1 00:00:04,260 --> 00:00:07,060 In the heart of the Americas, 2 00:00:07,060 --> 00:00:11,180 where continents collide, 3 00:00:11,180 --> 00:00:13,940 there's a land full of natural riches. 4 00:00:33,860 --> 00:00:35,980 A land of towering giants... 5 00:00:38,940 --> 00:00:40,660 ..scorching sands... 6 00:00:43,420 --> 00:00:45,620 ..and secret rivers. 7 00:00:52,780 --> 00:00:54,900 Where great civilisations rose... 8 00:00:56,220 --> 00:00:57,980 ..and fell. 9 00:01:02,740 --> 00:01:05,580 To succeed here takes passion and spirit. 10 00:01:12,180 --> 00:01:15,420 This is a country rich in colour and culture. 11 00:01:19,740 --> 00:01:22,180 A festival of life. 12 00:01:33,620 --> 00:01:36,060 This is Mexico. 13 00:02:05,100 --> 00:02:09,340 Just south of the American border is a little-known world... 14 00:02:13,820 --> 00:02:16,740 ..Northern Mexico's prairie lands. 15 00:02:31,860 --> 00:02:33,940 These dry grasslands are home 16 00:02:33,940 --> 00:02:36,260 to one of Mexico's most sociable animals... 17 00:02:40,220 --> 00:02:42,660 ..the black-tailed prairie dog. 18 00:02:47,980 --> 00:02:52,660 They live in extensive colonies comprised of dozens of families, 19 00:02:52,660 --> 00:02:56,180 each with a dominant male, several females 20 00:02:56,180 --> 00:02:57,900 and their offspring. 21 00:03:02,700 --> 00:03:06,820 In May, their six-week-old pups take their first steps above ground. 22 00:03:25,300 --> 00:03:28,460 Grasses and other prairie plants provide all the food 23 00:03:28,460 --> 00:03:30,780 and moisture these vegetarians need. 24 00:03:32,740 --> 00:03:35,260 But feeding in this open terrain 25 00:03:35,260 --> 00:03:36,860 comes with risks. 26 00:03:56,420 --> 00:04:00,060 Their burrows offer an escape from birds of prey 27 00:04:00,060 --> 00:04:02,220 and coyotes. 28 00:04:08,180 --> 00:04:10,220 But they're no protection 29 00:04:10,220 --> 00:04:13,780 from one of the prairie's most persistent hunters... 30 00:04:16,700 --> 00:04:19,260 ..the bullsnake. 31 00:04:26,620 --> 00:04:29,180 This powerful constrictor could easily 32 00:04:29,180 --> 00:04:31,100 suffocate an adult prairie dog. 33 00:04:31,100 --> 00:04:33,780 PRAIRIE DOG SQUEAKS 34 00:04:36,820 --> 00:04:39,060 But it's pups he's after. 35 00:04:48,260 --> 00:04:50,740 And they are hiding somewhere in their burrow. 36 00:05:03,660 --> 00:05:05,860 PRAIRIE DOG SQUEALS 37 00:05:05,860 --> 00:05:09,900 Their father would be foolhardy to follow this predator underground. 38 00:05:28,580 --> 00:05:31,660 The snake's found nothing down this hole, 39 00:05:31,660 --> 00:05:34,100 so he's on to the next. 40 00:05:41,020 --> 00:05:45,900 To save his pups, their father must somehow drive the snake away. 41 00:06:08,060 --> 00:06:09,900 PRAIRE DOG CALLS 42 00:06:09,900 --> 00:06:12,500 He stands to warn others where the snake is. 43 00:06:15,580 --> 00:06:18,340 Repeated strikes may just drive it away. 44 00:06:23,500 --> 00:06:25,660 PRAIRIE DOG CALLS 45 00:06:38,100 --> 00:06:40,940 The snake concedes defeat. 46 00:06:46,460 --> 00:06:49,660 On the open prairies, there's safety in numbers 47 00:06:49,660 --> 00:06:51,660 in this prairie-dog town. 48 00:06:55,340 --> 00:06:58,100 Thanks to their father's bravery, 49 00:06:58,100 --> 00:06:59,780 the pups are safe again. 50 00:07:08,780 --> 00:07:11,860 Northern Mexico sits at a latitude 51 00:07:11,860 --> 00:07:14,660 where high atmospheric pressure dominates. 52 00:07:14,660 --> 00:07:17,060 A little rain ever falls. 53 00:07:18,540 --> 00:07:22,140 This is Mexico's driest region. 54 00:07:22,140 --> 00:07:24,300 Much of it is desert. 55 00:07:30,300 --> 00:07:34,140 It's the least populated, wildest corner of the country. 56 00:07:38,860 --> 00:07:42,220 Journey west and conditions only get hotter, 57 00:07:42,220 --> 00:07:45,100 drier and more challenging. 58 00:07:50,220 --> 00:07:54,340 But for those who overcome these conditions, 59 00:07:54,340 --> 00:07:57,340 there are rich rewards... 60 00:07:59,900 --> 00:08:03,180 ..especially on Mexico's northern prairies. 61 00:08:04,900 --> 00:08:08,340 THUNDER 62 00:08:10,700 --> 00:08:12,940 Lying in the foothills of mountains, 63 00:08:12,940 --> 00:08:16,380 at an altitude of over 5,000 feet, 64 00:08:16,380 --> 00:08:20,460 these grasslands catch a little more rain than most of the north. 65 00:08:32,140 --> 00:08:34,860 Between June and September, 66 00:08:34,860 --> 00:08:38,340 monsoon storms roll in off the Caribbean, 67 00:08:38,340 --> 00:08:40,740 helping grass to grow. 68 00:08:47,420 --> 00:08:52,260 For the rest of the year, little, if any, rain falls. 69 00:08:56,860 --> 00:08:59,340 But even during drought, there is water here. 70 00:09:05,940 --> 00:09:07,740 Deep underground, 71 00:09:07,740 --> 00:09:11,420 great reservoirs are trapped in the porous limestone bedrock. 72 00:09:17,540 --> 00:09:20,140 These giant aquifers help support 73 00:09:20,140 --> 00:09:23,420 one of Mexico's most iconic ways of life. 74 00:09:23,420 --> 00:09:25,700 INDISTINCT SHOUTS 75 00:09:28,420 --> 00:09:29,940 HORSE WHINNIES 76 00:09:29,940 --> 00:09:32,140 This is cowboy country. 77 00:09:39,020 --> 00:09:42,540 With year-round water and plenty of pasture, 78 00:09:42,540 --> 00:09:45,580 these prairies are ideal for cattle ranching. 79 00:09:50,700 --> 00:09:54,300 For centuries, people like Servando Diaz Gomez 80 00:09:54,300 --> 00:09:56,260 have worked this land. 81 00:10:19,980 --> 00:10:23,620 Cowboys are rooted in American culture, 82 00:10:23,620 --> 00:10:28,100 but their true birthplace is here in the prairies of Northern Mexico. 83 00:10:37,500 --> 00:10:39,820 In the 16th century, the Spanish 84 00:10:39,820 --> 00:10:42,660 brought cattle and horses to the north, 85 00:10:42,660 --> 00:10:45,780 and trained locals to manage their herds. 86 00:10:52,020 --> 00:10:55,260 The vaquero, or cowboy, was born. 87 00:11:26,780 --> 00:11:29,580 But the dry conditions make ranching tough. 88 00:11:32,260 --> 00:11:34,660 These grasses are easily overgrazed. 89 00:11:36,660 --> 00:11:38,940 Over the last 100 years, 90 00:11:38,940 --> 00:11:42,380 farming and drought have damaged over half of the prairies. 91 00:11:50,340 --> 00:11:53,620 But Servando is one of a pioneering band 92 00:11:53,620 --> 00:11:56,060 trying to reverse this trend. 93 00:11:59,020 --> 00:12:01,020 Using electric fences, 94 00:12:01,020 --> 00:12:03,900 he confines his herd to small blocks of pasture. 95 00:12:09,140 --> 00:12:12,380 Every few hours, they're moved on to the next block. 96 00:12:18,140 --> 00:12:21,100 The grazed area is then left to recover. 97 00:12:25,660 --> 00:12:28,500 It's a practice that's having a big impact. 98 00:12:34,300 --> 00:12:38,860 This healthy pasture is helping Servando rear twice as many cattle. 99 00:12:41,580 --> 00:12:43,940 And wildlife is thriving. 100 00:12:51,260 --> 00:12:55,540 Well-managed prairies offer a rich diet of insects and seeds 101 00:12:55,540 --> 00:12:58,780 for up to three times as many grassland birds. 102 00:13:03,260 --> 00:13:07,700 And they provide food for one of Mexico's rarest creatures... 103 00:13:13,380 --> 00:13:15,420 ..the aplomado falcon. 104 00:13:19,700 --> 00:13:23,140 They range as far south as Argentina, 105 00:13:23,140 --> 00:13:26,380 but Mexico's prairies are their northern limit, 106 00:13:26,380 --> 00:13:29,420 where only a handful survive. 107 00:13:32,660 --> 00:13:35,100 Like its relative, the peregrine, 108 00:13:35,100 --> 00:13:37,500 it specialises in aerial assault. 109 00:13:53,420 --> 00:13:56,460 The falcon is much faster in level flight. 110 00:14:02,900 --> 00:14:05,900 But its prey is far quicker on the turn. 111 00:14:22,980 --> 00:14:26,420 Only one in five pursuits ends in success. 112 00:14:27,540 --> 00:14:30,180 But aplomado falcons have a secret weapon... 113 00:14:35,420 --> 00:14:37,980 ..breeding pairs hunt together. 114 00:15:07,780 --> 00:15:11,780 Their prey's only chance to escape is to hide. 115 00:15:24,020 --> 00:15:28,380 The falcons need to flush the bird out... 116 00:15:32,420 --> 00:15:35,300 ..and two birds are better than one. 117 00:16:02,620 --> 00:16:06,020 Working together, these birds are twice as successful. 118 00:16:07,460 --> 00:16:10,900 And every catch is vital when you're raising a family. 119 00:16:14,060 --> 00:16:16,620 Conservationists have put up platforms 120 00:16:16,620 --> 00:16:20,340 to protect the precious chicks from ravens and owls. 121 00:16:21,380 --> 00:16:24,500 Precious because they are so rare. 122 00:16:29,700 --> 00:16:33,300 There are only five pairs here, 123 00:16:33,300 --> 00:16:37,700 and these are the only ones to successfully breed this year. 124 00:16:42,340 --> 00:16:45,420 But with conservationists and ranchers 125 00:16:45,420 --> 00:16:48,300 looking out for these spectacular birds, 126 00:16:48,300 --> 00:16:50,740 they've hopefully got a brighter future. 127 00:16:54,820 --> 00:16:58,260 Teamwork is important for many in Mexico's prairies. 128 00:17:02,500 --> 00:17:04,940 So, too, is bravery. 129 00:17:33,420 --> 00:17:36,460 Charros are traditionally dressed cowboys 130 00:17:36,460 --> 00:17:39,660 who compete in Mexico's official national sport... 131 00:17:44,740 --> 00:17:46,540 ..the charreria. 132 00:17:54,740 --> 00:17:57,980 What was once a friendly competition between neighbours 133 00:17:57,980 --> 00:17:59,620 hundreds of years ago 134 00:17:59,620 --> 00:18:04,260 is now the ultimate display of cowboy bravado. 135 00:18:18,500 --> 00:18:21,740 Each team of charros is made up of specialists 136 00:18:21,740 --> 00:18:24,980 who perform nine different equestrian events across the day... 137 00:18:26,580 --> 00:18:29,260 ..that showcase all the cattle handling, 138 00:18:29,260 --> 00:18:32,900 riding and roping skills used in cowboy life. 139 00:18:35,980 --> 00:18:39,100 The most dangerous is saved until last. 140 00:18:43,820 --> 00:18:47,500 Martin specialises in el paso de la muerte... 141 00:18:52,100 --> 00:18:54,460 ..the pass of death. 142 00:18:57,300 --> 00:18:59,260 Galloping at full speed, 143 00:18:59,260 --> 00:19:03,580 he has to jump onto the back of a wild, untamed horse 144 00:19:03,580 --> 00:19:06,020 and hang on without reins. 145 00:19:12,180 --> 00:19:14,460 If he falls, he'll be trampled. 146 00:19:25,780 --> 00:19:30,180 Martin now risks everything to secure victory for his team. 147 00:20:26,500 --> 00:20:30,100 In the burning north, success favours the brave. 148 00:20:41,020 --> 00:20:45,980 Mexico's prairies run along the edge of great mountain ranges - 149 00:20:45,980 --> 00:20:49,700 the Western and Eastern Sierra Madres. 150 00:20:53,980 --> 00:20:56,260 Over 10,000 feet high, 151 00:20:56,260 --> 00:20:59,620 they intercept moist air coming from the Pacific Ocean 152 00:20:59,620 --> 00:21:01,140 and Gulf of Mexico. 153 00:21:05,740 --> 00:21:09,620 Beyond the prairies, the land is starved of rain... 154 00:21:13,020 --> 00:21:16,780 ..creating one of the biggest deserts in North America. 155 00:21:21,900 --> 00:21:24,460 The Chihuahuan Desert. 156 00:21:28,380 --> 00:21:31,020 It covers an area larger than Britain... 157 00:21:33,140 --> 00:21:36,540 ..and receives about half as much rain as the prairies. 158 00:21:43,180 --> 00:21:45,700 But in the heart of this desert 159 00:21:45,700 --> 00:21:48,700 is one of Mexico's greatest natural wonders... 160 00:21:50,420 --> 00:21:53,340 ..the valley of Cuatro Cienegas. 161 00:22:01,300 --> 00:22:03,540 It may look barren... 162 00:22:07,100 --> 00:22:09,740 ..but this valley hides an oasis. 163 00:22:37,020 --> 00:22:39,900 Here, aquifers break the surface, 164 00:22:39,900 --> 00:22:42,140 creating a water world. 165 00:22:46,420 --> 00:22:50,060 Most of these pools, known locally as pozas, 166 00:22:50,060 --> 00:22:52,740 are fed by thermal springs, 167 00:22:52,740 --> 00:22:57,460 where underground water is forced to the surface by geothermal heat. 168 00:23:03,140 --> 00:23:05,220 Millions of years ago, 169 00:23:05,220 --> 00:23:08,020 when this region was much wetter, 170 00:23:08,020 --> 00:23:10,940 ancient waterways brought fish into this valley. 171 00:23:14,260 --> 00:23:17,460 As the climate dried, the waters receded, 172 00:23:17,460 --> 00:23:20,580 and fish became isolated in pools, 173 00:23:20,580 --> 00:23:23,380 evolving into many new species. 174 00:23:29,860 --> 00:23:33,340 16 species live here, 175 00:23:33,340 --> 00:23:36,780 half of them found nowhere else on Earth. 176 00:23:41,180 --> 00:23:43,860 Including this one, 177 00:23:43,860 --> 00:23:46,540 a Cuatro Cienegas cichlid. 178 00:23:52,420 --> 00:23:55,740 This female has a family... 179 00:23:57,940 --> 00:24:01,340 ..and she is the most devoted mother. 180 00:24:06,860 --> 00:24:08,940 Stirring up the sediment, 181 00:24:08,940 --> 00:24:12,940 she exposes tiny plankton for her fry to feed on. 182 00:24:18,020 --> 00:24:22,860 But the biggest challenge isn't feeding her babies, 183 00:24:22,860 --> 00:24:25,260 it's protecting them. 184 00:24:34,300 --> 00:24:37,500 Some cichlids have evolved into predators... 185 00:24:42,940 --> 00:24:46,100 ..and in this small pool there are few places to hide. 186 00:25:05,180 --> 00:25:08,380 From dawn until dusk, she must defend her brood. 187 00:25:12,860 --> 00:25:15,780 She has no time to feed herself, 188 00:25:15,780 --> 00:25:18,540 and is getting weaker by the day. 189 00:25:25,460 --> 00:25:26,980 But it's worth it. 190 00:25:26,980 --> 00:25:31,860 Without her help, her young would never survive. 191 00:25:35,620 --> 00:25:37,820 When they're a centimetre long, 192 00:25:37,820 --> 00:25:39,860 they will fend for themselves. 193 00:25:42,180 --> 00:25:45,780 Until then, this mother must give her all. 194 00:25:50,220 --> 00:25:52,660 An astonishing diversity of life 195 00:25:52,660 --> 00:25:54,500 has evolved in this valley. 196 00:25:56,980 --> 00:25:59,260 It's home to more unique species 197 00:25:59,260 --> 00:26:02,380 than anywhere else on the North American continent. 198 00:26:04,660 --> 00:26:07,180 That's the exception to the norm. 199 00:26:16,220 --> 00:26:18,860 Most of this great desert is dominated 200 00:26:18,860 --> 00:26:21,020 by just a few hardy souls. 201 00:26:23,180 --> 00:26:25,980 And one plant copes better than most... 202 00:26:31,380 --> 00:26:34,140 ..the creosote bush - 203 00:26:34,140 --> 00:26:37,740 so-called because it smells like wood preservative. 204 00:26:42,940 --> 00:26:46,140 Locals call it la gobernadora - 205 00:26:46,140 --> 00:26:48,060 the governess. 206 00:26:48,060 --> 00:26:52,100 And it governs for a very long time. 207 00:26:56,620 --> 00:26:59,060 One plant is known to have survived 208 00:26:59,060 --> 00:27:02,540 for over 11,000 years. 209 00:27:07,300 --> 00:27:09,860 It's brilliant at coping with drought. 210 00:27:12,980 --> 00:27:15,100 Tiny, resin-coated leaves 211 00:27:15,100 --> 00:27:18,420 drastically reduce water loss. 212 00:27:22,100 --> 00:27:25,460 And its shallow roots quickly soak up any moisture... 213 00:27:27,460 --> 00:27:29,780 ..stopping anything growing in between. 214 00:27:38,540 --> 00:27:41,940 Creosote has truly conquered this desert. 215 00:27:45,820 --> 00:27:49,260 Its success has been exploited by a creature 216 00:27:49,260 --> 00:27:51,500 that's addicted to creosote... 217 00:27:51,500 --> 00:27:54,340 CHIRPING SOUNDS 218 00:28:04,300 --> 00:28:06,820 ..the creosote bush grasshopper. 219 00:28:13,220 --> 00:28:16,980 It's one of the few animals that can stomach this plant. 220 00:28:19,980 --> 00:28:24,020 It's resinous leaves are indigestible to most animals, 221 00:28:24,020 --> 00:28:27,380 but this grasshopper eats nothing else. 222 00:28:28,980 --> 00:28:31,900 It's even evolved to look like this plant 223 00:28:31,900 --> 00:28:34,140 to avoid becoming food itself. 224 00:28:38,260 --> 00:28:42,420 Most of the bushes have their own resident male. 225 00:28:42,420 --> 00:28:44,540 GRASSHOPPERS CHIRP 226 00:28:45,980 --> 00:28:49,900 Their calls let other males know this bush is occupied. 227 00:28:54,020 --> 00:28:57,020 They're also very attractive to the opposite sex. 228 00:29:02,380 --> 00:29:06,660 This newly-arrived female is exactly what he's been waiting for. 229 00:29:13,460 --> 00:29:15,780 But they are not alone for long. 230 00:29:15,780 --> 00:29:18,020 Another male flies in. 231 00:29:22,740 --> 00:29:25,780 A female is worth fighting for. 232 00:29:33,500 --> 00:29:36,980 He must throw his rival out of his bush. 233 00:29:54,660 --> 00:29:57,660 Easier said than done with so many legs. 234 00:30:09,660 --> 00:30:12,460 Victory for the resident male. 235 00:30:20,700 --> 00:30:25,500 But he's just one of millions of battling grasshoppers 236 00:30:25,500 --> 00:30:29,020 in this endless expanse of creosote. 237 00:30:29,020 --> 00:30:31,780 GRASSHOPPERS CHIRP 238 00:30:41,100 --> 00:30:43,380 Hundreds of miles to the west, 239 00:30:43,380 --> 00:30:46,580 the vast Chihuahuan Desert meets great mountains. 240 00:30:54,140 --> 00:30:58,660 These high sierras catch more rain than the desert below, 241 00:30:58,660 --> 00:31:00,860 enabling forests to grow. 242 00:31:04,100 --> 00:31:07,140 Offering a refuge for a special plant 243 00:31:07,140 --> 00:31:09,940 with the hottest reputation. 244 00:31:09,940 --> 00:31:12,580 THEY SPEAK SPANISH 245 00:31:15,260 --> 00:31:18,900 Every autumn, Armida Elena Contreras Duron 246 00:31:18,900 --> 00:31:23,260 and her husband Eliazar head out to their mountain ranch 247 00:31:23,260 --> 00:31:27,020 to pick wild chillies called chiltepin. 248 00:31:46,340 --> 00:31:49,780 These plants might have a fiery nature, 249 00:31:49,780 --> 00:31:52,660 but they can be remarkably delicate. 250 00:31:52,660 --> 00:31:55,540 They don't like constant exposure to the desert sun. 251 00:31:58,940 --> 00:32:02,260 But this woodland provides enough shade for them to thrive. 252 00:32:10,340 --> 00:32:15,180 6,000 years ago, this wild plant started a food revolution 253 00:32:15,180 --> 00:32:18,420 when it was first domesticated here in Mexico. 254 00:32:21,580 --> 00:32:25,340 It's given rise to thousands of varieties of chillies worldwide. 255 00:32:26,900 --> 00:32:30,820 And with fruit 20 times hotter than jalapenos, 256 00:32:30,820 --> 00:32:33,780 it gives a spectacular kick to Armida's cuisine. 257 00:33:04,100 --> 00:33:06,540 And an awful lot of chillies. 258 00:33:12,820 --> 00:33:16,540 Every type of chilli has a unique flavour. 259 00:33:16,540 --> 00:33:19,140 Chiltepins are particularly cherished 260 00:33:19,140 --> 00:33:21,860 because they are arrebatado, 261 00:33:21,860 --> 00:33:24,980 meaning rapid, or violent. 262 00:33:24,980 --> 00:33:29,620 They're hot, but their heat subsides quickly, and that's addictive. 263 00:33:47,220 --> 00:33:51,460 To Armida and her family, it's part of their national identity. 264 00:34:03,820 --> 00:34:06,460 These mountain forests are one of the few places 265 00:34:06,460 --> 00:34:09,980 where wild chiltepin thrive. 266 00:34:09,980 --> 00:34:13,100 And because of our love of this spicy plant, 267 00:34:13,100 --> 00:34:16,860 its descendants have spread all around the world. 268 00:34:34,940 --> 00:34:37,140 In the foothills to the west, 269 00:34:37,140 --> 00:34:39,740 the sun has shaped another desert 270 00:34:39,740 --> 00:34:41,820 that couldn't look more different. 271 00:34:49,180 --> 00:34:53,260 Stretching over 100,000 square miles, 272 00:34:53,260 --> 00:34:57,220 the Sonoran Desert covers much of Northwest Mexico. 273 00:35:05,740 --> 00:35:09,420 And it's home to the most iconic desert plant of all... 274 00:35:13,900 --> 00:35:16,260 ..the saguaro cactus. 275 00:35:22,860 --> 00:35:26,900 The Sonoran Desert is hotter and drier than the Chihuahuan. 276 00:35:30,460 --> 00:35:33,700 And one way to cope is to become gigantic. 277 00:35:42,140 --> 00:35:44,660 Towering up to 18 metres, 278 00:35:44,660 --> 00:35:47,820 saguaros can store great reserves of water. 279 00:35:50,380 --> 00:35:52,940 THUNDER 280 00:36:00,860 --> 00:36:05,780 During summer storms, a season's rain can fall in just a few hours. 281 00:36:11,420 --> 00:36:15,380 The saguaro is built to take advantage of this. 282 00:36:15,380 --> 00:36:19,660 Its shallow roots stretch as wide as the cactus is tall, 283 00:36:19,660 --> 00:36:24,380 and its split trunk allows it to expand like an accordion, 284 00:36:24,380 --> 00:36:26,660 enabling the largest cacti 285 00:36:26,660 --> 00:36:29,860 to absorb one tonne of water during one storm. 286 00:36:37,420 --> 00:36:40,460 It's enough water to last for a year, 287 00:36:40,460 --> 00:36:44,380 making saguaros the lifeblood of this desert. 288 00:36:52,660 --> 00:36:55,620 Even in a drought year, saguaros bloom. 289 00:36:55,620 --> 00:36:58,500 They're a magnet for wildlife. 290 00:37:10,340 --> 00:37:14,460 Almost every creature here relies on this plant, 291 00:37:14,460 --> 00:37:17,220 and not just as a source of food and moisture. 292 00:37:27,500 --> 00:37:31,260 Most of the older cacti are pockmarked with nest holes... 293 00:37:33,220 --> 00:37:36,460 ..excavated by Gila woodpeckers. 294 00:37:43,380 --> 00:37:45,420 But squatters often move in. 295 00:37:47,860 --> 00:37:49,900 In this world of giants, 296 00:37:49,900 --> 00:37:51,540 it helps to be tiny. 297 00:37:55,980 --> 00:37:59,300 Not much bigger than a sparrow, 298 00:37:59,300 --> 00:38:03,020 ferruginous pygmy owls easily squeeze into woodpecker holes. 299 00:38:05,740 --> 00:38:09,020 And this female has a family to feed. 300 00:38:18,740 --> 00:38:22,020 Deep inside, chicks are safe. 301 00:38:23,740 --> 00:38:26,300 And not just from predators. 302 00:38:28,940 --> 00:38:31,380 Outside is 40 degrees... 303 00:38:39,100 --> 00:38:42,140 ..but this plant's enormous stores of water 304 00:38:42,140 --> 00:38:44,980 keep the interior up to eight degrees cooler 305 00:38:44,980 --> 00:38:46,700 than the surroundings. 306 00:38:55,340 --> 00:38:59,180 A vital refuge for a family of tiny owls 307 00:38:59,180 --> 00:39:01,620 in the crippling heat of the day. 308 00:39:14,140 --> 00:39:19,460 At night, the daytime heat is lost to the heavens. 309 00:39:28,860 --> 00:39:32,940 With such clear skies and no light pollution, 310 00:39:32,940 --> 00:39:36,940 Northern Mexico is one of the best places on Earth 311 00:39:36,940 --> 00:39:38,980 to stargaze. 312 00:39:51,020 --> 00:39:55,220 Under the cooler conditions, the desert comes alive. 313 00:39:59,420 --> 00:40:02,340 Many animals switch to a night routine 314 00:40:02,340 --> 00:40:04,260 to avoid the heat of the day. 315 00:40:13,500 --> 00:40:17,260 Including one of Mexico's most infamous residents. 316 00:40:22,060 --> 00:40:23,660 The scorpion. 317 00:40:27,980 --> 00:40:33,900 Mexico is home to the greatest diversity of scorpions on Earth 318 00:40:33,900 --> 00:40:36,860 and the Sonoran Desert is a stronghold. 319 00:40:45,460 --> 00:40:49,660 But even fearsome predators must tread carefully. 320 00:40:51,100 --> 00:40:53,740 Others are listening in. 321 00:41:00,780 --> 00:41:05,220 In the desert, you've got to grab any opportunity for a meal, 322 00:41:05,220 --> 00:41:07,220 no matter how dangerous. 323 00:41:12,180 --> 00:41:16,500 Pallid bats have become scorpion-hunting specialists. 324 00:41:30,140 --> 00:41:33,820 Their large ears are especially sensitive, 325 00:41:33,820 --> 00:41:37,420 capable of hearing the footsteps of their prey. 326 00:41:45,380 --> 00:41:49,180 As long as this scorpion stays still, it's safe. 327 00:41:52,940 --> 00:41:56,740 But this bat has another way of increasing its chances. 328 00:42:04,020 --> 00:42:06,060 It stalks its prey. 329 00:42:16,980 --> 00:42:20,620 The slightest flinch will give the scorpion away. 330 00:42:49,340 --> 00:42:52,300 Its sting is no defence. 331 00:42:52,300 --> 00:42:55,300 Pallid bats are immune to scorpion venom. 332 00:42:59,980 --> 00:43:04,580 By learning how to hunt one of the desert's most common creatures, 333 00:43:04,580 --> 00:43:07,700 these bats have found a unique way to prosper 334 00:43:07,700 --> 00:43:09,500 in this difficult environment. 335 00:43:13,700 --> 00:43:15,340 It's a big meal, too, 336 00:43:15,340 --> 00:43:19,180 and a vital source of moisture in such a dry place. 337 00:43:37,220 --> 00:43:40,340 On the western edge of the Sonoran Desert, 338 00:43:40,340 --> 00:43:44,060 daytime conditions couldn't be more extreme. 339 00:43:48,340 --> 00:43:50,460 This is El Pinacate. 340 00:43:51,780 --> 00:43:54,940 A landscape with a violent past. 341 00:43:54,940 --> 00:44:00,220 Pitted with volcanic craters and extensive lava flows. 342 00:44:03,860 --> 00:44:07,740 Temperatures can reach 56 Celsius. 343 00:44:09,420 --> 00:44:12,020 Years can pass without rain. 344 00:44:17,580 --> 00:44:21,620 In 1970, astronauts on the Apollo 14 mission 345 00:44:21,620 --> 00:44:25,420 came here to test their lunar equipment... 346 00:44:33,700 --> 00:44:37,140 ..because the conditions have created a moonscape. 347 00:44:46,020 --> 00:44:49,220 This is Mexico's driest region. 348 00:44:56,180 --> 00:45:00,140 All the more surprising as it borders the sea. 349 00:45:10,300 --> 00:45:14,060 The Sonoran Desert stretches for hundreds of miles along 350 00:45:14,060 --> 00:45:16,780 Mexico's Pacific coast 351 00:45:16,780 --> 00:45:18,900 and the Gulf of California. 352 00:45:22,740 --> 00:45:26,500 These waters have helped shape this parched coastline. 353 00:45:30,420 --> 00:45:33,580 Fed by the cold Californian current, 354 00:45:33,580 --> 00:45:37,940 these seas produce cool and dry onshore winds, 355 00:45:37,940 --> 00:45:39,980 starving the land of moisture. 356 00:45:42,380 --> 00:45:44,220 Clouds struggle to form... 357 00:45:47,300 --> 00:45:51,740 ..creating a coastal desert that extends far out to sea. 358 00:46:06,980 --> 00:46:10,700 In the most isolated corner of the Gulf of California 359 00:46:10,700 --> 00:46:12,660 is a true desert island. 360 00:46:19,140 --> 00:46:21,620 Isla San Pedro Martir. 361 00:46:28,540 --> 00:46:33,100 Giant cardon cacti are one of the few things that can withstand 362 00:46:33,100 --> 00:46:35,420 the drought-ravaged conditions. 363 00:46:41,780 --> 00:46:43,340 There's no fresh water... 364 00:46:45,020 --> 00:46:47,620 ..and few obvious opportunities for a meal. 365 00:46:53,900 --> 00:46:57,340 But it's home to an especially resilient resident. 366 00:47:01,620 --> 00:47:04,620 The side-blotched lizard. 367 00:47:06,900 --> 00:47:11,180 Endemic to this island, it's ancestors became isolated on this 368 00:47:11,180 --> 00:47:14,380 barren outcrop seven million years ago. 369 00:47:25,180 --> 00:47:31,100 Being marooned would have been a death sentence for most creatures, 370 00:47:31,100 --> 00:47:35,860 but this stowaway has made a remarkable success of being stranded... 371 00:47:37,300 --> 00:47:40,380 ..because of a banquet found just offshore. 372 00:48:00,540 --> 00:48:04,140 The cold seas that created this desert island are some of 373 00:48:04,140 --> 00:48:05,900 the richest on earth. 374 00:48:10,220 --> 00:48:14,340 Nutrient-rich waters are forced to the surface around islands like 375 00:48:14,340 --> 00:48:17,020 Isla San Pedro Martir, 376 00:48:17,020 --> 00:48:19,900 fuelling an explosion of marine life. 377 00:48:40,620 --> 00:48:45,020 In May, the island is transformed into one of the world's largest 378 00:48:45,020 --> 00:48:48,060 breeding colonies of this aptly-named bird... 379 00:48:49,700 --> 00:48:51,300 ..the blue-footed booby. 380 00:48:54,780 --> 00:48:58,740 It's the lifeline this lizard has been waiting months for. 381 00:49:04,140 --> 00:49:06,660 Raising a family is a messy affair. 382 00:49:10,420 --> 00:49:13,020 Nests are littered with leftovers. 383 00:49:15,380 --> 00:49:18,700 And this lizard has learned to eat fish. 384 00:49:30,540 --> 00:49:34,740 But to secure a meal, it has to be quick, 385 00:49:34,740 --> 00:49:36,820 there's an awful lot of competition. 386 00:49:51,700 --> 00:49:55,300 These birds have had an extraordinary impact on the lizards 387 00:49:55,300 --> 00:49:56,900 isolated on this island. 388 00:50:02,820 --> 00:50:06,900 With so few species to share this unusual bounty, 389 00:50:06,900 --> 00:50:09,620 they have completely overrun this place. 390 00:50:24,300 --> 00:50:28,020 This island has one of the world's highest densities of lizards... 391 00:50:29,420 --> 00:50:32,900 ..over 30 times more than the Mexican mainland. 392 00:50:37,140 --> 00:50:41,220 They are the ultimate proof that even the most barren places 393 00:50:41,220 --> 00:50:42,700 can be bountiful. 394 00:50:46,060 --> 00:50:48,180 If you can find a way, 395 00:50:48,180 --> 00:50:52,260 you really can thrive in Mexico's burning north. 396 00:50:58,060 --> 00:51:01,500 Mexico is blessed with an astonishing diversity of life. 397 00:51:02,820 --> 00:51:05,140 A country bursting with colour... 398 00:51:07,820 --> 00:51:10,420 ..and the richest natural heritage... 399 00:51:13,900 --> 00:51:19,380 ..with a spirit and vibrancy found nowhere else on Earth. 400 00:51:33,780 --> 00:51:35,460 In making this episode, 401 00:51:35,460 --> 00:51:38,700 the crew travelled to some of Mexico's remotest regions, 402 00:51:38,700 --> 00:51:42,140 capturing remarkable animal behaviour in the wild. 403 00:51:44,300 --> 00:51:48,860 But there was one exception - pallid bats. 404 00:51:48,860 --> 00:51:51,860 They cover many miles of desert every night 405 00:51:51,860 --> 00:51:54,620 hunting scorpions in the pitch-black - 406 00:51:54,620 --> 00:51:57,740 impossible to film under natural conditions. 407 00:51:59,340 --> 00:52:03,180 So the crew teamed up with bat scientist Winifred Frick, 408 00:52:03,180 --> 00:52:06,060 who studies how these bats feed in captivity. 409 00:52:07,540 --> 00:52:11,460 With her help, they brought the desert into a special bat lab 410 00:52:11,460 --> 00:52:14,420 to hopefully film this rarely-seen behaviour. 411 00:52:18,100 --> 00:52:22,180 This makeshift lab on the Baja Peninsula may not be remote, 412 00:52:22,180 --> 00:52:26,660 but it's still presents problems for cameraman Luke Barnett. 413 00:52:26,660 --> 00:52:30,900 It's dark, it's 40 degrees, stuff keeps not working 414 00:52:30,900 --> 00:52:35,060 and power supplies keep packing up, so it's going to be a challenge. 415 00:52:36,540 --> 00:52:39,660 While the finishing touches are put to the set, 416 00:52:39,660 --> 00:52:44,460 Winifred is looking after the stars of the show backstage. 417 00:52:44,460 --> 00:52:46,140 I just think they're beautiful. 418 00:52:46,140 --> 00:52:50,180 They've got these big ears, they have this...almost this little 419 00:52:50,180 --> 00:52:53,380 piggy snout, they've just got a lot of character to their face. 420 00:52:54,860 --> 00:52:57,780 For her studies, Winifred catches wild bats 421 00:52:57,780 --> 00:53:01,140 which she releases a few weeks later. 422 00:53:01,140 --> 00:53:04,580 She feeds and weighs them every day to make sure they're healthy. 423 00:53:08,220 --> 00:53:10,740 To understand their predatory behaviour for scorpions 424 00:53:10,740 --> 00:53:13,140 and understand... I mean, scorpions, they eat, 425 00:53:13,140 --> 00:53:15,740 we have to bring them into the flight cage because 426 00:53:15,740 --> 00:53:17,220 you can't record that in the wild 427 00:53:17,220 --> 00:53:19,300 because we don't know where a scorpion is going to be 428 00:53:19,300 --> 00:53:21,020 and when the bat's going to hit it. 429 00:53:23,860 --> 00:53:27,620 To enter the bat's world, the crew switch to night shifts, 430 00:53:27,620 --> 00:53:32,420 filming in complete darkness using infrared cameras. 431 00:53:32,420 --> 00:53:34,380 But will the bats perform? 432 00:53:47,860 --> 00:53:50,340 Well, it's been quite slow, really, 433 00:53:50,340 --> 00:53:53,500 cos the bats aren't used to the environment perhaps. 434 00:53:53,500 --> 00:53:55,780 And the bats are somewhere in the corner. 435 00:53:55,780 --> 00:53:57,220 I think they're all huddling. 436 00:53:57,220 --> 00:53:59,940 They've got a better idea, they've gone to sleep. 437 00:53:59,940 --> 00:54:04,100 Yeah, midnight and we're all a bit tired and a bit hot. 438 00:54:08,900 --> 00:54:11,260 It ends up being an exhausting 439 00:54:11,260 --> 00:54:15,900 and fruitless first evening for them all. 440 00:54:15,900 --> 00:54:19,940 And a quiet few hours soon turns into a quiet few nights. 441 00:54:23,220 --> 00:54:25,660 Without knowing when a bat might strike, 442 00:54:25,660 --> 00:54:28,500 Luke and the team must stay alert. 443 00:54:29,740 --> 00:54:34,780 Easier said than done when working all night in 40-degree heat. 444 00:54:34,780 --> 00:54:37,380 We're losing you. I know. 445 00:54:39,260 --> 00:54:42,580 The bats are resting. The bat biologist is resting. 446 00:54:42,580 --> 00:54:47,140 Must be the worst bit about being a bat biologist, not falling asleep. 447 00:54:47,140 --> 00:54:49,380 You find it hard? Yeah. 448 00:54:49,380 --> 00:54:51,660 Well, it's funny, I'm actually not a night person. 449 00:54:51,660 --> 00:54:54,300 So my joke is I'm the world's worst bat biologist 450 00:54:54,300 --> 00:54:56,660 cos I'm also claustrophobic. 451 00:54:56,660 --> 00:54:59,900 So not a night person, I don't like to go into caves. Brilliant. 452 00:55:05,060 --> 00:55:07,900 It's now just come up to six o'clock in the morning 453 00:55:07,900 --> 00:55:11,300 and we started about five with great expectations. 454 00:55:11,300 --> 00:55:13,220 A few came down and circled around, 455 00:55:13,220 --> 00:55:16,860 but there wasn't a lot going on, so it's very disappointing. 456 00:55:18,300 --> 00:55:22,540 The bats never go hungry as Winifred feeds them every day. 457 00:55:22,540 --> 00:55:26,820 But after five frustrating nights, the team needs to rethink. 458 00:55:26,820 --> 00:55:29,460 A raised set makes filming more manageable, 459 00:55:29,460 --> 00:55:31,900 but Winifred thinks this is the problem. 460 00:55:31,900 --> 00:55:33,540 We may have to accommodate them, 461 00:55:33,540 --> 00:55:36,340 rather than hoping that they're going to accommodate us. 462 00:55:36,340 --> 00:55:38,660 I think make it work with the cameras and everything, 463 00:55:38,660 --> 00:55:41,220 trying to get the set down on to the ground level 464 00:55:41,220 --> 00:55:43,620 will be the next thing to try. Sure. 465 00:55:50,940 --> 00:55:52,620 We've had to lower the set, 466 00:55:52,620 --> 00:55:55,860 so hopefully now the bats will fly around much more over the top. 467 00:55:55,860 --> 00:55:58,820 It's not been a job that we really wanted to do 468 00:55:58,820 --> 00:56:02,100 cos all we want to do is have a cold shower and sleep, so... 469 00:56:03,980 --> 00:56:06,900 Yeah, another night coming up. 470 00:56:08,620 --> 00:56:13,660 With a more bat-friendly filming set, there's renewed hope. 471 00:56:13,660 --> 00:56:15,060 This looks awesome, you guys. 472 00:56:15,060 --> 00:56:18,180 This looks like exactly where they'd be hunting out in the wild 473 00:56:18,180 --> 00:56:19,620 and getting it down on the floor. 474 00:56:19,620 --> 00:56:23,660 I think it's going to be really key. So I feel pumped. This looks good. 475 00:56:26,340 --> 00:56:28,980 As the bats start to stretch their wings, 476 00:56:28,980 --> 00:56:31,460 they're already showing a lot more interest. 477 00:56:32,620 --> 00:56:36,660 And Luke manages to get some great flying shots of these bats 478 00:56:36,660 --> 00:56:37,900 in hunting mode. 479 00:56:47,020 --> 00:56:48,740 It was much better today, 480 00:56:48,740 --> 00:56:52,940 we lowered the set to the floor and it seemed to make a big difference, 481 00:56:52,940 --> 00:56:55,380 the bats are flying right over the set for a change, 482 00:56:55,380 --> 00:56:58,260 rather than around the outside, low to the ground, so... 483 00:56:58,260 --> 00:57:00,420 we're all feeling a bit more excited. 484 00:57:03,700 --> 00:57:06,740 But Luke still hasn't managed to film the key shot 485 00:57:06,740 --> 00:57:08,500 of a bat catching a scorpion. 486 00:57:10,220 --> 00:57:13,500 As wildlife cameramen know only too well, 487 00:57:13,500 --> 00:57:16,940 capturing behaviour takes patience. 488 00:57:16,940 --> 00:57:19,540 With only a couple of days of filming left, 489 00:57:19,540 --> 00:57:21,580 the bats finally settle in. 490 00:57:28,700 --> 00:57:31,580 Look at that. Oh, look at that. He's moved back. Oh! 491 00:57:33,060 --> 00:57:36,380 I can't believe... He's just gone again. We just got a shot. 492 00:57:36,380 --> 00:57:38,380 That is such a relief. 493 00:57:38,380 --> 00:57:39,860 That makes... 494 00:57:39,860 --> 00:57:42,780 That makes me happy because it means that at last we've actually got 495 00:57:42,780 --> 00:57:44,940 what is looking like a sequence. 496 00:57:44,940 --> 00:57:48,100 Without that moment of capture, we'd have nothing. 497 00:57:50,620 --> 00:57:55,020 And there's behaviour that Winifred has never seen before. 498 00:57:55,020 --> 00:57:57,300 When it comes in, it cups it straightaway. 499 00:57:57,300 --> 00:57:59,020 Yeah. 500 00:57:59,020 --> 00:58:01,860 Yeah, look, she just makes that awesome tent with her wings 501 00:58:01,860 --> 00:58:03,700 and her tail. 502 00:58:03,700 --> 00:58:05,860 And the only way out is teeth. 503 00:58:07,820 --> 00:58:10,100 We just never get to see this in the wild. 504 00:58:10,100 --> 00:58:11,580 This is amazing. 505 00:58:11,580 --> 00:58:13,740 Oh, that is beautiful. 506 00:58:17,020 --> 00:58:18,300 Off she goes. Yeah. 507 00:58:20,500 --> 00:58:24,140 It's time to take the bats back to their wild desert home. 508 00:58:27,780 --> 00:58:29,380 There... She's off. 509 00:58:30,380 --> 00:58:32,540 It's been a unique glimpse into 510 00:58:32,540 --> 00:58:35,900 the life of one of Mexico's most secretive animals.