1 00:00:03,860 --> 00:00:05,900 From high in space, 2 00:00:05,900 --> 00:00:09,540 we can see the familiar shapes of countries... 3 00:00:11,660 --> 00:00:13,540 ..and continents. 4 00:00:18,100 --> 00:00:20,700 But now, satellite images 5 00:00:20,700 --> 00:00:22,540 allow us to look closer... 6 00:00:27,700 --> 00:00:31,740 ..revealing our planet as a patchwork 7 00:00:31,740 --> 00:00:34,140 of extraordinary landscapes... 8 00:00:39,500 --> 00:00:42,020 ..created by natural forces... 9 00:00:50,220 --> 00:00:51,980 ..by animals... 10 00:00:59,100 --> 00:01:00,940 ..and by us. 11 00:01:04,020 --> 00:01:08,660 These patterns give an insight into the health of our planet. 12 00:01:12,740 --> 00:01:15,340 Behind every line and every pattern... 13 00:01:17,380 --> 00:01:19,420 ..there's a story. 14 00:01:38,220 --> 00:01:39,540 Around the world... 15 00:01:40,580 --> 00:01:44,820 ..tropical coastlines are fringed with coral reefs. 16 00:01:48,700 --> 00:01:51,220 At first glance, 17 00:01:51,220 --> 00:01:53,420 their shapes seem random. 18 00:02:01,420 --> 00:02:04,620 But a closer look reveals a pattern... 19 00:02:08,900 --> 00:02:12,620 ..pale discs surrounding patches of dark coral. 20 00:02:15,460 --> 00:02:17,740 Using satellite images, 21 00:02:17,740 --> 00:02:20,340 scientists have now found these shapes 22 00:02:20,340 --> 00:02:22,460 on coral reefs across the globe. 23 00:02:32,380 --> 00:02:34,740 Understanding how they are formed 24 00:02:34,740 --> 00:02:38,220 offers a new insight into the health of our oceans... 25 00:02:43,540 --> 00:02:46,820 ..and the animals that call them home. 26 00:03:01,620 --> 00:03:06,500 For fish that live on coral reefs, there are different strategies 27 00:03:06,500 --> 00:03:08,540 for finding food. 28 00:03:10,140 --> 00:03:12,380 Some stay close to the reef... 29 00:03:13,580 --> 00:03:16,660 ..feeding from the coral itself. 30 00:03:23,340 --> 00:03:25,380 Others venture out 31 00:03:25,380 --> 00:03:27,380 to the surrounding seabed. 32 00:03:32,260 --> 00:03:34,100 But feeding in the open... 33 00:03:35,380 --> 00:03:37,140 ..can be dangerous. 34 00:03:40,820 --> 00:03:44,820 Predators, like coral groupers... 35 00:03:47,340 --> 00:03:49,460 ..and sharks, 36 00:03:49,460 --> 00:03:52,780 patrol the reef perimeter. 37 00:03:55,700 --> 00:04:00,300 So small fish only feed as far from the coral 38 00:04:00,300 --> 00:04:03,380 as is absolutely necessary... 39 00:04:04,980 --> 00:04:08,220 ..staying within easy reach of safety. 40 00:04:18,820 --> 00:04:25,300 Over time, the seabed around each patch of coral is stripped of food... 41 00:04:27,940 --> 00:04:31,980 ..creating rings of bare sand 42 00:04:31,980 --> 00:04:35,740 that scientists call grazing halos. 43 00:04:41,700 --> 00:04:47,420 They are a sign that both predator and prey populations are healthy. 44 00:04:49,020 --> 00:04:51,980 But where this pattern disappears, 45 00:04:51,980 --> 00:04:55,420 it may be a sign that predator numbers are falling. 46 00:04:58,980 --> 00:05:01,900 These halos now allow scientists 47 00:05:01,900 --> 00:05:06,500 to monitor the reefs' delicate balance from space. 48 00:05:12,860 --> 00:05:17,060 Satellite cameras can now look down on every part of our planet... 49 00:05:18,140 --> 00:05:21,940 ..allowing us to explore Earth's most remote habitats. 50 00:05:27,860 --> 00:05:30,900 The Congo jungle in central Africa. 51 00:05:32,940 --> 00:05:36,780 This forest is home to thousands of animal species. 52 00:05:37,860 --> 00:05:43,580 But from space, it appears as little more than a blanket of green... 53 00:05:52,260 --> 00:05:58,300 ..except, that is, if we look down over one remote corner. 54 00:06:02,220 --> 00:06:06,420 Satellite images reveal a strange shape... 55 00:06:11,740 --> 00:06:15,780 ..with dozens of trails leading in from the surrounding forest. 56 00:06:19,420 --> 00:06:24,460 This shape was created by the Congo's mightiest residents. 57 00:06:36,340 --> 00:06:40,380 They spend most of their lives hidden in the thick jungle... 58 00:06:44,220 --> 00:06:49,020 ..but travel hundreds of kilometres to gather here. 59 00:06:50,420 --> 00:06:52,540 Forest elephants. 60 00:06:59,580 --> 00:07:03,100 ELEPHANTS TRUMPET 61 00:07:05,540 --> 00:07:09,180 Locals call this place Dzanga Bai... 62 00:07:13,460 --> 00:07:16,500 ..the Village of Elephants. 63 00:07:38,100 --> 00:07:43,540 Forest elephants spend most of their lives in small family groups. 64 00:07:46,020 --> 00:07:50,220 But here, up to 150 individuals 65 00:07:50,220 --> 00:07:52,940 are drawn together every day. 66 00:07:58,420 --> 00:08:02,420 Their diet of tough leaves and jungle fruit is lacking 67 00:08:02,420 --> 00:08:04,260 in vital minerals. 68 00:08:07,620 --> 00:08:12,140 So generations of elephants have come to this one spot in the forest... 69 00:08:16,780 --> 00:08:20,820 ..where deposits of sodium, potassium and calcium 70 00:08:20,820 --> 00:08:23,140 lie just below the surface. 71 00:08:26,380 --> 00:08:30,900 Using their tusks to dig at the soil 72 00:08:30,900 --> 00:08:34,300 and their trunks to blow into the water... 73 00:08:37,420 --> 00:08:41,820 ..these elephants have excavated a network of boreholes... 74 00:08:45,540 --> 00:08:50,380 ..allowing them to extract these minerals from under ground. 75 00:09:02,540 --> 00:09:05,820 Over hundreds of years, the constant digging 76 00:09:05,820 --> 00:09:09,860 and movement of elephants has caused this clearing to grow. 77 00:09:13,500 --> 00:09:15,460 ELEPHANT TRUMPETS 78 00:09:15,460 --> 00:09:18,620 It's now more than 500 metres long... 79 00:09:20,500 --> 00:09:23,900 ..and clearly visible from space. 80 00:09:35,300 --> 00:09:39,260 For a young forest elephant, a first visit to the Bai 81 00:09:39,260 --> 00:09:41,540 is full of new experiences. 82 00:09:48,020 --> 00:09:50,860 While the adults drink effortlessly... 83 00:09:53,060 --> 00:09:56,580 ..she's still getting to grips with her trunk. 84 00:10:07,740 --> 00:10:11,540 Infants are raised by their mothers for up to four years... 85 00:10:15,300 --> 00:10:18,220 ..and learning how to drink from these wells 86 00:10:18,220 --> 00:10:20,700 is one of life's vital lessons. 87 00:10:27,900 --> 00:10:30,820 For a calf who spends most of her time with her mother... 88 00:10:34,020 --> 00:10:38,220 ..this is a rare opportunity to socialise. 89 00:10:48,820 --> 00:10:52,900 Relationships formed at this young age can last a lifetime. 90 00:11:02,900 --> 00:11:04,980 But while they play... 91 00:11:06,540 --> 00:11:09,580 ..mothers must keep a close watch. 92 00:11:10,540 --> 00:11:12,540 DEEP TRUMPETING 93 00:11:19,300 --> 00:11:23,100 Male forest elephants are also drawn here. 94 00:11:24,980 --> 00:11:29,180 This gathering is the ideal place to find a fertile female. 95 00:11:34,140 --> 00:11:36,540 To display their size and strength... 96 00:11:38,500 --> 00:11:41,020 ..bull elephants charge around the clearing. 97 00:11:53,620 --> 00:11:55,860 And if more than one male appears... 98 00:11:58,100 --> 00:12:00,300 ..tensions run high. 99 00:12:20,220 --> 00:12:24,860 Young forest elephants have been killed here by charging males. 100 00:12:30,620 --> 00:12:32,780 TRUMPETING 101 00:12:39,620 --> 00:12:42,940 Mother retreats to the safety of the forest. 102 00:12:48,260 --> 00:12:50,500 Her baby should be able to return 103 00:12:50,500 --> 00:12:53,340 to this clearing throughout its lifetime. 104 00:12:57,820 --> 00:13:00,980 But these elephants face an uncertain future. 105 00:13:06,540 --> 00:13:08,900 In the last 20 years, 106 00:13:08,900 --> 00:13:12,380 more than half of all the forest elephants in the world 107 00:13:12,380 --> 00:13:16,060 have been killed by poachers for their ivory. 108 00:13:20,300 --> 00:13:23,380 But cameras in space may be able to help. 109 00:13:26,660 --> 00:13:29,900 Scientists can now use satellite images 110 00:13:29,900 --> 00:13:32,940 to identify other clearings used by forest elephants... 111 00:13:36,460 --> 00:13:38,620 ..protecting them from poachers... 112 00:13:40,220 --> 00:13:43,700 ..and preserving these unique gatherings. 113 00:13:56,940 --> 00:13:59,340 But you don't need to be as big as an elephant 114 00:13:59,340 --> 00:14:02,020 to make a mark visible from space. 115 00:14:06,420 --> 00:14:08,460 In South Australia, 116 00:14:08,460 --> 00:14:12,740 the outback is speckled with mysterious light patches... 117 00:14:16,620 --> 00:14:19,780 ..interlinked with narrow trails... 118 00:14:23,540 --> 00:14:27,460 ..the work of an unlikely architect. 119 00:14:35,420 --> 00:14:38,540 He's a southern hairy-nosed wombat... 120 00:14:44,620 --> 00:14:48,260 ..a marsupial only found in this part of Australia. 121 00:14:55,620 --> 00:14:58,060 Exposing the thinner fur of his belly 122 00:14:58,060 --> 00:15:02,700 helps to keep him cool as he waits for the midday heat to pass. 123 00:15:10,220 --> 00:15:13,260 Then there's work to be done. 124 00:15:21,380 --> 00:15:23,580 It's springtime, 125 00:15:23,580 --> 00:15:27,820 and with each passing day temperatures are steadily rising. 126 00:15:30,140 --> 00:15:32,060 In just a few weeks, 127 00:15:32,060 --> 00:15:35,180 it could be close to 50 degrees Celsius. 128 00:15:39,980 --> 00:15:42,500 Wrapped in a thick fur coat, 129 00:15:42,500 --> 00:15:44,900 this heat could be deadly. 130 00:15:50,420 --> 00:15:53,220 But the wombat has a solution. 131 00:15:55,460 --> 00:15:59,380 With sharp claws and short, powerful limbs, 132 00:15:59,380 --> 00:16:01,900 he's built for digging. 133 00:16:19,900 --> 00:16:23,580 It's 15 degrees cooler below ground... 134 00:16:23,580 --> 00:16:27,420 ..a hiding place from the worst of the summer sun. 135 00:16:32,300 --> 00:16:36,380 But high temperatures aren't the only threat wombats face. 136 00:16:36,380 --> 00:16:40,900 Habitat loss and the impact of invasive species 137 00:16:40,900 --> 00:16:45,260 caused wombat numbers to plummet in the early 20th century. 138 00:16:48,580 --> 00:16:52,940 But now, using satellite images to locate their burrows... 139 00:16:54,980 --> 00:16:58,300 ..scientists can see they're bouncing back... 140 00:17:02,020 --> 00:17:05,460 ..with around one million southern hairy-nosed wombats 141 00:17:05,460 --> 00:17:08,260 now living in this corner of Australia. 142 00:17:23,140 --> 00:17:25,340 In South America, 143 00:17:25,340 --> 00:17:29,980 vast areas are covered with lush, green tropical forest. 144 00:17:33,300 --> 00:17:36,300 But on the coast of north-east Brazil, 145 00:17:36,300 --> 00:17:40,340 the forest is interrupted by a very different landscape. 146 00:17:51,340 --> 00:17:55,940 Vegetation is being swallowed up by sand. 147 00:18:01,300 --> 00:18:06,540 Washed up by the ocean and blown inland over thousands of years... 148 00:18:11,100 --> 00:18:16,620 ..a field of sand dunes covering more than 800 square kilometres. 149 00:18:20,540 --> 00:18:23,380 The Lencois Maranhenses. 150 00:18:27,660 --> 00:18:30,620 The surface of the scorched sand 151 00:18:30,620 --> 00:18:33,300 can reach 80 degrees Celsius. 152 00:18:37,060 --> 00:18:41,060 To survive here you have to be made of tough stuff. 153 00:18:46,380 --> 00:18:49,980 A Pininga turtle. 154 00:18:49,980 --> 00:18:53,860 She's left the surrounding forest behind... 155 00:18:54,980 --> 00:18:59,420 ..and is making her way into the heart of this desert... 156 00:19:06,660 --> 00:19:08,700 ..walking for days 157 00:19:08,700 --> 00:19:10,700 beneath the burning sun... 158 00:19:21,140 --> 00:19:26,540 ..each step on the soft sand sapping away her precious energy. 159 00:19:32,020 --> 00:19:35,300 Without food and water, she won't survive for long. 160 00:19:42,660 --> 00:19:45,460 But she's made this journey for a reason. 161 00:19:46,860 --> 00:19:49,060 THUNDER RUMBLES 162 00:19:52,580 --> 00:19:54,580 It's the wet season. 163 00:20:04,740 --> 00:20:06,780 And in these dunes, 164 00:20:06,780 --> 00:20:10,020 the rain changes everything. 165 00:20:26,780 --> 00:20:31,660 Only from space can we see the scale of the transformation. 166 00:20:33,820 --> 00:20:37,260 Once a year, rainwater floods the desert... 167 00:20:48,340 --> 00:20:51,660 ..forming thousands of freshwater lagoons. 168 00:21:04,220 --> 00:21:09,180 Beneath the sand, a layer of solid rock stops rainwater escaping... 169 00:21:17,660 --> 00:21:19,100 ..creating a landscape 170 00:21:19,100 --> 00:21:22,140 like nowhere else on Earth. 171 00:21:29,500 --> 00:21:31,820 And that's just what she came for. 172 00:21:46,740 --> 00:21:48,420 As the lagoons grow, 173 00:21:48,420 --> 00:21:52,220 fish make their way into the pools from surrounding rivers. 174 00:21:57,660 --> 00:22:00,540 They'll keep her fed for weeks. 175 00:22:07,860 --> 00:22:10,500 But this water won't last forever. 176 00:22:14,100 --> 00:22:18,420 In the tropical sun, these lagoons will soon evaporate. 177 00:22:27,820 --> 00:22:32,460 Dozens of desert species now race 178 00:22:32,460 --> 00:22:35,940 to make the most of the life-giving water... 179 00:22:37,940 --> 00:22:41,380 ..even after the sun has set. 180 00:22:56,220 --> 00:22:59,060 A tiny four-eyed frog. 181 00:23:01,100 --> 00:23:04,100 He's been lying dormant in the cool sand. 182 00:23:08,540 --> 00:23:11,620 But the rains have triggered the breeding season. 183 00:23:15,140 --> 00:23:18,140 And there are thousands just like him. 184 00:23:23,420 --> 00:23:25,060 In other parts of the world, 185 00:23:25,060 --> 00:23:29,220 frogs migrate for kilometres to reach their breeding pools. 186 00:23:30,780 --> 00:23:34,340 But here, the water has come to them. 187 00:23:40,500 --> 00:23:44,580 Around the lagoons, grasses have sprung up, 188 00:23:44,580 --> 00:23:47,580 creating sheltered spots for breeding. 189 00:23:55,900 --> 00:23:58,940 And it's not only four-eyed frogs who come here. 190 00:24:02,500 --> 00:24:05,700 Seven different species of frogs and toads 191 00:24:05,700 --> 00:24:07,900 are all hoping to breed. 192 00:24:10,620 --> 00:24:13,300 CROAKS 193 00:24:16,260 --> 00:24:18,500 ANIMALS AND BIRDS CALL 194 00:24:20,620 --> 00:24:24,500 It's a struggle to make yourself heard above the noise. 195 00:24:32,700 --> 00:24:36,540 Eventually, the four-eyed frogs find each other. 196 00:24:42,180 --> 00:24:46,300 Each pair may produce more than a thousand eggs... 197 00:24:52,220 --> 00:24:54,620 ..an explosion of new life. 198 00:24:57,700 --> 00:24:59,780 And just in time. 199 00:25:11,740 --> 00:25:16,140 When the rains ease, the lagoons begin to disappear... 200 00:25:20,460 --> 00:25:25,100 ..and sand reclaims this corner of Brazil. 201 00:25:33,460 --> 00:25:37,580 Around the world, the forces of nature 202 00:25:37,580 --> 00:25:41,340 create mysterious and intriguing patterns 203 00:25:41,340 --> 00:25:44,340 visible only from space. 204 00:25:47,660 --> 00:25:51,740 Star-like shapes in the Sahara desert 205 00:25:51,740 --> 00:25:54,620 are sand dunes whipped up by the wind. 206 00:25:59,700 --> 00:26:04,180 In West Africa, a ring of concentric circles... 207 00:26:05,340 --> 00:26:09,180 ..formed by magma forcing its way through the Earth's crust. 208 00:26:14,820 --> 00:26:17,300 And in Iran's salt desert, 209 00:26:17,300 --> 00:26:21,540 these abstract swirls are the remains of an ancient ocean... 210 00:26:23,620 --> 00:26:28,060 ..sculpted by the wind over millions of years. 211 00:26:38,220 --> 00:26:41,260 In the Amazon rainforest, hundreds 212 00:26:41,260 --> 00:26:44,180 of rivers wind through the jungle. 213 00:26:54,540 --> 00:26:55,900 Alongside them... 214 00:26:57,340 --> 00:27:01,180 ..are strange arcs and horseshoe shapes. 215 00:27:08,100 --> 00:27:11,460 Satellite images taken over 30 years 216 00:27:11,460 --> 00:27:14,180 reveal how these patterns are formed. 217 00:27:23,140 --> 00:27:25,940 As the water forges a path through the jungle... 218 00:27:27,100 --> 00:27:31,900 ..bends in the river are cut off and left behind... 219 00:27:43,940 --> 00:27:48,020 ..creating isolated oxbow lakes... 220 00:27:52,380 --> 00:27:55,460 ..like El Dorado Lake in northern Peru. 221 00:28:00,900 --> 00:28:03,580 A special place for wildlife 222 00:28:03,580 --> 00:28:06,180 and for local people. 223 00:28:10,860 --> 00:28:13,060 CHILD CHATTERS 224 00:28:22,420 --> 00:28:24,660 Elvira is nine years old. 225 00:28:29,780 --> 00:28:32,980 She and her friends live in a small village 226 00:28:32,980 --> 00:28:34,820 close to the oxbow lake. 227 00:28:38,100 --> 00:28:41,900 They're fascinated by animals... 228 00:28:43,860 --> 00:28:47,700 ..and their favourite is perhaps the most elusive... 229 00:28:48,820 --> 00:28:51,460 ..the Amazonian manatee. 230 00:28:54,140 --> 00:28:56,580 Manatees spend their lives hidden 231 00:28:56,580 --> 00:28:58,980 in the murky water of jungle rivers... 232 00:29:06,260 --> 00:29:09,860 ..surfacing only briefly to take a breath 233 00:29:09,860 --> 00:29:11,980 or to feed on floating plants. 234 00:29:17,940 --> 00:29:22,460 In many parts of the Amazon, manatees are hunted for their meat, 235 00:29:22,460 --> 00:29:25,780 and their numbers are declining. 236 00:29:31,300 --> 00:29:34,780 Elvira has never laid eyes on a manatee. 237 00:29:39,100 --> 00:29:40,820 ELVIRA: Vamos, chicas! 238 00:29:46,220 --> 00:29:48,460 But that's all about to change. 239 00:29:59,140 --> 00:30:02,020 The oxbow lake has all the benefits of a river... 240 00:30:07,500 --> 00:30:11,900 ..but its isolated waters are still and safe... 241 00:30:18,100 --> 00:30:23,660 ..perfect for manatees in need of a second chance. 242 00:30:37,100 --> 00:30:39,420 TRANSLATION: 243 00:30:51,340 --> 00:30:54,180 For Elvira, it's an opportunity 244 00:30:54,180 --> 00:30:56,380 to finally come face-to-face 245 00:30:56,380 --> 00:30:59,460 with her favourite animal. 246 00:31:11,660 --> 00:31:15,100 This manatee is one of a lucky few. 247 00:31:19,140 --> 00:31:22,700 They were rescued from illegal captivity and rehabilitated 248 00:31:22,700 --> 00:31:25,860 by an international team of experts. 249 00:31:28,700 --> 00:31:30,740 They're now fit and well enough 250 00:31:30,740 --> 00:31:32,580 to be released. 251 00:31:37,860 --> 00:31:41,940 Radio tags will allow their progress to be monitored... 252 00:31:47,420 --> 00:31:52,060 ..as they start their new life in the safety of the oxbow lake. 253 00:32:15,940 --> 00:32:20,020 The twists and turns that lead to oxbow lakes 254 00:32:20,020 --> 00:32:25,100 are typical of slow jungle rivers meandering over flat ground. 255 00:32:37,140 --> 00:32:40,780 But across the globe, each river 256 00:32:40,780 --> 00:32:43,260 has its own unique character. 257 00:32:49,380 --> 00:32:54,620 In Egypt, the River Nile brings life to the desert... 258 00:32:56,660 --> 00:32:58,860 ..creating a ribbon of green. 259 00:33:07,420 --> 00:33:10,500 At the base of the Himalayas, 260 00:33:10,500 --> 00:33:15,300 the Brahmaputra River pulls in water from hundreds of streams 261 00:33:15,300 --> 00:33:16,980 pouring out of the mountains... 262 00:33:18,460 --> 00:33:22,380 ..creating a complex channel 10km wide. 263 00:33:28,420 --> 00:33:32,380 In the USA, the movement of Utah's Green River 264 00:33:32,380 --> 00:33:35,100 has carved out deep canyons 265 00:33:35,100 --> 00:33:37,460 over millions of years. 266 00:33:44,500 --> 00:33:46,100 In eastern China... 267 00:33:47,380 --> 00:33:50,020 ..five major rivers converge... 268 00:33:52,820 --> 00:33:56,620 ..to form a body of fresh water so huge 269 00:33:56,620 --> 00:34:01,180 that the only way to see it in its entirety is from space. 270 00:34:06,100 --> 00:34:07,940 Poyang Lake. 271 00:34:12,220 --> 00:34:14,500 This is no ordinary lake. 272 00:34:18,740 --> 00:34:21,860 Each year, when the dry season arrives... 273 00:34:23,820 --> 00:34:26,020 ..it begins to shrink. 274 00:34:32,340 --> 00:34:37,780 Within three months, it almost totally disappears... 275 00:34:43,740 --> 00:34:48,140 ..leaving behind huge areas of nutrient-rich mud... 276 00:34:57,340 --> 00:35:01,260 ..and hundreds of shallow freshwater pools. 277 00:35:11,980 --> 00:35:15,660 This transformation is the cue 278 00:35:15,660 --> 00:35:20,620 for one of the greatest migrations on our planet. 279 00:35:26,700 --> 00:35:31,260 Half a million birds flock here from all across Asia. 280 00:35:38,140 --> 00:35:40,820 But none have travelled further 281 00:35:40,820 --> 00:35:44,020 than the critically endangered Siberian cranes. 282 00:35:46,100 --> 00:35:50,940 This is the end of a month-long journey from northern Russia, 283 00:35:50,940 --> 00:35:54,540 almost 5,000 kilometres away. 284 00:36:04,740 --> 00:36:08,620 They've come for a unique feeding opportunity. 285 00:36:08,620 --> 00:36:10,460 BIRDS CALL 286 00:36:16,300 --> 00:36:18,740 The falling water has revealed 287 00:36:18,740 --> 00:36:21,660 the nutritious roots of aquatic plants. 288 00:36:25,100 --> 00:36:29,540 The cranes gorge themselves after their long journey. 289 00:36:31,380 --> 00:36:33,980 And they aren't interested in sharing. 290 00:36:39,660 --> 00:36:41,540 Among the many families 291 00:36:41,540 --> 00:36:44,860 are two parents with their five-month-old offspring. 292 00:36:52,180 --> 00:36:55,540 He's successfully completed his first migration. 293 00:36:57,980 --> 00:37:01,820 But 5,000 kilometres was a long way to fly 294 00:37:01,820 --> 00:37:03,260 on young wings. 295 00:37:07,780 --> 00:37:09,660 He begs for food. 296 00:37:13,700 --> 00:37:15,300 But his mother... 297 00:37:16,220 --> 00:37:18,180 ..ignores him. 298 00:37:20,500 --> 00:37:22,740 It's every bird for themself. 299 00:37:29,220 --> 00:37:30,660 And from space, 300 00:37:30,660 --> 00:37:32,500 it's clear to see why. 301 00:37:33,780 --> 00:37:36,940 As the dry season progresses, the pools shrink... 302 00:37:39,380 --> 00:37:42,860 ..increasing competition for the best feeding spots. 303 00:37:44,660 --> 00:37:46,420 BIRDS CALL 304 00:37:48,180 --> 00:37:51,180 A rival has strayed onto the family's patch. 305 00:37:55,420 --> 00:37:58,820 This cannot go unchallenged. 306 00:38:09,060 --> 00:38:11,700 Father squares up to the intruder. 307 00:38:16,820 --> 00:38:19,620 Neither is willing to back down. 308 00:38:34,260 --> 00:38:36,620 Their claws are razor-sharp. 309 00:38:43,980 --> 00:38:46,220 15-centimetre-long beaks 310 00:38:46,220 --> 00:38:48,140 become weapons. 311 00:39:26,020 --> 00:39:27,860 The intruder... 312 00:39:27,860 --> 00:39:29,700 ..is seen off. 313 00:39:42,780 --> 00:39:46,500 But the youngster still hasn't been able to get a meal. 314 00:39:50,220 --> 00:39:52,580 There's only one thing for it. 315 00:39:59,780 --> 00:40:03,620 He finally works out how to feed for himself. 316 00:40:06,740 --> 00:40:10,100 The whole family can now fuel up for the return journey 317 00:40:10,100 --> 00:40:11,940 to Siberia. 318 00:40:19,500 --> 00:40:24,540 After four months, the rivers that flow into Poyang begin to rise again... 319 00:40:30,660 --> 00:40:33,700 ..and the cranes start the long flight home. 320 00:40:37,980 --> 00:40:39,180 An epic journey... 321 00:40:40,980 --> 00:40:44,580 ..triggered by a remarkable transformation. 322 00:40:55,060 --> 00:40:57,700 The coming and going of water 323 00:40:57,700 --> 00:41:01,620 makes for some of the most beautiful landscapes on Earth. 324 00:41:09,420 --> 00:41:12,300 Rivers arriving at the coast 325 00:41:12,300 --> 00:41:14,860 deposit vast quantities of sediment... 326 00:41:21,020 --> 00:41:24,060 ..creating deltas that reach out 327 00:41:24,060 --> 00:41:25,460 into the ocean. 328 00:41:29,500 --> 00:41:30,900 In northern Russia, 329 00:41:30,900 --> 00:41:34,780 the Lena River forks into thousands of separate channels. 330 00:41:40,900 --> 00:41:43,020 And in the Gulf of Mexico, 331 00:41:43,020 --> 00:41:45,420 the Mississippi River Delta 332 00:41:45,420 --> 00:41:48,580 spans 10,000 square kilometres. 333 00:41:53,660 --> 00:41:56,940 But the largest delta in the world 334 00:41:56,940 --> 00:41:59,620 lies in the Bay of Bengal. 335 00:42:01,220 --> 00:42:03,060 This maze of waterways 336 00:42:03,060 --> 00:42:04,900 is the Sundarbans. 337 00:42:06,940 --> 00:42:11,020 Twice a day, it's transformed by the tide... 338 00:42:14,380 --> 00:42:15,780 ..blue... 339 00:42:19,100 --> 00:42:20,900 ..to brown... 340 00:42:22,180 --> 00:42:24,020 ..as the tide falls, 341 00:42:24,020 --> 00:42:26,460 exposing the mud below. 342 00:42:33,380 --> 00:42:37,460 Silt from river water is trapped by mangrove roots... 343 00:42:38,420 --> 00:42:41,460 ..creating a habitat like no other. 344 00:42:44,700 --> 00:42:46,940 A home for timid chital deer... 345 00:42:48,380 --> 00:42:50,780 ..troops of macaques... 346 00:42:54,660 --> 00:42:57,140 ..elusive Bengal tigers... 347 00:42:58,300 --> 00:43:00,540 ..and over three million... 348 00:43:02,180 --> 00:43:04,420 ..people. 349 00:43:08,700 --> 00:43:12,180 Bhoben and his son Hridoy live 350 00:43:12,180 --> 00:43:14,380 in the north of the Sundarbans. 351 00:43:29,580 --> 00:43:31,820 Bhoben is a fisherman. 352 00:43:33,500 --> 00:43:36,300 He's teaching his son the family trade. 353 00:43:41,460 --> 00:43:44,420 But they won't be fishing with lines or poles. 354 00:43:48,500 --> 00:43:50,940 Instead, they'll be using 355 00:43:50,940 --> 00:43:54,180 ten smooth-coated otters. 356 00:44:00,060 --> 00:44:02,900 The people here have been fishing together with otters 357 00:44:02,900 --> 00:44:05,580 since the sixth century. 358 00:44:05,580 --> 00:44:10,260 Wild otter populations are declining in the Sundarbans. 359 00:44:10,260 --> 00:44:14,620 This specially bred captive population could be crucial 360 00:44:14,620 --> 00:44:17,740 for the survival of the species. 361 00:44:20,020 --> 00:44:23,860 And they're extremely precious to their owners. 362 00:44:23,860 --> 00:44:25,860 TRANSLATION: 363 00:44:36,060 --> 00:44:40,460 But they can only fish at very precise times of the day. 364 00:44:41,660 --> 00:44:44,140 They have to wait for the tide. 365 00:44:48,780 --> 00:44:51,140 While it's high, 366 00:44:51,140 --> 00:44:55,300 thousands of tiny inlets crisscross through the mangrove forest. 367 00:44:59,180 --> 00:45:03,260 Water dominates the landscape, 368 00:45:03,260 --> 00:45:05,860 giving fish plenty of places to hide. 369 00:45:08,300 --> 00:45:09,940 But from space, 370 00:45:09,940 --> 00:45:12,620 we can watch the tide turn. 371 00:45:16,380 --> 00:45:19,220 Water is replaced with mud. 372 00:45:25,180 --> 00:45:28,580 And at the very lowest tide, 373 00:45:28,580 --> 00:45:33,260 fish are forced into the few remaining stretches of water. 374 00:45:34,820 --> 00:45:37,860 And the otters get to work. 375 00:45:51,380 --> 00:45:55,820 Their sensitive whiskers detect the movement of fish... 376 00:46:02,820 --> 00:46:05,780 ..and they flush them towards the nets. 377 00:46:12,100 --> 00:46:14,860 Young otters swim freely. 378 00:46:14,860 --> 00:46:18,060 They're supposed to be learning from the adults, 379 00:46:18,060 --> 00:46:20,220 but it's easy to get distracted. 380 00:46:48,420 --> 00:46:52,820 The otters bring in up to twice as many fish as using nets alone. 381 00:47:00,780 --> 00:47:02,900 And they take their cut. 382 00:47:08,180 --> 00:47:12,700 Ten otters can eat eight kilos of fish every day. 383 00:47:18,540 --> 00:47:21,980 But it's getting harder for fishermen here to make a living. 384 00:47:24,460 --> 00:47:28,620 Large-scale fishing and pollution from growing industry 385 00:47:28,620 --> 00:47:33,140 are decimating the fish stocks in the Sundarbans. 386 00:47:36,580 --> 00:47:39,060 From over 200, 387 00:47:39,060 --> 00:47:43,900 this is now just one of eight boats keeping this ancient skill alive. 388 00:47:51,260 --> 00:47:52,900 The tide turns, 389 00:47:52,900 --> 00:47:56,300 and the fishermen follow the water home. 390 00:48:04,500 --> 00:48:08,500 Humans have always found ways to survive 391 00:48:08,500 --> 00:48:11,260 alongside our planet's natural landscapes. 392 00:48:16,820 --> 00:48:19,500 But around 10,000 years ago, 393 00:48:19,500 --> 00:48:22,460 we began to create patterns of our very own. 394 00:48:28,700 --> 00:48:31,220 Alongside nature's chaotic curves, 395 00:48:31,220 --> 00:48:33,460 more ordered shapes appeared... 396 00:48:40,660 --> 00:48:42,820 ..designed with great precision... 397 00:48:46,700 --> 00:48:49,620 ..to help us feed ourselves. 398 00:48:53,340 --> 00:48:55,980 At first, farming could only take place 399 00:48:55,980 --> 00:48:58,380 alongside natural water sources. 400 00:49:01,220 --> 00:49:04,940 But now, even in the driest desert, 401 00:49:04,940 --> 00:49:07,500 crops are being grown. 402 00:49:13,700 --> 00:49:16,700 And one shape has come to dominate. 403 00:49:20,620 --> 00:49:24,140 By using rotating sprinklers, 404 00:49:24,140 --> 00:49:29,500 farmers can water a circular field more easily than any other shape. 405 00:49:39,100 --> 00:49:41,140 In the American Midwest, 406 00:49:41,140 --> 00:49:46,220 these irrigation circles stretch for hundreds of kilometres. 407 00:49:50,740 --> 00:49:54,940 Intensive farming like this can force out wildlife. 408 00:49:57,820 --> 00:50:01,420 But no matter how tightly circles are packed together... 409 00:50:02,580 --> 00:50:05,420 ..there'll always be gaps left between them. 410 00:50:10,620 --> 00:50:15,660 In Missouri, farmers are encouraged to keep these spaces wild... 411 00:50:17,100 --> 00:50:20,180 ..creating pockets of habitat for animals... 412 00:50:23,980 --> 00:50:25,980 ..like the bobwhite quail. 413 00:50:28,020 --> 00:50:30,460 On the edge of this circle, 414 00:50:30,460 --> 00:50:33,300 just enough space has been left 415 00:50:33,300 --> 00:50:36,260 for quail to raise their chicks. 416 00:50:42,060 --> 00:50:44,540 With hungry new mouths to feed, 417 00:50:44,540 --> 00:50:48,580 families are always on the move in search of food. 418 00:50:55,460 --> 00:50:58,140 Young chicks are inquisitive - 419 00:50:58,140 --> 00:51:00,940 keen to explore their new world. 420 00:51:03,900 --> 00:51:06,260 But in the thick undergrowth, 421 00:51:06,260 --> 00:51:10,100 parents can find it difficult to keep an eye on all of them. 422 00:51:20,980 --> 00:51:23,700 CHICK CHIRPS 423 00:51:23,700 --> 00:51:25,940 And there are others here 424 00:51:25,940 --> 00:51:28,820 looking for a meal. 425 00:51:31,660 --> 00:51:35,020 Kestrels have their own young to feed. 426 00:51:57,220 --> 00:51:59,900 Mothers know the best thing to do 427 00:51:59,900 --> 00:52:02,700 is hunker down and stay still. 428 00:52:10,820 --> 00:52:12,780 But a lone chick's instinct 429 00:52:12,780 --> 00:52:14,900 is to keep running. 430 00:52:31,660 --> 00:52:33,940 She's inside the circle of crops. 431 00:52:38,660 --> 00:52:40,260 An alien world. 432 00:52:47,540 --> 00:52:50,660 Row upon row of soybeans 433 00:52:50,660 --> 00:52:54,380 arranged in a circle almost a kilometre wide. 434 00:53:00,220 --> 00:53:02,860 There's nothing to eat 435 00:53:02,860 --> 00:53:06,460 and, in the height of summer, nothing to drink. 436 00:53:09,380 --> 00:53:12,780 Dry conditions are bad for the crops, too. 437 00:53:14,780 --> 00:53:18,060 But here in Missouri, they have a solution for that. 438 00:53:23,780 --> 00:53:28,420 Millions of gallons of water pumped from deep underground... 439 00:53:33,340 --> 00:53:37,780 ..and piped along a rotating arm 300 metres long. 440 00:53:43,260 --> 00:53:46,100 A life-saver for the crops... 441 00:53:47,460 --> 00:53:50,340 ..but potentially deadly for a quail chick. 442 00:54:35,980 --> 00:54:40,060 Life beside industrial farming comes with dangers. 443 00:54:45,380 --> 00:54:48,580 But each small patch of wild habitat 444 00:54:48,580 --> 00:54:51,700 can be an important oasis for animals. 445 00:55:06,020 --> 00:55:11,060 There are now 125,000 circular fields in the USA. 446 00:55:13,260 --> 00:55:16,340 Who knows what dramas may be unfolding 447 00:55:16,340 --> 00:55:19,060 in the spaces left between them? 448 00:55:26,540 --> 00:55:30,300 Human agriculture now covers more than one third 449 00:55:30,300 --> 00:55:32,540 of the Earth's land surface. 450 00:55:40,900 --> 00:55:46,180 Add to that the space taken up by our homes and our industries 451 00:55:46,180 --> 00:55:49,980 and humanity's impact can now be seen on more than half 452 00:55:49,980 --> 00:55:51,620 of the planet's land. 453 00:55:57,540 --> 00:56:02,380 For millions of years, natural forces have shaped Earth's surface. 454 00:56:05,220 --> 00:56:10,140 But now, it is undoubtedly us who will decide 455 00:56:10,140 --> 00:56:13,860 what our home will look like in the future. 456 00:56:21,500 --> 00:56:22,700 Next time... 457 00:56:24,780 --> 00:56:29,020 The view from space reveals our blue planet 458 00:56:29,020 --> 00:56:32,460 as a kaleidoscope of incredible colours. 459 00:56:35,300 --> 00:56:38,100 Vast turquoise swirls in the ocean 460 00:56:38,100 --> 00:56:40,780 trigger the planet's biggest feeding frenzy. 461 00:56:43,020 --> 00:56:47,260 Billions of flowers turn a Chinese landscape bright yellow. 462 00:56:50,780 --> 00:56:54,420 And a lake in East Africa is transformed 463 00:56:54,420 --> 00:56:58,260 by the pink of thousands of flamingos. 464 00:56:59,900 --> 00:57:04,940 Each colour has its own remarkable secrets to reveal. 465 00:57:10,660 --> 00:57:15,540 The Open University has produced a poster exploring Earth from space. 466 00:57:15,540 --> 00:57:17,140 To order your free copy, call... 467 00:57:20,380 --> 00:57:21,780 ..or go to... 468 00:57:25,100 --> 00:57:27,900 ..and follow the links to the Open University.