1 00:00:09,273 --> 00:00:11,897 Deep in the heart of the Amazon rainforest 2 00:00:11,897 --> 00:00:15,044 lies the largest collection of river islands in the world. 3 00:00:18,906 --> 00:00:21,883 Thousands of kilometers from the nearest ocean, 4 00:00:21,883 --> 00:00:25,142 these are some of the most unusual habitats on Earth. 5 00:00:28,028 --> 00:00:29,996 Stranded on the mighty Rio Negro, 6 00:00:32,300 --> 00:00:35,582 the islands are engulfed by seasonal floods, 7 00:00:35,582 --> 00:00:38,670 changing their landscape completely. 8 00:00:38,670 --> 00:00:41,854 Everything living here is forced to adapt 9 00:00:41,854 --> 00:00:42,937 or die. 10 00:00:47,711 --> 00:00:51,404 This is life on the floating forests of the Amazon. 11 00:01:38,210 --> 00:01:39,778 The Amazon Rain Forest 12 00:01:39,778 --> 00:01:43,956 covers 4,000,000 square kilometers of our planet. 13 00:01:43,956 --> 00:01:45,748 Sprawling across almost half 14 00:01:45,748 --> 00:01:47,908 of the South American continent, 15 00:01:47,908 --> 00:01:50,497 it is fed by the might Amazon River. 16 00:01:56,918 --> 00:01:59,414 And at its heart are a group of islands 17 00:01:59,414 --> 00:02:01,319 knows as the Anavilhanas 18 00:02:01,319 --> 00:02:03,473 and Mariua Archipelagos. 19 00:02:08,295 --> 00:02:10,348 More than a thousand islands stretch along 20 00:02:10,348 --> 00:02:12,761 the Rio Negro branch of the Amazon River 21 00:02:15,953 --> 00:02:18,592 and together make up the largest collection 22 00:02:18,592 --> 00:02:20,651 of river islands in the world. 23 00:02:23,761 --> 00:02:26,481 Thousands of kilometers from the nearest ocean, 24 00:02:26,481 --> 00:02:28,669 these river islands are unique. 25 00:02:31,667 --> 00:02:33,715 Surrounded not by coral reefs 26 00:02:33,715 --> 00:02:35,907 and crystal clear waters, 27 00:02:35,907 --> 00:02:37,811 but by flooded forests 28 00:02:37,811 --> 00:02:41,477 and hidden dangers. 29 00:02:41,477 --> 00:02:44,469 This is home to some of the most unusual creatures 30 00:02:44,469 --> 00:02:47,284 in the world. 31 00:02:52,311 --> 00:02:54,610 Flooded for six months of the year, 32 00:02:54,610 --> 00:02:57,240 the islands are a mass of submerged trees 33 00:02:57,240 --> 00:02:58,980 and wandering vines. 34 00:03:01,882 --> 00:03:05,178 This is a world like no other. 35 00:03:05,178 --> 00:03:08,586 The forest floor becomes the river bed. 36 00:03:08,586 --> 00:03:12,698 Fish feed from the treetops. 37 00:03:12,698 --> 00:03:14,714 And canopy dwellers are stalked 38 00:03:14,714 --> 00:03:16,726 by creatures that lurk beneath. 39 00:03:27,564 --> 00:03:31,205 It's May and the flood waters are starting to rise. 40 00:03:36,044 --> 00:03:38,860 The lives of the animals that call the islands home 41 00:03:38,860 --> 00:03:40,504 take a dramatic turn. 42 00:03:48,658 --> 00:03:51,267 Only two primates live here, 43 00:03:51,267 --> 00:03:53,043 red howler monkeys 44 00:03:53,043 --> 00:03:55,268 and the more common squirrel monkeys, 45 00:03:55,268 --> 00:03:57,508 who have the run of the canopy. 46 00:04:16,979 --> 00:04:18,276 Because they spend much of the year 47 00:04:18,276 --> 00:04:20,260 cut off from the mainland, 48 00:04:20,260 --> 00:04:23,486 they've learned to adapt to life above the water. 49 00:04:29,043 --> 00:04:31,331 It's early morning and a large group 50 00:04:31,331 --> 00:04:34,371 is heading out on a foraging expedition. 51 00:04:40,276 --> 00:04:42,598 The monkeys make the most of the daylight hours 52 00:04:42,598 --> 00:04:44,449 as they move through the canopy. 53 00:04:54,248 --> 00:04:56,439 They're on the lookout for fruits, flowers, 54 00:04:56,439 --> 00:04:58,930 and insects that make up their diet. 55 00:05:07,160 --> 00:05:09,844 Long tails provide them with excellent balance. 56 00:05:16,138 --> 00:05:18,762 And aided by nimble hands and feet, 57 00:05:18,762 --> 00:05:21,492 they're able to investigate any opportunity. 58 00:05:31,593 --> 00:05:33,768 But the canopy offers slim pickings. 59 00:05:37,295 --> 00:05:39,823 Surrounded by water, the archipelagos 60 00:05:39,823 --> 00:05:41,903 do not support the abundance of food 61 00:05:41,903 --> 00:05:44,763 that is available to monkeys elsewhere in the Amazon. 62 00:05:53,408 --> 00:05:55,203 Some of the young males aren't impressed 63 00:05:55,203 --> 00:05:58,389 with what's on offer. 64 00:05:58,389 --> 00:06:00,758 So they decide to venture down, 65 00:06:00,758 --> 00:06:03,203 deeper inside the flooded forest. 66 00:06:13,373 --> 00:06:14,857 The rewards are worth it. 67 00:06:22,622 --> 00:06:25,294 Young monkeys have incredibly good eyesight 68 00:06:25,294 --> 00:06:26,878 and they're able to spot food 69 00:06:26,878 --> 00:06:29,081 amongst the dense vegetation with ease. 70 00:06:38,479 --> 00:06:39,914 They found a favorite. 71 00:06:48,064 --> 00:06:51,276 The Clitoria flower's sweet nectar is irresistible. 72 00:06:59,586 --> 00:07:01,891 After a frantic morning foraging, 73 00:07:01,891 --> 00:07:04,556 one of the youngsters is desperate for a drink. 74 00:07:11,954 --> 00:07:15,730 But it's a risky business. 75 00:07:15,730 --> 00:07:17,999 Black caiman lurk below. 76 00:07:23,345 --> 00:07:26,471 An alarm call alerts him to the danger, 77 00:07:26,471 --> 00:07:28,424 but he's not out of trouble yet. 78 00:07:32,025 --> 00:07:35,348 The slightest slip could be fatal for the plucky primate. 79 00:07:42,010 --> 00:07:44,458 Finally, he makes it back to the canopy, 80 00:07:44,458 --> 00:07:47,171 where he's safe for now. 81 00:07:52,795 --> 00:07:54,906 Giant reptiles are not the only predators 82 00:07:54,906 --> 00:07:57,101 patrolling these waterways. 83 00:08:02,270 --> 00:08:04,798 None has a more fearsome reputation 84 00:08:04,798 --> 00:08:06,044 than the piranha. 85 00:08:13,201 --> 00:08:15,122 Blood in the water will whip them 86 00:08:15,122 --> 00:08:16,830 into a feeding frenzy. 87 00:08:26,838 --> 00:08:28,828 These red-bellied piranhas 88 00:08:28,828 --> 00:08:30,412 could strip a monkey to the bone 89 00:08:30,412 --> 00:08:32,128 in a matter of seconds. 90 00:08:36,781 --> 00:08:39,315 Jaws filled with razor-sharp teeth 91 00:08:39,315 --> 00:08:42,456 are designed to slice off bite-sized pieces of flesh. 92 00:09:00,296 --> 00:09:02,537 As the waters continue to rise, 93 00:09:02,537 --> 00:09:04,725 many animals become cut off. 94 00:09:06,908 --> 00:09:09,515 A three-toed sloth is forced to brave 95 00:09:09,515 --> 00:09:12,326 the treacherous waters in search of a new home. 96 00:09:14,220 --> 00:09:17,430 Despite the dangers, it has no choice. 97 00:09:20,683 --> 00:09:23,019 Built for life in the treetops, 98 00:09:23,019 --> 00:09:25,493 sloths are surprisingly good swimmers. 99 00:09:28,139 --> 00:09:30,731 They paddle efficiently with their long arms 100 00:09:30,731 --> 00:09:32,540 and are able to move much faster 101 00:09:32,540 --> 00:09:33,991 than they do on land. 102 00:09:40,014 --> 00:09:42,505 But not quickly enough to go unnoticed. 103 00:09:59,488 --> 00:10:02,192 Green anaconda are always on the lookout 104 00:10:02,192 --> 00:10:03,339 for an easy meal. 105 00:10:12,578 --> 00:10:15,025 This is an opportunity too good to be missed 106 00:10:15,025 --> 00:10:17,533 for one of the forest's deadliest predators. 107 00:10:25,891 --> 00:10:28,146 Chemoreceptors on the snake's tongue 108 00:10:28,146 --> 00:10:31,181 help it track its prey's movements through the water. 109 00:10:34,659 --> 00:10:38,115 Finally, the sloth makes it to a suitable tree, 110 00:10:38,115 --> 00:10:42,197 but it's a long way to the top 111 00:10:42,197 --> 00:10:45,429 and time is against it. 112 00:10:54,504 --> 00:10:58,295 Once caught, the sloth stands no chance of escape. 113 00:11:06,348 --> 00:11:08,253 After such a big meal, 114 00:11:08,253 --> 00:11:10,413 the giant reptile will last for weeks 115 00:11:10,413 --> 00:11:13,384 or even months until it has to hunt again. 116 00:11:18,255 --> 00:11:20,974 Life on the river islands is ever-changing 117 00:11:20,974 --> 00:11:23,385 as water levels continue to rise. 118 00:11:26,351 --> 00:11:29,327 The flood waters originate hundreds of kilometers away, 119 00:11:29,327 --> 00:11:32,994 high up in the Andean peaks. 120 00:11:35,810 --> 00:11:39,202 In December, as temperatures begin to rise, 121 00:11:39,202 --> 00:11:41,754 melt water from the mountains starts to pour down 122 00:11:41,754 --> 00:11:43,956 the Amazon's many tributaries. 123 00:11:51,540 --> 00:11:56,051 They flow east and gather forces. 124 00:12:01,588 --> 00:12:03,844 These are joined by rainwater 125 00:12:03,844 --> 00:12:06,144 as the wet season begins in earnest. 126 00:12:11,340 --> 00:12:13,719 On the Rio Negro, rainfall is measured 127 00:12:13,719 --> 00:12:17,026 not in centimeters but in meters. 128 00:12:22,259 --> 00:12:25,508 The river bursts its banks and overflows, 129 00:12:25,508 --> 00:12:27,217 flooding the river islands. 130 00:12:33,673 --> 00:12:37,177 Amazingly, the rainforest creates almost half 131 00:12:37,177 --> 00:12:39,307 of the yearly rainfall itself. 132 00:12:45,261 --> 00:12:49,517 While the other half blows in from the Atlantic Ocean. 133 00:12:56,849 --> 00:12:58,576 The islands of the Anavilhanas 134 00:12:58,576 --> 00:13:01,691 and Mariua Archipelagos are transformed. 135 00:13:03,793 --> 00:13:07,184 Water penetrates for a distance of up to 20 kilometers 136 00:13:07,184 --> 00:13:09,386 on either side of the main channels. 137 00:13:14,001 --> 00:13:17,265 Whole islands disappear underwater, 138 00:13:17,265 --> 00:13:20,506 and in places, only the treetops remain. 139 00:13:34,481 --> 00:13:36,769 By June, the floodwaters have risen 140 00:13:36,769 --> 00:13:38,785 by up to 10 meters 141 00:13:38,785 --> 00:13:42,748 but there's still more to come. 142 00:13:42,748 --> 00:13:44,994 Curtains of green hide the islands' 143 00:13:44,994 --> 00:13:46,749 mysterious inner world. 144 00:13:52,035 --> 00:13:53,603 Trees and plants have developed 145 00:13:53,603 --> 00:13:55,508 a number of techniques for surviving 146 00:13:55,508 --> 00:13:57,087 their months underwater. 147 00:14:02,390 --> 00:14:04,018 Some choose to hibernate. 148 00:14:07,624 --> 00:14:09,315 Some lose all their leaves. 149 00:14:14,312 --> 00:14:16,712 And some even continue to photosynthesize 150 00:14:16,712 --> 00:14:18,042 while submerged. 151 00:14:25,980 --> 00:14:27,821 Throughout the river islands, 152 00:14:27,821 --> 00:14:29,932 animals are adapting to the new challenges 153 00:14:29,932 --> 00:14:33,758 the waters bring. 154 00:14:35,711 --> 00:14:37,951 Over two hundred species of birds 155 00:14:37,951 --> 00:14:40,957 live on the islands of the Anavilhanas Archipelago. 156 00:14:46,227 --> 00:14:50,242 While some are looking for food, 157 00:14:50,242 --> 00:14:52,124 others are looking for love. 158 00:14:56,434 --> 00:14:58,914 Living out of reach of the flood waters, 159 00:14:58,914 --> 00:15:00,754 birds are able to put all their energy 160 00:15:00,754 --> 00:15:03,282 into courtship. 161 00:15:06,692 --> 00:15:09,253 A male streak-throated hummingbird 162 00:15:09,253 --> 00:15:12,741 uses its enchanting song and simple display 163 00:15:12,741 --> 00:15:14,789 to attract potential mates. 164 00:15:23,809 --> 00:15:26,902 Although the flash of tail feathers is impressive, 165 00:15:26,902 --> 00:15:30,466 it's usually the best song that wins the female's heart. 166 00:15:44,186 --> 00:15:46,457 Deeper in the forest, another bird 167 00:15:46,457 --> 00:15:49,267 goes to even greater extremes to find a mate. 168 00:15:54,809 --> 00:15:57,948 The wire-tailed manakin. 169 00:15:57,948 --> 00:16:01,019 There are over 50 species of manakin in the world 170 00:16:01,019 --> 00:16:02,651 and the majority of these are found 171 00:16:02,651 --> 00:16:04,374 in the forests of South America. 172 00:16:10,333 --> 00:16:12,759 Stiff tail feathers give the birds their name. 173 00:16:17,389 --> 00:16:19,054 A male surveys the forest 174 00:16:19,054 --> 00:16:22,606 from his private display perch. 175 00:16:22,606 --> 00:16:24,574 He's ready to strut his stuff 176 00:16:24,574 --> 00:16:26,472 at the first sign of a female. 177 00:16:30,495 --> 00:16:32,569 It doesn't take long for one to arrive. 178 00:16:37,519 --> 00:16:40,624 But unlike most manakins, who display on their own, 179 00:16:40,624 --> 00:16:43,343 wire-tailed manakins dance in pairs 180 00:16:43,343 --> 00:16:45,929 as they attempt to win the female's affections. 181 00:16:54,512 --> 00:16:57,180 The pair take to the stage. 182 00:17:01,897 --> 00:17:03,682 It's a dance off 183 00:17:03,682 --> 00:17:05,554 and both are desperate to impress. 184 00:17:29,084 --> 00:17:32,057 The female sizes up her suitors from a distance. 185 00:17:44,866 --> 00:17:47,008 Keeping a close eye on proceedings. 186 00:18:05,525 --> 00:18:07,173 The dance comes to an end 187 00:18:07,173 --> 00:18:09,158 with a show of dominance 188 00:18:09,158 --> 00:18:12,326 and the female makes her choice. 189 00:18:12,326 --> 00:18:14,950 All the loser can do is look on 190 00:18:14,950 --> 00:18:18,454 as she leads the victor away. 191 00:18:29,704 --> 00:18:32,169 Manakins are not the only island inhabitants 192 00:18:32,169 --> 00:18:34,612 preoccupied with passing on their genes. 193 00:18:40,986 --> 00:18:42,585 Throughout the islands, 194 00:18:42,585 --> 00:18:44,745 the larger and more established trees 195 00:18:44,745 --> 00:18:46,330 have been waiting all year 196 00:18:46,330 --> 00:18:50,507 for the flood waters to arrive. 197 00:18:50,507 --> 00:18:54,193 Now, finally, they get what they've been waiting for. 198 00:19:00,154 --> 00:19:03,900 The trees use the waters to distribute their seeds 199 00:19:03,900 --> 00:19:06,307 far and wide. 200 00:19:27,939 --> 00:19:29,874 The pods of a munguba tree 201 00:19:29,874 --> 00:19:31,934 have spent the dry season maturing. 202 00:19:35,316 --> 00:19:39,237 Now they burst open in spectacular style, 203 00:19:39,237 --> 00:19:40,901 revealing seeds hidden 204 00:19:40,901 --> 00:19:42,786 amongst the giant balls of fluff. 205 00:19:48,631 --> 00:19:50,452 The seeds are scattered in the wind. 206 00:19:53,419 --> 00:19:57,380 Each is attached to a parachute to carry it on its way. 207 00:20:02,427 --> 00:20:05,466 The seeds will be transported throughout the islands, 208 00:20:05,466 --> 00:20:07,771 hopefully, germinating where they land 209 00:20:07,771 --> 00:20:09,957 and helping to maintain the forest. 210 00:20:12,859 --> 00:20:16,812 But the munguba trees need to be quick. 211 00:20:16,812 --> 00:20:19,069 Fresh food doesn't go unnoticed for long 212 00:20:19,069 --> 00:20:21,133 on these islands. 213 00:20:24,670 --> 00:20:26,477 Tui parakeets make the most 214 00:20:26,477 --> 00:20:28,458 of the freshly opened seed pods. 215 00:20:31,952 --> 00:20:33,724 The munguba tree is a favorite. 216 00:20:36,913 --> 00:20:39,298 They use their beaks to pry the seeds 217 00:20:39,298 --> 00:20:40,973 from their fluffy cocoons. 218 00:20:47,203 --> 00:20:48,868 It doesn't take long for the hungry birds 219 00:20:48,868 --> 00:20:50,237 to strip a pod. 220 00:20:53,316 --> 00:20:55,427 At this time of the year, there's more food 221 00:20:55,427 --> 00:20:56,800 than they could wish for. 222 00:21:00,581 --> 00:21:02,991 And they quickly move on to the next tree. 223 00:21:11,093 --> 00:21:12,677 Parakeets are not the only animals 224 00:21:12,677 --> 00:21:14,980 to take advantage of the fruit in trees. 225 00:21:19,705 --> 00:21:21,994 Some seeds make a break for freedom 226 00:21:21,994 --> 00:21:24,038 and float down into the forest 227 00:21:28,266 --> 00:21:31,738 where more hungry mouths lie in wait. 228 00:21:44,480 --> 00:21:47,440 While trees adapt to life in the water, 229 00:21:47,440 --> 00:21:50,274 fish adapt to life among the trees. 230 00:22:02,449 --> 00:22:05,041 South American trout, or brycon, 231 00:22:05,041 --> 00:22:08,155 leap from the water to be first to the falling seeds. 232 00:22:16,134 --> 00:22:18,697 They can jump up to four times their body length 233 00:22:18,697 --> 00:22:20,291 in their quest for food. 234 00:22:29,305 --> 00:22:32,137 Each mouthful is a priceless source of protein 235 00:22:32,137 --> 00:22:33,464 for the hungry fish. 236 00:22:52,210 --> 00:22:54,004 Even though the seeds of the munguba tree 237 00:22:54,004 --> 00:22:56,516 don't last long, some trees have learned 238 00:22:56,516 --> 00:22:58,836 to use the fish to their advantage. 239 00:23:04,980 --> 00:23:06,934 Amazonian flooded forests 240 00:23:06,934 --> 00:23:09,462 are the only place in the world where fish 241 00:23:09,462 --> 00:23:11,808 act as the major seed disbursers. 242 00:23:16,405 --> 00:23:19,782 Trees can rely on more than 200 species of fish 243 00:23:19,782 --> 00:23:21,535 to distribute their seeds. 244 00:23:40,869 --> 00:23:42,742 Many eat the fleshy fruit 245 00:23:42,742 --> 00:23:45,264 before spitting out the unpalatable seed. 246 00:23:50,086 --> 00:23:52,614 And by doing so, they help the trees 247 00:23:52,614 --> 00:23:55,488 to deposit their seeds throughout the archipelagos. 248 00:24:00,993 --> 00:24:02,855 The flooded islands are inundated 249 00:24:02,855 --> 00:24:06,295 with aquatic visitors of all different shapes and sizes. 250 00:24:13,432 --> 00:24:15,560 But despite the wealth of food, 251 00:24:15,560 --> 00:24:17,737 the islands are not always the easiest place 252 00:24:17,737 --> 00:24:18,918 for fish to live. 253 00:24:23,719 --> 00:24:26,439 The quantity of decaying leaves in the water 254 00:24:26,439 --> 00:24:28,563 means that oxygen levels are low. 255 00:24:32,393 --> 00:24:35,097 Bacteria and other microorganisms 256 00:24:35,097 --> 00:24:37,827 use up supplies as they break down the leaves. 257 00:24:41,305 --> 00:24:44,936 As more and more of the river's oxygen is used up, 258 00:24:44,936 --> 00:24:47,715 very little is left for the animals that live here. 259 00:25:02,393 --> 00:25:04,915 The electric eel is a deadly predator. 260 00:25:09,176 --> 00:25:11,513 But without a regular supply of oxygen, 261 00:25:11,513 --> 00:25:13,315 it will not be able to hunt. 262 00:25:21,016 --> 00:25:23,257 Like many fish in the black waters, 263 00:25:23,257 --> 00:25:25,811 it's forced to the surface to gulp air. 264 00:25:29,176 --> 00:25:31,225 Its mouth acts like a lung, 265 00:25:31,225 --> 00:25:33,747 absorbing oxygen from the world above. 266 00:25:43,225 --> 00:25:46,073 Another air-breather is the gigantic, 267 00:25:46,073 --> 00:25:50,172 pike-like, pirarucu. 268 00:25:50,172 --> 00:25:53,531 One of the largest known freshwater fish in the world, 269 00:25:53,531 --> 00:25:56,870 fully grown adults can weigh up to 200 kilograms. 270 00:26:01,547 --> 00:26:04,556 The three-meter-long monsters rise to the surface 271 00:26:04,556 --> 00:26:06,762 every 10 to 15 minutes to breathe. 272 00:26:09,760 --> 00:26:11,600 This armor-plated giant 273 00:26:11,600 --> 00:26:14,154 has survived for nearly 100 million years. 274 00:26:17,602 --> 00:26:20,609 The Anavilhanas and Mariua Archipelagos 275 00:26:20,609 --> 00:26:22,946 still provide a safe haven for them 276 00:26:22,946 --> 00:26:24,654 and many other creatures. 277 00:26:36,824 --> 00:26:38,793 These ancient islands were formed 278 00:26:38,793 --> 00:26:41,320 during a time of change in the Amazon 279 00:26:41,320 --> 00:26:43,155 over 1500 years ago. 280 00:26:47,193 --> 00:26:49,625 Then, the black waters of the Rio Negro 281 00:26:49,625 --> 00:26:52,932 did not flow so freely into the mighty Amazon River. 282 00:26:56,041 --> 00:26:57,779 Conditions were much calmer. 283 00:27:03,456 --> 00:27:05,947 Sediment arriving from the Rio Branco to the north 284 00:27:05,947 --> 00:27:09,404 started to settle. 285 00:27:09,404 --> 00:27:12,910 Joined by waters from the Rio Negro's upper reaches, 286 00:27:12,910 --> 00:27:15,192 pockets of forest started to form. 287 00:27:22,751 --> 00:27:25,841 They developed into the islands we see today. 288 00:27:31,698 --> 00:27:35,458 Over time, the Rio Negro once again picked up pace 289 00:27:35,458 --> 00:27:37,852 and started to flow back into the Amazon. 290 00:27:48,594 --> 00:27:51,854 The islands were left and survive to this day. 291 00:27:56,261 --> 00:27:58,005 But they wouldn't exist at all 292 00:27:58,005 --> 00:28:00,687 if weren't for the white waters of the Rio Branco. 293 00:28:04,853 --> 00:28:06,868 Where, even to this day, 294 00:28:06,868 --> 00:28:10,007 life doesn't just survive, 295 00:28:10,007 --> 00:28:11,392 it flourishes. 296 00:28:22,951 --> 00:28:25,960 One of the Rio Branco's most charismatic creatures 297 00:28:25,960 --> 00:28:27,650 is the giant river otter. 298 00:28:32,377 --> 00:28:34,771 The otters spend most of their time hunting. 299 00:28:46,889 --> 00:28:48,776 Moving as a pack, 300 00:28:48,776 --> 00:28:50,729 they're able to corral fish 301 00:28:50,729 --> 00:28:53,274 before picking them off one by one. 302 00:29:10,448 --> 00:29:12,906 Fresh fish make a fine breakfast. 303 00:29:18,400 --> 00:29:21,505 Otters need to fuel their energetic lifestyle 304 00:29:21,505 --> 00:29:23,777 and can crunch through up to four kilograms 305 00:29:23,777 --> 00:29:25,130 of fish a day. 306 00:29:28,657 --> 00:29:30,896 Catching the fish with their mouths, 307 00:29:30,896 --> 00:29:33,345 they then hold them with their forepaws 308 00:29:33,345 --> 00:29:36,266 as they devour their prey, scales and all. 309 00:29:39,857 --> 00:29:43,121 But these deadly predators have a softer side 310 00:29:43,121 --> 00:29:45,137 and when breakfast is over, 311 00:29:45,137 --> 00:29:46,428 it's time to play. 312 00:29:58,291 --> 00:30:01,298 Giant river otters live in large family groups 313 00:30:01,298 --> 00:30:04,003 and it will be some time before last year's cubs 314 00:30:04,003 --> 00:30:06,078 head off to form families of their own. 315 00:30:26,355 --> 00:30:28,686 Family life revolves around the den. 316 00:30:32,405 --> 00:30:34,101 The mother remains hidden 317 00:30:34,101 --> 00:30:36,142 while she raises the next generation. 318 00:30:40,420 --> 00:30:43,412 With several dens dotted around their territory, 319 00:30:43,412 --> 00:30:46,932 the family move regularly in the search for fish 320 00:30:46,932 --> 00:30:49,822 and to avoid unwanted attention from predators. 321 00:30:57,046 --> 00:30:58,711 Just a few months old, 322 00:30:58,711 --> 00:31:00,614 the cubs must be carried 323 00:31:00,614 --> 00:31:02,592 as they're still too young to swim. 324 00:31:07,206 --> 00:31:09,161 The family head off up river. 325 00:31:22,537 --> 00:31:24,553 Arriving at their next den, 326 00:31:24,553 --> 00:31:27,288 the first priority is to get the cubs inside 327 00:31:27,288 --> 00:31:28,420 where it's safe. 328 00:31:36,650 --> 00:31:38,394 The father keeps watch 329 00:31:38,394 --> 00:31:41,598 while his family settles into their new home. 330 00:31:49,326 --> 00:31:51,662 The males scent mark the entrance 331 00:31:51,662 --> 00:31:54,425 to warn others that they are now in residence. 332 00:31:58,416 --> 00:32:00,672 It's a pungent concoction that will keep 333 00:32:00,672 --> 00:32:02,649 even the nosiest neighbors away. 334 00:32:21,392 --> 00:32:23,279 All along the Rio Branco, 335 00:32:23,279 --> 00:32:25,882 life flourishes on the sediment-rich waters. 336 00:32:30,172 --> 00:32:34,070 The river banks are dotted with wildlife. 337 00:32:43,046 --> 00:32:46,144 Including the largest rodents in the world. 338 00:32:51,798 --> 00:32:54,118 Closely related to the guinea pig, 339 00:32:54,118 --> 00:32:57,634 capybaras are equally at home in or out of the water. 340 00:33:02,344 --> 00:33:05,186 But the wealth of animals attracts unwanted attention. 341 00:33:16,848 --> 00:33:18,958 A jaguar stalks the river bank. 342 00:33:24,148 --> 00:33:26,238 Capybaras make a tasty meal. 343 00:33:29,380 --> 00:33:31,444 The Amazon's apex predator 344 00:33:31,444 --> 00:33:34,116 is rarely found far from the river, 345 00:33:34,116 --> 00:33:36,228 and the abundance of food on the Rio Branco 346 00:33:36,228 --> 00:33:38,446 makes it an ideal hunting ground. 347 00:33:43,270 --> 00:33:46,806 When escaping dangers, the giant rodents can dive 348 00:33:46,806 --> 00:33:49,584 and remain underwater for up to five minutes. 349 00:34:09,014 --> 00:34:11,478 The jaguar stalks off silently 350 00:34:11,478 --> 00:34:13,472 to continue its search for food. 351 00:34:22,296 --> 00:34:24,023 Back on the river islands, 352 00:34:24,023 --> 00:34:26,617 the mid-morning peace is shattered. 353 00:34:35,017 --> 00:34:36,649 Red howler monkeys can be heard 354 00:34:36,649 --> 00:34:37,959 throughout the islands. 355 00:34:48,637 --> 00:34:51,100 These secretive primates don't only use 356 00:34:51,100 --> 00:34:54,157 their roaring calls to deter predators, 357 00:34:54,157 --> 00:34:57,182 they also use them to mark their territory. 358 00:35:10,338 --> 00:35:13,538 Unlike their island neighbors, the squirrel monkeys, 359 00:35:13,538 --> 00:35:15,810 they tend to travel in smaller groups 360 00:35:15,810 --> 00:35:17,869 and stick to the top of the canopy. 361 00:35:25,140 --> 00:35:27,235 Excellent acrobats, the monkeys 362 00:35:27,235 --> 00:35:29,375 rarely come down to the ground, 363 00:35:29,375 --> 00:35:32,558 and during the floods, they're even more reluctant, 364 00:35:32,558 --> 00:35:35,486 all too aware of the dangers that lurk beneath. 365 00:35:58,282 --> 00:36:02,119 It's now late July and water levels are at their peak. 366 00:36:03,005 --> 00:36:06,134 The forest floor has sunk under 15 meters of water. 367 00:36:14,237 --> 00:36:16,237 The flood waters bring about a change 368 00:36:16,237 --> 00:36:17,689 in everyone's lives. 369 00:36:23,263 --> 00:36:25,659 A colony of fire ants has been forced out 370 00:36:25,659 --> 00:36:27,249 of their underground home 371 00:36:27,249 --> 00:36:28,847 by the rising water levels, 372 00:36:33,620 --> 00:36:37,465 providing an easy meal, despite their painful sting. 373 00:36:43,339 --> 00:36:45,675 This tree will provide a safe haven 374 00:36:45,675 --> 00:36:47,547 until the waters fall 375 00:36:47,547 --> 00:36:49,508 and they can return to the forest floor. 376 00:36:53,723 --> 00:36:55,627 The resilient ants quickly move 377 00:36:55,627 --> 00:36:57,718 into a vacant crack in the bark. 378 00:37:04,477 --> 00:37:06,797 Some animals don't just survive, 379 00:37:06,797 --> 00:37:09,471 they thrive in the new conditions. 380 00:37:18,405 --> 00:37:21,359 Leaf cutter ants swarm through the trees. 381 00:37:25,941 --> 00:37:27,653 Able to carry pieces of leaf 382 00:37:27,653 --> 00:37:30,053 weighing 20 times their body weight, 383 00:37:30,053 --> 00:37:31,535 they're born to work. 384 00:37:36,373 --> 00:37:37,919 These are no ordinary ants. 385 00:37:44,277 --> 00:37:46,533 It's believed their a separate species 386 00:37:46,533 --> 00:37:48,805 to the ones who nest underground, 387 00:37:48,805 --> 00:37:50,991 and they've developed a unique behavior. 388 00:37:58,309 --> 00:38:01,119 They've swapped the forest floor for the treetops. 389 00:38:06,693 --> 00:38:09,045 By building their nests in the canopy, 390 00:38:09,045 --> 00:38:11,813 they avoid the annual floods, 391 00:38:11,813 --> 00:38:14,085 so, despite the rising waters, 392 00:38:14,085 --> 00:38:16,159 they continue undisturbed. 393 00:38:22,021 --> 00:38:25,077 Colonies can contain up to 8,000,000 individuals, 394 00:38:25,077 --> 00:38:26,966 making it one of the most dominant creatures 395 00:38:26,966 --> 00:38:28,223 in South America. 396 00:38:30,661 --> 00:38:33,423 And one of the river islands' most resilient residents. 397 00:38:36,485 --> 00:38:39,168 Worker ants are sent out to collect supplies. 398 00:38:44,086 --> 00:38:46,230 Foraging far and wide, 399 00:38:46,230 --> 00:38:48,134 they're able to find their way home 400 00:38:48,134 --> 00:38:50,193 by laying out a thermal trail. 401 00:38:54,311 --> 00:38:58,087 The pheromone is so powerful, one gram of the scent 402 00:38:58,087 --> 00:38:59,815 would be enough to lay an ant trail 403 00:38:59,815 --> 00:39:01,346 all the way around the world. 404 00:39:05,401 --> 00:39:08,402 Only the freshest and juiciest leaves are selected. 405 00:39:12,536 --> 00:39:15,943 Powerful jaws slice through the cellulose with ease. 406 00:39:27,431 --> 00:39:30,167 Once loaded up, the ants then begin their journey 407 00:39:30,167 --> 00:39:31,473 back to the nest. 408 00:39:47,495 --> 00:39:50,695 Leaf cutter ants cultivate a special fungus garden 409 00:39:50,695 --> 00:39:52,695 deep within the nest. 410 00:39:59,379 --> 00:40:02,611 And are almost entirely dependent on the fungus for food. 411 00:40:19,656 --> 00:40:21,673 Maintaining the garden is crucial 412 00:40:21,673 --> 00:40:23,331 to the survival of the colony. 413 00:40:33,193 --> 00:40:36,907 Only the queen is able to produce offspring. 414 00:40:36,907 --> 00:40:40,202 She's capable of laying thousands of eggs per day, 415 00:40:40,202 --> 00:40:42,965 most of which are destined to become workers. 416 00:41:00,907 --> 00:41:03,563 The ants are true forest specialists, 417 00:41:03,563 --> 00:41:06,107 and, out of the reach of the flood waters, 418 00:41:06,107 --> 00:41:07,783 they continue to dominate. 419 00:41:19,613 --> 00:41:21,260 Other insects have not adapted 420 00:41:21,260 --> 00:41:23,511 to their new aquatic home quite so well. 421 00:41:27,628 --> 00:41:30,540 Some are forced to venture across the water's surface 422 00:41:30,540 --> 00:41:32,134 in search of dry land. 423 00:41:36,797 --> 00:41:38,854 It's a crossing fraught with danger. 424 00:41:42,173 --> 00:41:44,119 Arowana lurk beneath. 425 00:41:49,884 --> 00:41:52,252 The fish patrol close to the surface, 426 00:41:52,252 --> 00:41:53,670 scanning for prey. 427 00:42:01,758 --> 00:42:03,272 No insect is safe. 428 00:42:07,471 --> 00:42:09,119 As the flood waters rise, 429 00:42:09,119 --> 00:42:11,386 more and more get washed into reach. 430 00:42:20,432 --> 00:42:23,216 It's a time for the arowana to fatten up 431 00:42:23,216 --> 00:42:25,819 before the long dry season returns. 432 00:42:32,277 --> 00:42:35,029 Some of the waterways' more unusual creatures 433 00:42:35,029 --> 00:42:38,095 are also taking advantage of the new food available. 434 00:42:46,182 --> 00:42:49,151 Needlefish lie just beneath surface. 435 00:42:52,966 --> 00:42:56,079 Their slim profile helps them to avoid detection. 436 00:42:59,365 --> 00:43:01,446 They hunt by sight and are ready 437 00:43:01,446 --> 00:43:03,714 to take advantage of any stragglers. 438 00:43:19,304 --> 00:43:21,570 Unlucky spiders are picked off with ease. 439 00:43:36,776 --> 00:43:39,976 Carnivorous fish are not the only underwater animals 440 00:43:39,976 --> 00:43:41,714 enjoying a glut of food. 441 00:43:44,984 --> 00:43:47,000 One of South America's largest animals 442 00:43:47,000 --> 00:43:48,466 lurks in these waters. 443 00:43:54,136 --> 00:43:57,464 The Amazonian manatee is an iconic symbol 444 00:43:57,464 --> 00:44:00,307 of the Anavilhanas and Mariua Archipelagos. 445 00:44:09,523 --> 00:44:12,259 Hiding out in the quiet backwaters, 446 00:44:12,259 --> 00:44:14,195 they gorge on the food that arrives 447 00:44:14,195 --> 00:44:15,470 with the flood waters. 448 00:44:20,260 --> 00:44:22,414 For the manatee, this is a time of plenty. 449 00:44:26,005 --> 00:44:28,031 And also a time to rear their young. 450 00:44:33,461 --> 00:44:37,429 These shy mammals give birth to a single calf 451 00:44:37,429 --> 00:44:38,943 once every two years. 452 00:44:48,276 --> 00:44:51,014 The mother will spend time teaching the youngster 453 00:44:51,014 --> 00:44:53,969 the best routes through the maze of river channels. 454 00:44:58,982 --> 00:45:02,407 The calf will need all its mothers knowledge and support 455 00:45:02,407 --> 00:45:04,609 with the dry season fast approaching. 456 00:45:21,320 --> 00:45:22,872 It's now August 457 00:45:22,872 --> 00:45:25,027 and the rainy season is coming to an end. 458 00:45:27,752 --> 00:45:30,067 Water levels are finally starting to fall. 459 00:45:34,408 --> 00:45:37,544 The animals and plants that have survived the floods 460 00:45:37,544 --> 00:45:39,747 can look forward to drier times ahead. 461 00:45:43,720 --> 00:45:46,361 Eking out a living on the ever-changing islands 462 00:45:46,361 --> 00:45:48,184 can be a challenge, 463 00:45:48,184 --> 00:45:50,851 but there are always ways and means of doing so. 464 00:45:53,672 --> 00:45:55,704 As the flood waters start to fall, 465 00:45:55,704 --> 00:45:57,960 spectacular fish begin to appear 466 00:45:57,960 --> 00:46:01,470 in the shallows of the forest. 467 00:46:01,470 --> 00:46:03,658 Cardinal tetras are found deep in the heart 468 00:46:03,658 --> 00:46:05,973 of palm forests along the black waters 469 00:46:05,973 --> 00:46:07,262 of the Rio Negro. 470 00:46:19,851 --> 00:46:21,826 This family makes the eight-hour round trip 471 00:46:21,826 --> 00:46:23,697 from their village each day 472 00:46:23,697 --> 00:46:25,692 in order to gather the tiny fish. 473 00:47:01,369 --> 00:47:04,058 Their catch is destined for exotic fish tanks 474 00:47:04,058 --> 00:47:05,657 around the world 475 00:47:05,657 --> 00:47:08,532 and provides the family with a vital source of income. 476 00:47:18,297 --> 00:47:22,458 Come midday, it's time to head back to the village. 477 00:47:41,221 --> 00:47:44,169 On their return, the fish are quickly sorted. 478 00:47:48,075 --> 00:47:50,363 The highly prized cardinal tetras 479 00:47:50,363 --> 00:47:52,852 are separated and piled into boxes. 480 00:47:57,851 --> 00:48:00,980 A thousand fish sells for around five dollars. 481 00:48:04,059 --> 00:48:06,235 A decent income, but the family supplements 482 00:48:06,235 --> 00:48:07,812 by hunting and fishing. 483 00:48:15,243 --> 00:48:17,307 Once the morning's work is done, 484 00:48:17,307 --> 00:48:19,301 the pace of village life slows. 485 00:48:37,702 --> 00:48:41,223 By the end of September, the heavy rains cease 486 00:48:41,223 --> 00:48:43,271 and the water engulfing the river islands 487 00:48:43,271 --> 00:48:45,265 has fallen by almost a third. 488 00:48:53,895 --> 00:48:57,947 As the levels drop, beaches reappear. 489 00:48:57,947 --> 00:49:00,908 For many, life starts to become easier. 490 00:49:06,434 --> 00:49:09,180 Butterflies feed on freshly exposed land. 491 00:49:16,066 --> 00:49:18,055 Migrant birds return to nest. 492 00:49:24,604 --> 00:49:27,772 Newly exposed plants burst back into life 493 00:49:27,772 --> 00:49:29,093 with a flush of green. 494 00:49:33,324 --> 00:49:34,844 Squirrel monkeys are less fearful 495 00:49:34,844 --> 00:49:37,723 of the world below as the retreating flood waters 496 00:49:37,723 --> 00:49:39,445 lead the dangers away. 497 00:49:47,240 --> 00:49:49,538 Which is also good news for the sloths. 498 00:49:56,535 --> 00:49:59,143 But for the islands' wet season visitors, 499 00:49:59,143 --> 00:50:00,605 it's time to move out. 500 00:50:03,716 --> 00:50:05,604 The manatee mother and calf 501 00:50:05,604 --> 00:50:07,677 have feasted for the past four months. 502 00:50:10,484 --> 00:50:13,556 They must now prepare to return to the main channels 503 00:50:13,556 --> 00:50:15,725 and begin their dry season fast. 504 00:50:20,180 --> 00:50:22,180 And fish are also forced to leave 505 00:50:22,180 --> 00:50:24,211 the islands' flooded forest 506 00:50:24,211 --> 00:50:26,549 and return to the deeper river channels. 507 00:50:42,693 --> 00:50:45,526 The Anivilhanas and Mariua Archipelagos 508 00:50:45,526 --> 00:50:49,164 spread along a 1,000 kilometer stretch of the Rio Negro. 509 00:50:55,105 --> 00:50:57,841 They provide a home for some of the hardiest animals 510 00:50:57,841 --> 00:50:58,855 in the world. 511 00:51:12,749 --> 00:51:15,725 As flood waters engulf the islands each year, 512 00:51:15,725 --> 00:51:17,645 those that live here are forced to endure 513 00:51:17,645 --> 00:51:19,287 incredible extremes. 514 00:51:24,541 --> 00:51:27,085 But animals have developed ways of coping 515 00:51:27,085 --> 00:51:30,134 and have learned to master their ever-changing environment. 516 00:51:35,229 --> 00:51:37,340 It's either sink or swim 517 00:51:37,340 --> 00:51:39,969 here in the floating forests of the Amazon.