1 00:00:06,589 --> 00:00:08,675 [somber music playing] 2 00:00:13,471 --> 00:00:15,598 [David Attenborough] A million wildebeest, 3 00:00:16,099 --> 00:00:18,810 after 1,000 kilometers on the march, 4 00:00:18,893 --> 00:00:22,772 are facing their greatest obstacle on their annual migration. 5 00:00:22,856 --> 00:00:24,024 [bleating] 6 00:00:25,442 --> 00:00:27,610 Tanzania's Mara River. 7 00:00:34,659 --> 00:00:39,456 Traveling with them are zebras. Some, females with foals. 8 00:00:47,088 --> 00:00:48,506 And waiting for them… 9 00:00:51,676 --> 00:00:52,677 crocodiles. 10 00:00:53,511 --> 00:00:55,346 [music becomes dramatic] 11 00:01:03,354 --> 00:01:07,067 The smaller a foal, the lower its chances. 12 00:01:10,737 --> 00:01:13,740 -[foal whinnying] -And he is one of the smallest. 13 00:01:15,116 --> 00:01:16,326 [music intensifies] 14 00:01:17,410 --> 00:01:18,828 [music abates] 15 00:01:19,412 --> 00:01:20,413 [music intensifies] 16 00:01:21,164 --> 00:01:24,167 He tries to stay as close as possible to his mother. 17 00:01:24,834 --> 00:01:28,755 Those that get separated are unlikely to survive. 18 00:01:28,838 --> 00:01:31,341 -[music intensifies] -[foal whinnying] 19 00:01:34,219 --> 00:01:35,970 He's struggling to keep up. 20 00:01:37,680 --> 00:01:39,682 [foal whinnying anxiously] 21 00:01:45,105 --> 00:01:46,856 All he can do is kick… 22 00:01:46,940 --> 00:01:48,399 [snorting] 23 00:01:48,483 --> 00:01:50,985 …while others take the fall. 24 00:01:51,528 --> 00:01:52,821 [music continues] 25 00:01:55,824 --> 00:01:56,825 [buffalo bellows] 26 00:01:57,659 --> 00:01:59,244 [foal snorts, whinnies] 27 00:02:01,663 --> 00:02:03,456 [groans] 28 00:02:07,127 --> 00:02:08,336 [music ends abruptly] 29 00:02:08,419 --> 00:02:11,923 The distractions last just long enough 30 00:02:12,006 --> 00:02:14,968 to enable him to reach his mother… 31 00:02:17,178 --> 00:02:21,224 continuing their march with the planet's largest herd. 32 00:02:21,724 --> 00:02:23,476 [rousing music playing] 33 00:02:32,360 --> 00:02:33,736 [music abruptly trails off] 34 00:02:33,820 --> 00:02:35,321 [theme tune playing] 35 00:02:44,372 --> 00:02:45,832 [music fades out] 36 00:02:48,626 --> 00:02:51,087 [gentle classical music fades in] 37 00:02:59,179 --> 00:03:02,557 Some animals give their young the best start in life 38 00:03:03,433 --> 00:03:06,519 by making truly astonishing journeys. 39 00:03:07,937 --> 00:03:12,150 And it's not only where they go that's important but when. 40 00:03:12,984 --> 00:03:14,861 [music becomes optimistic] 41 00:03:15,862 --> 00:03:18,406 Mexico's Pacific Coast. 42 00:03:27,290 --> 00:03:28,333 [music abates] 43 00:03:28,416 --> 00:03:30,710 The beach looks deserted. 44 00:03:35,340 --> 00:03:37,300 But beneath the sand, 45 00:03:37,884 --> 00:03:40,845 thousands of animals are on the move. 46 00:03:40,929 --> 00:03:43,389 [subdued classical music playing] 47 00:03:47,810 --> 00:03:49,771 [music becomes optimistic] 48 00:03:52,190 --> 00:03:54,609 Olive ridley turtle hatchlings. 49 00:03:59,030 --> 00:04:04,118 In October, the sand is at exactly the right temperature for an emergence. 50 00:04:07,247 --> 00:04:09,207 The first to surface 51 00:04:10,500 --> 00:04:11,834 stay still. 52 00:04:16,673 --> 00:04:19,384 Any movement might attract attention. 53 00:04:22,220 --> 00:04:23,763 They must wait for others. 54 00:04:27,934 --> 00:04:29,477 They are about to start 55 00:04:29,560 --> 00:04:32,981 on the most dangerous journey of their lives. 56 00:04:35,650 --> 00:04:38,653 And it's better to do that together. 57 00:04:38,736 --> 00:04:40,488 [music becomes dramatic] 58 00:04:50,915 --> 00:04:52,000 [music crescendoes] 59 00:04:52,083 --> 00:04:52,917 [music ends] 60 00:04:54,127 --> 00:04:55,086 [music reprises] 61 00:04:59,841 --> 00:05:01,759 -For the hunters… -[turtle chirping] 62 00:05:04,012 --> 00:05:06,389 …this is the biggest feast of the year. 63 00:05:06,472 --> 00:05:07,849 [music intensifies] 64 00:05:12,520 --> 00:05:13,354 [chirps] 65 00:05:14,355 --> 00:05:16,065 -[muffled chirp] -[music fades out] 66 00:05:17,567 --> 00:05:21,154 They take half of the emerging hatchlings on the beach. 67 00:05:21,654 --> 00:05:22,780 [tense music playing] 68 00:05:22,864 --> 00:05:26,743 But the little turtles keep arriving in such numbers 69 00:05:26,826 --> 00:05:29,287 that the predators simply can't keep up. 70 00:05:29,370 --> 00:05:30,455 [hatchlings chirping] 71 00:05:30,538 --> 00:05:34,292 And that is their only chance of reaching the water. 72 00:05:35,877 --> 00:05:36,836 [music intensifies] 73 00:05:43,843 --> 00:05:44,719 [caws loudly] 74 00:05:48,973 --> 00:05:50,099 [gulls squawks] 75 00:05:54,145 --> 00:05:55,063 [chirps] 76 00:05:57,982 --> 00:05:59,484 [music ends abruptly] 77 00:06:04,405 --> 00:06:05,531 [snorts softly] 78 00:06:06,532 --> 00:06:08,117 [somber music playing] 79 00:06:17,710 --> 00:06:19,295 [music becomes tense] 80 00:06:21,506 --> 00:06:23,966 -The tide is going out. -[snarling] 81 00:06:28,971 --> 00:06:33,059 Things are getting even more dangerous for the little turtles. 82 00:06:36,020 --> 00:06:38,856 Their only chance is to follow the others. 83 00:06:38,940 --> 00:06:40,525 [music becomes urgent] 84 00:06:50,076 --> 00:06:51,369 [birds squawking] 85 00:06:54,288 --> 00:06:55,123 [music abates] 86 00:06:55,206 --> 00:06:57,166 Some reach the shallows. 87 00:07:00,586 --> 00:07:03,047 But even now, they're not safe. 88 00:07:14,851 --> 00:07:16,352 [whimsical music playing] 89 00:07:16,436 --> 00:07:17,770 Those that survive 90 00:07:18,396 --> 00:07:21,315 will swim harder in the next 24 hours 91 00:07:21,399 --> 00:07:23,276 than they will ever do again. 92 00:07:25,403 --> 00:07:30,199 As they travel, they are imprinted by the Earth's magnetic field. 93 00:07:31,826 --> 00:07:36,581 A mental marker that will guide them back when it's their time to breed. 94 00:07:42,378 --> 00:07:44,338 Every olive ridley turtle 95 00:07:44,422 --> 00:07:48,009 will spend the first 15 years of its life in the Pacific, 96 00:07:48,634 --> 00:07:51,053 feeding and growing alone. 97 00:07:52,263 --> 00:07:55,683 Each will travel hundreds of thousands of kilometers 98 00:07:56,309 --> 00:07:59,145 until one day, they change course… 99 00:08:01,606 --> 00:08:05,860 and begin the long journey back to the beach where they hatched. 100 00:08:10,615 --> 00:08:12,950 For the first time in over a decade, 101 00:08:13,534 --> 00:08:15,453 this teenage turtle 102 00:08:16,078 --> 00:08:18,581 meets others of its own kind. 103 00:08:23,127 --> 00:08:24,879 [music becomes rousing] 104 00:08:26,506 --> 00:08:28,716 A quarter of a million of them. 105 00:08:31,511 --> 00:08:34,472 The greatest gathering of turtles on Earth. 106 00:08:39,268 --> 00:08:40,645 [music intensifies] 107 00:08:53,824 --> 00:08:57,912 Here she will mate, then swim ashore to lay. 108 00:09:07,964 --> 00:09:10,466 She is no longer a tiny hatchling. 109 00:09:11,467 --> 00:09:14,387 But the shallows are still just as daunting. 110 00:09:41,539 --> 00:09:43,499 [optimistic music playing] 111 00:09:49,714 --> 00:09:50,590 [gasps] 112 00:09:51,424 --> 00:09:52,383 Land. 113 00:09:53,467 --> 00:09:57,263 -[growls softly] -The first she's touched in 15 years. 114 00:09:58,806 --> 00:10:02,977 -[gasps, sighs] -Now she has urgent things to do. 115 00:10:08,316 --> 00:10:10,818 Her eggs are ready to be laid, 116 00:10:11,652 --> 00:10:13,863 and she must dig a nest for them. 117 00:10:18,284 --> 00:10:20,995 If she deposits them below the tide line, 118 00:10:21,078 --> 00:10:22,288 they would drown. 119 00:10:23,372 --> 00:10:25,249 But too far up the beach, 120 00:10:25,333 --> 00:10:26,834 and they could dry out. 121 00:10:28,794 --> 00:10:31,881 So the middle ground is very popular. 122 00:10:34,800 --> 00:10:36,552 [music becomes rousing] 123 00:10:38,888 --> 00:10:41,223 As thousands more adults arrive, 124 00:10:41,974 --> 00:10:44,727 as many as 80% of the eggs laid here 125 00:10:44,810 --> 00:10:49,315 are accidentally destroyed by other nesting females. 126 00:10:49,398 --> 00:10:50,441 [music abates] 127 00:10:57,865 --> 00:10:59,367 But so many eggs are laid 128 00:11:00,951 --> 00:11:05,122 that millions will remain undamaged, deep in the sand. 129 00:11:10,544 --> 00:11:13,089 She lays a hundred or so. 130 00:11:14,298 --> 00:11:17,259 And with that, her work is done. 131 00:11:20,054 --> 00:11:23,057 But next year, at this same time, 132 00:11:23,140 --> 00:11:27,103 she will return to this particular beach to lay again 133 00:11:28,771 --> 00:11:32,316 and will keep doing that for the rest of her life. 134 00:11:42,785 --> 00:11:45,663 Most of the journeys made in order to breed 135 00:11:45,746 --> 00:11:48,082 have barely changed for millennia. 136 00:11:48,165 --> 00:11:49,250 [stillness] 137 00:11:50,084 --> 00:11:51,460 [thunder rumbling] 138 00:11:54,380 --> 00:11:58,342 In a remote part of the Atlantic, east of South America, 139 00:11:58,426 --> 00:12:00,469 lie the Falkland Islands. 140 00:12:10,855 --> 00:12:13,983 Elephant seals have been coming here to breed 141 00:12:14,066 --> 00:12:15,526 for thousands of years. 142 00:12:15,609 --> 00:12:18,070 [making fart-like noises] 143 00:12:18,779 --> 00:12:21,490 Here on this beach, in late October, 144 00:12:21,574 --> 00:12:23,033 there are only pups. 145 00:12:23,117 --> 00:12:24,034 [trills] 146 00:12:25,035 --> 00:12:26,912 Their mothers left them weeks ago, 147 00:12:26,996 --> 00:12:29,498 and now they must fend for themselves. 148 00:12:30,082 --> 00:12:33,127 [barking softly, making fart-like sounds] 149 00:12:34,795 --> 00:12:37,131 In a few days, they too will leave 150 00:12:37,214 --> 00:12:41,093 and begin their lives as ocean wanderers in the deep sea. 151 00:12:41,886 --> 00:12:43,763 [making fart-like sounds] 152 00:12:46,599 --> 00:12:49,560 But they have yet to learn how to swim! 153 00:12:54,857 --> 00:12:57,485 This sheltered beachside pool 154 00:12:57,568 --> 00:13:00,446 would seem a good place to do that. 155 00:13:02,490 --> 00:13:04,408 [growls softly] 156 00:13:05,159 --> 00:13:06,243 [honks] 157 00:13:07,912 --> 00:13:09,413 -[growls] -[honks] 158 00:13:09,997 --> 00:13:10,956 [blowing] 159 00:13:12,500 --> 00:13:15,044 They get acquainted with the sea. 160 00:13:15,127 --> 00:13:15,961 [croaks] 161 00:13:19,131 --> 00:13:22,468 They make the right swimming movements instinctively 162 00:13:23,219 --> 00:13:27,223 but are, as yet, unable to understand danger. 163 00:13:28,766 --> 00:13:30,601 [menacing music playing] 164 00:13:33,229 --> 00:13:34,104 Orca. 165 00:13:35,064 --> 00:13:36,232 Killer whales. 166 00:13:41,028 --> 00:13:41,946 [music abates] 167 00:13:43,739 --> 00:13:46,492 This is no passing pod. 168 00:13:47,451 --> 00:13:52,581 They've traveled hundreds of kilometers to get here at this precise time. 169 00:13:56,502 --> 00:13:57,670 Twenty years ago, 170 00:13:57,753 --> 00:14:01,924 the lead female discovered when the pups go to their play pool. 171 00:14:03,050 --> 00:14:07,346 And when, as the tide rises, she too could reach it. 172 00:14:09,431 --> 00:14:11,141 [pup barking] 173 00:14:13,853 --> 00:14:16,063 Until then, she must wait. 174 00:14:16,605 --> 00:14:18,399 [menacing music reprises] 175 00:14:19,024 --> 00:14:20,860 If she mistimes her attack, 176 00:14:20,943 --> 00:14:23,445 she will get stranded on the rocks. 177 00:14:25,364 --> 00:14:26,282 [music abates] 178 00:14:32,329 --> 00:14:33,998 At half tide, 179 00:14:34,081 --> 00:14:37,751 it's just deep enough for a killer whale. 180 00:14:38,627 --> 00:14:40,546 [menacing music reprises] 181 00:14:43,299 --> 00:14:45,050 [music becomes dramatic] 182 00:14:53,893 --> 00:14:56,604 The pups don't recognize the threat, 183 00:14:58,230 --> 00:15:00,733 even when it's staring them in the face. 184 00:15:16,165 --> 00:15:18,792 She needs a pup to be in the water, 185 00:15:18,876 --> 00:15:21,921 but it's still dangerously shallow for her. 186 00:15:25,341 --> 00:15:26,467 A wrong turn 187 00:15:27,676 --> 00:15:29,136 and she could get stuck. 188 00:15:29,219 --> 00:15:30,262 [music abates] 189 00:15:35,809 --> 00:15:38,187 [low voice] The pups are almost within reach. 190 00:15:42,316 --> 00:15:44,902 She watches and waits 191 00:15:46,153 --> 00:15:49,031 for one to come close enough to snatch. 192 00:15:50,324 --> 00:15:51,700 [disquieting music playing] 193 00:15:59,333 --> 00:16:00,459 [seal barking] 194 00:16:07,174 --> 00:16:08,342 [music climaxes] 195 00:16:11,345 --> 00:16:12,262 [seal trills] 196 00:16:14,515 --> 00:16:18,352 She carries it, still alive, out to sea. 197 00:16:24,817 --> 00:16:28,862 This female orca is the only one who hunts in this way. 198 00:16:31,240 --> 00:16:34,410 And she does so for her entire family. 199 00:16:39,164 --> 00:16:42,584 The pup remains alive for hours. 200 00:16:48,716 --> 00:16:52,219 These orcas have learned to take advantage 201 00:16:52,302 --> 00:16:55,055 of the seals' annual journeys here to breed. 202 00:16:56,974 --> 00:16:59,643 And, perhaps equally remarkably, 203 00:17:00,227 --> 00:17:03,981 know exactly when they should come back every year. 204 00:17:04,064 --> 00:17:05,357 [birds squawking] 205 00:17:11,822 --> 00:17:13,741 [birds chirping] 206 00:17:17,703 --> 00:17:19,621 [spiritual music playing] 207 00:17:20,122 --> 00:17:22,791 Breeding in safety, for some animals, 208 00:17:23,459 --> 00:17:25,878 means avoiding crowds. 209 00:17:33,010 --> 00:17:34,511 New Zealand. 210 00:17:34,595 --> 00:17:38,724 The last habitable landmass to be reached by people. 211 00:17:38,807 --> 00:17:40,184 [music intensifies] 212 00:17:46,106 --> 00:17:46,940 To get here, 213 00:17:47,024 --> 00:17:51,820 the Polynesians had to cross thousands of kilometers of open ocean. 214 00:17:53,030 --> 00:17:55,949 And so indeed does any animal. 215 00:18:01,205 --> 00:18:05,751 But nonetheless, one visitor makes a 6,000-kilometer journey 216 00:18:05,834 --> 00:18:08,629 across the Southern Ocean every year 217 00:18:09,588 --> 00:18:12,508 to the island's most secluded corners. 218 00:18:13,175 --> 00:18:14,760 [bird call] 219 00:18:17,387 --> 00:18:18,972 [quirky music playing] 220 00:18:22,601 --> 00:18:23,936 [chirruping] 221 00:18:26,063 --> 00:18:29,191 It's shy and mysterious. 222 00:18:29,942 --> 00:18:31,485 [peeping] 223 00:18:40,494 --> 00:18:43,372 Fiordland's tawaki penguin. 224 00:18:44,373 --> 00:18:46,333 The jungle penguin. 225 00:18:47,793 --> 00:18:50,504 He's looking after his eight-week-old chick 226 00:18:51,547 --> 00:18:55,217 while his partner is at sea finding food. 227 00:18:56,593 --> 00:19:00,389 If he doesn't do so adequately, she might leave him. 228 00:19:00,889 --> 00:19:02,141 [music continues] 229 00:19:02,224 --> 00:19:04,309 [chick chirping] 230 00:19:07,771 --> 00:19:10,691 Penguin divorce rates are indeed high! 231 00:19:14,111 --> 00:19:16,655 So he had better keep everyone away. 232 00:19:17,447 --> 00:19:18,782 -[squawks] -[cheeps] 233 00:19:20,075 --> 00:19:20,909 [squawks] 234 00:19:22,536 --> 00:19:27,249 His partner has returned to the coast after a busy day collecting food. 235 00:19:30,335 --> 00:19:32,754 But getting ashore is not easy. 236 00:19:32,838 --> 00:19:35,090 [somber dramatic music playing] 237 00:19:40,262 --> 00:19:41,263 [music abates] 238 00:19:41,805 --> 00:19:43,891 It's a question of timing. 239 00:19:44,391 --> 00:19:45,559 [music reprises] 240 00:19:50,480 --> 00:19:51,398 [music abates] 241 00:19:51,481 --> 00:19:52,649 Almost! 242 00:19:52,733 --> 00:19:53,901 [music reprises] 243 00:20:00,115 --> 00:20:01,158 [music abates] 244 00:20:08,707 --> 00:20:09,958 [music fades out] 245 00:20:10,542 --> 00:20:11,960 Nicely done. 246 00:20:12,044 --> 00:20:13,420 [whimsical music playing] 247 00:20:14,671 --> 00:20:16,215 To reach her hungry chick, 248 00:20:17,257 --> 00:20:19,551 she has to travel over boulders, 249 00:20:20,677 --> 00:20:21,595 roots, 250 00:20:22,846 --> 00:20:24,014 and ravines. 251 00:20:25,974 --> 00:20:27,226 [chirping] 252 00:20:34,107 --> 00:20:35,108 [peeping] 253 00:20:37,736 --> 00:20:38,946 [chick chirping] 254 00:20:39,029 --> 00:20:42,699 This is Deliveroo, penguin-style. 255 00:20:43,909 --> 00:20:45,160 [mother chirping] 256 00:20:46,370 --> 00:20:49,623 -[chick peeps] -Dad can only watch with envy. 257 00:20:51,625 --> 00:20:52,501 [music fades out] 258 00:20:52,584 --> 00:20:53,752 [mother chirping] 259 00:20:53,835 --> 00:20:57,506 As the chick grows, so too does its appetite. 260 00:20:59,508 --> 00:21:01,468 To keep up with the demand, 261 00:21:01,551 --> 00:21:05,222 Mum must complete the obstacle course through the jungle… 262 00:21:05,305 --> 00:21:06,431 [quirky music playing] 263 00:21:06,515 --> 00:21:07,766 …again 264 00:21:09,434 --> 00:21:10,727 and again. 265 00:21:17,651 --> 00:21:18,652 [mother chirping] 266 00:21:22,364 --> 00:21:25,951 To rear her chick, she will walk the distance of a marathon 267 00:21:26,034 --> 00:21:28,870 and swim over a thousand kilometers. 268 00:21:28,954 --> 00:21:30,080 [music continues] 269 00:21:30,163 --> 00:21:33,834 And she will lose up to half of her body weight. 270 00:21:34,459 --> 00:21:37,045 -[squawking] -[peeping] 271 00:21:38,380 --> 00:21:40,716 But that doesn't stop her. 272 00:21:40,799 --> 00:21:42,134 [lively percussion playing] 273 00:21:49,141 --> 00:21:50,267 [high-pitched chirps] 274 00:21:57,065 --> 00:21:58,150 [music ends abruptly] 275 00:21:58,233 --> 00:22:00,527 -[chick cheeping] -[spiritual music playing] 276 00:22:00,610 --> 00:22:03,739 And then, after ten long weeks, 277 00:22:04,823 --> 00:22:06,658 she's finally had enough. 278 00:22:09,536 --> 00:22:12,205 With the delivery service ended, 279 00:22:12,289 --> 00:22:15,292 hunger drives the chick to the sea. 280 00:22:19,963 --> 00:22:22,674 There's plenty of food to be had just offshore, 281 00:22:23,675 --> 00:22:26,887 but strangely, he swims away with others 282 00:22:26,970 --> 00:22:29,556 and keeps going for thousands of kilometers, 283 00:22:29,639 --> 00:22:31,933 halfway to Antarctica. 284 00:22:33,602 --> 00:22:37,481 It's the longest single journey made by any penguin 285 00:22:37,981 --> 00:22:40,776 and quite possibly pointless. 286 00:22:45,364 --> 00:22:49,242 It's thought their ancestors started doing this two million years ago 287 00:22:49,326 --> 00:22:52,120 when their food was only found out here. 288 00:22:52,829 --> 00:22:55,749 And it's clearly been a hard routine to break. 289 00:22:59,169 --> 00:23:00,879 [ambient music playing] 290 00:23:05,467 --> 00:23:06,468 In November, 291 00:23:06,551 --> 00:23:10,680 an increase in the daily sunlight heats the Indian Ocean 292 00:23:11,181 --> 00:23:13,683 and kick-starts the monsoon. 293 00:23:15,227 --> 00:23:18,146 In its path lies Christmas Island. 294 00:23:19,439 --> 00:23:21,108 [quirky electronic music playing] 295 00:23:21,191 --> 00:23:25,946 The rise in humidity it brings awakens a sleeping army. 296 00:23:36,540 --> 00:23:37,749 [music becomes dramatic] 297 00:23:37,833 --> 00:23:39,709 Christmas Island red crabs 298 00:23:39,793 --> 00:23:42,587 now live almost entirely on land. 299 00:23:44,423 --> 00:23:45,632 But to breathe, 300 00:23:45,715 --> 00:23:48,093 they still need moisture in their gills 301 00:23:49,010 --> 00:23:51,805 and the sea in which to lay their eggs. 302 00:23:53,932 --> 00:23:59,563 So they make an annual trek to the coast, as they have done for 200,000 years. 303 00:24:01,940 --> 00:24:05,026 Lately, however, a lot has changed. 304 00:24:06,445 --> 00:24:07,279 [car horn hoots] 305 00:24:12,242 --> 00:24:14,578 But help is now at hand. 306 00:24:15,620 --> 00:24:17,080 [music intensifies] 307 00:24:29,092 --> 00:24:32,554 Local people have also built special bridges 308 00:24:32,637 --> 00:24:36,725 that allow them to cross the busiest roads at their own speed, 309 00:24:38,101 --> 00:24:40,979 and a network of subways guides them. 310 00:24:44,941 --> 00:24:46,067 [rapid squeaking] 311 00:24:46,735 --> 00:24:48,403 They increase their pace, 312 00:24:48,904 --> 00:24:51,114 for they must catch the high tide. 313 00:24:51,907 --> 00:24:52,991 [music ends abruptly] 314 00:24:53,074 --> 00:24:54,743 [waves gently crashing] 315 00:24:55,702 --> 00:24:59,915 In a single night, four million crabs reach the coast. 316 00:25:01,208 --> 00:25:03,543 [optimistic ambient music playing] 317 00:25:08,381 --> 00:25:12,802 Each female shakes 100,000 eggs into the surf. 318 00:25:25,857 --> 00:25:30,111 They hatch immediately and become free-swimming larvae. 319 00:25:34,032 --> 00:25:39,120 Most years, the vast majority are eaten or washed into the deep, 320 00:25:39,788 --> 00:25:41,540 and none return. 321 00:25:44,292 --> 00:25:47,629 But with luck, on the next month's high tide, 322 00:25:47,712 --> 00:25:50,924 they will be swept back to the island's shores. 323 00:25:53,635 --> 00:25:54,886 [music fades out] 324 00:25:57,806 --> 00:26:00,183 Thousands of kilometers further south, 325 00:26:00,267 --> 00:26:02,978 another first journey is about to begin. 326 00:26:03,853 --> 00:26:06,481 [atmospheric panpipe music playing] 327 00:26:08,400 --> 00:26:09,609 Late November, 328 00:26:10,151 --> 00:26:12,988 midsummer, at the end of the world. 329 00:26:15,490 --> 00:26:20,120 Patagonia, the southernmost tip of the Americas. 330 00:26:22,914 --> 00:26:24,666 [music becomes rousing] 331 00:26:26,418 --> 00:26:30,922 Only one large land predator lives as far south as this. 332 00:26:33,592 --> 00:26:34,551 The puma. 333 00:26:41,099 --> 00:26:42,642 This is Machito. 334 00:26:42,726 --> 00:26:44,728 -[growls softly] -The gray one. 335 00:26:46,062 --> 00:26:50,609 He is one year old and about to face the biggest test of his life. 336 00:26:51,985 --> 00:26:53,445 Not that he knows it. 337 00:26:53,528 --> 00:26:54,863 [rousing music playing] 338 00:26:55,530 --> 00:26:56,448 [Machito snarls] 339 00:26:58,867 --> 00:27:00,577 [brown puma vocalizing] 340 00:27:02,370 --> 00:27:04,623 He and his sister, Niña, 341 00:27:05,248 --> 00:27:07,834 are at the age where they should separate, 342 00:27:07,917 --> 00:27:10,795 and each find a territory of their own. 343 00:27:20,013 --> 00:27:21,264 [music fades out] 344 00:27:21,348 --> 00:27:23,391 Competition between males 345 00:27:23,475 --> 00:27:27,646 means Machito will have to travel much further than his sister. 346 00:27:31,441 --> 00:27:34,986 -But now, each must learn to hunt. -[snorts] 347 00:27:35,779 --> 00:27:37,864 [subdued tense music playing] 348 00:27:40,241 --> 00:27:41,242 [prey grunts] 349 00:27:44,788 --> 00:27:46,164 Even for their mother, 350 00:27:47,540 --> 00:27:49,542 there is no greater challenge… 351 00:27:49,626 --> 00:27:52,379 [music intensifies, abates] 352 00:27:52,462 --> 00:27:55,548 …than catching an adult bull guanaco 353 00:27:56,174 --> 00:27:58,343 three times her size. 354 00:28:00,595 --> 00:28:02,055 But she's an expert. 355 00:28:04,933 --> 00:28:06,935 The cubs watch closely. 356 00:28:07,435 --> 00:28:09,437 [disquieting music playing] 357 00:28:15,360 --> 00:28:19,072 To succeed, she must get within a few meters. 358 00:28:19,781 --> 00:28:21,157 [music intensifies] 359 00:28:38,591 --> 00:28:40,427 [music becomes dramatic] 360 00:28:46,307 --> 00:28:49,936 And then hold on, no matter how wild the ride. 361 00:28:50,019 --> 00:28:51,104 [puma snarls] 362 00:28:57,777 --> 00:28:59,070 [music builds] 363 00:29:03,074 --> 00:29:04,492 [music builds] 364 00:29:04,576 --> 00:29:06,244 [guanaco whinnying] 365 00:29:08,705 --> 00:29:10,457 [guanaco bellowing] 366 00:29:15,170 --> 00:29:16,296 [silence] 367 00:29:19,591 --> 00:29:22,844 The cubs should make the most of the free meal. 368 00:29:24,095 --> 00:29:27,766 Their easy living is about to come to an end. 369 00:29:28,892 --> 00:29:30,727 [whimsical music playing] 370 00:29:34,022 --> 00:29:36,983 Their mother has done all she can for them. 371 00:29:40,737 --> 00:29:42,363 After a year together, 372 00:29:42,447 --> 00:29:45,492 her territory is no longer theirs. 373 00:29:54,793 --> 00:29:57,045 It's time for them to leave. 374 00:29:57,879 --> 00:29:59,798 [music becomes nostalgic] 375 00:30:07,055 --> 00:30:10,850 For several weeks, the siblings stay close to each other. 376 00:30:11,726 --> 00:30:14,854 But they will soon need to go their separate ways. 377 00:30:16,606 --> 00:30:18,274 Niña, the female, 378 00:30:18,358 --> 00:30:21,653 will be allowed to live close to her mother's home range. 379 00:30:23,363 --> 00:30:25,824 Machito will not. 380 00:30:30,870 --> 00:30:33,373 Male territories are much larger. 381 00:30:33,456 --> 00:30:35,333 And to find enough space, 382 00:30:35,416 --> 00:30:38,253 he may have to travel for hundreds of kilometers. 383 00:30:49,597 --> 00:30:51,724 For the first time in his life, 384 00:30:52,642 --> 00:30:54,227 he is alone. 385 00:30:55,144 --> 00:30:57,605 [music climaxes, fades] 386 00:31:01,442 --> 00:31:03,111 After weeks on the move, 387 00:31:03,736 --> 00:31:05,154 he is starving. 388 00:31:05,238 --> 00:31:06,406 [guanaco whinnies] 389 00:31:06,489 --> 00:31:08,491 [apprehensive music playing] 390 00:31:15,874 --> 00:31:17,333 He's seen how to hunt, 391 00:31:18,334 --> 00:31:20,420 but has he learned enough? 392 00:31:21,921 --> 00:31:23,339 [music accelerates] 393 00:31:28,553 --> 00:31:30,471 [guanaco shrieking] 394 00:31:31,806 --> 00:31:32,849 Not quite. 395 00:31:32,932 --> 00:31:34,225 [music abates] 396 00:31:37,103 --> 00:31:39,772 To find food, he must keep moving, 397 00:31:40,815 --> 00:31:44,652 heading deeper into unfamiliar lands. 398 00:31:44,736 --> 00:31:45,987 [music reprises] 399 00:31:52,285 --> 00:31:54,996 He doesn't stop until… 400 00:31:56,122 --> 00:31:57,290 [sniffs] 401 00:31:57,373 --> 00:32:01,753 …he picks up the unmistakable scent of a fresh kill. 402 00:32:01,836 --> 00:32:03,046 [snarling] 403 00:32:10,470 --> 00:32:11,846 But it was made… 404 00:32:11,930 --> 00:32:14,307 [ominous music playing] 405 00:32:14,390 --> 00:32:16,100 …by a huge male. 406 00:32:24,192 --> 00:32:25,443 [music fades out] 407 00:32:26,027 --> 00:32:28,321 [gentle growling] 408 00:32:28,404 --> 00:32:30,406 [tense string music playing] 409 00:32:32,700 --> 00:32:35,703 [gentle snarling] 410 00:32:40,750 --> 00:32:41,918 [snorting] 411 00:32:44,212 --> 00:32:45,296 [growling] 412 00:32:46,673 --> 00:32:48,967 He's twice Machito's size… 413 00:32:49,050 --> 00:32:50,343 [growling] 414 00:32:51,344 --> 00:32:52,720 [music intensifies] 415 00:32:52,804 --> 00:32:55,056 …and could kill him in seconds. 416 00:32:56,140 --> 00:32:57,266 -[growls] -[snarls] 417 00:33:02,355 --> 00:33:03,606 [soft growling] 418 00:33:05,441 --> 00:33:08,361 But he's too hungry to give up now. 419 00:33:08,444 --> 00:33:09,862 [soft growling] 420 00:33:17,537 --> 00:33:19,914 [growling] 421 00:33:23,918 --> 00:33:24,752 [snorts] 422 00:33:25,461 --> 00:33:26,796 [silence] 423 00:33:26,879 --> 00:33:29,424 Remarkably, the old puma backs down 424 00:33:30,675 --> 00:33:32,719 and allows the youngster to feed, 425 00:33:33,302 --> 00:33:36,514 behavior that is very rare among males. 426 00:33:38,850 --> 00:33:42,145 Machito's courage may have bought him more time, 427 00:33:43,688 --> 00:33:46,774 but his journey has only just begun. 428 00:33:47,942 --> 00:33:49,777 [poignant music playing] 429 00:33:52,572 --> 00:33:55,658 Male pumas travel far and quickly. 430 00:33:56,492 --> 00:34:00,830 As a consequence, very little is known about their independent lives. 431 00:34:06,002 --> 00:34:10,006 It's thought that few survive their first year alone. 432 00:34:12,675 --> 00:34:13,509 With luck, 433 00:34:14,218 --> 00:34:15,386 he'll be one of them. 434 00:34:19,599 --> 00:34:21,309 [ambient music playing] 435 00:34:26,981 --> 00:34:28,191 [chirping] 436 00:34:33,863 --> 00:34:35,740 It's Christmas Eve, 437 00:34:35,823 --> 00:34:39,494 and the shores of Christmas Island are bright red. 438 00:34:42,872 --> 00:34:44,207 Once in a decade, 439 00:34:44,707 --> 00:34:48,544 the ocean currents are just right for the crablets to return. 440 00:34:49,212 --> 00:34:50,713 [optimistic music playing] 441 00:34:50,797 --> 00:34:53,633 And this is one of the biggest ever seen. 442 00:34:55,426 --> 00:34:57,470 Billions crowd the reefs… 443 00:35:02,975 --> 00:35:04,268 [music speeds up] 444 00:35:04,352 --> 00:35:06,062 …bewildering the locals. 445 00:35:07,105 --> 00:35:07,939 [music slows] 446 00:35:08,022 --> 00:35:10,525 They try to reach dry land 447 00:35:11,567 --> 00:35:13,236 in whatever way they can. 448 00:35:17,698 --> 00:35:21,077 They need to get to the forest from where their parents came 449 00:35:21,160 --> 00:35:25,581 and where they will be safe, just two kilometers away. 450 00:35:26,999 --> 00:35:30,378 But their parents weren't the size of a pinhead. 451 00:35:31,546 --> 00:35:33,381 -[music speeds up] -[squeaking] 452 00:35:33,464 --> 00:35:37,135 Now they shed their shells, changing their wetsuits 453 00:35:37,218 --> 00:35:39,929 for something in which it's easier to breathe. 454 00:35:43,891 --> 00:35:44,725 Ready. 455 00:35:45,393 --> 00:35:47,770 -[squeaking] -But before they've even left the beach… 456 00:35:48,646 --> 00:35:50,314 [big crab growls] 457 00:35:50,398 --> 00:35:53,317 …they are attacked by someone unexpected. 458 00:35:57,697 --> 00:35:58,781 [music abruptly ends] 459 00:35:58,865 --> 00:35:59,824 Mother? 460 00:35:59,907 --> 00:36:01,409 [quirky music playing] 461 00:36:04,912 --> 00:36:10,084 Clearly, adult red crabs are not very child-friendly. 462 00:36:12,753 --> 00:36:15,798 Time to leave the beach, and quickly. 463 00:36:17,133 --> 00:36:18,634 [squeaking] 464 00:36:20,052 --> 00:36:23,598 That requires climbing the seawall. 465 00:36:23,681 --> 00:36:24,640 [music speeds up] 466 00:36:25,558 --> 00:36:29,103 As formidable as a skyscraper would be for us. 467 00:36:30,021 --> 00:36:31,314 [music speeds up] 468 00:36:34,150 --> 00:36:35,443 [music abates] 469 00:36:35,526 --> 00:36:39,030 Once at the top, they must creep through the town. 470 00:36:39,113 --> 00:36:40,489 [music intensifies] 471 00:36:41,991 --> 00:36:44,785 [woman speaking English] 472 00:36:46,037 --> 00:36:48,497 [Attenborough] But it's hard to keep a low profile 473 00:36:48,581 --> 00:36:52,001 when you're part of an army of several billion. 474 00:36:52,084 --> 00:36:53,544 [music intensifies] 475 00:37:09,852 --> 00:37:12,605 The world is very, very dangerous 476 00:37:12,688 --> 00:37:14,649 when you're very, very small. 477 00:37:14,732 --> 00:37:15,942 [squeaking] 478 00:37:16,025 --> 00:37:18,277 So they need to watch their step. 479 00:37:25,910 --> 00:37:27,411 The forest edge. 480 00:37:27,495 --> 00:37:29,455 Safety is in sight. 481 00:37:29,538 --> 00:37:30,498 [music ends] 482 00:37:30,581 --> 00:37:32,416 But it's too soon to relax. 483 00:37:32,500 --> 00:37:35,086 [shrieking string music playing] 484 00:37:35,169 --> 00:37:36,254 [music subsides] 485 00:37:36,337 --> 00:37:38,297 Yellow crazy ants, 486 00:37:39,590 --> 00:37:41,509 which eat crablets. 487 00:37:45,012 --> 00:37:46,639 Those that make it through 488 00:37:47,390 --> 00:37:49,892 are home for Christmas. 489 00:37:51,560 --> 00:37:52,728 [squeaking] 490 00:37:53,771 --> 00:37:57,733 They will spend the next five years feeding and growing 491 00:37:58,484 --> 00:38:01,612 before making the return journey to the sea 492 00:38:02,238 --> 00:38:05,032 and then producing little crablets of their own. 493 00:38:12,206 --> 00:38:14,000 An animal's first journey 494 00:38:14,083 --> 00:38:17,253 will almost always be its most challenging. 495 00:38:18,713 --> 00:38:21,382 But some are especially daunting. 496 00:38:22,758 --> 00:38:25,052 -[optimistic music playing] -[squawking] 497 00:38:26,971 --> 00:38:28,931 Young demoiselle cranes 498 00:38:29,015 --> 00:38:32,893 face one of the toughest migrations made by any bird. 499 00:38:37,481 --> 00:38:39,567 Fleeing frozen Mongolia, 500 00:38:39,650 --> 00:38:43,404 they travel south to spend the winter in India. 501 00:38:45,781 --> 00:38:49,076 But the journey there wasn't always as hard as this. 502 00:38:54,623 --> 00:38:55,499 [music ends] 503 00:38:56,125 --> 00:38:57,918 Forty-five million years ago, 504 00:38:58,002 --> 00:39:00,629 the land beneath them was comparatively flat. 505 00:39:01,630 --> 00:39:05,551 It was then crushed and pushed upwards into great folds, 506 00:39:05,634 --> 00:39:09,638 creating what was to become the highest mountain range on Earth. 507 00:39:10,431 --> 00:39:11,640 [dramatic music playing] 508 00:39:11,724 --> 00:39:12,933 The Himalayas. 509 00:39:19,648 --> 00:39:24,862 To cross, the cranes must now ascend to 8,000 meters above sea level. 510 00:39:25,905 --> 00:39:27,740 [cawing] 511 00:39:27,823 --> 00:39:31,660 The higher they fly, the lower the oxygen. 512 00:39:32,536 --> 00:39:34,538 [music becomes suspenseful] 513 00:39:40,378 --> 00:39:43,172 Exhausted, they're vulnerable to attack. 514 00:39:44,131 --> 00:39:45,424 [music fades out] 515 00:39:50,679 --> 00:39:55,351 Golden eagles, lifted by the warm air rising from the steep slopes, 516 00:39:55,976 --> 00:39:58,354 soar above the cranes. 517 00:39:58,437 --> 00:39:59,730 [cranes squawking] 518 00:40:06,320 --> 00:40:08,072 [menacing music playing] 519 00:40:12,243 --> 00:40:14,995 And then, they dive down towards them. 520 00:40:22,253 --> 00:40:23,838 [tense music playing] 521 00:40:32,012 --> 00:40:34,014 To bring down such large prey, 522 00:40:34,098 --> 00:40:36,058 the eagles work as a pair. 523 00:40:39,478 --> 00:40:41,480 [music climaxes, slowly fading out] 524 00:40:49,238 --> 00:40:50,823 This chick's first journey 525 00:40:52,450 --> 00:40:53,951 has become its last. 526 00:41:10,885 --> 00:41:13,804 There are lower, safer routes than this. 527 00:41:14,972 --> 00:41:16,849 But the cranes' instinct 528 00:41:16,932 --> 00:41:20,019 is to fly in the direction they have always taken. 529 00:41:20,102 --> 00:41:21,937 [poignant music playing] 530 00:41:24,482 --> 00:41:25,691 [squawking] 531 00:41:32,031 --> 00:41:34,992 Until very recently, they faced hunting 532 00:41:35,701 --> 00:41:38,996 and the loss of many of their traditional feeding sites. 533 00:41:46,795 --> 00:41:50,633 Then one small village in Northern India 534 00:41:51,217 --> 00:41:53,010 changed their fortunes. 535 00:41:53,093 --> 00:41:55,012 [optimistic music playing] 536 00:42:12,613 --> 00:42:17,785 The people of Khichan began to feed and protect the cranes. 537 00:42:24,291 --> 00:42:25,251 [squawks] 538 00:42:34,927 --> 00:42:38,180 More and more cranes arrived each winter. 539 00:42:46,897 --> 00:42:50,734 Fifteen thousand of them now visit Khichan every year. 540 00:42:50,818 --> 00:42:52,736 [music becomes rousing] 541 00:42:54,029 --> 00:42:58,075 It's the greatest gathering of the species to be seen anywhere. 542 00:43:01,412 --> 00:43:02,371 For the chicks, 543 00:43:02,454 --> 00:43:06,083 their journey south across the tallest mountain range on Earth 544 00:43:06,166 --> 00:43:07,585 is finally over. 545 00:43:08,502 --> 00:43:10,546 Until next year. 546 00:43:10,629 --> 00:43:12,673 [cawing] 547 00:43:13,424 --> 00:43:14,425 [squawks] 548 00:43:14,508 --> 00:43:15,467 [music fades out] 549 00:43:20,097 --> 00:43:22,099 In this changing world, 550 00:43:22,182 --> 00:43:25,978 animals on the move need our help more than ever. 551 00:43:29,231 --> 00:43:31,275 The tropical forests of Yunnan 552 00:43:31,358 --> 00:43:35,988 are the last home of the endangered wild elephants of China. 553 00:43:41,910 --> 00:43:45,664 [elephants roar, growl] 554 00:43:49,001 --> 00:43:50,419 [snarls] 555 00:43:53,297 --> 00:43:55,132 In March 2020, 556 00:43:56,008 --> 00:44:00,888 the forest was hit by the biggest, longest drought on record. 557 00:44:03,265 --> 00:44:04,725 Trees died 558 00:44:06,060 --> 00:44:07,978 and elephants starved. 559 00:44:10,648 --> 00:44:12,316 [growling] 560 00:44:15,444 --> 00:44:18,322 With a new member of the family about to be born… 561 00:44:18,947 --> 00:44:21,825 [snorts, growls] 562 00:44:21,909 --> 00:44:24,745 …the herd decided to move. 563 00:44:27,831 --> 00:44:31,001 But this was to be no ordinary journey. 564 00:44:31,502 --> 00:44:33,128 [rousing music playing] 565 00:44:33,212 --> 00:44:36,715 Their story captured the world's imagination. 566 00:44:38,258 --> 00:44:39,468 [growls] 567 00:44:39,551 --> 00:44:42,596 Here was the largest land animal 568 00:44:43,806 --> 00:44:45,849 trying to find somewhere to live 569 00:44:47,601 --> 00:44:50,688 in the most populated country on Earth. 570 00:44:57,361 --> 00:44:59,071 The family headed north 571 00:44:59,154 --> 00:45:03,492 into a very different China from the one they had left behind. 572 00:45:06,787 --> 00:45:10,582 For eight months, they trekked through strange new lands 573 00:45:11,208 --> 00:45:13,419 but couldn't find anywhere to settle. 574 00:45:15,087 --> 00:45:19,007 So their newest arrival was born on the move. 575 00:45:21,135 --> 00:45:22,010 [barks] 576 00:45:22,094 --> 00:45:25,055 That, for elephants, was highly unusual. 577 00:45:27,683 --> 00:45:31,019 His start to life would be very tiring. 578 00:45:34,857 --> 00:45:39,486 But the now 17-strong family had to keep traveling. 579 00:45:40,195 --> 00:45:41,613 [music intensifies] 580 00:45:51,749 --> 00:45:54,918 And for those who'd only just learned to walk, 581 00:45:55,002 --> 00:45:57,129 every hurdle was a problem. 582 00:45:57,212 --> 00:45:58,172 [growls] 583 00:46:00,424 --> 00:46:02,551 -And every slope… -[trumpets] 584 00:46:02,634 --> 00:46:03,719 …a steep one. 585 00:46:10,350 --> 00:46:11,310 [music abates] 586 00:46:11,393 --> 00:46:15,147 They continued for another 400 kilometers. 587 00:46:18,233 --> 00:46:20,360 And the further north they trudged, 588 00:46:21,195 --> 00:46:22,905 the less they belonged. 589 00:46:24,114 --> 00:46:25,240 [roars] 590 00:46:28,452 --> 00:46:29,828 To eat or drink, 591 00:46:31,497 --> 00:46:33,499 they were forced to steal. 592 00:46:38,587 --> 00:46:40,172 But remarkably, 593 00:46:41,256 --> 00:46:43,467 instead of driving them away… 594 00:46:43,550 --> 00:46:44,510 [roars] 595 00:46:44,593 --> 00:46:46,887 …people gave them safe passage… 596 00:46:48,013 --> 00:46:48,847 [trumpets] 597 00:46:48,931 --> 00:46:51,308 …and allowed them to plunder. 598 00:46:54,561 --> 00:46:56,563 [snorting] 599 00:46:58,065 --> 00:46:59,107 [growls] 600 00:47:01,276 --> 00:47:03,237 After marching for a year, 601 00:47:03,904 --> 00:47:05,489 they were exhausted. 602 00:47:05,572 --> 00:47:07,574 [snoring] 603 00:47:07,658 --> 00:47:09,409 [poignant music playing] 604 00:47:13,956 --> 00:47:16,458 Elephants usually sleep on their feet 605 00:47:16,542 --> 00:47:21,171 and only lie down when they are completely fatigued. 606 00:47:25,759 --> 00:47:26,802 [snoring] 607 00:47:26,885 --> 00:47:29,638 If we continue to change our planet, 608 00:47:30,305 --> 00:47:31,890 more and more animals 609 00:47:31,974 --> 00:47:35,727 will be forced to make new journeys such as this. 610 00:47:36,728 --> 00:47:38,105 [music intensifies] 611 00:47:46,363 --> 00:47:48,991 But it was their next move 612 00:47:49,074 --> 00:47:51,702 that would be the most extraordinary of all. 613 00:47:52,828 --> 00:47:54,204 [music intensifies] 614 00:47:58,166 --> 00:47:59,334 [music fades out] 615 00:47:59,418 --> 00:48:01,086 [theme tune playing] 616 00:48:49,009 --> 00:48:51,011 [music crescendoes] 617 00:49:26,296 --> 00:49:27,631 [music fades out]