1 00:00:02,560 --> 00:00:04,720 Earth's great rivers... 2 00:00:06,280 --> 00:00:08,200 ..from source to sea... 3 00:00:09,360 --> 00:00:11,480 ..make extraordinary journeys... 4 00:00:11,480 --> 00:00:12,880 CRACKING 5 00:00:18,360 --> 00:00:20,240 ..carving through continents... 6 00:00:22,720 --> 00:00:25,640 ..nurturing ancient civilisations... 7 00:00:30,760 --> 00:00:34,400 ..feeding and connecting life across our world... 8 00:00:34,400 --> 00:00:36,680 ROARING 9 00:00:36,680 --> 00:00:40,080 ..from the mountains and deserts of the Nile... 10 00:00:44,160 --> 00:00:48,520 ..to the cities and mysterious swamps of the Mississippi... 11 00:00:51,800 --> 00:00:55,560 ..and the steaming waters and the secret worlds 12 00:00:55,560 --> 00:00:57,760 of the tropical Amazon. 13 00:00:59,280 --> 00:01:04,520 Great rivers are the lifeblood of planet Earth. 14 00:01:21,280 --> 00:01:24,560 One river dwarfs all others. 15 00:01:26,600 --> 00:01:28,600 The biggest on the planet. 16 00:01:29,720 --> 00:01:31,040 The Amazon. 17 00:01:33,200 --> 00:01:38,360 It flows through nine countries across one third of South America... 18 00:01:40,160 --> 00:01:43,840 ..sustaining the largest rainforest on Earth... 19 00:01:46,040 --> 00:01:50,080 ..supporting the world's greatest diversity of wildlife... 20 00:01:53,320 --> 00:01:56,160 ..inspiring vibrant cultures. 21 00:01:59,240 --> 00:02:01,200 THUNDER RUMBLES 22 00:02:01,200 --> 00:02:04,160 The Amazon's annual floods are so vast... 23 00:02:05,400 --> 00:02:08,680 ..they create what seems to be an inland sea. 24 00:02:11,120 --> 00:02:15,320 Even today, it hides mysterious worlds. 25 00:02:19,040 --> 00:02:20,840 To explore the unknown 26 00:02:20,840 --> 00:02:23,280 and experience the mightiest river on Earth... 27 00:02:27,840 --> 00:02:33,600 ..the story begins with a single drop. 28 00:02:40,760 --> 00:02:43,600 The glaciers of the Peruvian Andes. 29 00:02:46,080 --> 00:02:51,720 Here, glacial meltwater tumbles down the mountainsides, 30 00:02:51,720 --> 00:02:56,160 the start of a 4,000-mile journey to the sea. 31 00:03:01,000 --> 00:03:05,280 On lower slopes, where the humid air from below 32 00:03:05,280 --> 00:03:08,200 meets the cold, mountain atmosphere, 33 00:03:08,200 --> 00:03:13,080 cloud forests thrive, shrouded in mist. 34 00:03:21,160 --> 00:03:26,480 Tiny plants create hanging gardens on the branches of ancient trees... 35 00:03:29,440 --> 00:03:33,760 ..condensing the water vapour into sparkling droplets. 36 00:03:33,760 --> 00:03:35,840 GENTLE PLOPPING 37 00:03:36,960 --> 00:03:42,280 All around is the sound of the Amazon coming to life. 38 00:03:44,240 --> 00:03:47,040 TRICKLING WATER 39 00:04:02,720 --> 00:04:07,920 The Amazon is the greatest river basin in the world 40 00:04:07,920 --> 00:04:12,760 gathering water from right across tropical South America, 41 00:04:12,760 --> 00:04:17,200 amassing one fifth of the Earth's fresh water, 42 00:04:17,200 --> 00:04:20,080 as it flows east across the continent. 43 00:04:26,160 --> 00:04:33,280 Its 1,100 tributaries drain an area of nearly 2.5 million square miles. 44 00:04:37,840 --> 00:04:41,720 And one remote stretch of white-water rapids 45 00:04:41,720 --> 00:04:43,520 and deep, dark pools 46 00:04:43,520 --> 00:04:47,840 is home to one of its largest and rarest predators. 47 00:05:04,680 --> 00:05:07,400 GRUNTING AND CHIRPING 48 00:05:09,000 --> 00:05:11,240 Giant river otters. 49 00:05:12,520 --> 00:05:15,520 Some nearly two metres long. 50 00:05:20,440 --> 00:05:24,080 This family are exploring a new territory, 51 00:05:24,080 --> 00:05:27,320 a stretch they are keen to claim. 52 00:05:28,720 --> 00:05:29,960 SPLUTTERING 53 00:05:29,960 --> 00:05:33,440 Led by dad, the family follow his calls 54 00:05:33,440 --> 00:05:36,800 with a chorus that is unique to their group. 55 00:05:36,800 --> 00:05:39,480 PURRING 56 00:05:45,960 --> 00:05:52,040 They are looking for a spot rich in fish. 57 00:05:57,160 --> 00:06:01,520 Now, the parents can teach their young how to hunt. 58 00:06:04,760 --> 00:06:08,560 It will be a testing time for the most inexperienced cub. 59 00:06:11,600 --> 00:06:13,600 SQUEALING 60 00:06:14,640 --> 00:06:15,960 GROWLING 61 00:06:15,960 --> 00:06:18,960 Father coordinates the hunting party. 62 00:06:26,000 --> 00:06:30,560 Because fish can evade otters in the deep water, 63 00:06:30,560 --> 00:06:34,520 the family's best chance is to corral the fish 64 00:06:34,520 --> 00:06:36,360 up against the bank. 65 00:07:05,600 --> 00:07:09,400 This youngster has missed out. 66 00:07:13,200 --> 00:07:17,360 Everyone seems to have a fish but him. 67 00:07:21,840 --> 00:07:24,160 MEOWING 68 00:07:25,640 --> 00:07:29,680 Luckily, the others are usually generous enough to share. 69 00:07:35,400 --> 00:07:37,600 Which won't impress Father. 70 00:07:38,960 --> 00:07:40,760 GROWLING 71 00:07:48,280 --> 00:07:51,120 It takes three years for an otter cub 72 00:07:51,120 --> 00:07:54,960 to master the complexities of fishing in these rivers. 73 00:08:06,000 --> 00:08:08,160 The remote headwaters of the Amazon 74 00:08:08,160 --> 00:08:11,800 have an unpredictable and dangerous reputation. 75 00:08:13,600 --> 00:08:17,840 Many call currents and rapids like these "boat breakers". 76 00:08:21,280 --> 00:08:24,280 And there are accounts of early European explorers 77 00:08:24,280 --> 00:08:26,640 disappearing without a trace. 78 00:08:34,680 --> 00:08:39,520 These upper reaches are home to legendary river monsters... 79 00:08:42,240 --> 00:08:48,600 ..electric eels capable of generating more than 500 volts... 80 00:08:53,040 --> 00:08:58,920 ..enormous pacus, some up to 25 kilos in weight... 81 00:09:00,960 --> 00:09:03,120 ..and giant anacondas, 82 00:09:03,120 --> 00:09:06,320 amongst the largest snakes in the world. 83 00:09:09,480 --> 00:09:13,240 Some of these Amazon headwaters are so inaccessible, 84 00:09:13,240 --> 00:09:18,640 they conceal mysteries that are only now being revealed. 85 00:09:27,320 --> 00:09:31,000 On the bank of one distant tributary, 86 00:09:31,000 --> 00:09:34,800 the forest conceals a rare treasure. 87 00:09:42,000 --> 00:09:45,920 A pool of crystal-clear water. 88 00:09:53,080 --> 00:09:55,800 With strange, bubbling sand... 89 00:09:59,480 --> 00:10:03,640 ..this pool is in fact a spring. 90 00:10:07,920 --> 00:10:10,760 Rising from deep underground, 91 00:10:10,760 --> 00:10:13,800 the water is filtered... 92 00:10:19,400 --> 00:10:23,840 ..leaving it as spotless as an aquarium. 93 00:10:37,360 --> 00:10:43,560 With such clean, pure water, it's a perfect nursery... 94 00:10:45,800 --> 00:10:48,400 ..tempting out of the murky river, 95 00:10:48,400 --> 00:10:50,720 a pair of cichlids, 96 00:10:50,720 --> 00:10:53,000 so new to science 97 00:10:53,000 --> 00:10:57,400 that this particular species doesn't even have a name. 98 00:11:02,000 --> 00:11:06,360 This couple are here to raise their family... 99 00:11:11,240 --> 00:11:14,320 ..a brood of 100 tiny fry. 100 00:11:36,480 --> 00:11:40,800 Cichlids form strong bonds with their partners 101 00:11:40,800 --> 00:11:45,400 and are as loyal to their babies as they are to each other. 102 00:11:50,360 --> 00:11:53,680 This family seems to have found their perfect home. 103 00:11:57,880 --> 00:12:03,040 But out here, danger is never far away. 104 00:12:12,520 --> 00:12:17,600 Between the clear, spring waters and the murky main channel, 105 00:12:17,600 --> 00:12:20,080 a unique feature forms. 106 00:12:24,600 --> 00:12:26,120 A water wall. 107 00:12:30,240 --> 00:12:36,240 It hides voracious predators like these freshwater Amazon barracuda 108 00:12:36,240 --> 00:12:39,920 and a five-kilo wolffish. 109 00:12:45,480 --> 00:12:48,800 They lurk, watching and waiting. 110 00:12:50,440 --> 00:12:52,960 But the big fish seem strangely reluctant 111 00:12:52,960 --> 00:12:54,680 to enter the clear water... 112 00:12:56,240 --> 00:13:01,280 ..for fear, perhaps, of being spotted and eaten themselves. 113 00:13:15,280 --> 00:13:18,680 A well-armed stingray tries his luck. 114 00:13:21,680 --> 00:13:24,320 Using natural camouflage, 115 00:13:24,320 --> 00:13:28,720 they can hide themselves, even in these clear waters... 116 00:13:30,840 --> 00:13:34,360 ..setting an ambush from where they might hoover up 117 00:13:34,360 --> 00:13:38,800 100 fry in one fell swoop. 118 00:13:52,360 --> 00:13:54,520 Dad spots something... 119 00:13:59,880 --> 00:14:01,720 ..and defends his brood. 120 00:14:09,160 --> 00:14:12,400 The stingray is sent packing. 121 00:14:31,120 --> 00:14:36,960 These dedicated and brave parents will have to be ever-watchful, 122 00:14:36,960 --> 00:14:40,080 shepherding their young until, perhaps, one day, 123 00:14:40,080 --> 00:14:42,960 they are old enough and bold enough 124 00:14:42,960 --> 00:14:47,440 to face the perils of the main channel for themselves. 125 00:14:58,320 --> 00:15:02,360 The Upper Amazon has many strange and secret worlds 126 00:15:02,360 --> 00:15:04,760 which teem with life. 127 00:15:06,440 --> 00:15:09,040 But there is one remote river 128 00:15:09,040 --> 00:15:15,400 whose waters are apparently devoid of anything living. 129 00:15:19,120 --> 00:15:24,400 As dawn breaks, an ethereal apparition appears. 130 00:15:28,440 --> 00:15:33,240 Wisps of steam snaking across the canopy... 131 00:15:57,720 --> 00:16:03,880 ..revealing below an Amazon tributary which boils. 132 00:16:15,520 --> 00:16:17,880 Only recently mapped, 133 00:16:17,880 --> 00:16:23,440 it's the largest stretch of thermal river anywhere on the planet. 134 00:16:38,240 --> 00:16:41,920 At around 100 Celsius, 135 00:16:41,920 --> 00:16:47,840 fish unlucky enough to stray into these waters will be poached alive. 136 00:17:02,840 --> 00:17:06,040 Hot bedrock from deep within the Earth's crust 137 00:17:06,040 --> 00:17:08,760 lies unusually close to the surface here, 138 00:17:08,760 --> 00:17:11,560 heating and purifying the water... 139 00:17:14,760 --> 00:17:17,960 ..ensuring that this stretch of the river 140 00:17:17,960 --> 00:17:21,720 has always been cherished by those who live here. 141 00:17:30,840 --> 00:17:32,400 The Ashaninka people 142 00:17:32,400 --> 00:17:35,720 have been visiting the boiling river for generations... 143 00:17:35,720 --> 00:17:38,200 HE CHANTS 144 00:17:40,280 --> 00:17:43,920 ..and revere it for its healing properties. 145 00:17:47,680 --> 00:17:50,400 Juan Flores is their shaman. 146 00:17:50,400 --> 00:17:54,440 HE CONTINUES TO CHANT 147 00:17:57,400 --> 00:18:00,560 TRANSLATION: 148 00:18:22,000 --> 00:18:25,400 Juan and his family have developed 149 00:18:25,400 --> 00:18:28,720 a deep connection with this precious place. 150 00:18:31,280 --> 00:18:33,680 They've learned how to make medicine 151 00:18:33,680 --> 00:18:37,120 from mixing these steaming purified waters 152 00:18:37,120 --> 00:18:39,920 with plants from the forest. 153 00:18:43,080 --> 00:18:45,880 HE CHANTS 154 00:18:48,160 --> 00:18:52,280 TRANSLATION: 155 00:19:05,800 --> 00:19:09,480 Many medicines used today across the world 156 00:19:09,480 --> 00:19:11,760 have their origins in the rainforests. 157 00:19:13,320 --> 00:19:17,720 Yet less than 5% of the plants here in the Amazon 158 00:19:17,720 --> 00:19:20,680 have been studied by modern science. 159 00:19:24,040 --> 00:19:28,360 The rest remain a mystery known only to the local healers. 160 00:19:41,920 --> 00:19:46,280 This extraordinary river simmers for the next four miles 161 00:19:46,280 --> 00:19:50,200 before it blows away from the last of the foothills, 162 00:19:50,200 --> 00:19:53,400 down to the plains of the Amazon basin. 163 00:19:59,720 --> 00:20:04,800 Here, the tributaries meet and the river channels swell... 164 00:20:06,040 --> 00:20:08,920 ..surging faster and deeper. 165 00:20:11,480 --> 00:20:14,200 The strength of the currents 166 00:20:14,200 --> 00:20:16,880 erode at the soft river banks. 167 00:20:25,600 --> 00:20:30,360 But out of this destruction comes fresh opportunity. 168 00:20:31,720 --> 00:20:33,920 SQUAWKING 169 00:20:37,080 --> 00:20:38,600 Hidden treasure... 170 00:20:40,840 --> 00:20:44,520 ..which attracts green-winged macaws 171 00:20:44,520 --> 00:20:48,760 who flock together to gather on the newly-exposed banks. 172 00:20:49,960 --> 00:20:54,440 They have come to eat fresh clay - 173 00:20:54,440 --> 00:20:57,520 which might seem strange - but there's a very good reason. 174 00:21:03,840 --> 00:21:08,480 This particular clay is naturally rich in salt, 175 00:21:08,480 --> 00:21:11,400 a vital dietary supplement. 176 00:21:14,000 --> 00:21:19,320 Far from the ocean, and washed away by the Amazon's high rainfall, 177 00:21:19,320 --> 00:21:22,480 salt is a rare mineral here. 178 00:21:26,520 --> 00:21:31,440 So, the macaws bicker over the best deposits 179 00:21:31,440 --> 00:21:37,040 creating one of the Amazon's loudest and most colourful spectacles. 180 00:21:37,040 --> 00:21:41,840 SQUAWKING AND CAWING 181 00:21:47,960 --> 00:21:53,000 These lowland rivers set off out across the plains... 182 00:21:59,640 --> 00:22:04,000 ..many flowing with different colours, 183 00:22:04,000 --> 00:22:09,240 their waters tainted by the great variety of rocks and forests 184 00:22:09,240 --> 00:22:11,480 through which they have passed. 185 00:22:20,600 --> 00:22:23,040 Ultimately, they all join together 186 00:22:23,040 --> 00:22:26,880 to create one gigantic muddy river channel. 187 00:22:31,720 --> 00:22:34,440 The mighty Amazon itself. 188 00:22:40,800 --> 00:22:44,840 This central stretch of the river is so wide and deep, 189 00:22:44,840 --> 00:22:50,320 ocean-going ships can sail over 2,000 miles inland. 190 00:22:56,520 --> 00:23:01,800 At its halfway point where it meets the inky-black Rio Negro 191 00:23:01,800 --> 00:23:04,520 lies the Amazon's largest city... 192 00:23:09,600 --> 00:23:11,160 ..Manaus. 193 00:23:17,080 --> 00:23:20,360 With a population of over two million people, 194 00:23:20,360 --> 00:23:23,560 this city made its fortune in the late 19th century 195 00:23:23,560 --> 00:23:27,080 from the riches of the river and surrounding rainforest... 196 00:23:30,280 --> 00:23:34,600 ..rubber, gold and minerals. 197 00:23:41,840 --> 00:23:44,600 Today, the thriving markets of Manaus 198 00:23:44,600 --> 00:23:48,360 depend on a constant supply of local produce. 199 00:23:54,120 --> 00:23:56,040 For the last century, 200 00:23:56,040 --> 00:23:58,800 this flamboyant city has built a reputation 201 00:23:58,800 --> 00:24:01,120 as the Paris of the tropics... 202 00:24:02,600 --> 00:24:06,640 ..dominated by an extravagant opera house. 203 00:24:20,680 --> 00:24:24,520 The people of Manaus depend on local farmers 204 00:24:24,520 --> 00:24:26,960 like Edmar Fernandes da Lira 205 00:24:26,960 --> 00:24:32,040 who grows crops on the fertile muddy banks of the Amazon 206 00:24:32,040 --> 00:24:33,960 not far from the city. 207 00:24:36,320 --> 00:24:39,320 TRANSLATION: 208 00:24:55,760 --> 00:24:58,960 These are the good times for Edmar 209 00:24:58,960 --> 00:25:03,160 but he must work all the daylight hours he can. 210 00:25:05,040 --> 00:25:08,440 TRANSLATION: 211 00:25:16,840 --> 00:25:20,280 The Amazon's banks here are very productive. 212 00:25:22,040 --> 00:25:25,240 Three times a week, for eight months of the year, 213 00:25:25,240 --> 00:25:31,400 Edmar carries 400 kilos of leaves down to the waiting boat. 214 00:25:31,400 --> 00:25:33,200 TRANSLATION: 215 00:25:41,400 --> 00:25:44,000 But time is running out. 216 00:25:44,000 --> 00:25:46,080 These are some of the last crops 217 00:25:46,080 --> 00:25:49,240 Edmar will be able to sell for months. 218 00:25:52,720 --> 00:25:56,640 He must prepare for huge change. 219 00:25:56,640 --> 00:25:58,320 THUNDER RUMBLES 220 00:25:58,320 --> 00:26:04,120 Every year in November, the tropical wet season sweeps in. 221 00:26:11,120 --> 00:26:16,280 Six months of rainstorms inject trillions of gallons of water 222 00:26:16,280 --> 00:26:19,520 into the Amazon river system, transforming it. 223 00:26:49,720 --> 00:26:52,240 THUNDER RUMBLING 224 00:27:02,680 --> 00:27:04,360 In the mid-Amazon, 225 00:27:04,360 --> 00:27:09,720 stretches of river can quadruple in width and rise by ten metres. 226 00:27:26,160 --> 00:27:31,800 The port of Manaus has a harbour wall built to hold back the water. 227 00:27:36,840 --> 00:27:43,120 Beyond the city, though, it's a different story. 228 00:27:44,400 --> 00:27:47,400 Edmar's farm is submerged. 229 00:27:51,520 --> 00:27:53,960 Because he has prepared, 230 00:27:53,960 --> 00:27:58,440 Edmar simply shifts his attention to his stilt garden. 231 00:28:00,400 --> 00:28:03,920 For the next four months, the only vegetables to grow on his farm 232 00:28:03,920 --> 00:28:07,400 will be those above the flood. 233 00:28:16,480 --> 00:28:19,160 And when the river does recede, 234 00:28:19,160 --> 00:28:22,600 it leaves behind a fresh layer of sediment 235 00:28:22,600 --> 00:28:25,920 which will fertilise a new season of planting. 236 00:28:35,360 --> 00:28:39,200 But the floods can be very powerful 237 00:28:39,200 --> 00:28:42,960 and living with them comes with huge challenges. 238 00:28:44,200 --> 00:28:47,840 TRANSLATION: 239 00:28:58,000 --> 00:29:02,600 In recent years, the Amazon has faced more extreme weather events. 240 00:29:06,360 --> 00:29:08,520 Drier dry seasons... 241 00:29:11,400 --> 00:29:14,840 ..and even wetter wet seasons. 242 00:29:17,120 --> 00:29:22,400 Within the last two decades, rainfall has become so intense 243 00:29:22,400 --> 00:29:27,640 that the floods have been the highest since records began. 244 00:29:27,640 --> 00:29:29,920 TRANSLATION: 245 00:29:41,840 --> 00:29:44,960 The river that has previously provided 246 00:29:44,960 --> 00:29:47,720 so abundantly for Edmar and his family 247 00:29:47,720 --> 00:29:51,320 is now threatening to destroy their way of life. 248 00:29:58,840 --> 00:30:02,440 For nature, the arrival of the annual floods 249 00:30:02,440 --> 00:30:05,640 still bring incredible opportunities. 250 00:30:14,080 --> 00:30:18,920 As vast tracts of land become completely submerged, 251 00:30:18,920 --> 00:30:24,640 they create the Amazon's legendary flooded forests. 252 00:30:43,520 --> 00:30:48,680 Almost 200,000 square miles of rainforest become inundated... 253 00:30:50,840 --> 00:30:54,920 ..creating a new home for countless fish 254 00:30:54,920 --> 00:31:00,880 that shoal amongst the branches where birds once flew. 255 00:31:07,480 --> 00:31:11,520 The Amazon has over 3,000 species. 256 00:31:13,760 --> 00:31:18,080 Many breed in the flooded forests during high water. 257 00:31:25,720 --> 00:31:27,800 Hot on their tails 258 00:31:27,800 --> 00:31:32,680 come the Amazon's most revered and mysterious creatures. 259 00:32:09,960 --> 00:32:11,480 SQUEAKING 260 00:32:13,280 --> 00:32:16,680 Pink river dolphins, 261 00:32:16,680 --> 00:32:20,200 known locally as botos... 262 00:32:21,400 --> 00:32:25,440 ..the largest river dolphins in the world. 263 00:32:41,680 --> 00:32:47,000 A flooded forest of this scale creates new opportunities 264 00:32:47,000 --> 00:32:48,640 and challenges. 265 00:32:52,080 --> 00:32:56,920 Leaves from the forests stain the floodwater dark brown. 266 00:33:03,560 --> 00:33:07,840 Sunken branches create an obstacle course 267 00:33:07,840 --> 00:33:10,720 but botos have specialist equipment. 268 00:33:20,280 --> 00:33:22,920 Like their ocean cousins, 269 00:33:22,920 --> 00:33:25,960 their domed forehead, known as the melon, 270 00:33:25,960 --> 00:33:30,880 allows botos to scan this submerged world using sonar. 271 00:33:42,560 --> 00:33:47,200 As if that's not enough, botos have another unique weapon. 272 00:33:48,400 --> 00:33:52,360 They are the only adult dolphins with whiskers. 273 00:34:03,160 --> 00:34:07,320 These help pinpoint exactly where their prey is, 274 00:34:07,320 --> 00:34:11,560 no matter how it twists and turns. 275 00:34:42,800 --> 00:34:45,280 The Amazon's flooded forests 276 00:34:45,280 --> 00:34:49,040 have existed for at least eight million years... 277 00:34:50,360 --> 00:34:54,120 ..creating a world so special and unique, 278 00:34:54,120 --> 00:34:59,120 it's home to some of the most bizarre birds on Earth. 279 00:35:03,400 --> 00:35:05,080 Hoatzins... 280 00:35:07,760 --> 00:35:12,720 ..whose unusual lifestyle sets them apart from other birds. 281 00:35:16,680 --> 00:35:20,000 They feed almost exclusively on leaves, 282 00:35:20,000 --> 00:35:24,320 a diet which has an unfortunate and gassy effect... 283 00:35:27,120 --> 00:35:28,840 ..leading to their nickname... 284 00:35:30,360 --> 00:35:31,960 ..stink birds. 285 00:35:35,800 --> 00:35:38,040 During the flood season, 286 00:35:38,040 --> 00:35:41,920 certain riverside plants burst into new growth, 287 00:35:41,920 --> 00:35:46,000 the cue for hoatzins to breed. 288 00:35:49,360 --> 00:35:53,120 But the new leaves attract spider monkeys, too. 289 00:35:56,440 --> 00:35:58,560 Some monkeys can be a threat 290 00:35:58,560 --> 00:36:02,120 and will often devour any eggs they find. 291 00:36:09,080 --> 00:36:14,120 The hoatzins' only safety is in the most inaccessible branches 292 00:36:14,120 --> 00:36:16,920 furthest out over the river... 293 00:36:24,600 --> 00:36:27,560 ..safe from the reach of greedy monkeys, 294 00:36:27,560 --> 00:36:30,360 but now in danger from the floodwater. 295 00:36:33,120 --> 00:36:35,800 THUNDER RUMBLES 296 00:36:39,840 --> 00:36:43,160 Even near the end of the Amazon's wet season, 297 00:36:43,160 --> 00:36:48,880 sudden intense storms can bring ten centimetres of rain in a day... 298 00:36:52,640 --> 00:36:55,480 ..drowning any nests built too low... 299 00:36:56,880 --> 00:37:01,600 ..and putting others in reach of river predators... 300 00:37:03,440 --> 00:37:05,480 ..like black caiman. 301 00:37:12,520 --> 00:37:15,320 To make matters even more perilous, 302 00:37:15,320 --> 00:37:20,120 hoatzin chicks are curious and more than a little clumsy. 303 00:37:32,560 --> 00:37:37,480 Fortunately, they are not entirely helpless... 304 00:37:39,280 --> 00:37:43,840 ..as they are born with an unusual piece of climbing equipment... 305 00:37:50,040 --> 00:37:52,600 ..claws on their wings. 306 00:37:59,520 --> 00:38:04,680 So even this little chick can clamber back up to safety. 307 00:38:20,960 --> 00:38:23,120 At the peak of high water, 308 00:38:23,120 --> 00:38:28,240 just under 300,000 square miles of the Amazon's flood plain 309 00:38:28,240 --> 00:38:30,320 can be submerged. 310 00:38:33,920 --> 00:38:37,000 Under this colossal weight of water, 311 00:38:37,000 --> 00:38:42,800 the Earth's crust itself can sink by eight centimetres. 312 00:38:48,040 --> 00:38:51,600 The floodwaters can remain high for three months 313 00:38:51,600 --> 00:38:56,160 before they finally drain away down into the Lower Amazon. 314 00:39:00,640 --> 00:39:04,160 River banks down here can be 15 miles apart. 315 00:39:07,720 --> 00:39:11,560 Stretches of the Lower Amazon look more like a sea 316 00:39:11,560 --> 00:39:16,280 and on its shore there are some spectacular beaches. 317 00:39:23,080 --> 00:39:27,120 This region is often called the Caribbean of the Amazon. 318 00:39:29,640 --> 00:39:33,120 Even though it's more than 300 miles from the ocean... 319 00:39:37,760 --> 00:39:42,440 ..every year, crowds of river people, Riberenos, 320 00:39:42,440 --> 00:39:46,120 gather in the Lower Amazon town of Alter do Chao 321 00:39:46,120 --> 00:39:49,280 for a seasonal celebration of the river. 322 00:40:07,040 --> 00:40:10,440 As the party preparations begin in the town, 323 00:40:10,440 --> 00:40:12,920 Sandro Branco and his grandfather 324 00:40:12,920 --> 00:40:16,120 enjoy a moment of quiet before the fiesta. 325 00:40:18,160 --> 00:40:20,600 TRANSLATION: 326 00:40:34,600 --> 00:40:39,120 Sandro is right to be nervous as Alter do Chao stages 327 00:40:39,120 --> 00:40:42,400 one of the most colourful and surprising river carnivals 328 00:40:42,400 --> 00:40:44,160 in all of Brazil. 329 00:40:46,160 --> 00:40:48,480 And Sandro is the lead man. 330 00:40:48,480 --> 00:40:52,600 TRANSLATION: 331 00:41:17,720 --> 00:41:20,720 CHEERING AND WHISTLING 332 00:41:22,160 --> 00:41:26,520 Sandro is the star of the show, playing the pink boto... 333 00:41:29,760 --> 00:41:32,360 ..a legendary creature for the river people. 334 00:41:35,360 --> 00:41:39,400 The local belief is that on the night of the full moon, 335 00:41:39,400 --> 00:41:42,760 the boto dolphin turns into a handsome and seductive man 336 00:41:42,760 --> 00:41:45,200 with a hat and a white suit. 337 00:41:48,280 --> 00:41:53,880 Once on land, his challenge is to seduce young women. 338 00:42:02,600 --> 00:42:05,040 BEATING DRUMS, CROWD NOISES 339 00:42:08,880 --> 00:42:10,800 Despite the pressure... 340 00:42:15,480 --> 00:42:18,760 ..the dance has been a success. 341 00:42:20,640 --> 00:42:23,640 TRANSLATION: 342 00:42:29,680 --> 00:42:34,560 Sandro is the third generation of boto dancers in his family 343 00:42:34,560 --> 00:42:37,840 but he's facing stiff competition. 344 00:42:39,840 --> 00:42:43,800 The next wave of talent is hot on his heels. 345 00:42:45,920 --> 00:42:48,800 TRANSLATION: 346 00:42:56,400 --> 00:43:00,280 It's a celebration that has been going on for hundreds of years... 347 00:43:07,000 --> 00:43:09,760 ..showing just how the life of this great river... 348 00:43:13,200 --> 00:43:16,200 ..and the lives of millions that live along its banks 349 00:43:16,200 --> 00:43:18,760 are inextricably intertwined. 350 00:43:20,640 --> 00:43:23,320 MUTED CHEERING AND APPLAUSE 351 00:43:36,320 --> 00:43:38,560 By the time it reaches the sea, 352 00:43:38,560 --> 00:43:43,640 the Amazon River discharges around 175,000 tonnes of water 353 00:43:43,640 --> 00:43:46,680 into the Atlantic Ocean per second. 354 00:43:49,240 --> 00:43:54,760 This is more water than the next six largest rivers combined. 355 00:44:03,920 --> 00:44:10,040 The Amazon's fresh water floats above the sea as a vast brown cloud 356 00:44:10,040 --> 00:44:14,720 covering an area of up to 400,000 square miles. 357 00:44:19,080 --> 00:44:22,920 Until recently, it's been very difficult to find exactly 358 00:44:22,920 --> 00:44:25,160 what lies and lives beneath. 359 00:44:34,560 --> 00:44:37,760 But today, the very latest technology 360 00:44:37,760 --> 00:44:41,040 and the most advanced submarines are allowing scientists 361 00:44:41,040 --> 00:44:45,560 to explore this last secret world of the Amazon. 362 00:44:56,240 --> 00:45:00,400 In a dive 300 miles north of the Amazon's mouth, 363 00:45:00,400 --> 00:45:03,800 the expedition is revealing that the river's nutrients 364 00:45:03,800 --> 00:45:09,200 are fertilising the ocean's waters, creating a bloom of plankton. 365 00:45:14,160 --> 00:45:18,280 It is hard to imagine that there would be life underneath this murk. 366 00:45:32,360 --> 00:45:35,360 As the dive continues below the plume, 367 00:45:35,360 --> 00:45:39,880 chief scientist Rodrigo Moura and pilot Allan Scott 368 00:45:39,880 --> 00:45:43,280 discover something extraordinary. 369 00:45:43,280 --> 00:45:47,320 Ah, I've never seen anything like this before, never. 370 00:45:49,560 --> 00:45:54,200 A massive reef of colourful, rock-like algae. 371 00:46:01,640 --> 00:46:02,800 Oh, look. 372 00:46:02,800 --> 00:46:06,160 Look at the size of these guys! 373 00:46:10,880 --> 00:46:14,800 Thronging with rich and varied marine life... 374 00:46:17,840 --> 00:46:20,360 Angel fish. Heaven. 375 00:46:20,360 --> 00:46:21,640 CHUCKLING 376 00:46:23,280 --> 00:46:26,680 ..under the dense plume of the fertile river water, 377 00:46:26,680 --> 00:46:30,280 it turns out there is a hidden world. 378 00:46:32,120 --> 00:46:37,920 An enormous algal reef more than 600 miles long. 379 00:46:45,560 --> 00:46:48,040 And that's not all. 380 00:46:48,040 --> 00:46:51,560 An underwater garden of giant sponges. 381 00:47:02,560 --> 00:47:06,600 Some of the sponges are more than a metre across 382 00:47:06,600 --> 00:47:09,000 and 1,000 years old... 383 00:47:11,240 --> 00:47:16,760 ..all feeding on nutrients which the Amazon has collected 384 00:47:16,760 --> 00:47:18,360 on its incredible journey. 385 00:47:44,160 --> 00:47:48,840 We don't see this every day, huh? No, not every day, this is special. 386 00:47:50,160 --> 00:47:53,080 No other river on Earth is known to have the power 387 00:47:53,080 --> 00:47:57,880 to shape such an extraordinary ecosystem out in the ocean. 388 00:48:04,680 --> 00:48:08,120 Every dive is now rewriting the textbooks. 389 00:48:18,440 --> 00:48:22,160 From its humble beginnings as a drop in the mountains, 390 00:48:22,160 --> 00:48:25,560 the Amazon is a river like no other. 391 00:48:27,800 --> 00:48:30,680 From its source to the sea, 392 00:48:30,680 --> 00:48:34,640 it has forged its own path, created new worlds 393 00:48:34,640 --> 00:48:37,840 and is so powerful and so vast, 394 00:48:37,840 --> 00:48:42,880 who knows what other secrets it has yet to reveal? 395 00:48:55,600 --> 00:48:58,560 Intrepid Brazilian film-maker Joao Krajewski 396 00:48:58,560 --> 00:49:00,640 has spent the last ten years 397 00:49:00,640 --> 00:49:03,400 filming and travelling right across the Amazon. 398 00:49:08,040 --> 00:49:11,920 Over that time, he's been lucky enough to have close encounters 399 00:49:11,920 --> 00:49:15,680 with many of its exotic and bizarre wildlife. 400 00:49:15,680 --> 00:49:20,520 The Amazon is outstanding because of its size and diversity. 401 00:49:22,480 --> 00:49:24,760 The river, gigantic. 402 00:49:24,760 --> 00:49:27,400 You can spend your whole life exploring this region 403 00:49:27,400 --> 00:49:29,880 and there will always be something different to see. 404 00:49:32,440 --> 00:49:35,960 But the Earth's Great Rivers series 405 00:49:35,960 --> 00:49:41,520 set him a new challenge to film Amazon wildlife underwater... 406 00:49:47,160 --> 00:49:50,440 ..an almost impossible mission 407 00:49:50,440 --> 00:49:53,880 as the Amazon River is perhaps the muddiest. 408 00:49:58,000 --> 00:50:02,520 However, its great size means it has 1,100 tributaries 409 00:50:02,520 --> 00:50:04,720 each with its own distinct character. 410 00:50:06,920 --> 00:50:11,040 Joao has heard of a region in the Amazon's remote south 411 00:50:11,040 --> 00:50:14,000 where the water is said to be clear. 412 00:50:14,000 --> 00:50:17,960 So, he and his wife Roberta, his diving partner, 413 00:50:17,960 --> 00:50:19,760 prepare an expedition. 414 00:50:22,840 --> 00:50:24,040 TRANSLATION: 415 00:50:26,360 --> 00:50:28,040 So, this is a very special day 416 00:50:28,040 --> 00:50:31,560 because it'll be the first scuba dive ever in this river. 417 00:50:39,200 --> 00:50:43,520 This is a true dive into the unknown. 418 00:50:48,880 --> 00:50:53,400 It was the first time that I actually see the underwater world. 419 00:50:54,480 --> 00:50:57,520 I would say there's more than 100 species of fish 420 00:50:57,520 --> 00:51:00,040 just in this little area. 421 00:51:00,040 --> 00:51:02,880 Every single species is new for me. 422 00:51:04,080 --> 00:51:09,040 But just because the water is clear, it doesn't mean it's not dangerous. 423 00:51:10,240 --> 00:51:12,880 I was there comfortably having fun with my fish 424 00:51:12,880 --> 00:51:16,480 and, all of a sudden, I saw this shape coming towards me. 425 00:51:17,560 --> 00:51:20,440 It's a giant electric eel. 426 00:51:21,360 --> 00:51:24,000 I can't lie, I was really afraid of them 427 00:51:24,000 --> 00:51:26,840 because you don't need to be bitten or anything. 428 00:51:26,840 --> 00:51:31,000 If you just touch it accidentally, it can zap you really, really bad. 429 00:51:32,040 --> 00:51:35,280 They are not afraid of you at all, they just come and come. 430 00:51:35,280 --> 00:51:37,160 HE GASPS 431 00:51:37,160 --> 00:51:40,360 And some of them can give you a shock of more than 1,000 volts. 432 00:51:40,360 --> 00:51:43,560 If you are in the water, you can drown, you can die. 433 00:51:43,560 --> 00:51:46,440 The problem is that on a hot day like this, 434 00:51:46,440 --> 00:51:49,120 the eels are looking for shade 435 00:51:49,120 --> 00:51:51,640 and actively swim towards Joao. 436 00:51:54,840 --> 00:51:56,760 ROBERTA SPEAKS 437 00:51:56,760 --> 00:51:58,080 A bit tense, yeah. 438 00:51:58,080 --> 00:52:00,520 They are curious. They are slow 439 00:52:00,520 --> 00:52:02,560 but they can... 440 00:52:02,560 --> 00:52:04,880 If you touch them, ugh. 441 00:52:04,880 --> 00:52:08,200 It's unsafe for Joao to film them in the water, 442 00:52:08,200 --> 00:52:10,400 so he needs to make a plan. 443 00:52:10,400 --> 00:52:13,160 This is the Brazilian way, we call it gambia, improvising, 444 00:52:13,160 --> 00:52:16,000 last-minute idea but it will work. 445 00:52:17,360 --> 00:52:18,960 This is the final touch. 446 00:52:18,960 --> 00:52:20,760 A very special one. 447 00:52:20,760 --> 00:52:22,600 So, it should work. 448 00:52:22,600 --> 00:52:28,400 These strange eels have a bizarre behaviour which Joao hopes to film. 449 00:52:31,920 --> 00:52:33,720 Yay! 450 00:52:34,960 --> 00:52:36,360 I got it! 451 00:52:36,360 --> 00:52:38,160 That was a good one. 452 00:52:39,640 --> 00:52:44,080 He captures the moment when an eel comes up for a breath of air. 453 00:52:44,080 --> 00:52:48,320 The lining of their mouth acts like a lung. 454 00:52:48,320 --> 00:52:53,560 This ensures the eels survive dry seasons when the water is shallow, 455 00:52:53,560 --> 00:52:56,560 often very low in oxygen. 456 00:52:56,560 --> 00:53:00,000 Wow, what a day. Phew. 457 00:53:04,360 --> 00:53:07,600 As Joao explores the region further, 458 00:53:07,600 --> 00:53:11,920 he comes across some locations which are a wildlife film-maker's 459 00:53:11,920 --> 00:53:14,480 dream come true. 460 00:53:14,480 --> 00:53:17,640 Very, very unusually for the Amazon, 461 00:53:17,640 --> 00:53:22,880 he finds some springs where the water is as clear as gin. 462 00:53:25,280 --> 00:53:29,120 Joao is hoping the pools will give him the chance 463 00:53:29,120 --> 00:53:30,640 to film new behaviour. 464 00:53:34,280 --> 00:53:36,960 And he is not disappointed. 465 00:53:36,960 --> 00:53:40,520 It's not long before a new species of cichlid 466 00:53:40,520 --> 00:53:43,640 invite him into their family. 467 00:53:43,640 --> 00:53:45,000 Wow! 468 00:53:47,640 --> 00:53:51,680 One of the springs is like an underwater garden. 469 00:53:51,680 --> 00:53:54,960 There are more than 1,000 fish in front of me, I'm not kidding. 470 00:53:57,000 --> 00:54:02,040 But though it looks beautiful, there is danger. 471 00:54:04,200 --> 00:54:08,200 Black caiman patrol the murky waters of the main river. 472 00:54:08,200 --> 00:54:15,080 They can be up to four metres long, and weigh in excess of 400 kilos. 473 00:54:15,080 --> 00:54:18,960 Roberta acts as lookout. 474 00:54:18,960 --> 00:54:22,640 I'm keeping an eye out for caimans because we never know, 475 00:54:22,640 --> 00:54:26,160 like, there is one big one who lives right there 476 00:54:26,160 --> 00:54:30,240 and we need to watch to make sure Joao is going to be safe. 477 00:54:36,120 --> 00:54:40,640 Joao has no idea what is lurking in the gloam. 478 00:54:42,920 --> 00:54:44,920 The dividing line is so clear - 479 00:54:44,920 --> 00:54:47,840 you have dark in one side and crystal clear on the other. 480 00:54:47,840 --> 00:54:49,400 I never thought it was so clear. 481 00:54:51,240 --> 00:54:54,080 And just as Joao is on the boundary, 482 00:54:54,080 --> 00:54:58,200 the ranger spots something in the river. 483 00:55:01,720 --> 00:55:03,360 Heading straight for Joao... 484 00:55:05,960 --> 00:55:09,560 ..the largest wild mammal in South America. 485 00:55:11,760 --> 00:55:12,960 A tapir. 486 00:55:15,600 --> 00:55:18,480 That's a crazy tapir. I've never seen a tapir looking like that, 487 00:55:18,480 --> 00:55:21,360 stay for such a long time in the middle of the river. 488 00:55:21,360 --> 00:55:24,040 Look. It's swimming upriver now. 489 00:55:24,040 --> 00:55:28,640 Tapirs aren't usually dangerous but it could attack a caiman. 490 00:55:28,640 --> 00:55:32,680 It's a reminder that Joao is vulnerable when he's in the water. 491 00:55:32,680 --> 00:55:34,840 I'll just get a close-up 492 00:55:34,840 --> 00:55:37,560 and then we go upriver which is safer. 493 00:55:42,360 --> 00:55:44,800 As well as filming underwater, 494 00:55:44,800 --> 00:55:47,000 for the final phase of his expedition, 495 00:55:47,000 --> 00:55:49,720 Joao is hoping to get really close 496 00:55:49,720 --> 00:55:52,920 to one of the Amazon's largest and most secretive predators. 497 00:55:54,760 --> 00:56:00,160 And one of the southern rivers, the Cristalino, might just deliver. 498 00:56:04,760 --> 00:56:08,960 Joao has heard rumours that this area of the river 499 00:56:08,960 --> 00:56:13,040 is home to a particularly approachable family of giant otters. 500 00:56:15,320 --> 00:56:17,760 They're usually very shy, 501 00:56:17,760 --> 00:56:23,000 so it's a real surprise to see an entire family out in the open. 502 00:56:24,760 --> 00:56:27,400 Absolutely amazing, amazing. 503 00:56:27,400 --> 00:56:28,960 I never expected that. 504 00:56:28,960 --> 00:56:31,280 The whole family is right in front of us. 505 00:56:31,280 --> 00:56:34,400 We are four metres away. 506 00:56:34,400 --> 00:56:36,720 All of them here. 507 00:56:36,720 --> 00:56:40,000 Unbelievable. In the middle of the wilderness. 508 00:56:40,000 --> 00:56:41,400 HE LAUGHS 509 00:56:46,640 --> 00:56:50,320 They even allow him to join their fishing trip. 510 00:56:53,040 --> 00:56:58,200 Having earned their trust, Joao attempts to get even closer. 511 00:56:58,200 --> 00:57:04,920 Another improvised camera rig means Joao can join them in the water. 512 00:57:04,920 --> 00:57:06,480 GROWLING 513 00:57:12,680 --> 00:57:16,880 Oh, I've never seen them do this, absolutely unbelievable. 514 00:57:16,880 --> 00:57:19,160 Right in front of me and they're still doing it, 515 00:57:19,160 --> 00:57:21,760 they're playing, out of the water, amazing, amazing. 516 00:57:34,240 --> 00:57:38,720 So, although the sheer scale of the Amazon seemed so daunting... 517 00:57:40,600 --> 00:57:44,280 ..the mighty river revealed its secrets... 518 00:57:46,120 --> 00:57:50,960 ..giving Joao a window into its hidden underwater worlds. 519 00:58:01,640 --> 00:58:02,960 Next time... 520 00:58:04,280 --> 00:58:06,000 ..the majestic Nile. 521 00:58:08,240 --> 00:58:12,840 The world's longest river flowing from the equator to the Sahara... 522 00:58:17,120 --> 00:58:19,680 ..through astonishing unexpected worlds... 523 00:58:23,080 --> 00:58:28,360 ..bringing life to the driest parts of the hottest continent on Earth.