1 00:00:06,920 --> 00:00:09,680 DAVID ATTENBOROUGH: 66 million years ago, 2 00:00:09,680 --> 00:00:12,960 an asteroid was on a direct collision course 3 00:00:12,960 --> 00:00:14,520 with the Earth. 4 00:00:15,880 --> 00:00:19,280 Its impact was to dramatically change 5 00:00:19,280 --> 00:00:21,160 the course of life on our planet... 6 00:00:26,120 --> 00:00:28,400 ..leading to a mass extinction 7 00:00:28,400 --> 00:00:32,320 that wiped out three-quarters of all animal life. 8 00:00:35,880 --> 00:00:37,920 Out of the darkness that followed, 9 00:00:37,920 --> 00:00:42,040 emerged a group that went on to dominate the world. 10 00:00:44,080 --> 00:00:46,280 That group is the mammals. 11 00:00:46,280 --> 00:00:49,520 Highly adaptable and remarkably widespread, 12 00:00:49,520 --> 00:00:51,720 they are now found in every ocean 13 00:00:51,720 --> 00:00:53,240 and on every continent, 14 00:00:53,240 --> 00:00:55,600 in the air and underground. 15 00:00:55,600 --> 00:00:57,200 In this series, 16 00:00:57,200 --> 00:00:59,960 we'll reveal the secrets behind their success 17 00:00:59,960 --> 00:01:02,000 and the challenges they now face 18 00:01:02,000 --> 00:01:03,680 in a world dominated 19 00:01:03,680 --> 00:01:06,680 by the most successful mammal of all - 20 00:01:06,680 --> 00:01:07,920 us. 21 00:01:38,400 --> 00:01:40,440 OVERLAPPING ANIMAL CALLS 22 00:01:43,440 --> 00:01:46,880 Evening in the forests of central Africa. 23 00:01:55,680 --> 00:01:57,760 RUSTLING 24 00:01:59,720 --> 00:02:02,320 A family of chimpanzees is looking 25 00:02:02,320 --> 00:02:04,240 for somewhere to spend the night. 26 00:02:14,360 --> 00:02:17,880 Like us, they have excellent daytime vision... 27 00:02:19,840 --> 00:02:23,000 ..but at night, they could be caught unawares. 28 00:02:24,720 --> 00:02:26,640 As the light fades, 29 00:02:26,640 --> 00:02:28,920 they climb up into the canopy, 30 00:02:28,920 --> 00:02:30,480 where it's safer. 31 00:02:42,880 --> 00:02:46,120 There, they start to make beds for themselves. 32 00:02:53,240 --> 00:02:55,000 Here, in the treetops, 33 00:02:55,000 --> 00:02:58,080 the whole family will be able to sleep soundly 34 00:02:58,080 --> 00:03:00,080 through the darkest hours. 35 00:03:04,400 --> 00:03:08,560 But sleeping at night is unusual among mammals. 36 00:03:14,120 --> 00:03:17,000 More than two thirds of them only become active 37 00:03:17,000 --> 00:03:19,040 after the sun has set. 38 00:03:20,640 --> 00:03:24,200 So, while you and I and chimpanzees 39 00:03:24,200 --> 00:03:25,800 are fast asleep... 40 00:03:27,040 --> 00:03:29,160 ..most mammals the world over 41 00:03:29,160 --> 00:03:31,840 are as active as they will ever be. 42 00:03:44,440 --> 00:03:46,160 Zambia. 43 00:03:46,160 --> 00:03:48,040 OVERLAPPING ANIMAL CALLS 44 00:03:48,040 --> 00:03:52,240 It's evening, and the light is fading. 45 00:03:57,680 --> 00:04:02,040 A female leopard is starting to think about hunting. 46 00:04:14,480 --> 00:04:17,600 She can see there is plenty of possible prey. 47 00:04:25,200 --> 00:04:27,160 But, in daylight, 48 00:04:27,160 --> 00:04:31,280 they can see her just as easily as she can see them. 49 00:04:31,280 --> 00:04:33,320 THEY CHIRP 50 00:04:40,360 --> 00:04:43,520 That, however, is all about to change... 51 00:04:46,160 --> 00:04:49,120 ..when her remarkable night vision will give her 52 00:04:49,120 --> 00:04:50,840 a crucial advantage. 53 00:05:03,440 --> 00:05:06,640 The leopard's eyes have a reflective structure 54 00:05:06,640 --> 00:05:09,880 behind the retina, called a tapetum, 55 00:05:09,880 --> 00:05:13,160 that amplifies even the tiniest amount of light. 56 00:05:14,960 --> 00:05:17,000 OVERLAPPING ANIMAL CALLS 57 00:05:18,280 --> 00:05:20,560 That now becomes very valuable, 58 00:05:20,560 --> 00:05:23,920 because, tonight, it is particularly dark. 59 00:05:29,520 --> 00:05:32,320 Impala have learnt to be wary. 60 00:05:44,280 --> 00:05:46,080 With her prey so alert... 61 00:05:47,200 --> 00:05:49,600 ..she has little chance of catching one here. 62 00:05:56,920 --> 00:05:59,680 But there are other opportunities nearby. 63 00:06:17,720 --> 00:06:20,680 20 metres above the forest floor, 64 00:06:20,680 --> 00:06:23,640 a troop of yellow baboons 65 00:06:23,640 --> 00:06:25,600 are settling down for the night. 66 00:06:33,120 --> 00:06:35,720 Even on such a dark night as this... 67 00:06:37,080 --> 00:06:39,960 ..a leopard can pick out the most vulnerable. 68 00:07:10,480 --> 00:07:13,560 Baboons have poor night vision. 69 00:07:25,480 --> 00:07:28,320 Their hearing, though, is excellent. 70 00:07:33,280 --> 00:07:35,000 The closer she gets, 71 00:07:35,000 --> 00:07:37,360 the greater the risk of waking them. 72 00:07:46,760 --> 00:07:48,440 BRANCH SNAPS 73 00:07:48,440 --> 00:07:50,480 BABOONS GRUNT AND BARK 74 00:07:55,000 --> 00:07:57,480 The troop is now fully alarmed... 75 00:08:00,360 --> 00:08:02,640 ..so she becomes bolder. 76 00:08:03,920 --> 00:08:05,960 BARKING CONTINUES 77 00:08:32,800 --> 00:08:34,360 In all the commotion, 78 00:08:34,360 --> 00:08:36,960 a mother and baby take a wrong turn... 79 00:08:43,360 --> 00:08:46,880 ..and now they are trapped at the end of a branch. 80 00:08:54,880 --> 00:08:56,920 SHE BARKS 81 00:09:01,480 --> 00:09:03,920 There seems to be no escape. 82 00:09:23,560 --> 00:09:27,920 The thinnest of branches offers the mother and baby a lifeline. 83 00:09:27,920 --> 00:09:29,960 PANTS 84 00:09:34,040 --> 00:09:36,320 BABOONS GRUNT AND BARK 85 00:09:40,000 --> 00:09:42,160 With the baboons so alarmed, 86 00:09:42,160 --> 00:09:45,440 she will need all her power and agility now. 87 00:09:51,320 --> 00:09:53,560 The troop scatters again, 88 00:09:53,560 --> 00:09:56,120 and one makes a fatal mistake. 89 00:10:01,200 --> 00:10:03,320 LOW GROWLING 90 00:10:14,640 --> 00:10:17,640 Many nocturnal mammals, like the leopard, 91 00:10:17,640 --> 00:10:20,600 have extremely sensitive night vision. 92 00:10:25,720 --> 00:10:28,560 But how do you find your prey 93 00:10:28,560 --> 00:10:30,840 if it is completely out of sight? 94 00:10:38,680 --> 00:10:40,320 The Sahara. 95 00:10:42,960 --> 00:10:45,120 Under a moonlit sky, 96 00:10:45,120 --> 00:10:48,120 it's one of the quietest places on Earth. 97 00:10:53,720 --> 00:10:56,400 In the cool air of night, 98 00:10:56,400 --> 00:10:58,040 sound travels further 99 00:10:58,040 --> 00:11:00,200 than it does in the heat of the day. 100 00:11:04,520 --> 00:11:07,920 And one mammal uses that to its advantage. 101 00:11:14,360 --> 00:11:17,400 It's a creature that's rarely seen... 102 00:11:21,000 --> 00:11:24,120 ..because it can hear us coming. 103 00:11:28,800 --> 00:11:30,240 A fennec fox. 104 00:11:32,440 --> 00:11:35,800 Its body is scarcely bigger than that of a guinea pig. 105 00:11:37,440 --> 00:11:40,080 But those ears are huge. 106 00:11:40,080 --> 00:11:42,320 If anyone can hear a pin drop, 107 00:11:42,320 --> 00:11:44,200 a fennec fox can. 108 00:11:45,520 --> 00:11:48,640 And in this vast open space, 109 00:11:48,640 --> 00:11:52,200 it's listening for the tiny footsteps of its prey. 110 00:11:57,520 --> 00:11:59,120 A gerbil. 111 00:12:09,520 --> 00:12:13,080 But, at the first sign of danger, 112 00:12:13,080 --> 00:12:15,720 gerbils hide underground. 113 00:12:21,480 --> 00:12:23,760 The fox searches dune... 114 00:12:25,200 --> 00:12:27,960 ..after dune, 115 00:12:27,960 --> 00:12:31,800 listening for the faintest of audible clues. 116 00:12:35,080 --> 00:12:37,920 Those enormous ears are so sensitive, 117 00:12:37,920 --> 00:12:42,440 they can even hear the movements of prey hiding underground. 118 00:12:48,160 --> 00:12:50,520 But then they have to be dug out. 119 00:13:01,400 --> 00:13:03,080 There is no gerbil. 120 00:13:05,040 --> 00:13:07,440 But those ears help pinpoint 121 00:13:07,440 --> 00:13:11,040 all sorts of other smaller creatures under the sand. 122 00:13:14,160 --> 00:13:17,600 Such as beetles and lizards. 123 00:13:21,000 --> 00:13:24,280 And they don't only help to find food. 124 00:13:27,160 --> 00:13:28,920 DISTANT CHITTERING CALL 125 00:13:28,920 --> 00:13:31,320 This fox can hear... 126 00:13:31,320 --> 00:13:33,720 ..a distant call 127 00:13:33,720 --> 00:13:36,400 echoing across the dunes. 128 00:13:41,440 --> 00:13:43,480 DISTANT CHITTERING CALL 129 00:13:52,160 --> 00:13:53,880 It's January. 130 00:13:55,360 --> 00:13:58,080 The beginning of the breeding season. 131 00:14:11,720 --> 00:14:13,520 But for this pair... 132 00:14:15,120 --> 00:14:18,440 ..perhaps it's just a little too early. 133 00:14:30,960 --> 00:14:33,880 To meet the challenges brought by darkness, 134 00:14:33,880 --> 00:14:36,600 nocturnal mammals have sharpened their senses 135 00:14:36,600 --> 00:14:38,920 in extraordinary ways. 136 00:14:40,880 --> 00:14:43,000 And that's all been possible... 137 00:14:44,120 --> 00:14:47,840 ...because mammals started their journeys into night 138 00:14:47,840 --> 00:14:50,400 a very long time ago. 139 00:15:03,520 --> 00:15:06,120 DISTANT ROARING 140 00:15:08,800 --> 00:15:11,360 200 million years ago, 141 00:15:11,360 --> 00:15:14,080 the land was dominated by dinosaurs 142 00:15:14,080 --> 00:15:17,360 and other great reptilian hunters, 143 00:15:17,360 --> 00:15:21,080 but they were mostly active during the warmth of the day. 144 00:15:22,520 --> 00:15:25,680 So the early mammals kept out of their way 145 00:15:25,680 --> 00:15:28,760 by only emerging to feed at night. 146 00:15:33,280 --> 00:15:35,120 They were very small, 147 00:15:35,120 --> 00:15:38,160 they had hairy coats which kept them warm... 148 00:15:39,560 --> 00:15:42,600 ..and they found their way around by using 149 00:15:42,600 --> 00:15:45,280 one of the most ancient senses of all. 150 00:15:47,040 --> 00:15:48,560 Touch. 151 00:15:51,840 --> 00:15:53,080 In fact, 152 00:15:53,080 --> 00:15:55,800 they were probably very like this little creature, 153 00:15:55,800 --> 00:15:58,360 a tiny Etruscan shrew. 154 00:16:01,800 --> 00:16:03,760 This one is a mother. 155 00:16:06,480 --> 00:16:08,640 And she's taking her young family 156 00:16:08,640 --> 00:16:11,400 for their first night-time walk. 157 00:16:15,200 --> 00:16:17,960 To ensure they don't get lost in the darkness, 158 00:16:17,960 --> 00:16:20,640 they, literally, keep in touch. 159 00:16:27,560 --> 00:16:29,800 The babies hold on tight... 160 00:16:32,280 --> 00:16:35,920 ..until they reach the safety of a new nest. 161 00:16:39,880 --> 00:16:43,040 Touch not only helps them find their way... 162 00:16:44,440 --> 00:16:47,160 ..they use it when hunting. 163 00:16:50,720 --> 00:16:53,600 Weighing less than a ping-pong ball, 164 00:16:53,600 --> 00:16:57,920 Etruscan shrews are the world's smallest terrestrial mammal. 165 00:17:01,240 --> 00:17:04,040 But they're still formidable predators. 166 00:17:14,400 --> 00:17:17,080 Some of the hairs on the end of their noses 167 00:17:17,080 --> 00:17:19,360 have become enlarged into whiskers, 168 00:17:19,360 --> 00:17:22,000 that are especially sensitive to touch. 169 00:17:23,080 --> 00:17:25,120 SNIFFS 170 00:17:26,200 --> 00:17:29,120 Like an extra pair of hands, 171 00:17:29,120 --> 00:17:30,840 they guide them 172 00:17:30,840 --> 00:17:33,120 on a never-ending search for a meal. 173 00:17:44,000 --> 00:17:46,040 SQUELCHING 174 00:17:48,840 --> 00:17:51,320 To fuel their frenetic lifestyle, 175 00:17:51,320 --> 00:17:53,920 they feed every few hours. 176 00:17:55,680 --> 00:17:57,400 A bush cricket. 177 00:17:58,800 --> 00:18:00,720 It's almost as big as she is... 178 00:18:02,840 --> 00:18:06,200 ..and well able to make a quick getaway. 179 00:18:09,760 --> 00:18:11,880 She will need the lightest of touches 180 00:18:11,880 --> 00:18:13,440 if she's to catch it. 181 00:18:18,920 --> 00:18:22,640 So she switches to whisker mode. 182 00:18:27,480 --> 00:18:29,960 To prevent it escaping, 183 00:18:29,960 --> 00:18:32,600 she must grab one of its jumping legs. 184 00:18:44,920 --> 00:18:47,080 She won't get a second chance. 185 00:19:02,280 --> 00:19:05,440 It's a relatively enormous meal. 186 00:19:07,240 --> 00:19:09,160 But she must eat a lot 187 00:19:09,160 --> 00:19:11,800 to feed her ever-growing family 188 00:19:11,800 --> 00:19:14,880 and fuel her fast-paced lifestyle. 189 00:19:17,120 --> 00:19:19,760 So she'll soon be out hunting again. 190 00:19:27,800 --> 00:19:31,760 Feeling their way by touch is not the only method 191 00:19:31,760 --> 00:19:34,800 by which mammals deal with the problems of darkness. 192 00:19:36,880 --> 00:19:39,200 MOOING 193 00:19:39,200 --> 00:19:42,160 In Argentina, as night falls, 194 00:19:42,160 --> 00:19:47,000 life starts to stir in an abandoned farm building. 195 00:19:51,800 --> 00:19:55,720 There are all kinds of smells drifting through the air - 196 00:19:55,720 --> 00:19:57,360 some powerful... 197 00:19:59,000 --> 00:20:00,560 ..some faint. 198 00:20:02,920 --> 00:20:05,600 And one nocturnal mammal has 199 00:20:05,600 --> 00:20:08,280 an extraordinarily sensitive way of detecting 200 00:20:08,280 --> 00:20:10,240 even the faintest of them. 201 00:20:15,680 --> 00:20:17,240 An armadillo. 202 00:20:19,040 --> 00:20:22,240 There are 21 species in the Americas. 203 00:20:24,200 --> 00:20:27,680 This one is the large... 204 00:20:27,680 --> 00:20:29,520 ..hairy... 205 00:20:29,520 --> 00:20:31,400 ..armadillo. 206 00:20:38,800 --> 00:20:40,360 After dark, 207 00:20:40,360 --> 00:20:43,040 he heads out into the surrounding pasture... 208 00:20:47,720 --> 00:20:51,360 ..guided by a highly sensitive nose. 209 00:20:53,640 --> 00:20:55,680 SNIFFING 210 00:21:02,520 --> 00:21:05,040 This male has detected a smell 211 00:21:05,040 --> 00:21:07,600 that he finds especially enticing... 212 00:21:14,960 --> 00:21:17,680 ..and soon locates the source. 213 00:21:20,280 --> 00:21:22,160 A female in season... 214 00:21:23,480 --> 00:21:26,920 ..and she's producing an irresistible perfume. 215 00:21:31,040 --> 00:21:32,560 He's fallen for her. 216 00:21:37,320 --> 00:21:40,320 But she is not so sure about him. 217 00:21:43,640 --> 00:21:45,880 So she takes the lead. 218 00:21:50,000 --> 00:21:53,160 The male has to keep up, as best he can. 219 00:21:53,160 --> 00:21:55,200 MOOS 220 00:21:58,200 --> 00:22:00,360 Back in the abandoned building, 221 00:22:00,360 --> 00:22:03,320 the clutter in the rooms makes things more difficult. 222 00:22:10,800 --> 00:22:12,480 He's lost her... 223 00:22:14,680 --> 00:22:17,000 ..but her scent is everywhere. 224 00:22:20,360 --> 00:22:22,240 He's not giving up. 225 00:22:45,840 --> 00:22:50,080 Eventually, she leads him to a quiet corner. 226 00:22:57,920 --> 00:23:00,080 Her choice is made. 227 00:23:07,400 --> 00:23:11,840 Equipped with an array of sharp super-senses, 228 00:23:11,840 --> 00:23:14,560 nocturnal mammals have little difficulty 229 00:23:14,560 --> 00:23:17,000 in finding not only food, 230 00:23:17,000 --> 00:23:18,720 but mates. 231 00:23:21,360 --> 00:23:24,120 But some of the most successful of all 232 00:23:24,120 --> 00:23:26,360 don't only use their own senses... 233 00:23:27,760 --> 00:23:30,600 ..they also rely on each other. 234 00:23:42,160 --> 00:23:46,120 The Ngorongoro Crater in northern Tanzania. 235 00:23:49,160 --> 00:23:53,640 One of the greatest mammal hot spots in the world. 236 00:24:11,080 --> 00:24:13,560 ZEBRA YIP WILDEBEEST LOW 237 00:24:20,920 --> 00:24:23,680 With such an abundance of prey, 238 00:24:23,680 --> 00:24:27,360 the crater attracts great numbers of predators. 239 00:24:29,400 --> 00:24:32,280 Amongst them, spotted hyenas. 240 00:24:38,120 --> 00:24:40,200 And this female is a member 241 00:24:40,200 --> 00:24:44,120 of one of the most exceptional and caring families. 242 00:24:44,120 --> 00:24:46,360 YIPPING 243 00:24:59,000 --> 00:25:02,720 She will nurture her cubs for 18 months. 244 00:25:08,840 --> 00:25:11,280 And she is not a single parent. 245 00:25:12,480 --> 00:25:13,960 Far from it. 246 00:25:16,520 --> 00:25:19,240 She has the support of a sisterhood. 247 00:25:21,640 --> 00:25:24,920 A clan ruled by females, 248 00:25:24,920 --> 00:25:27,440 60 adults strong. 249 00:25:36,480 --> 00:25:39,720 With so many mouths to feed, 250 00:25:39,720 --> 00:25:43,160 hyenas must hunt almost every night. 251 00:25:54,640 --> 00:25:57,960 As dusk falls, they head out, 252 00:25:57,960 --> 00:26:00,600 splitting up into small groups... 253 00:26:02,200 --> 00:26:04,640 ..to widen their search for prey. 254 00:26:26,600 --> 00:26:30,320 They are well equipped to hunt in darkness, 255 00:26:30,320 --> 00:26:33,800 with excellent low-light vision, 256 00:26:33,800 --> 00:26:35,880 a superb sense of smell 257 00:26:35,880 --> 00:26:38,360 and highly acute hearing. 258 00:26:41,320 --> 00:26:44,400 But they aren't the only ones out hunting. 259 00:26:49,040 --> 00:26:52,440 A pride of lions has already made a kill. 260 00:26:54,720 --> 00:26:57,120 BELLOWING 261 00:26:59,120 --> 00:27:01,680 LOUD MUNCHING 262 00:27:07,520 --> 00:27:10,080 The hyenas try their luck at scavenging. 263 00:27:12,120 --> 00:27:14,160 DEEP GROWL 264 00:27:16,880 --> 00:27:18,960 HYENAS YELP 265 00:27:34,840 --> 00:27:37,440 HYENAS YELP 266 00:27:48,200 --> 00:27:51,560 There is no easy meal to be had here. 267 00:27:55,000 --> 00:27:56,560 But not far away, 268 00:27:56,560 --> 00:27:59,400 they find one of the most impressive mammals 269 00:27:59,400 --> 00:28:00,920 in the crater. 270 00:28:02,640 --> 00:28:04,440 One with the reputation 271 00:28:04,440 --> 00:28:07,000 of being particularly dangerous. 272 00:28:09,960 --> 00:28:11,760 Cape buffalo. 273 00:28:15,640 --> 00:28:17,600 A single one of them would be enough food 274 00:28:17,600 --> 00:28:19,520 for the whole hyena clan. 275 00:28:21,240 --> 00:28:25,520 But a full-grown buffalo weighs three quarters of a tonne 276 00:28:25,520 --> 00:28:27,200 and is very formidable. 277 00:28:31,280 --> 00:28:34,120 The small group of hyenas look for a weakness 278 00:28:34,120 --> 00:28:36,640 in the buffalo's defence. 279 00:28:36,640 --> 00:28:38,680 BUFFALO SNORTS HYENA YELPS 280 00:28:43,160 --> 00:28:45,320 YELPING 281 00:28:48,520 --> 00:28:50,600 It's just too risky. 282 00:28:57,760 --> 00:29:01,320 But when the odds are stacked against them, 283 00:29:01,320 --> 00:29:03,440 hyenas play their trump card. 284 00:29:04,520 --> 00:29:07,320 DEEP WHOOPING 285 00:29:10,840 --> 00:29:13,840 They summon reinforcements. 286 00:29:13,840 --> 00:29:16,600 WHOOPS 287 00:29:16,600 --> 00:29:19,840 Their calls echo across the crater. 288 00:29:19,840 --> 00:29:22,520 WHOOPS 289 00:29:24,840 --> 00:29:27,280 CHORUS OF WHOOPING 290 00:29:29,480 --> 00:29:32,400 Clan members up to three miles away... 291 00:29:34,120 --> 00:29:36,320 ..hear their cry for assistance. 292 00:29:38,080 --> 00:29:40,360 CHATTERING 293 00:29:40,360 --> 00:29:42,840 DISTANT WHOOPING 294 00:29:51,520 --> 00:29:53,440 BUFFALO GRUNTS 295 00:29:53,440 --> 00:29:55,720 HYENAS YELP 296 00:29:55,720 --> 00:29:58,680 The buffalo is still standing strong. 297 00:30:03,200 --> 00:30:05,520 More reinforcements are needed. 298 00:30:05,520 --> 00:30:07,640 BUFFALO BELLOWS 299 00:30:09,640 --> 00:30:11,760 WHOOPING 300 00:30:32,520 --> 00:30:36,400 Now, with the combined strength of the whole clan... 301 00:30:36,400 --> 00:30:37,960 BUFFALO SNORTS 302 00:30:37,960 --> 00:30:40,800 ..they have a chance. 303 00:30:40,800 --> 00:30:44,680 But a wounded buffalo is particularly dangerous. 304 00:30:48,320 --> 00:30:51,080 One stab from those horns could kill. 305 00:31:02,720 --> 00:31:04,760 YELPING 306 00:31:07,800 --> 00:31:10,800 They must force the buffalo off its feet. 307 00:31:34,800 --> 00:31:39,440 There's no escape from so many hyena. 308 00:31:54,400 --> 00:31:57,040 Their ability to work as a team 309 00:31:57,040 --> 00:31:58,880 makes the spotted hyena 310 00:31:58,880 --> 00:32:02,160 one of Africa's most successful predators. 311 00:32:08,760 --> 00:32:13,120 But there is one mammal that has brought working together 312 00:32:13,120 --> 00:32:15,400 to a whole new level. 313 00:32:22,160 --> 00:32:25,080 Nearly a metre beneath the surface 314 00:32:25,080 --> 00:32:28,360 of the Kalahari Desert, 315 00:32:28,360 --> 00:32:29,720 there are tunnels... 316 00:32:31,480 --> 00:32:36,040 ..where normally, animals live in permanent darkness. 317 00:32:36,040 --> 00:32:38,800 Only our lights make them visible. 318 00:32:45,440 --> 00:32:47,920 Damaraland mole-rats. 319 00:32:56,040 --> 00:33:00,640 The heart of their colony is their nesting chamber. 320 00:33:07,200 --> 00:33:08,520 And here, 321 00:33:08,520 --> 00:33:11,160 amongst the mass of bodies, 322 00:33:11,160 --> 00:33:13,040 lies the queen. 323 00:33:18,560 --> 00:33:22,000 She is the only female who breeds. 324 00:33:23,360 --> 00:33:26,280 All the rest, whether male or female, 325 00:33:26,280 --> 00:33:28,040 are workers. 326 00:33:34,400 --> 00:33:37,760 Their main task is to dig for food. 327 00:33:45,760 --> 00:33:48,560 But the dry season brings a challenge. 328 00:33:50,800 --> 00:33:54,360 The soil becomes so hard and dry 329 00:33:54,360 --> 00:33:57,440 that mole-rats are unable to dig out the tubers 330 00:33:57,440 --> 00:33:59,200 on which they feed. 331 00:34:07,440 --> 00:34:10,600 And their larder is nearly empty. 332 00:34:15,880 --> 00:34:19,080 Digging is now so difficult, 333 00:34:19,080 --> 00:34:21,240 they have to save their energies 334 00:34:21,240 --> 00:34:23,600 until conditions improve. 335 00:34:28,200 --> 00:34:30,560 THUNDER RUMBLES 336 00:34:30,560 --> 00:34:32,600 THUNDER CRACKS 337 00:34:36,520 --> 00:34:38,040 It's late November. 338 00:34:39,400 --> 00:34:42,200 The rains, at last, have returned. 339 00:34:47,160 --> 00:34:50,600 Each downpour helps to soften the soil. 340 00:34:54,880 --> 00:34:58,480 And the workers can start digging again. 341 00:34:59,920 --> 00:35:02,760 Now, using their huge incisors, 342 00:35:02,760 --> 00:35:06,920 they are able to cut through the rain-soaked soil. 343 00:35:10,920 --> 00:35:14,280 The first tubers they find, they eat on the spot. 344 00:35:19,240 --> 00:35:21,480 Once they've had their fill, 345 00:35:21,480 --> 00:35:23,920 they carry away the tubers they find 346 00:35:23,920 --> 00:35:26,880 to a chamber that serves as a larder. 347 00:35:30,080 --> 00:35:32,560 The colony works without pause. 348 00:35:35,320 --> 00:35:40,600 After the rains, they may dig half a mile of new tunnels, 349 00:35:40,600 --> 00:35:43,480 shifting nearly three tonnes of soil. 350 00:35:51,640 --> 00:35:55,120 All in order to restock their larder. 351 00:36:02,400 --> 00:36:05,640 Finally, they have accumulated enough food 352 00:36:05,640 --> 00:36:08,240 to see them through the next dry season. 353 00:36:13,800 --> 00:36:17,520 Thanks to their dedicated teams of workers, 354 00:36:17,520 --> 00:36:19,640 mole-rats have succeeded 355 00:36:19,640 --> 00:36:23,400 in an underground world in permanent darkness. 356 00:36:29,560 --> 00:36:31,680 But there is one group of mammals, 357 00:36:31,680 --> 00:36:34,640 that has colonised the dark with such success 358 00:36:34,640 --> 00:36:37,840 that they've spread to almost every land on Earth 359 00:36:37,840 --> 00:36:39,840 outside the polar regions. 360 00:36:42,160 --> 00:36:45,320 Dusk on the north-west coast of Trinidad. 361 00:36:52,800 --> 00:36:55,080 WAVES LAP AND CRASH 362 00:36:55,080 --> 00:36:57,560 Deep inside a sea cave, 363 00:36:57,560 --> 00:37:00,040 a colony of greater bulldog bats 364 00:37:00,040 --> 00:37:01,600 are waking up. 365 00:37:09,320 --> 00:37:11,360 RAPID SQUEAKING 366 00:37:14,240 --> 00:37:17,520 Whether their English name is a libel or a compliment 367 00:37:17,520 --> 00:37:19,760 is, perhaps, debatable. 368 00:37:22,880 --> 00:37:27,320 Bats are the only mammals that have true powered flight. 369 00:37:31,000 --> 00:37:34,800 Getting airborne requires a thorough preflight check. 370 00:37:40,760 --> 00:37:43,160 Their wings are membranes of skin 371 00:37:43,160 --> 00:37:46,240 stretched between greatly elongated fingers. 372 00:37:49,840 --> 00:37:52,560 Licking helps keep them supple. 373 00:37:56,760 --> 00:37:59,560 These particular bats are also equipped 374 00:37:59,560 --> 00:38:01,640 with an unusual feature. 375 00:38:04,160 --> 00:38:08,680 Their feet have enormously elongated hook-like claws. 376 00:38:14,320 --> 00:38:16,840 They're certainly useful for back scratching. 377 00:38:22,560 --> 00:38:24,320 And ear picking. 378 00:38:29,200 --> 00:38:31,320 But most importantly of all, 379 00:38:31,320 --> 00:38:33,240 they are for hunting. 380 00:38:40,000 --> 00:38:43,160 Inside their cave, it's pitch-black. 381 00:38:44,400 --> 00:38:47,080 But these bats have a sixth sense 382 00:38:47,080 --> 00:38:50,360 that enables them, in effect, to see in the dark. 383 00:38:53,600 --> 00:38:55,920 CHIRPING 384 00:38:55,920 --> 00:38:58,120 Echolocation. 385 00:39:00,640 --> 00:39:03,080 QUICKFIRE CHIRPING 386 00:39:03,080 --> 00:39:06,240 They make a series of very loud, short calls... 387 00:39:08,160 --> 00:39:09,960 ..and by listening to the echoes, 388 00:39:09,960 --> 00:39:12,480 are able to create a mental map 389 00:39:12,480 --> 00:39:14,640 of their surroundings. 390 00:39:14,640 --> 00:39:16,920 ECHOING CHIRPS 391 00:39:21,400 --> 00:39:23,240 It's so detailed 392 00:39:23,240 --> 00:39:26,120 that they can navigate in total darkness. 393 00:39:28,120 --> 00:39:30,440 CHIRPING 394 00:39:31,640 --> 00:39:37,640 And bulldog bats use this talent to catch fish, 395 00:39:37,640 --> 00:39:39,840 which is not easy. 396 00:39:50,000 --> 00:39:53,680 Their calls bounce off the surface of water 397 00:39:53,680 --> 00:39:57,320 so they can't reveal anything beneath. 398 00:39:57,320 --> 00:40:00,560 But they can, nonetheless, give clues. 399 00:40:08,720 --> 00:40:11,640 A bat will scan the surface of the water 400 00:40:11,640 --> 00:40:14,360 with broad echolocation calls. 401 00:40:14,360 --> 00:40:16,480 SLOW CHIRPING 402 00:40:17,680 --> 00:40:19,480 When something is detected, 403 00:40:19,480 --> 00:40:21,640 they're able to focus on it. 404 00:40:26,440 --> 00:40:28,520 A fin cutting the surface 405 00:40:28,520 --> 00:40:30,760 is enough to make them start fishing. 406 00:40:35,720 --> 00:40:39,400 But catching one requires precision flying. 407 00:40:51,640 --> 00:40:53,960 Using its feet like grappling hooks, 408 00:40:53,960 --> 00:40:56,640 it rakes the surface of the sea. 409 00:41:01,960 --> 00:41:05,000 But this is, literally, a shot in the dark. 410 00:41:10,640 --> 00:41:14,040 The bat's timing has to be exactly right 411 00:41:14,040 --> 00:41:16,960 to coincide with the fish breaking the surface. 412 00:41:29,800 --> 00:41:33,400 Eventually, repetition brings a reward. 413 00:41:44,520 --> 00:41:46,960 Thanks to this super-sense, 414 00:41:46,960 --> 00:41:49,440 these remarkable bats have become 415 00:41:49,440 --> 00:41:52,320 astonishingly successful fishermen. 416 00:42:18,680 --> 00:42:22,280 Bats were almost certainly flying in the night skies 417 00:42:22,280 --> 00:42:24,560 when the dinosaurs became extinct. 418 00:42:26,360 --> 00:42:31,640 And now, nearly one quarter of all mammal species are bats. 419 00:42:34,320 --> 00:42:36,000 And that is not all. 420 00:42:40,800 --> 00:42:42,200 They also form 421 00:42:42,200 --> 00:42:45,320 the most numerous gatherings made by any mammal. 422 00:42:50,760 --> 00:42:53,200 Austin, in Texas. 423 00:42:58,320 --> 00:43:01,280 Every evening in early August, 424 00:43:01,280 --> 00:43:04,320 crowds gather around Congress Avenue Bridge... 425 00:43:06,840 --> 00:43:09,880 ..waiting for one of the city's great spectacles. 426 00:43:12,560 --> 00:43:14,200 As the sun sets... 427 00:43:15,680 --> 00:43:17,800 ..the stars appear. 428 00:43:21,760 --> 00:43:23,920 CLAMOROUS CHIRPING 429 00:43:27,400 --> 00:43:30,240 Mexican free-tailed bats. 430 00:43:33,320 --> 00:43:36,400 The gaps on the underside of the bridge 431 00:43:36,400 --> 00:43:39,600 provide excellent roosts for the bats. 432 00:43:45,880 --> 00:43:49,480 And now, 1.5 million of them live there. 433 00:44:25,160 --> 00:44:28,920 These free-tailed bats live very successfully 434 00:44:28,920 --> 00:44:31,040 right alongside us. 435 00:44:32,440 --> 00:44:35,920 There are now more bats than people in Austin... 436 00:44:37,560 --> 00:44:40,240 ..and their numbers are still increasing. 437 00:45:12,040 --> 00:45:14,640 Mammals have evolved many ways 438 00:45:14,640 --> 00:45:17,800 to deal with the problems of living in the dark. 439 00:45:22,280 --> 00:45:26,240 But none have done so more successfully than bats. 440 00:45:28,920 --> 00:45:30,920 In recent years, however, 441 00:45:30,920 --> 00:45:34,800 other mammals have started to alter their habits... 442 00:45:36,360 --> 00:45:38,400 VEHICLES HONK 443 00:45:38,400 --> 00:45:41,160 ..and are changing from being active in the day 444 00:45:41,160 --> 00:45:43,000 to coming out at night. 445 00:45:46,320 --> 00:45:48,400 TRAINS RATTLE OVER TRACKS 446 00:45:50,240 --> 00:45:54,200 And they're doing so in order to avoid us. 447 00:46:06,400 --> 00:46:07,760 A coyote. 448 00:46:09,200 --> 00:46:12,560 A species of dog as wild and untamed 449 00:46:12,560 --> 00:46:15,240 as any wolf or jackal. 450 00:46:16,400 --> 00:46:19,960 And this animal that was once mostly active in the day 451 00:46:19,960 --> 00:46:23,440 has started to take the night shift. 452 00:46:26,280 --> 00:46:28,080 Under the cover of darkness, 453 00:46:28,080 --> 00:46:30,480 they're now living right in the heart 454 00:46:30,480 --> 00:46:32,600 of America's biggest cities. 455 00:46:42,680 --> 00:46:47,880 This is Chicago, home to over nine million people. 456 00:46:54,040 --> 00:46:56,400 For an animal to be successful here, 457 00:46:56,400 --> 00:47:00,280 it helps to be active when we are not. 458 00:47:08,440 --> 00:47:11,120 Just as early mammals became nocturnal 459 00:47:11,120 --> 00:47:14,280 in order to avoid daytime dinosaurs, 460 00:47:14,280 --> 00:47:16,720 these coyotes are now doing so 461 00:47:16,720 --> 00:47:19,760 in order to avoid us. 462 00:47:19,760 --> 00:47:21,800 DISTANT SIRENS 463 00:47:25,120 --> 00:47:28,400 And, as a consequence, they're thriving. 464 00:47:30,480 --> 00:47:35,440 Greater Chicago is now home to over 4,000 coyotes. 465 00:47:41,600 --> 00:47:44,360 They keep a low profile where they can. 466 00:47:48,200 --> 00:47:51,800 Though Chicago, like any city, is full of dangers. 467 00:47:55,000 --> 00:47:58,360 But these clever coyotes are now streetwise. 468 00:48:01,920 --> 00:48:03,520 Some have even learnt 469 00:48:03,520 --> 00:48:05,760 when it's safe to cross the road. 470 00:48:17,640 --> 00:48:19,840 The reason for these urban journeys? 471 00:48:21,600 --> 00:48:24,800 Chicago's downtown parks. 472 00:48:28,240 --> 00:48:30,440 Little oases of wilderness 473 00:48:30,440 --> 00:48:32,760 that attract a surprising variety 474 00:48:32,760 --> 00:48:34,600 of other wildlife 475 00:48:34,600 --> 00:48:36,440 in considerable numbers. 476 00:48:43,880 --> 00:48:46,480 The coyotes don't live on trash. 477 00:48:51,040 --> 00:48:53,520 DISTANT SIRENS 478 00:48:58,680 --> 00:49:00,640 They are skilful hunters. 479 00:49:16,680 --> 00:49:18,640 Before dawn arrives... 480 00:49:20,160 --> 00:49:24,080 ..these wily coyotes retreat into the shadows. 481 00:49:29,320 --> 00:49:33,080 It's the adaptability and ingenuity of these mammals, 482 00:49:33,080 --> 00:49:35,800 indeed of all nocturnal mammals, 483 00:49:35,800 --> 00:49:38,240 that has enabled them to become active 484 00:49:38,240 --> 00:49:40,440 in conditions that we avoid. 485 00:49:43,040 --> 00:49:45,000 They have mastered the dark 486 00:49:45,000 --> 00:49:47,000 and found the richest rewards. 487 00:49:49,080 --> 00:49:52,000 And it should really be no surprise. 488 00:49:52,000 --> 00:49:53,320 After all, 489 00:49:53,320 --> 00:49:57,200 they've been doing just that for millions of years. 490 00:50:15,840 --> 00:50:18,960 One of the greatest challenges facing the Dark team 491 00:50:18,960 --> 00:50:20,960 was filming fennec foxes. 492 00:50:22,160 --> 00:50:26,520 They travelled to Tunisia and into the Sahara. 493 00:50:26,520 --> 00:50:29,800 Helping them was Italian wildlife photographer 494 00:50:29,800 --> 00:50:31,600 Bruno D'Amicis. 495 00:50:31,600 --> 00:50:33,400 Having worked here before, 496 00:50:33,400 --> 00:50:36,480 he knew just how difficult this would be. 497 00:50:36,480 --> 00:50:38,800 We don't know much about fennec foxes. 498 00:50:38,800 --> 00:50:41,440 The studies done on this species in the wild 499 00:50:41,440 --> 00:50:43,920 can be counted on one single hand. 500 00:50:45,080 --> 00:50:47,920 You have this animal living in the largest desert of all, 501 00:50:47,920 --> 00:50:49,880 moving mostly at night, 502 00:50:49,880 --> 00:50:51,880 so, yeah, it is... 503 00:50:51,880 --> 00:50:54,560 ..it is super challenging, it is very difficult. 504 00:50:54,560 --> 00:50:57,520 Bechir Belhadj, a local fennec expert, 505 00:50:57,520 --> 00:51:01,000 was key to helping them track down the best place to film. 506 00:51:01,000 --> 00:51:02,720 Bruno, Bruno. 507 00:51:03,880 --> 00:51:06,720 Oh, there's the fennec. 508 00:51:06,720 --> 00:51:08,880 Yeah, that's great. 509 00:51:08,880 --> 00:51:10,800 Thank goodness they're here. 510 00:51:10,800 --> 00:51:12,520 Oh, here. You see, you see? 511 00:51:13,480 --> 00:51:15,120 You're looking at fennec scats. 512 00:51:15,120 --> 00:51:17,080 Looks like a...beetle casings. 513 00:51:17,080 --> 00:51:19,840 Yeah, many beetle casings. 514 00:51:19,840 --> 00:51:22,200 The signs were encouraging. 515 00:51:22,200 --> 00:51:24,280 But producer Stuart Armstrong knew 516 00:51:24,280 --> 00:51:27,440 that the challenge was still immense. 517 00:51:27,440 --> 00:51:30,320 Great that we've found tracks and signs of fennecs 518 00:51:30,320 --> 00:51:33,080 but it's rolling dunes, you know, 519 00:51:33,080 --> 00:51:36,480 something will disappear so quickly behind a dune, 520 00:51:36,480 --> 00:51:39,320 and then you add in the challenge of doing it in the dark. 521 00:51:40,880 --> 00:51:44,240 Early next morning, Bruno and Stuart got to work 522 00:51:44,240 --> 00:51:47,200 setting up numerous camera traps. 523 00:51:47,200 --> 00:51:50,040 Using super-sensitive low-light cameras 524 00:51:50,040 --> 00:51:52,400 would give them the best chance. 525 00:51:52,400 --> 00:51:55,080 With new technologies, we can get a beautiful glimpse 526 00:51:55,080 --> 00:51:57,120 of what goes on at night, 527 00:51:57,120 --> 00:51:59,560 with...directly with the moonlight. 528 00:51:59,560 --> 00:52:01,200 So it is super exciting. 529 00:52:02,360 --> 00:52:05,000 And wildlife cameramen Pete Cayless 530 00:52:05,000 --> 00:52:08,400 and Marco Andreini started their night shifts. 531 00:52:08,400 --> 00:52:10,960 At least we know that there are foxes around. 532 00:52:10,960 --> 00:52:15,280 Our wish is to see one, um, in front of us. 533 00:52:29,280 --> 00:52:31,920 With clear skies and a full moon, 534 00:52:31,920 --> 00:52:34,120 filming conditions are excellent. 535 00:52:35,320 --> 00:52:36,800 But being nocturnal, 536 00:52:36,800 --> 00:52:40,120 extremely shy and living in such remote locations, 537 00:52:40,120 --> 00:52:43,200 fennec foxes have been filmed only rarely. 538 00:52:44,760 --> 00:52:46,880 But after only a few nights, 539 00:52:46,880 --> 00:52:50,520 this ghost of the desert revealed itself. 540 00:52:50,520 --> 00:52:51,880 WHISPERS: Oh, wow. 541 00:52:54,960 --> 00:52:56,840 HE CHUCKLES QUIETLY 542 00:52:56,840 --> 00:52:58,760 I actually can't believe it. 543 00:53:06,440 --> 00:53:08,680 And when they checked the camera traps, 544 00:53:08,680 --> 00:53:10,840 the news got even better. 545 00:53:10,840 --> 00:53:12,320 Yay! 546 00:53:14,000 --> 00:53:15,480 Look at that! No way. 547 00:53:15,480 --> 00:53:17,800 Look at the size of those ears. 548 00:53:17,800 --> 00:53:20,280 Yeah. They're huge. Yeah. 549 00:53:21,680 --> 00:53:23,760 Sweet little thing. 550 00:53:23,760 --> 00:53:25,920 That's so encouraging. 551 00:53:25,920 --> 00:53:27,760 That's super encouraging. 552 00:53:27,760 --> 00:53:29,960 Yay! 553 00:53:29,960 --> 00:53:31,840 All was going well. 554 00:53:33,440 --> 00:53:36,000 But their good luck soon vanished. 555 00:53:37,680 --> 00:53:39,160 HE SIGHS 556 00:53:39,160 --> 00:53:41,120 The foxes had disappeared. 557 00:53:41,120 --> 00:53:43,320 HE EXHALES 558 00:53:43,320 --> 00:53:45,880 Night after night brought no rewards 559 00:53:45,880 --> 00:53:49,680 for camera operators or camera traps. 560 00:53:49,680 --> 00:53:52,200 Keep trying, that's the only thing I can do. 561 00:53:52,200 --> 00:53:54,760 I really hope they will...they will come. 562 00:53:59,080 --> 00:54:00,520 Nothing. 563 00:54:04,400 --> 00:54:06,400 Nothing, nothing, nothing. 564 00:54:08,960 --> 00:54:10,840 Frustrating to say the least. 565 00:54:15,720 --> 00:54:18,080 The crew eventually discovered the reason 566 00:54:18,080 --> 00:54:20,320 for the fox's sudden disappearance. 567 00:54:22,040 --> 00:54:26,480 A few miles away, they found a recently abandoned camp, 568 00:54:26,480 --> 00:54:30,360 and amongst the litter was the most shocking find. 569 00:54:33,160 --> 00:54:34,840 We're all a bit stunned. 570 00:54:36,280 --> 00:54:38,320 We discovered one of the foxes on the floor 571 00:54:38,320 --> 00:54:40,520 and we thought that was shocking enough, 572 00:54:40,520 --> 00:54:42,680 and then just...just up here... 573 00:54:46,680 --> 00:54:48,440 ..is a second fox. 574 00:54:51,080 --> 00:54:53,120 It's just heartbreaking. 575 00:54:56,480 --> 00:54:59,080 There's...no end to this horror. 576 00:55:00,120 --> 00:55:03,240 Here, it is illegal to kill a fennec fox. 577 00:55:04,640 --> 00:55:07,600 But it's difficult to police such a remote place 578 00:55:07,600 --> 00:55:11,600 and, sadly, they are still heavily persecuted - 579 00:55:11,600 --> 00:55:16,120 trapped for pets, but also for food, fur 580 00:55:16,120 --> 00:55:18,120 and, in this case, more shockingly, 581 00:55:18,120 --> 00:55:20,200 it seemed, for fun. 582 00:55:21,480 --> 00:55:23,720 I'm heartbroken, I'm heartbroken. 583 00:55:31,000 --> 00:55:35,720 Saharan wildlife is some of the most threatened on Earth, 584 00:55:35,720 --> 00:55:39,680 and only with local champions can the situation here change. 585 00:55:41,000 --> 00:55:44,320 As a young man, Bechir used to trap foxes, 586 00:55:44,320 --> 00:55:46,080 but he hunts no more. 587 00:55:47,280 --> 00:55:49,160 He's become an advocate, 588 00:55:49,160 --> 00:55:52,640 helping to spread the message throughout the local communities 589 00:55:52,640 --> 00:55:54,920 that fennecs need protecting, 590 00:55:54,920 --> 00:56:00,000 and he hopes a film about these foxes could help with that, 591 00:56:00,000 --> 00:56:01,880 which made him and the crew 592 00:56:01,880 --> 00:56:05,120 even more determined to not give up. 593 00:56:09,560 --> 00:56:12,800 Bechir knew of another potential location. 594 00:56:12,800 --> 00:56:14,440 A remote oasis, 595 00:56:14,440 --> 00:56:17,680 and the signs are encouraging for everyone. 596 00:56:18,680 --> 00:56:21,200 Wow. There are loads of tracks. 597 00:56:21,200 --> 00:56:24,320 There must be more than one animal. This cannot be one animal. 598 00:56:24,320 --> 00:56:27,280 This is very exciting, isn't it? Yeah. 599 00:56:27,280 --> 00:56:31,360 New location, a new day, new hope. 600 00:56:34,400 --> 00:56:37,600 But would the tracks and signs turn into success 601 00:56:37,600 --> 00:56:39,120 for Marco and Pete? 602 00:56:42,800 --> 00:56:44,600 How are you doing? How was your night? 603 00:56:44,600 --> 00:56:47,960 Ah, it was a long, long, long, long night. 604 00:56:49,400 --> 00:56:54,680 I must have been crazy when I chose this hide. 605 00:56:54,680 --> 00:56:56,960 HE GRUNTS It's too small. 606 00:57:01,800 --> 00:57:03,480 But it worked. 607 00:57:04,720 --> 00:57:07,640 There was one fluffy... 608 00:57:07,640 --> 00:57:09,400 HE LAUGHS 609 00:57:09,400 --> 00:57:12,760 ..then two fennec foxes there. 610 00:57:14,520 --> 00:57:18,360 To see two foxes, possibly a courting pair, 611 00:57:18,360 --> 00:57:21,000 brought the team a lot of hope. 612 00:57:22,200 --> 00:57:24,520 These animals are so incredible. 613 00:57:24,520 --> 00:57:28,200 It's like the spirit of this desert. 614 00:57:30,040 --> 00:57:31,680 It was so beautiful. 615 00:57:31,680 --> 00:57:32,880 I'm so happy... 616 00:57:32,880 --> 00:57:34,440 HE LAUGHS ..now. 617 00:57:37,640 --> 00:57:41,480 In remote corners and against many odds, 618 00:57:41,480 --> 00:57:45,320 these endearing foxes still survive. 619 00:57:45,320 --> 00:57:48,760 And, hopefully, the support of local communities 620 00:57:48,760 --> 00:57:51,720 will help to conserve not just fennecs 621 00:57:51,720 --> 00:57:55,320 but other threatened wildlife across the Sahara. 622 00:58:05,120 --> 00:58:07,120 Next time... GROWLING 623 00:58:07,120 --> 00:58:10,240 ..mammals continue their journey into our world... 624 00:58:10,240 --> 00:58:12,760 THEY SQUEAK AND CHIRP 625 00:58:12,760 --> 00:58:14,440 ELEPHANT TRUMPETS 626 00:58:14,440 --> 00:58:17,280 ..a world changing faster than ever before... 627 00:58:21,320 --> 00:58:24,200 ..and full of new challenges.