040 ..here, summer is just beginning. 416 00:45:47,080 --> 00:45:52,240 Below the waves, vast clouds of plankton are blooming. 417 00:45:53,400 --> 00:45:56,120 Triggered by the sunlight, 418 00:45:56,120 --> 00:45:58,720 these tiny marine organisms 419 00:45:58,720 --> 00:46:01,800 are food for crustaceans - krill. 420 00:46:04,640 --> 00:46:07,440 This is the sun-fuelled bounty 421 00:46:07,440 --> 00:46:10,240 for which the shearwaters have crossed the planet. 422 00:46:17,040 --> 00:46:19,000 By cheating the tilt, 423 00:46:19,000 --> 00:46:22,720 they're able to enjoy the riches of summer the year round. 424 00:46:29,880 --> 00:46:34,680 But shearwaters are not the only ones to visit the warming seas. 425 00:46:36,480 --> 00:46:39,720 WHALES CALL 426 00:46:41,000 --> 00:46:43,120 Humpback whales. 427 00:46:45,280 --> 00:46:48,760 They've been breeding in the tropics... 428 00:46:48,760 --> 00:46:51,600 ..and haven't fed for six months. 429 00:47:02,120 --> 00:47:07,240 Up to 6,000 whales are now heading for these islands - 430 00:47:07,240 --> 00:47:12,880 the only place where they can find food in the quantities they need. 431 00:47:17,440 --> 00:47:22,200 The shearwaters begin to dive into a huge shoal of krill. 432 00:47:27,880 --> 00:47:30,560 The humpbacks attack from below. 433 00:47:37,960 --> 00:47:42,120 Each year, a million shearwaters join the whales 434 00:47:42,120 --> 00:47:45,040 in these dramatic feeding frenzies. 435 00:47:58,360 --> 00:48:02,400 It's one of the greatest gatherings of life on Earth. 436 00:48:03,640 --> 00:48:08,360 And it only happens because some whales and some birds 437 00:48:08,360 --> 00:48:12,680 have found a way to live in a summer that never ends. 438 00:48:32,320 --> 00:48:35,760 Rolf Steinmann has wanted to be a wildlife cameraman 439 00:48:35,760 --> 00:48:41,720 since he was a child, even if he has to remind himself from time to time. 440 00:48:41,720 --> 00:48:44,040 I'm a lucky cameraman. 441 00:48:44,040 --> 00:48:46,040 I'm a lucky cameraman. 442 00:48:46,040 --> 00:48:48,280 I'm a lucky cameraman... 443 00:48:48,280 --> 00:48:52,400 To those who've worked with Rolf, his love of the wild is legendary. 444 00:48:52,400 --> 00:48:54,600 You know, if he's not on location, he's at home watching 445 00:48:54,600 --> 00:48:56,960 every other wildlife documentary that's ever been made. 446 00:48:56,960 --> 00:49:00,960 I think Rolf is motivated by the beauty in the world. 447 00:49:00,960 --> 00:49:03,160 I think he really has this pure heart. 448 00:49:03,160 --> 00:49:06,120 Rolf alone with nature is Rolf at his best. 449 00:49:06,120 --> 00:49:09,360 Rolf is a man obsessed. 450 00:49:09,360 --> 00:49:12,480 The opportunity to be the first to film arctic wolves 451 00:49:12,480 --> 00:49:16,200 in the polar night is Rolf's dream of a lifetime. 452 00:49:17,480 --> 00:49:21,160 We have a lot of luggage. This is a major expedition. 453 00:49:21,160 --> 00:49:24,920 And there's one piece of luggage that is very, 454 00:49:24,920 --> 00:49:27,200 very special to me, and it's... 455 00:49:27,200 --> 00:49:30,160 It's actually this book by Jim Brandenburg. 456 00:49:30,160 --> 00:49:32,160 It's 30 years old, it's from the '80s. 457 00:49:32,160 --> 00:49:34,680 And when I saw this book the first time, 458 00:49:34,680 --> 00:49:38,480 it really triggered a dream to become a wildlife cameraman. 459 00:49:38,480 --> 00:49:40,720 And this was the shot. 460 00:49:40,720 --> 00:49:42,520 It's unmatched to this day. 461 00:49:42,520 --> 00:49:45,680 When I saw it, I just wanted to experience it myself. 462 00:49:45,680 --> 00:49:50,120 To go to Ellesmere now and to film wolves is... 463 00:49:50,120 --> 00:49:52,920 ..is my biggest dream coming true. 464 00:49:52,920 --> 00:49:56,800 If I'm honest, I'm not just excited about the shoot, 465 00:49:56,800 --> 00:49:59,080 I'm also a little bit anxious. 466 00:49:59,080 --> 00:50:02,320 I haven't worked in -50 degrees, 467 00:50:02,320 --> 00:50:06,640 and actually trying to find wolves in darkness, in the polar night, 468 00:50:06,640 --> 00:50:11,000 is something that has not even been tried by anyone. 469 00:50:17,680 --> 00:50:23,600 Ellesmere Island lies just 500 miles from the North Pole. 470 00:50:23,600 --> 00:50:27,640 In the winter, the sun doesn't rise for four months. 471 00:50:28,680 --> 00:50:33,800 The temperature regularly drops to -50 degrees... 472 00:50:33,800 --> 00:50:37,480 ..making it one of the coldest places on Earth. 473 00:50:39,120 --> 00:50:41,120 It's such an unreal place. 474 00:50:41,120 --> 00:50:44,200 It's like a...like a frozen dream. 475 00:50:46,040 --> 00:50:48,960 There's so much space. 476 00:50:48,960 --> 00:50:51,560 It's really like a different planet. 477 00:50:54,040 --> 00:50:57,360 The wolves here can range for thousands of miles 478 00:50:57,360 --> 00:50:59,480 across the frozen landscape. 479 00:51:01,040 --> 00:51:04,240 If you look at that landscape, 480 00:51:04,240 --> 00:51:06,400 how vast it is, 481 00:51:06,400 --> 00:51:09,720 you can imagine how hard it is to find the wolves, 482 00:51:09,720 --> 00:51:12,800 a white animal in a white landscape. 483 00:51:15,560 --> 00:51:18,720 One wolf has a radio collar, 484 00:51:18,720 --> 00:51:24,600 but this kind of telemetry only gives a rough direction to explore. 485 00:51:24,600 --> 00:51:27,080 The fjord is just to the south, so I think the best plan 486 00:51:27,080 --> 00:51:30,440 is cut across on the ice and see if we can find a way up. 487 00:51:30,440 --> 00:51:34,360 The team race towards the wolf's last broadcast position 488 00:51:34,360 --> 00:51:36,080 and get lucky. 489 00:51:36,080 --> 00:51:38,520 They find the whole pack, 490 00:51:38,520 --> 00:51:41,440 and something never seen before. 491 00:51:42,920 --> 00:51:46,160 This is so incredible. 492 00:51:42,920 --> 00:51:46,160 HE LAUGHS 493 00:51:46,160 --> 00:51:48,880 A herd of hundreds of arctic hares 494 00:51:48,880 --> 00:51:52,120 are under attack from Rolf's white wolves. 495 00:51:54,200 --> 00:51:57,120 HE CHUCKLES 496 00:51:54,200 --> 00:51:57,120 Wow. 497 00:51:57,120 --> 00:51:59,240 We found our... 498 00:51:59,240 --> 00:52:01,880 ..our pack of seven wolves, 499 00:52:01,880 --> 00:52:04,840 in their full beauty, which is amazing. 500 00:52:06,560 --> 00:52:11,040 Filming the new behaviour ramps up the pressure on Rolf. 501 00:52:11,040 --> 00:52:15,000 Oh, God, the situation is just right in the wrong spot. 502 00:52:16,520 --> 00:52:20,960 Rolf is well known for his self-criticism. 503 00:52:20,960 --> 00:52:22,480 He's a perfectionist. 504 00:52:22,480 --> 00:52:26,120 You know, he wants that image to be absolutely perfect. 505 00:52:27,760 --> 00:52:31,400 You're amazing, but I'm stupid, unfortunately. 506 00:52:35,240 --> 00:52:40,400 A day later, the wolves disappear out of range of the telemetry. 507 00:52:40,400 --> 00:52:43,920 It said they were here, but now they aren't here 508 00:52:43,920 --> 00:52:46,960 and we don't get any signal from the telemetry. 509 00:52:46,960 --> 00:52:52,120 So, now I think we realise how hard it will be to find the wolves 510 00:52:52,120 --> 00:52:54,400 if we don't just run into them. 511 00:52:55,560 --> 00:52:58,400 With no wolves to film, Rolf is determined 512 00:52:58,400 --> 00:53:01,800 to capture the beauty of the landscape with a drone. 513 00:53:11,920 --> 00:53:14,200 We just can't get the thing in the air. 514 00:53:14,200 --> 00:53:18,520 Um, the motors, they've physically frozen solid. 515 00:53:18,520 --> 00:53:21,840 And the drone's not the only thing that's freezing. 516 00:53:21,840 --> 00:53:25,560 Look what I just found under my mask. 517 00:53:25,560 --> 00:53:27,080 ROLF LAUGHS 518 00:53:31,200 --> 00:53:33,920 THEY LAUGH 519 00:53:44,440 --> 00:53:49,400 A plan to warm up the drone with a hairdryer and a duffel bag 520 00:53:49,400 --> 00:53:53,880 could mean that the world record for the coldest flight is still on. 521 00:53:55,640 --> 00:53:57,440 Success! 522 00:54:04,200 --> 00:54:08,880 But the cold soon takes its toll on Jesse, the drone operator. 523 00:54:08,880 --> 00:54:12,600 Argh! I'm sorry, I can't feel my hands. 524 00:54:12,600 --> 00:54:16,320 I think we have to drift to the right a little bit more. 525 00:54:16,320 --> 00:54:20,000 When you're on a shoot with Rolf, he'll just keep going 526 00:54:20,000 --> 00:54:22,560 and going and going. 527 00:54:22,560 --> 00:54:24,520 We can fly towards the big mountain. 528 00:54:24,520 --> 00:54:27,680 I can get the... Argh! ..the big mountain, you know... 529 00:54:27,680 --> 00:54:29,600 Yeah. ..like, more centred. 530 00:54:29,600 --> 00:54:32,320 Argh! My hands! 531 00:54:32,320 --> 00:54:36,280 Come on, it's coming, it's coming. You just fly straight, Jesse. 532 00:54:36,280 --> 00:54:38,720 But I'm losing my sensation in my hands, Rolf. 533 00:54:38,720 --> 00:54:41,160 Yeah, let's hit roll on it before we die... Let's record. 534 00:54:41,160 --> 00:54:42,800 Come on, do it. 535 00:54:44,960 --> 00:54:48,640 This feels like a totally different planet. It's really crazy. 536 00:54:48,640 --> 00:54:52,560 OK, and I think now we could do a forward view. Yeah. 537 00:54:52,560 --> 00:54:55,680 Argh! Perfect, Jesse. You can go a bit slower. 538 00:54:55,680 --> 00:54:58,680 If you can, go a bit slower. My fingers are hurting. 539 00:55:00,280 --> 00:55:01,560 Argh! 540 00:55:01,560 --> 00:55:03,600 That looks really cool! 541 00:55:03,600 --> 00:55:05,640 It's incredible. 542 00:55:09,560 --> 00:55:12,240 With no sighting of the wolves in weeks, 543 00:55:12,240 --> 00:55:15,680 the team decide to follow their prey instead. 544 00:55:17,120 --> 00:55:19,680 Muskoxen. 545 00:55:19,680 --> 00:55:21,280 And the tactic pays off. 546 00:55:22,280 --> 00:55:25,200 The herd is being shadowed by the wolves. 547 00:55:25,200 --> 00:55:27,840 MUSKOX GRUNT 548 00:55:30,920 --> 00:55:33,680 They are very close to a herd of muskoxen there, 549 00:55:33,680 --> 00:55:35,280 and something might happen. 550 00:55:39,880 --> 00:55:44,000 Rolf is in the perfect spot to capture the first arctic wolf hunt 551 00:55:44,000 --> 00:55:47,240 ever filmed in the polar night. 552 00:55:52,800 --> 00:55:54,800 WOLVES WHINE 553 00:55:54,800 --> 00:55:58,760 God, there was some good stuff, I think, if I got it in focus. 554 00:56:00,520 --> 00:56:06,240 With the shots in the can, there is a magical experience for Rolf... 555 00:56:06,240 --> 00:56:09,680 ..one he's dreamed of since he was a child. 556 00:56:16,080 --> 00:56:18,600 It doesn't get better than this. 557 00:56:21,480 --> 00:56:23,640 WOLVES WHINE 558 00:56:23,640 --> 00:56:26,680 Oh, my God. This is an absolutely... 559 00:56:26,680 --> 00:56:28,680 ..dream of a lifetime. 560 00:56:32,160 --> 00:56:37,400 Honestly, you are the most beautiful living being I've ever seen. 561 00:56:37,400 --> 00:56:38,920 Incredible. 562 00:56:48,600 --> 00:56:50,360 Next time... 563 00:56:50,360 --> 00:56:51,760 ..weather. 564 00:56:54,960 --> 00:56:59,560 This powerful force carries vital freshwater around the globe. 565 00:57:01,800 --> 00:57:07,320 And all life on land is perfectly in tune with its annual rhythms. 566 00:57:14,240 --> 00:57:17,480 The Open University has produced a free poster 567 00:57:17,480 --> 00:57:19,920 exploring our perfect planet. 568 00:57:19,920 --> 00:57:25,280 To order, please call 0300 303 0901. 569 00:57:25,280 --> 00:57:29,920 Or go to bbc.co.uk/perfectplanet 570 00:57:29,920 --> 00:57:32,880 and follow the links to the Open University.