1 00:00:56,290 --> 00:01:00,730 Beneath the Yucatan Peninsula of Mexico... 2 00:01:02,250 --> 00:01:04,730 ..lies another world. 3 00:01:08,490 --> 00:01:11,010 A labyrinth of caves... 4 00:01:14,010 --> 00:01:17,730 ..carved by freshwater... 5 00:01:24,010 --> 00:01:27,610 ..and essential for life on Earth. 6 00:01:54,010 --> 00:01:59,810 Freshwater shapes the land and the creatures that live in it... 7 00:02:02,010 --> 00:02:04,650 ..in the most surprising ways. 8 00:02:20,490 --> 00:02:23,650 The rainforest of Costa Rica. 9 00:02:25,010 --> 00:02:29,490 As you might expect, it rains most days. 10 00:02:31,490 --> 00:02:34,730 But it's only during the wet season 11 00:02:34,730 --> 00:02:38,010 that the rains become torrential. 12 00:02:46,490 --> 00:02:48,210 And with them... 13 00:02:49,210 --> 00:02:52,250 ..comes a most remarkable creature. 14 00:03:07,250 --> 00:03:10,450 Gliding tree frogs. 15 00:03:15,850 --> 00:03:18,650 Thousands drop in... 16 00:03:22,010 --> 00:03:26,010 ..to gather at this newly-formed pond. 17 00:03:33,250 --> 00:03:36,410 They all have an urgent need. 18 00:03:42,330 --> 00:03:44,010 To breed. 19 00:03:57,250 --> 00:04:00,730 This female needs to find a leaf 20 00:04:00,730 --> 00:04:02,930 and lay her eggs. 21 00:04:08,010 --> 00:04:12,010 The breeding frenzy will only last one day... 22 00:04:13,010 --> 00:04:16,010 ..so she needs to get a move on. 23 00:04:21,490 --> 00:04:24,250 There are lots of eager males. 24 00:04:30,370 --> 00:04:32,650 Nine for every female. 25 00:04:36,490 --> 00:04:41,170 And all are ready to spring into action. 26 00:04:46,730 --> 00:04:51,010 So, for her, getting a partner is no problem. 27 00:05:00,610 --> 00:05:03,730 But the other males are desperate. 28 00:05:24,290 --> 00:05:28,730 For this female, mating is rather chaotic. 29 00:05:40,050 --> 00:05:42,730 Things are getting out of hand. 30 00:05:50,970 --> 00:05:54,410 There is one way to deal with this. 31 00:06:00,490 --> 00:06:03,050 A few well-placed kicks... 32 00:06:06,010 --> 00:06:08,010 ..usually does the job. 33 00:06:20,490 --> 00:06:22,250 Problem solved. 34 00:06:26,490 --> 00:06:30,490 She and her partner can now finally mate... 35 00:06:32,010 --> 00:06:34,010 ..in relative peace. 36 00:07:04,490 --> 00:07:08,010 The eggs are positioned perfectly... 37 00:07:08,010 --> 00:07:11,010 ..directly overhanging the pond. 38 00:07:29,450 --> 00:07:34,250 This is the ideal nursery for tadpoles. 39 00:07:37,730 --> 00:07:40,730 For now, her work here is done. 40 00:07:41,730 --> 00:07:46,010 She'll be back next year when the heavy rains return. 41 00:07:50,010 --> 00:07:53,010 As quickly as freshwater appears... 42 00:07:55,490 --> 00:07:57,330 ..it can vanish. 43 00:08:09,490 --> 00:08:11,770 Southeast Sri Lanka. 44 00:08:14,810 --> 00:08:17,490 It's the middle of the dry season. 45 00:08:34,010 --> 00:08:39,010 This is the only remaining water hole for miles around. 46 00:09:37,690 --> 00:09:40,010 Mugger crocodiles - 47 00:09:40,010 --> 00:09:43,490 giants, five metres long. 48 00:09:46,410 --> 00:09:48,730 Dozens are hiding... 49 00:09:49,730 --> 00:09:52,010 ..beneath the surface. 50 00:10:00,010 --> 00:10:01,810 And others... 51 00:10:02,810 --> 00:10:04,730 ..are on their way. 52 00:10:22,730 --> 00:10:26,010 This male has been travelling for hours. 53 00:10:32,730 --> 00:10:36,330 The water hole is the only place where he has a chance 54 00:10:36,330 --> 00:10:38,090 to catch a deer. 55 00:10:49,650 --> 00:10:55,010 A single adult would be enough to feed him for the entire dry season. 56 00:11:06,010 --> 00:11:09,090 But hunting prey that knows you're here... 57 00:11:10,090 --> 00:11:13,250 ..requires something truly remarkable. 58 00:11:31,250 --> 00:11:33,010 He creates... 59 00:11:34,010 --> 00:11:35,730 ..a trap. 60 00:11:45,690 --> 00:11:48,730 He digs down into the mud... 61 00:12:02,010 --> 00:12:05,730 ..deep enough to hide beneath the vegetation. 62 00:12:23,010 --> 00:12:25,650 Perfect camouflage. 63 00:12:37,010 --> 00:12:41,010 He has built his trap right on the water's edge... 64 00:12:42,730 --> 00:12:47,330 ..so it's the first place that thirsty deer will come to drink. 65 00:14:43,010 --> 00:14:46,250 These crocodiles have learned to exploit 66 00:14:46,250 --> 00:14:49,490 the deer's desperate need for freshwater. 67 00:15:02,250 --> 00:15:06,490 Freshwater transforms not only the lives of animals... 68 00:15:08,250 --> 00:15:10,730 ..but entire landscapes. 69 00:15:23,250 --> 00:15:27,010 Every year, over a trillion litres of water 70 00:15:27,010 --> 00:15:30,010 flow into the Kalahari Desert. 71 00:15:38,330 --> 00:15:43,010 It has travelled a thousand miles from where it fell as rain. 72 00:15:48,250 --> 00:15:50,130 And on arrival... 73 00:15:52,010 --> 00:15:54,850 ..it turns the Kalahari... 74 00:15:54,850 --> 00:15:58,010 ..into a vast oasis. 75 00:16:07,010 --> 00:16:09,330 The Okavango Delta. 76 00:16:31,570 --> 00:16:35,490 These waters attract millions of animals. 77 00:16:44,250 --> 00:16:50,010 And for some, now is the perfect time to raise a family. 78 00:17:03,250 --> 00:17:05,090 A lily-trotter. 79 00:17:11,490 --> 00:17:14,010 And he is a father... 80 00:17:14,010 --> 00:17:15,730 ..on duty. 81 00:17:34,730 --> 00:17:36,850 He has not just one... 82 00:17:38,610 --> 00:17:42,410 ..but four newly-hatched chicks. 83 00:17:58,010 --> 00:18:02,490 They won't be able to fly for another six weeks... 84 00:18:05,450 --> 00:18:10,010 ..so, until then, he alone is their protector. 85 00:18:16,490 --> 00:18:20,730 Walking on water is not straightforward... 86 00:18:23,490 --> 00:18:28,210 ..so he must show them how to be a lily-trotter. 87 00:18:49,490 --> 00:18:53,490 The floodwaters make the perfect training ground. 88 00:19:09,650 --> 00:19:12,010 And in two weeks... 89 00:19:13,250 --> 00:19:16,730 ..his chicks not only double in size... 90 00:19:17,730 --> 00:19:20,330 ..they grow in confidence. 91 00:19:32,010 --> 00:19:36,010 But this is a dangerous place to stray. 92 00:19:45,010 --> 00:19:47,450 He sounds the alarm, 93 00:19:47,450 --> 00:19:50,730 and his chicks instantly freeze. 94 00:19:52,730 --> 00:19:55,330 They can't yet fly to safety. 95 00:19:58,330 --> 00:20:01,730 But there is one thing he can do to protect them. 96 00:20:04,010 --> 00:20:06,250 And it's risky. 97 00:20:09,090 --> 00:20:12,250 Get close enough to distract... 98 00:20:13,490 --> 00:20:16,250 ..and hopefully divert the crocodile. 99 00:20:46,730 --> 00:20:48,730 Mission accomplished. 100 00:21:03,490 --> 00:21:06,010 He signals the all clear. 101 00:21:19,010 --> 00:21:21,490 But one chick is missing. 102 00:21:45,010 --> 00:21:47,490 His calls... 103 00:21:47,490 --> 00:21:49,490 ..go unanswered. 104 00:22:43,010 --> 00:22:46,650 A little bedraggled but alive and well. 105 00:22:52,850 --> 00:22:56,250 His chick just hadn't heard his call. 106 00:22:57,730 --> 00:22:59,890 And when danger threatens, 107 00:22:59,890 --> 00:23:03,250 its always better to be safe than sorry. 108 00:23:31,490 --> 00:23:34,530 He's brought his chicks, all four of them, 109 00:23:34,530 --> 00:23:37,250 to the verge of independence. 110 00:23:51,010 --> 00:23:53,730 Whilst lily-trotters are well adapted 111 00:23:53,730 --> 00:23:56,170 to life in this flooded world... 112 00:23:59,210 --> 00:24:03,170 ..these residents of the delta are not. 113 00:24:14,490 --> 00:24:17,010 African painted dogs. 114 00:24:20,250 --> 00:24:24,010 Normally, they are remarkably successful hunters. 115 00:24:25,010 --> 00:24:29,330 But this pack of five hasn't eaten in days. 116 00:24:35,010 --> 00:24:38,330 Finding prey isn't the problem. 117 00:24:45,250 --> 00:24:49,730 This herd of lechwe is only a few hundred metres away. 118 00:24:54,490 --> 00:24:58,010 But between them is deep water. 119 00:25:33,770 --> 00:25:36,730 It's not safe to cross here. 120 00:27:22,490 --> 00:27:27,250 On dry land, the dogs can run at over 40mph. 121 00:27:33,490 --> 00:27:38,490 But when threatened, lechwe always seek the safety of water. 122 00:27:44,250 --> 00:27:47,610 With their splayed hooves and long hind legs, 123 00:27:47,610 --> 00:27:50,250 they can power their way through the water. 124 00:27:52,010 --> 00:27:54,370 The dogs can't. 125 00:28:18,010 --> 00:28:22,290 The pack won't be able to outswim the lechwe. 126 00:28:25,330 --> 00:28:27,730 But they do have a strategy. 127 00:28:48,730 --> 00:28:53,010 The dogs drive the lechwe to where they have the advantage. 128 00:28:58,730 --> 00:29:01,450 Back towards dry land. 129 00:29:05,250 --> 00:29:09,010 Now the pack can regain lost ground. 130 00:29:56,610 --> 00:30:02,010 Success today, but tomorrow the pack will need to hunt again. 131 00:30:05,730 --> 00:30:07,450 In the Okavango, 132 00:30:07,450 --> 00:30:13,010 animals must always adapt to the coming and going of freshwater. 133 00:30:17,730 --> 00:30:22,730 But there are a few rare places, as here in Lake Malawi, 134 00:30:22,730 --> 00:30:26,730 where freshwater has lain for millions of years. 135 00:30:29,330 --> 00:30:32,490 And that has enabled life to evolve 136 00:30:32,490 --> 00:30:36,730 into a dazzling diversity of species. 137 00:30:43,410 --> 00:30:47,010 There are over a thousand different kinds of fish here... 138 00:30:48,250 --> 00:30:51,010 ..more than any other lake on Earth. 139 00:31:02,010 --> 00:31:06,250 Competition in these waters is intense. 140 00:31:28,890 --> 00:31:33,250 Meet Nimbochromis livingstonii. 141 00:31:36,490 --> 00:31:38,770 A master of deception 142 00:31:38,770 --> 00:31:43,010 that tricks other fish into thinking it's dead. 143 00:31:47,010 --> 00:31:51,490 Its mottled colouration mimics decaying flesh. 144 00:31:57,490 --> 00:31:59,890 But to appear dead... 145 00:32:03,010 --> 00:32:04,890 ..one must at least... 146 00:32:05,890 --> 00:32:07,930 ..act dead. 147 00:32:11,490 --> 00:32:14,650 This juvenile is fooling no-one. 148 00:32:19,810 --> 00:32:24,010 Perhaps faking his death will be more believable. 149 00:32:50,010 --> 00:32:51,650 Blown it. 150 00:33:02,010 --> 00:33:05,010 A more subtle performance will be needed. 151 00:33:18,250 --> 00:33:20,850 This is more convincing. 152 00:33:33,370 --> 00:33:36,250 But his aim must be better than that. 153 00:33:43,650 --> 00:33:45,170 Nearly. 154 00:33:52,730 --> 00:33:55,570 It seems he's overstayed his welcome. 155 00:34:28,650 --> 00:34:30,850 In a final effort... 156 00:34:30,850 --> 00:34:34,250 ..he appears to even hold his breath. 157 00:34:55,010 --> 00:34:57,490 Success at last. 158 00:35:17,250 --> 00:35:21,490 All it took was a million years of evolution... 159 00:35:30,250 --> 00:35:35,010 ..and the unique stability of this ancient lake. 160 00:35:43,730 --> 00:35:47,650 Off the western coast of Equatorial Africa 161 00:35:47,650 --> 00:35:51,730 lies the volcanic island of Bioko. 162 00:36:02,010 --> 00:36:06,330 Freshwater here has a turbulent nature. 163 00:36:42,010 --> 00:36:45,490 Few venture into such waters, 164 00:36:45,490 --> 00:36:50,010 but for those that do, there can be great rewards. 165 00:36:53,010 --> 00:36:56,170 After months feeding and growing out at sea, 166 00:36:56,170 --> 00:36:59,250 these gobies are ready to breed. 167 00:37:02,490 --> 00:37:05,650 And the safest place to lay their eggs 168 00:37:05,650 --> 00:37:09,490 is somewhere that ocean predators can't reach. 169 00:37:12,010 --> 00:37:14,490 The top of this waterfall. 170 00:37:20,250 --> 00:37:23,730 Surely an impossible journey for a fish. 171 00:37:27,730 --> 00:37:33,130 But over the coming days, the gobies transform themselves. 172 00:37:36,250 --> 00:37:38,090 They change colour. 173 00:37:43,010 --> 00:37:49,010 Their mouth rotates and acts like a kind of suction cup... 174 00:37:50,490 --> 00:37:53,010 ..which they will certainly need. 175 00:37:58,490 --> 00:38:02,530 Because the only way...is up. 176 00:38:23,730 --> 00:38:27,010 It is 30 metres to the top. 177 00:38:33,490 --> 00:38:37,050 They are only an inch long. 178 00:38:40,010 --> 00:38:44,490 This is the equivalent of a human being scaling a waterfall 179 00:38:44,490 --> 00:38:46,490 over a mile high. 180 00:38:56,010 --> 00:38:58,730 Millions attempt the climb... 181 00:39:00,010 --> 00:39:03,650 ..but less than 1% will make it. 182 00:39:13,250 --> 00:39:16,810 This goby has been climbing for days. 183 00:39:25,250 --> 00:39:26,970 Made it! 184 00:39:31,330 --> 00:39:35,730 Those that reach the top can now prepare to breed. 185 00:39:39,010 --> 00:39:44,250 And when the time comes, their young will be washed back out to sea. 186 00:40:05,250 --> 00:40:08,010 The extraordinary power of flowing water 187 00:40:08,010 --> 00:40:11,490 makes it our planet's greatest architect. 188 00:40:32,010 --> 00:40:36,490 This may look like the surface of an alien planet... 189 00:40:49,490 --> 00:40:55,170 ..but these strange patterns are channels of freshwater... 190 00:40:57,330 --> 00:40:59,730 .flowing towards the sea. 191 00:41:14,010 --> 00:41:17,010 For 3.8 billion years, 192 00:41:17,010 --> 00:41:19,890 ever since the first rains fell... 193 00:41:21,250 --> 00:41:24,650 ..freshwater has been making this journey. 194 00:41:40,250 --> 00:41:45,010 But today, two thirds of our world's great rivers 195 00:41:45,010 --> 00:41:47,650 no longer reach the sea. 196 00:42:20,010 --> 00:42:24,250 There is a finite amount of freshwater on Earth... 197 00:42:36,490 --> 00:42:40,330 ..so humans have devised extraordinary means 198 00:42:40,330 --> 00:42:46,010 to ensure that it is always available to meet our every demand. 199 00:42:56,290 --> 00:42:59,490 We now control freshwater... 200 00:43:01,010 --> 00:43:03,250 ..on a colossal scale. 201 00:43:08,010 --> 00:43:11,010 The largest irrigation system on Earth 202 00:43:11,010 --> 00:43:14,410 has been built here in Pakistan. 203 00:43:23,490 --> 00:43:27,330 A vast network of dams and canals... 204 00:43:30,010 --> 00:43:34,490 ..that diverts and drains the great Indus River. 205 00:43:40,490 --> 00:43:45,250 It's used to irrigate an area the size of England. 206 00:43:50,010 --> 00:43:52,850 This man-made freshwater world 207 00:43:52,850 --> 00:43:55,730 provides water and a livelihood 208 00:43:55,730 --> 00:43:57,970 for millions of people... 209 00:44:05,930 --> 00:44:09,730 ..but at a cost to the natural world. 210 00:44:22,490 --> 00:44:28,010 A rare creature has become stranded in this irrigation canal. 211 00:44:31,490 --> 00:44:34,450 And the water will soon be gone, 212 00:44:34,450 --> 00:44:38,010 used to supply the surrounding land. 213 00:44:44,250 --> 00:44:49,250 Endangered, they number fewer than 2,000 individuals. 214 00:44:54,730 --> 00:44:57,330 An Indus river dolphin. 215 00:45:11,250 --> 00:45:17,010 This female dolphin is 150 miles from the main river. 216 00:45:20,730 --> 00:45:23,370 She can't return on her own, 217 00:45:23,370 --> 00:45:28,490 so the only option is for this rescue team to take her. 218 00:45:52,490 --> 00:45:56,330 Out of water, she cannot survive for long. 219 00:46:03,010 --> 00:46:06,410 The journey back to the river will take hours. 220 00:46:16,010 --> 00:46:20,730 Her life now depends on these people. 221 00:48:11,730 --> 00:48:17,530 Nearly 30 dolphins had to be rescued in one month alone. 222 00:48:47,730 --> 00:48:52,250 Freshwater is not only a resource for humans. 223 00:48:58,250 --> 00:49:03,010 It is the home for countless species 224 00:49:03,010 --> 00:49:08,170 that simply cannot survive without it. 225 00:49:27,010 --> 00:49:30,770 Freshwater is the lifeblood 226 00:49:30,770 --> 00:49:33,250 of Planet Earth. 227 00:49:55,010 --> 00:49:59,490 To film the story of the most endangered freshwater dolphin, 228 00:49:59,490 --> 00:50:04,250 the Planet Earth team joined the world's leading expert - Uzma Khan. 229 00:50:04,250 --> 00:50:08,490 The first time I saw Indus dolphin, I was just amazed. 230 00:50:08,490 --> 00:50:10,490 It's a beautiful creature, you know, 231 00:50:10,490 --> 00:50:13,210 it's like love at first sight. It's so unique. 232 00:50:14,730 --> 00:50:18,730 Uzma has been studying the last remaining population 233 00:50:18,730 --> 00:50:20,730 for over 20 years. 234 00:50:22,250 --> 00:50:25,930 There's a dolphin that surfaced just right there. 235 00:50:25,930 --> 00:50:30,530 Indus river dolphin can only live in freshwater. 236 00:50:30,530 --> 00:50:33,730 It is only found in Pakistan and nowhere else. 237 00:50:33,730 --> 00:50:38,010 And we only have about 2,000 of them left in the Indus River. 238 00:50:38,010 --> 00:50:42,210 So, you know, each individual is special. 239 00:50:44,290 --> 00:50:49,290 Following the dolphins in the murky water is extremely challenging. 240 00:50:50,290 --> 00:50:53,290 They only surface for a split second 241 00:50:53,290 --> 00:50:57,010 and that makes protecting them difficult, too. 242 00:50:57,010 --> 00:51:03,010 Their greatest threat is becoming trapped in the irrigation canals. 243 00:51:04,010 --> 00:51:06,770 But Uzma may have a solution, 244 00:51:06,770 --> 00:51:10,010 and teams up with a rescue unit... 245 00:51:11,010 --> 00:51:14,690 ..to attempt something never done before. 246 00:51:17,050 --> 00:51:20,010 This is the first time we'll be putting satellite tags 247 00:51:20,010 --> 00:51:22,010 on river dolphins in Asia. 248 00:51:22,010 --> 00:51:25,010 Sensors has not been tested on this species, 249 00:51:25,010 --> 00:51:28,330 there's a little bit of anxiety, but if they work, 250 00:51:28,330 --> 00:51:31,330 then it's going to be a breakthrough for conservation. 251 00:51:34,370 --> 00:51:39,370 Uzma has been developing a suitable tag for over ten years 252 00:51:39,370 --> 00:51:43,490 and hopes it will help her collect critical data 253 00:51:43,490 --> 00:51:47,010 on how the dolphins are moving through the dams and canals. 254 00:51:48,250 --> 00:51:53,250 But in order to tag, she will first need a successful rescue. 255 00:52:03,010 --> 00:52:07,570 I'm usually very concerned when a rescue is happening. 256 00:52:17,490 --> 00:52:20,010 You know, the divers, they are very experienced, 257 00:52:20,010 --> 00:52:22,810 but a part of me is always very worried. 258 00:52:24,250 --> 00:52:27,490 They are wild animals that have never been handled. 259 00:52:29,410 --> 00:52:32,490 It's really quite a risky thing that they're undertaking here. 260 00:52:32,490 --> 00:52:34,730 There's a good chance the dolphin might die. 261 00:52:34,730 --> 00:52:37,490 But, of course, they're balancing that against the fact 262 00:52:37,490 --> 00:52:40,010 that they definitely will die if they stay in here, 263 00:52:40,010 --> 00:52:42,010 so it's a risk they have to take. 264 00:52:58,250 --> 00:53:01,170 Have they got the dolphin? Yeah, I think so. They've got it. 265 00:53:04,490 --> 00:53:07,250 Now speed is key. 266 00:53:16,490 --> 00:53:19,970 We're now bombing across the field on the way to the release site, 267 00:53:19,970 --> 00:53:22,490 and I think Uzma went ahead of us, so I'm really hopeful 268 00:53:22,490 --> 00:53:25,010 that she'll get her opportunity to tag the dolphin. 269 00:53:28,730 --> 00:53:33,010 But rescue missions don't always go to plan. 270 00:53:43,330 --> 00:53:45,010 A puncture. 271 00:53:52,490 --> 00:53:56,490 The dolphin is quickly moved to the film crew's truck. 272 00:54:17,370 --> 00:54:20,010 But with no roof for shelter, 273 00:54:20,010 --> 00:54:23,730 the dolphin is at greater risk of dehydration. 274 00:54:23,730 --> 00:54:26,330 The stakes are high, even right now. 275 00:54:27,330 --> 00:54:30,010 It's a cute little animal and we don't want it to die. 276 00:54:35,410 --> 00:54:39,090 The team re-route to the closest release site. 277 00:54:41,250 --> 00:54:43,330 There can be no more delay. 278 00:54:44,490 --> 00:54:46,970 Uzma calls off the tagging. 279 00:55:05,490 --> 00:55:08,170 It's unfortunate because we were all prepared, 280 00:55:08,170 --> 00:55:11,250 we were very excited since morning, all geared up, 281 00:55:11,250 --> 00:55:16,010 but hopefully we'll get an opportunity to tag the next rescue. 282 00:55:26,730 --> 00:55:31,250 A few days later, Uzma finally gets her chance. 283 00:55:37,290 --> 00:55:40,330 It's a very exciting day for us. 284 00:55:40,330 --> 00:55:42,250 It's OK. 285 00:55:42,250 --> 00:55:46,210 The moment that we have been waiting for, over ten years. 286 00:55:47,210 --> 00:55:49,090 Just stay calm. 287 00:55:54,210 --> 00:55:56,250 OK, it's good to go. 288 00:56:00,090 --> 00:56:02,330 Congratulations. 289 00:56:02,330 --> 00:56:04,410 Well done. 290 00:56:08,730 --> 00:56:12,290 I am very happy, very happy. 291 00:56:12,290 --> 00:56:14,850 I think it's a great accomplishment. 292 00:56:17,010 --> 00:56:19,730 It's the happiest moment of my life. 293 00:56:26,490 --> 00:56:32,250 Within a few weeks, the tags begin to reveal some new insights. 294 00:56:34,250 --> 00:56:38,090 They are moving quite a lot, which we never expected. 295 00:56:38,090 --> 00:56:43,250 So one of the dolphins actually went about 46km upstream 296 00:56:43,250 --> 00:56:46,810 from the release site, and the other thing is that we thought 297 00:56:46,810 --> 00:56:49,250 that they will stay in the main river stream, 298 00:56:49,250 --> 00:56:53,250 but they are using side channels. It is extremely interesting. 299 00:56:54,250 --> 00:56:57,210 Tracking the movement of the tagged dolphins 300 00:56:57,210 --> 00:56:59,490 will help Uzma better understand 301 00:56:59,490 --> 00:57:02,490 when and where they become trapped... 302 00:57:03,730 --> 00:57:08,730 ..helping safeguard the future of this most endangered animal. 303 00:57:14,730 --> 00:57:16,490 Next time... 304 00:57:17,610 --> 00:57:19,210 ..forests. 305 00:57:20,810 --> 00:57:23,050 A hidden world... 306 00:57:24,970 --> 00:57:28,490 ..where lives are intimately entwined... 307 00:57:30,330 --> 00:57:33,330 ..in the most unexpected ways. 308 00:57:39,010 --> 00:57:43,210 Habitat Explorer brings animals and their habitats to life. 309 00:57:43,210 --> 00:57:46,850 Explore this free interactive and make origami animals. 310 00:57:46,850 --> 00:57:50,650 Go to bbc.co.uk/planetearth3 311 00:57:50,650 --> 00:57:53,090 and follow the links to the Open University. 312 00:57:53,090 --> 00:57:55,490 Or to order a free printed version, 313 00:57:55,490 --> 00:57:58,730 visit the website or call the number on the screen.