1 00:00:35,520 --> 00:00:37,840 David Attenborough: The equator. 2 00:00:41,680 --> 00:00:44,360 It runs across the scorched plains 3 00:00:44,480 --> 00:00:46,440 of east Africa. 4 00:00:49,240 --> 00:00:52,920 This is as far from the Poles as you can get. 5 00:00:59,320 --> 00:01:02,360 But ice and snow are here too - 6 00:01:02,480 --> 00:01:04,680 up in the mountains. 7 00:01:18,360 --> 00:01:22,600 Every continent on earth has such high snowfields. 8 00:01:36,640 --> 00:01:39,880 And each has its own community of animals 9 00:01:40,000 --> 00:01:42,240 that have adapted in their own way 10 00:01:42,360 --> 00:01:46,840 to the crushing conditions that come with the cold. 11 00:02:14,360 --> 00:02:16,440 Dawn in east Africa, 12 00:02:16,560 --> 00:02:18,800 on the high slopes of mount Kenya... 13 00:02:20,320 --> 00:02:22,280 4,000 metres up. 14 00:02:25,920 --> 00:02:28,160 The temperature is just beginning 15 00:02:28,280 --> 00:02:30,240 to creep above freezing. 16 00:02:33,280 --> 00:02:36,120 It's hardly the place where you would expect to find 17 00:02:36,240 --> 00:02:37,880 a cold-blooded reptile. 18 00:02:40,960 --> 00:02:43,880 But there is one that lives up here - 19 00:02:44,000 --> 00:02:47,360 the high-casqued chameleon. 20 00:02:47,480 --> 00:02:49,440 This female has survived 21 00:02:49,560 --> 00:02:51,160 the night's freezing temperatures 22 00:02:51,280 --> 00:02:54,000 by allowing both her metabolism 23 00:02:54,120 --> 00:02:57,200 and her heart rate to drop significantly. 24 00:03:00,360 --> 00:03:04,000 Now, in the morning, she needs to eat. 25 00:03:09,800 --> 00:03:13,360 But it's so cold, she can't move her legs. 26 00:03:20,520 --> 00:03:23,960 Her spring-loaded tongue, however, still works. 27 00:03:42,080 --> 00:03:45,080 As the sun rises higher in the sky, 28 00:03:45,200 --> 00:03:47,840 frozen land begins to thaw... 29 00:03:50,280 --> 00:03:52,080 And the giant iobelias 30 00:03:52,200 --> 00:03:55,520 spread their leaves to soak up the sunshine. 31 00:04:05,320 --> 00:04:06,760 With her body temperature 32 00:04:06,880 --> 00:04:09,160 still only five degrees celsius, 33 00:04:09,280 --> 00:04:11,840 the chameleon becomes more mobile... 34 00:04:13,200 --> 00:04:16,960 And climbs up to bask in the sun. 35 00:04:24,160 --> 00:04:26,000 Her skin darkens... 36 00:04:27,640 --> 00:04:31,280 Enabling her to absorb the sun's heat more quickly. 37 00:04:33,160 --> 00:04:35,080 She is pregnant, 38 00:04:35,200 --> 00:04:39,240 and soon her temperature reaches 20 degrees celsius, 39 00:04:39,360 --> 00:04:41,040 which gives her 40 00:04:41,160 --> 00:04:44,560 the energy she needs to give birth. 41 00:04:53,400 --> 00:04:57,000 Most chameleon species lay eggs, 42 00:04:57,120 --> 00:04:58,880 but here it's too cold 43 00:04:59,000 --> 00:05:01,360 for an egg to develop in the open... 44 00:05:03,920 --> 00:05:06,880 So she produces live young. 45 00:05:19,360 --> 00:05:20,680 It takes just an hour 46 00:05:20,800 --> 00:05:25,720 for her to give birth to six baby chameleons. 47 00:05:30,200 --> 00:05:33,360 One of the advantages of life on the frozen peaks 48 00:05:33,480 --> 00:05:36,200 is that there are fewer predators here... 49 00:05:38,160 --> 00:05:41,640 And less competition for food. 50 00:05:43,800 --> 00:05:47,640 But there's a reason why comparatively few reptiles 51 00:05:47,760 --> 00:05:49,480 live in the high mountains. 52 00:05:51,440 --> 00:05:53,080 As the sun sets, 53 00:05:53,200 --> 00:05:55,680 the temperature falls to below zero 54 00:05:55,800 --> 00:05:57,880 in a matter of minutes. 55 00:06:02,840 --> 00:06:06,440 The babies must act fast. 56 00:06:21,680 --> 00:06:23,960 To escape the nightly freeze, 57 00:06:24,080 --> 00:06:27,080 they need the cover of thick vegetation. 58 00:06:35,520 --> 00:06:38,040 A young chameleon caught out in the cold 59 00:06:38,160 --> 00:06:41,520 will quickly lose its ability to move 60 00:06:41,640 --> 00:06:43,920 and may we” die. 61 00:06:57,800 --> 00:07:00,760 Most, however, react instinctively 62 00:07:00,880 --> 00:07:04,120 and find shelter as quickly as they can. 63 00:07:27,520 --> 00:07:30,960 Peaks on the equator, such as mount Kenya, 64 00:07:31,080 --> 00:07:35,160 are frost bound for only a few hours each night. 65 00:07:38,720 --> 00:07:40,480 But north of the equator, 66 00:07:40,600 --> 00:07:44,200 in the 750-mile-long European alps, 67 00:07:44,320 --> 00:07:46,720 the cold endures for months. 68 00:08:00,760 --> 00:08:03,840 The high mountains are continuously frozen 69 00:08:03,960 --> 00:08:05,280 for half the year. 70 00:08:13,240 --> 00:08:14,840 A testing time 71 00:08:14,960 --> 00:08:18,880 for the alps' greatest aerial predator. 72 00:08:24,640 --> 00:08:26,520 The golden eagle. 73 00:08:36,360 --> 00:08:37,520 In winter, 74 00:08:37,640 --> 00:08:41,120 there is just enough prey up here, dead or alive, 75 00:08:41,240 --> 00:08:42,520 to sustain them. 76 00:08:46,480 --> 00:08:50,480 But when spring arrives, the mountains are transformed. 77 00:09:07,200 --> 00:09:11,000 For a male and his lifelong partner... 78 00:09:12,440 --> 00:09:15,280 The need to find food is urgent. 79 00:09:19,200 --> 00:09:21,640 They have a three-week-old chick. 80 00:09:26,160 --> 00:09:29,720 It needs to be fed several times a day. 81 00:09:33,840 --> 00:09:38,000 To do that, both parents have to hunt. 82 00:09:44,800 --> 00:09:46,640 Yet, even in spring, 83 00:09:46,760 --> 00:09:50,000 few animals live up here in the high mountains, 84 00:09:50,120 --> 00:09:54,400 and finding prey is not easy. 85 00:09:59,280 --> 00:10:02,640 But chamois, a kind of mountain goat, 86 00:10:02,760 --> 00:10:05,880 are here, and they are giving birth. 87 00:10:08,120 --> 00:10:12,000 One of their kids can weigh as much as an eagle. 88 00:10:14,400 --> 00:10:17,240 When eagles hunt as a pair, 89 00:10:17,360 --> 00:10:19,480 they co-ordinate their approach. 90 00:10:27,360 --> 00:10:29,120 One stoops... 91 00:10:31,240 --> 00:10:34,680 Reaching a speed of over 150mph. 92 00:10:47,280 --> 00:10:50,120 Its attack scatters the herd. 93 00:10:53,200 --> 00:10:54,680 And that makes it easier 94 00:10:54,800 --> 00:10:56,920 for the other to select a target. 95 00:11:23,800 --> 00:11:25,520 A successful catch. 96 00:11:30,920 --> 00:11:32,760 It could still be alive... 97 00:11:37,360 --> 00:11:41,440 So the eagle carries it away, high over the gorge... 98 00:11:45,120 --> 00:11:46,200 And then... 99 00:11:48,160 --> 00:11:50,200 Deliberately drops it. 100 00:12:02,920 --> 00:12:06,080 The impact will kill it instantly. 101 00:12:43,080 --> 00:12:46,000 A chick can eat up to a third 102 00:12:46,120 --> 00:12:48,920 of its own body weight in a day. 103 00:12:54,080 --> 00:12:57,240 Parents can't afford to rest for long. 104 00:12:59,240 --> 00:13:02,840 Taking advantage of the long summer days, 105 00:13:02,960 --> 00:13:06,040 eagles hunt ceaselessly. 106 00:13:20,160 --> 00:13:21,920 Day in... 107 00:13:23,160 --> 00:13:24,280 Day out. 108 00:13:28,960 --> 00:13:33,160 After eight weeks, a chick is almost fully grown. 109 00:13:44,880 --> 00:13:46,000 And then, 110 00:13:46,120 --> 00:13:47,920 as summer comes to an end, 111 00:13:48,040 --> 00:13:51,400 the pressure on parents to feed their chicks... 112 00:13:51,520 --> 00:13:53,040 Disappears. 113 00:13:57,440 --> 00:13:59,960 Their young have flown the nest. 114 00:14:08,080 --> 00:14:10,320 And just in time. 115 00:14:11,720 --> 00:14:13,640 The worsening weather signals 116 00:14:13,760 --> 00:14:17,680 that the leaner times of winter are on their way. 117 00:14:20,160 --> 00:14:23,800 Finding prey has now got much harder. 118 00:14:29,400 --> 00:14:33,560 The young chamois have also grown up. 119 00:14:39,800 --> 00:14:42,160 A juvenile now weighs 120 00:14:42,280 --> 00:14:45,760 almost five times as much as an eagle. 121 00:14:52,080 --> 00:14:55,480 Animals of this size are no longer easy prey 122 00:14:55,600 --> 00:14:56,720 for the birds. 123 00:15:00,920 --> 00:15:03,680 They barely flinch under attack. 124 00:15:21,000 --> 00:15:23,800 But it's dangerous for a chamois to stray 125 00:15:23,920 --> 00:15:25,680 close to a cliff edge. 126 00:15:28,160 --> 00:15:30,280 The eagles seize their chance. 127 00:15:48,200 --> 00:15:49,480 Got it. 128 00:15:52,320 --> 00:15:55,360 The eagle drags the chamois towards the edge. 129 00:16:00,960 --> 00:16:04,440 It's an extremely risky move. 130 00:16:04,560 --> 00:16:06,120 If the eagle breaks a wing, 131 00:16:06,240 --> 00:16:07,720 it will be fatal. 132 00:16:55,760 --> 00:17:00,200 A kill this size will feed a pair for days. 133 00:17:02,920 --> 00:17:05,920 This is when they must build up the fat reserves 134 00:17:06,040 --> 00:17:09,640 that they will need to sustain themseres 135 00:17:09,760 --> 00:17:12,240 through the lean months that lie ahead. 136 00:17:20,320 --> 00:17:24,080 Winters in the alps are daunting. 137 00:17:24,200 --> 00:17:28,320 But in other mountain ranges, the challenges are even harder. 138 00:17:34,880 --> 00:17:36,080 In the far east, 139 00:17:36,200 --> 00:17:40,400 warm, wet winds blow in across the sea of Japan. 140 00:17:44,360 --> 00:17:46,600 As they meet the 3,000-metre-high 141 00:17:46,720 --> 00:17:48,360 Japanese alps, 142 00:17:48,480 --> 00:17:50,360 they're forced upwards. 143 00:17:57,400 --> 00:17:59,120 As the moist air rises, 144 00:17:59,240 --> 00:18:00,960 it freezes... 145 00:18:08,160 --> 00:18:12,480 And the water droplets they carry turn into snow. 146 00:18:19,080 --> 00:18:22,880 No two snow crystals are exactly the same. 147 00:18:30,000 --> 00:18:31,800 In the mountains of Japan, 148 00:18:31,920 --> 00:18:35,200 13 metres of snow can fall in just a few months. 149 00:18:37,000 --> 00:18:39,880 It's the snowiest place on earth. 150 00:18:45,720 --> 00:18:47,280 To survive here, 151 00:18:47,400 --> 00:18:50,480 an animal needs all the help it can get. 152 00:18:57,920 --> 00:19:01,120 In winter, Japanese macaques 153 00:19:01,240 --> 00:19:05,800 can live at altitudes of up to 1,500 metres... 154 00:19:07,160 --> 00:19:09,840 Higher than almost any other primate. 155 00:19:11,880 --> 00:19:15,320 But here, the warm volcanic pools 156 00:19:15,440 --> 00:19:17,240 are always ready and waiting. 157 00:19:20,120 --> 00:19:24,440 A nice hot bath lowers stress hormones for them, 158 00:19:24,560 --> 00:19:26,360 just as it does for us. 159 00:19:36,520 --> 00:19:39,840 Admission to this spa, however, is tightly controlled. 160 00:19:47,240 --> 00:19:51,600 The high-ranking females dictate who is allowed in... 161 00:19:56,280 --> 00:19:59,120 And who will be left out in the cold. 162 00:20:12,200 --> 00:20:14,160 This three-year-old male 163 00:20:14,280 --> 00:20:17,880 has recently been expelled from his troop. 164 00:20:24,280 --> 00:20:26,520 He's hungry. 165 00:20:27,560 --> 00:20:30,360 Macaques are largely vegetarian. 166 00:20:31,800 --> 00:20:34,720 In the winter, when food of any kind is scarce, 167 00:20:34,840 --> 00:20:37,720 they will tackle anything remotely edible. 168 00:20:39,480 --> 00:20:43,640 However, a lone young male is unlikely to survive much longer 169 00:20:43,760 --> 00:20:46,880 unless he can find a way of keeping warm. 170 00:21:03,760 --> 00:21:07,320 And to do so, he may have to travel through 171 00:21:07,440 --> 00:21:09,840 up to 50 miles of empty forest. 172 00:21:14,360 --> 00:21:16,640 Bare hands and feet 173 00:21:16,760 --> 00:21:19,400 can become painfully cold. 174 00:21:23,680 --> 00:21:27,040 Rubbing them helps restore the circulation. 175 00:21:29,920 --> 00:21:32,600 Frostbite could be fatal. 176 00:21:51,760 --> 00:21:55,600 Young male macaques are most likely to die 177 00:21:55,720 --> 00:21:58,960 in their first winter than at any other time. 178 00:22:08,000 --> 00:22:09,120 Butjust like him, 179 00:22:09,240 --> 00:22:12,800 here is another young male outcast. 180 00:22:38,760 --> 00:22:42,560 Offering to groom is a standard way of establishing 181 00:22:42,680 --> 00:22:45,720 a friendly relationship among macaques. 182 00:22:50,760 --> 00:22:54,680 And the stranger's warm embrace is very welcome. 183 00:22:59,360 --> 00:23:01,280 By huddling together, 184 00:23:01,400 --> 00:23:04,000 they shield each other from the snow, 185 00:23:04,120 --> 00:23:08,840 and both their temperatures rise... just a little. 186 00:23:11,360 --> 00:23:15,560 This could be enough to save the lives 187 00:23:15,680 --> 00:23:17,160 of both of them. 188 00:23:30,120 --> 00:23:34,880 Snow on lower mountain slopes can be a major challenge 189 00:23:35,000 --> 00:23:37,640 for any of the animals that live there. 190 00:23:41,680 --> 00:23:44,200 On the high peaks, however, 191 00:23:44,320 --> 00:23:47,360 really heavy snowfalls can be lethal. 192 00:23:51,600 --> 00:23:53,840 The rockies in North America. 193 00:24:00,320 --> 00:24:04,520 They rise to heights of over 4,400 metres. 194 00:24:08,080 --> 00:24:11,880 In the winter, the winds blowing across the high summits 195 00:24:12,000 --> 00:24:15,360 can create snowy overhangs - cornices - 196 00:24:15,480 --> 00:24:17,160 up to ten metres thick 197 00:24:17,280 --> 00:24:19,160 and weighing many tonnes. 198 00:24:20,960 --> 00:24:23,920 In the spring, as the temperatures rise, 199 00:24:24,040 --> 00:24:27,120 the cornices may become unstable... 200 00:24:31,600 --> 00:24:33,720 And that can be catastrophic. 201 00:24:44,080 --> 00:24:46,080 Avalanche. 202 00:24:52,800 --> 00:24:54,680 As it tumbles downwards, 203 00:24:54,800 --> 00:24:59,480 it accelerates to speeds of 100mph or more. 204 00:25:08,640 --> 00:25:12,280 Only a racer drone camera can follow its course. 205 00:25:36,960 --> 00:25:39,080 In just two minutes, 206 00:25:39,200 --> 00:25:43,720 up to a million tonnes of snow hurtle down the mountainside. 207 00:26:01,080 --> 00:26:04,280 Avalanches can be hugely destructive, 208 00:26:04,400 --> 00:26:06,120 and climate change is making them 209 00:26:06,240 --> 00:26:08,000 more and more unpredictable. 210 00:26:28,320 --> 00:26:30,080 In the south pacific, 211 00:26:30,200 --> 00:26:32,000 on the islands of New Zealand, 212 00:26:32,120 --> 00:26:34,480 one highly intelligent creature 213 00:26:34,600 --> 00:26:36,400 has learned how to take advantage 214 00:26:36,520 --> 00:26:39,920 of the volatile nature of mountains. 215 00:26:54,800 --> 00:26:56,640 The kea... 216 00:26:59,080 --> 00:27:02,400 A species of parrot. 217 00:27:07,640 --> 00:27:10,080 It's the only one of its family 218 00:27:10,200 --> 00:27:12,440 that can live above the snowline, 219 00:27:12,560 --> 00:27:18,320 and the only one that actively looks for meat. 220 00:27:21,680 --> 00:27:24,400 The carcass of a mountain goat. 221 00:27:27,560 --> 00:27:31,520 This adult male kea has a razor-sharp beak... 222 00:27:34,320 --> 00:27:37,320 Which is well suited for butchery. 223 00:27:40,960 --> 00:27:44,000 Flesh rich in calories 224 00:27:44,120 --> 00:27:46,840 will help him through the winter. 225 00:27:50,040 --> 00:27:54,040 But he doesn't have it for himself for long. 226 00:27:59,360 --> 00:28:02,400 A gang ofjuvenile keas. 227 00:28:19,400 --> 00:28:20,920 These younger keas 228 00:28:21,040 --> 00:28:24,960 shadow the older, more experienced adults... 229 00:28:27,160 --> 00:28:30,520 To learn the tricks of mountain survival... 230 00:28:35,200 --> 00:28:36,960 And where to find food. 231 00:28:38,480 --> 00:28:41,400 But while waiting their turn... 232 00:28:42,920 --> 00:28:45,640 There's time to play. 233 00:29:08,760 --> 00:29:13,280 There's a benefit to this apparently carefree behaviour. 234 00:29:13,400 --> 00:29:16,080 It helps establish long-lasting relationships 235 00:29:16,200 --> 00:29:18,040 between the youngsters... 236 00:29:20,200 --> 00:29:22,760 And even defuses tension... 237 00:29:29,440 --> 00:29:33,800 So that when one kea finds a rare but substantial meal... 238 00:29:35,280 --> 00:29:37,560 It often willingly shares it. 239 00:29:45,240 --> 00:29:48,400 And that is very important behaviour, 240 00:29:48,520 --> 00:29:50,560 particularly in winter, 241 00:29:50,680 --> 00:29:52,440 when food is so scarce. 242 00:30:03,160 --> 00:30:05,680 In larger mountain chains, 243 00:30:05,800 --> 00:30:09,640 the quest for food can become even more demanding. 244 00:30:11,160 --> 00:30:13,520 The andes in South America. 245 00:30:14,800 --> 00:30:17,040 The longest range on earth. 246 00:30:18,240 --> 00:30:21,560 It stretches for over 4,500 miles 247 00:30:21,680 --> 00:30:23,880 down towards the antarctic. 248 00:30:31,800 --> 00:30:33,720 At its southernmost end, 249 00:30:33,840 --> 00:30:36,880 the sun remains so low in the sky 250 00:30:37,000 --> 00:30:39,000 that it brings little warmth, 251 00:30:39,120 --> 00:30:42,200 and temperatures regularly drop below freezing. 252 00:30:56,880 --> 00:30:59,920 In winter, the land is shrouded in darkness 253 00:31:00,040 --> 00:31:02,160 for almost 15 hours a day. 254 00:31:07,920 --> 00:31:10,760 Here, a predator has to hunt 255 00:31:10,880 --> 00:31:14,600 when it's so dark that only a thermal camera 256 00:31:14,720 --> 00:31:18,120 can make its activities visible to our eyes. 257 00:31:20,560 --> 00:31:22,200 The puma. 258 00:31:31,440 --> 00:31:35,800 This one-year-old female faces a daunting prospect. 259 00:31:38,600 --> 00:31:42,240 She has just left her mother and become independent 260 00:31:42,360 --> 00:31:44,800 at the most demanding time of the year... 261 00:31:47,040 --> 00:31:49,720 When prey is at its most scarce. 262 00:31:55,360 --> 00:31:59,960 The only substantial targets are a kind of llama. 263 00:32:01,160 --> 00:32:02,560 Guanaco. 264 00:32:07,840 --> 00:32:10,640 An adult stands one-and-a-half metres tall 265 00:32:10,760 --> 00:32:12,840 and is twice the puma's weight. 266 00:32:17,960 --> 00:32:22,200 This female, however, has one advantage - 267 00:32:22,320 --> 00:32:25,040 excellent night vision. 268 00:32:28,280 --> 00:32:32,720 If the youngster can get within five metres of a guanaco, 269 00:32:32,840 --> 00:32:35,720 she has a chance of success. 270 00:32:45,440 --> 00:32:50,160 But the guanaco do have a very acute sense of smell... 271 00:32:58,000 --> 00:33:00,000 And excellent hearing. 272 00:33:07,400 --> 00:33:10,400 After six hours of patient stalking from downwind... 273 00:33:14,040 --> 00:33:18,360 The puma is finally within striking distance. 274 00:33:48,960 --> 00:33:51,040 A wasted opportunity. 275 00:34:12,800 --> 00:34:16,160 Three failed attempts in one night 276 00:34:16,280 --> 00:34:18,600 have drained her reserves. 277 00:34:26,840 --> 00:34:31,480 Her inexperience is leaving her close to starvation. 278 00:34:36,440 --> 00:34:38,600 Another faint scent. 279 00:34:43,200 --> 00:34:45,360 But it's leading this youngster 280 00:34:45,480 --> 00:34:48,880 into the territory of another puma. 281 00:34:52,840 --> 00:34:54,720 Her neighbour, a female, 282 00:34:54,840 --> 00:34:57,640 is older and more experienced than she is... 283 00:34:59,160 --> 00:35:01,240 And has already made a successful kill. 284 00:35:04,160 --> 00:35:07,000 The younger female must approach with caution. 285 00:35:09,960 --> 00:35:12,320 Adult pumas are solitary by nature... 286 00:35:15,760 --> 00:35:18,720 And don't normally welcome rivals. 287 00:35:29,760 --> 00:35:33,440 She falls back in a gesture of submission. 288 00:35:45,320 --> 00:35:48,560 But if she doesn't eat within the next few days, 289 00:35:48,680 --> 00:35:50,800 she's unlikely to survive. 290 00:35:56,520 --> 00:36:00,520 The larger female is now no longer actively feeding... 291 00:36:02,240 --> 00:36:04,640 So she makes another approach. 292 00:36:39,360 --> 00:36:43,520 At last, the owner ignores her. 293 00:36:51,040 --> 00:36:53,960 Pumas are the only solitary big cat 294 00:36:54,080 --> 00:36:56,840 known to share a meal with a neighbour. 295 00:37:05,720 --> 00:37:08,440 Maybe the young puma, with the help of its neighbour, 296 00:37:08,560 --> 00:37:11,240 will after all survive her first winter. 297 00:37:12,440 --> 00:37:16,320 And maybe the older cat one day 298 00:37:16,440 --> 00:37:20,160 will be in need of a favour returned. 299 00:37:30,880 --> 00:37:34,240 The lower slopes of the andes are harsh. 300 00:37:37,520 --> 00:37:38,720 But climb higher, 301 00:37:38,840 --> 00:37:42,240 and the mountains become othennorldly. 302 00:37:48,080 --> 00:37:50,720 Their altitude prevents rain clouds 303 00:37:50,840 --> 00:37:52,520 from blowing in from the east... 304 00:37:55,160 --> 00:37:58,600 Whilst another, lower range nearer the west coast, 305 00:37:58,720 --> 00:38:02,200 prevents rain coming in from the pacific ocean. 306 00:38:03,440 --> 00:38:05,360 This creates, between them, 307 00:38:05,480 --> 00:38:09,240 one of the driest high-altitude deserts on earth... 308 00:38:10,440 --> 00:38:11,800 The atacama. 309 00:38:14,800 --> 00:38:17,960 There is, nonetheless, a lake here - 310 00:38:18,080 --> 00:38:21,720 a volcanic one that is filled with extremely salty water 311 00:38:21,840 --> 00:38:23,320 from underground. 312 00:38:26,080 --> 00:38:28,600 And this attracts flamingos. 313 00:38:36,280 --> 00:38:38,880 They come here each summer. 314 00:38:41,120 --> 00:38:43,280 And here they nest and raise their young, 315 00:38:43,400 --> 00:38:46,680 taking advantage of the lake's plentiful algae. 316 00:38:51,640 --> 00:38:54,040 But with the arrival of winter, 317 00:38:54,160 --> 00:38:58,080 temperatures at night drop to below freezing... 318 00:39:01,520 --> 00:39:04,600 Conditions that even these Hardy birds 319 00:39:04,720 --> 00:39:07,280 cannot endure for long. 320 00:39:10,160 --> 00:39:13,600 The adults start to leave and head for warmer temperatures 321 00:39:13,720 --> 00:39:15,640 lower down the mountain. 322 00:39:40,120 --> 00:39:41,760 But they leave behind 323 00:39:41,880 --> 00:39:43,800 their four-month-old chicks, 324 00:39:43,920 --> 00:39:46,000 which are old enough to feed themseres 325 00:39:46,120 --> 00:39:48,680 but not yet strong enough to fly. 326 00:39:54,440 --> 00:39:56,440 With each passing night, 327 00:39:56,560 --> 00:39:58,440 temperatures continue to fall. 328 00:40:07,200 --> 00:40:09,400 And then, one morning, 329 00:40:09,520 --> 00:40:13,160 after a particularly cold night, 330 00:40:13,280 --> 00:40:17,840 the chicks find themselves surrounded by ice. 331 00:40:22,400 --> 00:40:24,400 Huddling together 332 00:40:24,520 --> 00:40:26,280 allows some to preserve 333 00:40:26,400 --> 00:40:28,440 precious body heat. 334 00:40:31,040 --> 00:40:33,240 But those on the outside 335 00:40:33,360 --> 00:40:36,200 are left even more exposed. 336 00:40:40,320 --> 00:40:44,880 And some have already succumbed to the freezing conditions. 337 00:40:48,240 --> 00:40:51,000 The salty ice is now so cold 338 00:40:51,120 --> 00:40:53,640 that it congeals on the chicks' feathers. 339 00:40:56,840 --> 00:41:01,440 Weighed down, their chances of flying are even more remote. 340 00:41:08,120 --> 00:41:12,240 Now 40mph winds whip across the lake, 341 00:41:12,360 --> 00:41:15,120 driving down temperatures even further. 342 00:41:36,200 --> 00:41:38,520 Yet this very wind that could kill them 343 00:41:38,640 --> 00:41:41,320 might just be their saviour. 344 00:41:45,600 --> 00:41:48,080 The youngsters turn to face it. 345 00:41:53,760 --> 00:41:55,960 If they can catch it just right, 346 00:41:56,080 --> 00:41:58,280 it could give them the lift they need 347 00:41:58,400 --> 00:42:00,400 to take their very first flight. 348 00:42:27,840 --> 00:42:31,280 For those encumbered with heavy loads of ice... 349 00:42:32,640 --> 00:42:35,080 The struggle is almost too much. 350 00:42:50,880 --> 00:42:52,920 Freedom at last. 351 00:43:06,560 --> 00:43:10,280 Many animals that live amongst the frozen peaks 352 00:43:10,400 --> 00:43:13,800 have, over thousands of years, become adapted 353 00:43:13,920 --> 00:43:18,120 to meet the challenges of a high-altitude existence. 354 00:43:22,720 --> 00:43:26,560 But now their world is changing 355 00:43:26,680 --> 00:43:29,040 because of global warming. 356 00:43:38,200 --> 00:43:42,200 Ice that has remained frozen deep within mountain glaciers 357 00:43:42,320 --> 00:43:44,160 is starting to melt... 358 00:43:52,720 --> 00:43:55,200 Accelerating their movement. 359 00:44:22,440 --> 00:44:25,680 Over the three years that it took to film this series, 360 00:44:25,800 --> 00:44:28,040 the quelccaya icecap, 361 00:44:28,160 --> 00:44:31,200 5,500 metres up in the Peruvian andes, 362 00:44:31,320 --> 00:44:35,200 has receded by a staggering 60 metres. 363 00:44:40,080 --> 00:44:42,840 In Europe, some alpine glaciers 364 00:44:42,960 --> 00:44:46,160 are now shrinking by 100 metres a year. 365 00:44:56,560 --> 00:44:58,320 One of them, 366 00:44:58,440 --> 00:45:00,880 the sankt annafirn glacier in Switzerland 367 00:45:01,000 --> 00:45:03,200 has almost completely disappeared. 368 00:45:06,240 --> 00:45:09,560 Most of the others are expected to have followed it 369 00:45:09,680 --> 00:45:11,160 by the turn of the century. 370 00:45:25,320 --> 00:45:27,800 The warming of the frozen slopes 371 00:45:27,920 --> 00:45:30,080 could threaten the life of perhaps 372 00:45:30,200 --> 00:45:32,680 the most famous mountain resident of all. 373 00:45:39,280 --> 00:45:43,000 Hidden within the bamboo forests of western China... 374 00:45:45,120 --> 00:45:50,080 Is a hot and bothered male giant panda. 375 00:46:00,000 --> 00:46:01,440 He has spent the winter 376 00:46:01,560 --> 00:46:04,080 sheltering lower down the valley. 377 00:46:06,360 --> 00:46:08,520 Now it's early summer, 378 00:46:08,640 --> 00:46:11,240 and his thick coat that protected him 379 00:46:11,360 --> 00:46:14,560 throughout the winter has become very uncomfortable. 380 00:46:18,480 --> 00:46:22,840 He needs to reach the cold of the higher slopes. 381 00:46:25,600 --> 00:46:27,600 But before he can start the ascent, 382 00:46:27,720 --> 00:46:31,480 he needs a good meal to give him the necessary energy. 383 00:46:46,360 --> 00:46:51,320 Giant pandas eat almost nothing except bamboo. 384 00:46:54,600 --> 00:46:57,880 But bamboo is so low in calories 385 00:46:58,000 --> 00:47:01,800 that he needs to spend ten hours a day eating. 386 00:47:07,200 --> 00:47:09,080 With breakfast over... 387 00:47:10,640 --> 00:47:14,240 He begins his climb to higher ground. 388 00:47:28,040 --> 00:47:30,440 But in no time at all... 389 00:47:32,960 --> 00:47:34,480 He's hungry again. 390 00:47:43,760 --> 00:47:47,480 This is going to be a long journey. 391 00:47:55,760 --> 00:48:00,160 And it may be an even longer one in the near future. 392 00:48:03,400 --> 00:48:07,880 As climate change raises the temperature in these mountains, 393 00:48:08,000 --> 00:48:12,000 giant pandas may we” need to climb higher and higher 394 00:48:12,120 --> 00:48:14,920 to find cooler conditions. 395 00:48:22,400 --> 00:48:25,960 But the cold-loving bamboo they most favour 396 00:48:26,080 --> 00:48:29,360 cannot move so easily... 397 00:48:30,840 --> 00:48:35,720 And may disappear from the warmer lower slopes altogether. 398 00:48:43,520 --> 00:48:47,000 So far, these snow-covered peaks 399 00:48:47,120 --> 00:48:50,960 continue to provide this male with enough space 400 00:48:51,080 --> 00:48:53,080 to feed and find a mate... 401 00:48:55,800 --> 00:48:58,720 So he scent-marks his territory... 402 00:49:00,160 --> 00:49:01,520 Panda-style - 403 00:49:01,640 --> 00:49:04,240 with a handstand. 404 00:49:08,360 --> 00:49:11,120 It may well be that in the next few decades 405 00:49:11,240 --> 00:49:13,840 the mountains of the world will warm. 406 00:49:18,080 --> 00:49:19,240 Should that happen, 407 00:49:19,360 --> 00:49:22,080 many species will inevitably disappear. 408 00:49:28,080 --> 00:49:32,640 But we should never forget the versatility and endurance 409 00:49:32,760 --> 00:49:36,400 of the animals that have succeeded in colonising... 410 00:49:37,960 --> 00:49:41,640 These icy islands in the sky. 411 00:50:01,000 --> 00:50:02,800 In the frozen peaks, 412 00:50:02,920 --> 00:50:05,320 the team's greatest challenge 413 00:50:05,440 --> 00:50:08,520 was to film a successful puma hunt at night 414 00:50:08,640 --> 00:50:09,840 for the first time. 415 00:50:14,680 --> 00:50:17,360 The crew travelled to patagonia 416 00:50:17,480 --> 00:50:20,720 in the depths of winter to torres del paine, 417 00:50:20,840 --> 00:50:23,600 home to over 200 pumas, 418 00:50:23,720 --> 00:50:26,200 the highest density on earth. 419 00:50:30,800 --> 00:50:33,640 Still to find them in this remote wilderness, 420 00:50:33,760 --> 00:50:35,800 greater than the size of London, 421 00:50:35,920 --> 00:50:39,760 they joined the local puma expert Diego araya, 422 00:50:39,880 --> 00:50:41,920 who has over 20 years' experience 423 00:50:42,040 --> 00:50:44,800 of tracking these big cats. 424 00:50:44,920 --> 00:50:47,360 This is something completely new for us, 425 00:50:47,480 --> 00:50:49,560 because we've never been actually in pitch black 426 00:50:49,680 --> 00:50:50,680 following cats, 427 00:50:50,760 --> 00:50:54,280 and being able to keep up with them on foot 428 00:50:54,400 --> 00:50:57,960 I think is going to be an incredible task. 429 00:50:59,280 --> 00:51:01,800 This far south, at the tip of South America, 430 00:51:01,920 --> 00:51:05,240 winter only gives them nine hours of daylight 431 00:51:05,360 --> 00:51:07,600 to find the pumas before night descends. 432 00:51:11,960 --> 00:51:14,880 But it's not long until they are treated to 433 00:51:15,000 --> 00:51:16,680 a surprise encounter. 434 00:51:18,560 --> 00:51:21,600 Definitely, we are not part of the menu, huh? 435 00:51:21,720 --> 00:51:24,960 Getting this close to a wild puma 436 00:51:25,080 --> 00:51:28,480 is a rare privilege for camerawoman Helen hobin. 437 00:51:30,000 --> 00:51:31,240 It's very surreal, actually, 438 00:51:31,360 --> 00:51:33,720 being in real life and seeing one. 439 00:51:36,000 --> 00:51:40,240 By day, these well-studied pumas are approachable. 440 00:51:44,000 --> 00:51:46,480 But as dusk descends, 441 00:51:46,600 --> 00:51:51,080 they pick up the pace as they switch to hunting mode. 442 00:51:52,640 --> 00:51:56,080 We're just going into the pitch black pretty soon 443 00:51:56,200 --> 00:51:57,480 and we have to rely on 444 00:51:57,600 --> 00:51:59,160 thermal the rest of the night. 445 00:51:59,280 --> 00:52:02,720 Armed with a state-of-the-art thermal-imaging camera 446 00:52:02,840 --> 00:52:05,800 and spotting scopes, 447 00:52:05,920 --> 00:52:08,600 they attempt to follow the puma in the pitch black. 448 00:52:08,720 --> 00:52:11,520 The cats are moving so fast at the moment, 449 00:52:11,640 --> 00:52:14,120 they can cover miles, 450 00:52:14,240 --> 00:52:17,120 and it's quite hard to keep up, with all of our equipment, 451 00:52:17,240 --> 00:52:19,920 and not really being able to see where you're going. 452 00:52:25,560 --> 00:52:27,480 A few hours later, 453 00:52:27,600 --> 00:52:30,840 and the pumas have given them the runaround. 454 00:52:30,960 --> 00:52:32,760 You can see a heat signal on the hill. 455 00:52:34,120 --> 00:52:35,200 Radio: Do you see them? 456 00:52:35,320 --> 00:52:37,520 Yeah, I think we've got eyes on them. 457 00:52:37,640 --> 00:52:39,160 Where is she? 458 00:52:39,280 --> 00:52:40,800 I'm on the guanaco. 459 00:52:44,400 --> 00:52:48,800 I feel like we had a puma that we all lost somehow. 460 00:52:48,920 --> 00:52:52,160 But I'm pretty sure we've been standing here 461 00:52:52,280 --> 00:52:54,920 staring at a bush with a hare in it. 462 00:52:59,920 --> 00:53:04,280 As weeks pass, the crew experience the full force 463 00:53:04,400 --> 00:53:06,000 of the patagonian winter - 464 00:53:06,120 --> 00:53:11,400 100mph gusts of wind and blizzard conditions. 465 00:53:11,520 --> 00:53:14,000 It's just one thing after another at the moment. 466 00:53:18,800 --> 00:53:21,200 Finally, with a break in the weather, 467 00:53:21,320 --> 00:53:22,920 their persistence pays off. 468 00:53:24,120 --> 00:53:25,720 The situation is that we found a puma 469 00:53:25,840 --> 00:53:28,120 and there's a group of guanacos. 470 00:53:28,240 --> 00:53:30,720 This could be the break the team need 471 00:53:30,840 --> 00:53:34,440 and offer them the opportunity to film another night hunt. 472 00:53:36,000 --> 00:53:38,480 To optimise their chances, 473 00:53:38,600 --> 00:53:41,440 Helen launches her secret weapon. 474 00:53:44,200 --> 00:53:46,160 A thermal camera drone 475 00:53:46,280 --> 00:53:48,840 that will act as their eyes in the sky... 476 00:53:50,160 --> 00:53:54,000 Guiding the ground crew to within 20 metres 477 00:53:54,120 --> 00:53:55,760 of the hunting big cat. 478 00:53:57,720 --> 00:53:59,960 It's pitch black. There's a puma. 479 00:54:02,000 --> 00:54:05,160 It's a little bit unnerving. 480 00:54:11,320 --> 00:54:13,800 She's off. She's moving. 481 00:54:17,880 --> 00:54:20,200 She was so close to that one to start. 482 00:54:20,320 --> 00:54:23,760 She just didn't quite reach it. It was like that close. 483 00:54:25,240 --> 00:54:28,600 Super frustrating, because now we're getting to walk 484 00:54:28,720 --> 00:54:29,960 many more miles. 485 00:54:31,440 --> 00:54:33,120 Over the coming nights, 486 00:54:33,240 --> 00:54:35,920 the team continues to follow the young puma 487 00:54:36,040 --> 00:54:38,240 as she attempts hunt after hunt. 488 00:54:39,760 --> 00:54:41,640 Helen: It's just a roller-coaster all the time. 489 00:54:41,760 --> 00:54:43,136 Something looks like it's gonna happen, 490 00:54:43,160 --> 00:54:45,360 your adrenaline gets pumping, trying to get the shot, 491 00:54:45,480 --> 00:54:46,840 and then just... 492 00:54:49,800 --> 00:54:55,720 Lost count how many failed attempts. Too many. 493 00:55:01,200 --> 00:55:05,120 With only a week left to film a successful night hunt, 494 00:55:05,240 --> 00:55:07,600 the pressure is mounting on the crew. 495 00:55:07,720 --> 00:55:11,080 We're still struggling to get the key behaviour 496 00:55:11,200 --> 00:55:12,560 we're looking for. 497 00:55:16,040 --> 00:55:19,920 But then the young female does something truly remarkable. 498 00:55:22,280 --> 00:55:24,120 She didn't manage to make a kill, 499 00:55:24,240 --> 00:55:25,736 but she came across another cat that has, 500 00:55:25,760 --> 00:55:27,176 and she's been slowly over the course 501 00:55:27,200 --> 00:55:28,640 of the last... I don't know how long, 502 00:55:28,760 --> 00:55:30,160 I think it's been hours, 503 00:55:30,280 --> 00:55:32,000 creeping towards her really submissively, 504 00:55:32,120 --> 00:55:34,600 trying to ask for a bit of food. 505 00:55:38,440 --> 00:55:41,600 It's quite the experience when you're standing 506 00:55:41,720 --> 00:55:43,480 in their proximity and you can't see 'em 507 00:55:43,600 --> 00:55:46,640 but you can just hear the crunching of the bones. 508 00:55:49,120 --> 00:55:52,480 It's just so amazing to see. You can hear it 509 00:55:52,600 --> 00:55:54,440 echoing all around as well when they growl. 510 00:55:54,560 --> 00:55:56,520 Ooh! 511 00:56:00,520 --> 00:56:05,080 Until recently, pumas were considered solitary animals, 512 00:56:05,200 --> 00:56:08,840 but the crew's success with the thermal camera 513 00:56:08,960 --> 00:56:11,000 reveals two unrelated cats 514 00:56:11,120 --> 00:56:13,320 sharing the same kill at night. 515 00:56:17,240 --> 00:56:22,840 You realise how far they are from solitary individuals. 516 00:56:22,960 --> 00:56:25,280 This is like a fellowship of creatures 517 00:56:25,400 --> 00:56:27,360 living in the same territory. 518 00:56:29,520 --> 00:56:32,280 New technology has shed light on 519 00:56:32,400 --> 00:56:36,640 the surprising survival strategy of the andean puma. 520 00:56:41,160 --> 00:56:43,920 Just one of the many mysterious animals 521 00:56:44,040 --> 00:56:48,000 that inhabit our planet's remote frozen peaks.