1 00:00:06,716 --> 00:00:09,594 [squeaking] 2 00:00:12,555 --> 00:00:14,557 [squeaking continues] 3 00:00:23,691 --> 00:00:26,319 [Uzo Aduba] There's something magical about dolphins. 4 00:00:30,990 --> 00:00:32,909 They appear so friendly. 5 00:00:35,453 --> 00:00:37,205 Yet so otherworldly. 6 00:00:37,288 --> 00:00:39,582 [uplifting music plays] 7 00:00:41,250 --> 00:00:43,294 They're clearly intelligent. 8 00:00:46,756 --> 00:00:47,840 And agile. 9 00:00:47,924 --> 00:00:49,675 [uplifting music continues] 10 00:00:56,808 --> 00:01:00,686 But we've still barely glimpsed beneath the surface. 11 00:01:00,770 --> 00:01:03,314 [uplifting music continues] 12 00:01:05,983 --> 00:01:08,861 Now we can immerse ourselves in their world, 13 00:01:09,529 --> 00:01:12,698 we're discovering just how sophisticated they are. 14 00:01:13,282 --> 00:01:14,242 [birds squawking] 15 00:01:14,325 --> 00:01:16,494 [uplifting music continues] 16 00:01:21,457 --> 00:01:23,084 And the deeper we look, 17 00:01:24,335 --> 00:01:25,878 the more like us they seem. 18 00:01:29,048 --> 00:01:31,050 [uplifting music swells] 19 00:01:36,055 --> 00:01:37,431 [music fades] 20 00:01:42,145 --> 00:01:44,147 [tranquil music plays] 21 00:01:52,738 --> 00:01:56,159 Born into a world where he can't even breathe, 22 00:01:57,827 --> 00:01:59,787 a young Atlantic spotted dolphin 23 00:01:59,871 --> 00:02:02,790 has a lot to learn about surviving at sea. 24 00:02:06,878 --> 00:02:09,755 A good thing he has someone to show him the way. 25 00:02:10,464 --> 00:02:12,466 [tranquil music continues] 26 00:02:13,926 --> 00:02:14,760 Mom. 27 00:02:19,557 --> 00:02:22,685 And a wider group of family and friends. 28 00:02:22,768 --> 00:02:27,315 [dolphins squeak] 29 00:02:27,398 --> 00:02:29,400 [tranquil music continues] 30 00:02:39,035 --> 00:02:40,912 They'll help teach him 31 00:02:41,704 --> 00:02:43,206 how to find food… 32 00:02:45,291 --> 00:02:47,835 and how to avoid danger. 33 00:02:54,300 --> 00:02:56,677 But dolphin society is complicated. 34 00:02:58,137 --> 00:02:59,805 The greatest challenge 35 00:02:59,889 --> 00:03:02,016 is learning how to fit in. 36 00:03:02,099 --> 00:03:04,101 [tranquil music continues] 37 00:03:15,071 --> 00:03:17,365 These warm, shallow waters 38 00:03:17,448 --> 00:03:19,909 are also home to another species. 39 00:03:21,827 --> 00:03:23,621 Bottlenose dolphins. 40 00:03:31,254 --> 00:03:35,508 This might seem the perfect place for a mother to raise her newborn calf… 41 00:03:37,635 --> 00:03:38,594 but even here, 42 00:03:39,303 --> 00:03:41,097 life isn't easy. 43 00:03:41,180 --> 00:03:43,849 [tense music plays] 44 00:03:49,397 --> 00:03:51,023 They're being followed. 45 00:03:51,649 --> 00:03:54,610 [suspenseful music plays] 46 00:03:55,778 --> 00:03:57,196 A group of males, 47 00:03:58,114 --> 00:03:59,615 looking for a mate. 48 00:03:59,699 --> 00:04:02,743 [suspenseful music continues] 49 00:04:02,827 --> 00:04:05,663 They could attack the baby to get to Mom. 50 00:04:06,455 --> 00:04:09,792 [suspenseful music continues] 51 00:04:12,962 --> 00:04:13,963 [dolphins click] 52 00:04:18,009 --> 00:04:20,177 More dolphins join the chase. 53 00:04:21,804 --> 00:04:23,806 [tense music plays] 54 00:04:28,394 --> 00:04:31,314 Mom does all she can to protect her calf. 55 00:04:32,106 --> 00:04:34,442 [dramatic music plays] 56 00:04:39,238 --> 00:04:40,323 Eventually, 57 00:04:40,948 --> 00:04:42,325 she fights them off. 58 00:04:42,408 --> 00:04:44,827 [dolphins squeak] 59 00:04:45,703 --> 00:04:47,747 But her baby is nowhere to be seen. 60 00:04:58,049 --> 00:05:01,177 Alone, he stands little chance. 61 00:05:21,655 --> 00:05:23,657 [tranquil music plays] 62 00:05:25,951 --> 00:05:28,371 Reunited with Mom… 63 00:05:30,539 --> 00:05:32,083 and her allies, 64 00:05:33,459 --> 00:05:37,546 the calf a little wiser in the ways of the world. 65 00:05:39,131 --> 00:05:43,719 But his lessons in becoming a dolphin have only just begun. 66 00:05:53,020 --> 00:05:54,647 [uplifting music plays] 67 00:05:57,900 --> 00:06:01,278 Dolphins are air-breathing mammals, like us. 68 00:06:03,989 --> 00:06:07,076 Their ancestors once lived on dry land, 69 00:06:08,702 --> 00:06:10,955 but 50 million years ago, 70 00:06:11,038 --> 00:06:13,165 they did something amazing. 71 00:06:14,875 --> 00:06:16,168 Left the land 72 00:06:16,252 --> 00:06:19,296 to enter a life aquatic. 73 00:06:19,380 --> 00:06:21,382 [uplifting music continues] 74 00:06:24,176 --> 00:06:25,845 While one branch of the family 75 00:06:25,928 --> 00:06:29,557 became huge, filter-feeding baleen whales… 76 00:06:31,976 --> 00:06:34,728 they turned into streamlined, 77 00:06:34,812 --> 00:06:36,939 quick-thinking predators. 78 00:06:39,817 --> 00:06:44,488 Today, over 40 species of dolphin hunt the oceans of the world. 79 00:06:44,572 --> 00:06:46,490 [uplifting music continues] 80 00:06:50,077 --> 00:06:51,996 From tropical waters… 81 00:06:55,958 --> 00:06:57,877 to polar seas, 82 00:06:59,462 --> 00:07:03,591 and even in rivers thousands of miles inland, 83 00:07:05,509 --> 00:07:07,303 wherever there is prey, 84 00:07:08,429 --> 00:07:11,849 there's a dolphin with a clever way of catching it. 85 00:07:11,932 --> 00:07:14,768 [uplifting music crescendos] 86 00:07:21,484 --> 00:07:24,945 Orca are the largest members of the family. 87 00:07:27,198 --> 00:07:29,867 They can grow nearly 30 feet long 88 00:07:30,409 --> 00:07:33,162 and weigh seven tons. 89 00:07:37,833 --> 00:07:41,504 Each needs to catch over 100 lb. of food a day. 90 00:07:41,587 --> 00:07:43,672 [tranquil music plays] 91 00:07:43,756 --> 00:07:45,841 Not easy in the polar winter. 92 00:07:46,967 --> 00:07:49,261 Unless you know where to look. 93 00:07:50,387 --> 00:07:53,766 [tranquil music continues] 94 00:08:02,733 --> 00:08:04,652 During the coldest months, 95 00:08:04,735 --> 00:08:07,988 their favorite prey shelters in protected fjords. 96 00:08:09,865 --> 00:08:11,867 [tranquil music continues] 97 00:08:13,786 --> 00:08:14,703 Herring. 98 00:08:16,038 --> 00:08:19,124 In their billions. 99 00:08:19,208 --> 00:08:21,210 [tranquil music swells] 100 00:08:28,801 --> 00:08:31,303 [tense music plays] 101 00:08:31,387 --> 00:08:33,973 Tracking down their exact location 102 00:08:34,056 --> 00:08:35,224 can be tricky. 103 00:08:39,603 --> 00:08:41,564 Catching them is even harder. 104 00:08:41,647 --> 00:08:43,482 [tense music continues] 105 00:08:46,443 --> 00:08:50,948 [squeaking] 106 00:08:51,031 --> 00:08:53,325 Led by an experienced female, 107 00:08:54,451 --> 00:08:58,664 the family pod home in on the vast shoal. 108 00:09:02,293 --> 00:09:04,587 As long as the herring keep formation, 109 00:09:05,963 --> 00:09:07,756 they're hard to single out. 110 00:09:08,757 --> 00:09:10,759 [tense music plays] 111 00:09:18,934 --> 00:09:20,811 But the orca have a plan. 112 00:09:20,894 --> 00:09:22,187 [tense music continues] 113 00:09:22,271 --> 00:09:24,023 [dolphins squeak] 114 00:09:24,106 --> 00:09:26,317 With pulsing calls, 115 00:09:27,276 --> 00:09:29,528 and by flashing their white bellies… 116 00:09:32,448 --> 00:09:35,409 they herd the herring into the shallows. 117 00:09:36,994 --> 00:09:38,996 [tense music continues] 118 00:09:50,507 --> 00:09:54,345 In the panic, the fish form tighter and tighter shoals. 119 00:09:54,428 --> 00:09:55,804 [tense music continues] 120 00:10:04,396 --> 00:10:06,023 Until finally, 121 00:10:06,106 --> 00:10:08,651 the orca can strike. 122 00:10:08,734 --> 00:10:11,028 [tense music continues] 123 00:10:11,111 --> 00:10:12,071 [thudding] 124 00:10:13,989 --> 00:10:15,157 [thudding] 125 00:10:19,828 --> 00:10:24,166 Smashing their tail flukes creates powerful pressure waves. 126 00:10:24,249 --> 00:10:26,794 -[thudding] -[dolphins squeak] 127 00:10:29,213 --> 00:10:31,799 A barrage of knockout blows. 128 00:10:31,882 --> 00:10:34,009 [somber music plays] 129 00:10:35,260 --> 00:10:36,220 [thudding] 130 00:10:38,138 --> 00:10:39,098 [dolphin squeaks] 131 00:10:39,598 --> 00:10:41,475 Once the fish are stunned, 132 00:10:42,267 --> 00:10:45,020 the orca can eat at leisure. 133 00:10:46,772 --> 00:10:48,273 [dolphins squeal] 134 00:10:49,692 --> 00:10:51,694 [tranquil music plays] 135 00:11:09,086 --> 00:11:13,340 Dolphins maximize their hunting success by working as a team. 136 00:11:15,259 --> 00:11:17,177 And out in the open ocean, 137 00:11:17,261 --> 00:11:19,555 they operate on an epic scale. 138 00:11:19,638 --> 00:11:23,642 [dramatic music plays] 139 00:11:25,102 --> 00:11:28,272 A stampede of spinner dolphins. 140 00:11:30,566 --> 00:11:34,236 A super pod over a thousand strong. 141 00:11:34,319 --> 00:11:35,946 [dramatic music continues] 142 00:11:51,128 --> 00:11:54,089 They make such an effective hunting force, 143 00:11:54,798 --> 00:11:57,885 they can afford plenty of downtime. 144 00:12:11,648 --> 00:12:13,484 {\an8}Two hundred miles east of Brazil, 145 00:12:14,651 --> 00:12:17,196 this archipelago is a favorite stop-off 146 00:12:17,279 --> 00:12:19,239 for Atlantic spinner dolphins. 147 00:12:22,951 --> 00:12:25,412 They head for the island's shallow bays. 148 00:12:28,624 --> 00:12:32,461 The first arrivals are in high spirits. 149 00:12:34,338 --> 00:12:37,049 [uplifting music plays] 150 00:12:47,976 --> 00:12:51,104 The Olympic gymnasts of the dolphin family. 151 00:12:52,439 --> 00:12:55,400 They can leap ten feet 152 00:12:56,276 --> 00:12:58,320 and spin seven times. 153 00:12:58,403 --> 00:13:00,489 [uplifting music continues] 154 00:13:11,166 --> 00:13:12,793 It looks a lot of fun. 155 00:13:15,087 --> 00:13:18,257 But it's thought there's more to these acrobatics. 156 00:13:19,424 --> 00:13:21,927 [uplifting music crescendos] 157 00:13:26,139 --> 00:13:28,225 Perhaps they're communicating, 158 00:13:28,308 --> 00:13:30,811 greeting other dolphins entering the bay. 159 00:13:30,894 --> 00:13:34,022 [dolphins squeak] 160 00:13:34,106 --> 00:13:36,108 [tranquil music plays] 161 00:13:45,868 --> 00:13:47,661 With safety in numbers, 162 00:13:48,495 --> 00:13:50,664 the spinners can relax. 163 00:13:50,747 --> 00:13:52,749 [tranquil music continues] 164 00:14:02,509 --> 00:14:04,720 But they can't switch off completely, 165 00:14:05,470 --> 00:14:07,055 or they would drown. 166 00:14:08,432 --> 00:14:11,810 So they shut down one side of their brain at a time… 167 00:14:13,896 --> 00:14:16,315 with one eye on where they're going. 168 00:14:18,233 --> 00:14:20,861 Sleep swimming at half speed. 169 00:14:20,944 --> 00:14:22,946 [tranquil music continues] 170 00:14:27,659 --> 00:14:30,037 While older dolphins rest, 171 00:14:31,413 --> 00:14:34,041 the younger ones play. 172 00:14:37,920 --> 00:14:39,922 [tranquil music plays] 173 00:14:52,351 --> 00:14:54,353 [jaunty music plays] 174 00:14:56,521 --> 00:14:58,523 A game of seaweed catch. 175 00:14:58,607 --> 00:15:00,901 [jaunty music continues] 176 00:15:28,261 --> 00:15:30,430 It seems simple enough. 177 00:15:30,514 --> 00:15:32,516 [jaunty music continues] 178 00:15:33,850 --> 00:15:37,396 But this is surprisingly sophisticated play. 179 00:15:39,606 --> 00:15:41,692 Manipulating objects, 180 00:15:43,068 --> 00:15:46,154 copying moves and, most importantly, 181 00:15:46,238 --> 00:15:47,823 understanding each other. 182 00:15:48,907 --> 00:15:54,496 A skill every young dolphin must master as it grows. 183 00:16:00,377 --> 00:16:02,254 By a year old, 184 00:16:02,337 --> 00:16:06,717 an Atlantic spotted calf is almost fluent in dolphin. 185 00:16:10,012 --> 00:16:12,014 [tranquil music plays] 186 00:16:14,391 --> 00:16:16,435 [dolphins click and squeak] 187 00:16:16,518 --> 00:16:18,854 [tranquil music continues] 188 00:16:22,232 --> 00:16:25,652 Much can be communicated through body language and touch. 189 00:16:27,738 --> 00:16:29,823 A flipper rub reassures, 190 00:16:30,824 --> 00:16:32,325 like holding hands. 191 00:16:33,368 --> 00:16:35,328 [dolphin clicks] 192 00:16:35,412 --> 00:16:39,416 But some things can only be said with sound. 193 00:16:39,499 --> 00:16:42,169 [dolphin squeaks] 194 00:16:43,003 --> 00:16:45,005 His mom repeats a unique call. 195 00:16:45,088 --> 00:16:46,006 [dolphin squeaks] 196 00:16:48,842 --> 00:16:50,343 Her signature whistle. 197 00:16:51,803 --> 00:16:52,679 [dolphin squeaks] 198 00:16:53,472 --> 00:16:55,807 It helps him to find her in a crowd. 199 00:16:56,558 --> 00:16:57,601 [dolphin squeaks] 200 00:17:00,645 --> 00:17:02,939 And once he's learned to copy it, 201 00:17:03,023 --> 00:17:04,900 he can call her by her name. 202 00:17:04,983 --> 00:17:05,942 [dolphin squeaks] 203 00:17:08,070 --> 00:17:11,615 Now it's time to experiment with a whistle of his own. 204 00:17:11,698 --> 00:17:12,783 [high-pitched squeak] 205 00:17:13,408 --> 00:17:14,493 [high-pitched squeak] 206 00:17:16,495 --> 00:17:17,788 Like children, 207 00:17:17,871 --> 00:17:20,707 dolphins take years learning to speak. 208 00:17:23,168 --> 00:17:25,128 And once they start talking… 209 00:17:25,212 --> 00:17:28,215 [squeaking] 210 00:17:28,298 --> 00:17:30,884 …they never let up. 211 00:17:31,676 --> 00:17:36,640 [dolphin clicks] 212 00:17:38,266 --> 00:17:42,229 But a dolphin's sonic skills go way beyond words. 213 00:17:42,771 --> 00:17:44,773 [tense music plays] 214 00:17:48,151 --> 00:17:51,947 The local bottlenose are searching for food on the sea floor. 215 00:17:52,489 --> 00:17:54,032 [squeaking] 216 00:17:54,116 --> 00:17:56,076 There doesn't appear to be much here. 217 00:17:57,869 --> 00:18:02,040 But they can see things we can't. 218 00:18:02,124 --> 00:18:04,209 [tense music continues] 219 00:18:09,381 --> 00:18:12,467 They fire a stream of high-pitched clicks. 220 00:18:13,677 --> 00:18:16,638 Five hundred per second. 221 00:18:16,721 --> 00:18:23,562 [dolphins clicking] 222 00:18:24,688 --> 00:18:26,690 And interpret the echoes 223 00:18:26,773 --> 00:18:29,609 to pinpoint fish hiding in the sand. 224 00:18:31,528 --> 00:18:38,410 [dolphin clicks] 225 00:18:43,707 --> 00:18:50,672 [dolphin clicks] 226 00:18:52,424 --> 00:18:55,844 Echolocation is an extraordinary sixth sense… 227 00:18:57,888 --> 00:19:03,185 that allows dolphins to hunt in the most unlikely of places. 228 00:19:15,155 --> 00:19:16,448 A muddy estuary, 229 00:19:17,490 --> 00:19:20,076 and the tide is dropping. 230 00:19:21,745 --> 00:19:25,999 Right now, heading inland could be a risky move. 231 00:19:27,042 --> 00:19:29,044 [tranquil music plays] 232 00:19:38,720 --> 00:19:43,308 But this dolphin knows the estuary is full of fish. 233 00:19:43,391 --> 00:19:45,393 [tranquil music continues] 234 00:19:53,944 --> 00:19:55,946 Using echolocation, 235 00:19:56,029 --> 00:20:00,659 she can navigate the silty waters and find her prey. 236 00:20:00,742 --> 00:20:05,413 [dolphin clicks] 237 00:20:05,497 --> 00:20:07,499 [tranquil music continues] 238 00:20:08,708 --> 00:20:10,293 Only problem is, 239 00:20:10,377 --> 00:20:13,338 at low tide they hide in the oyster beds. 240 00:20:15,257 --> 00:20:18,343 Charging in would shred her sensitive skin. 241 00:20:20,804 --> 00:20:25,141 Somehow, she needs to get the fish into the open. 242 00:20:30,188 --> 00:20:32,190 [tense music plays] 243 00:20:38,863 --> 00:20:42,784 Pumping her tail, she flushes them out of hiding 244 00:20:43,868 --> 00:20:47,289 and towards the sandy banks, where it's safe to strike. 245 00:20:47,372 --> 00:20:49,374 [tense music continues] 246 00:20:52,002 --> 00:20:54,045 [tense music crescendos] 247 00:20:55,755 --> 00:20:58,883 Only a few dolphins have learned to hunt like this. 248 00:21:03,722 --> 00:21:05,807 And the technique only works 249 00:21:05,890 --> 00:21:08,101 for a few hours each day. 250 00:21:14,774 --> 00:21:17,360 When the tide begins to rise, 251 00:21:17,444 --> 00:21:19,362 the fish disperse. 252 00:21:19,446 --> 00:21:21,448 [hopeful music plays] 253 00:21:22,741 --> 00:21:24,659 A new strategy is needed. 254 00:21:28,705 --> 00:21:30,707 She joins forces with friends 255 00:21:32,042 --> 00:21:35,503 and together they head towards wider channels. 256 00:21:35,587 --> 00:21:37,589 [hopeful music continues] 257 00:21:39,549 --> 00:21:40,550 Then, 258 00:21:42,427 --> 00:21:43,636 they wait. 259 00:21:53,146 --> 00:21:54,898 [dramatic music plays] 260 00:21:58,735 --> 00:22:00,987 [birds squawk] 261 00:22:01,071 --> 00:22:03,073 [dramatic music continues] 262 00:22:11,039 --> 00:22:13,083 [dolphins squeak] 263 00:22:13,166 --> 00:22:14,709 [dramatic music continues] 264 00:22:18,797 --> 00:22:20,799 [dramatic music fades] 265 00:22:28,056 --> 00:22:30,266 Each time a shoal swims past, 266 00:22:30,350 --> 00:22:32,227 the dolphins attack, 267 00:22:33,895 --> 00:22:37,023 creating bow waves that wash the fish ashore. 268 00:22:37,607 --> 00:22:39,776 [dramatic music plays] 269 00:22:54,624 --> 00:22:58,378 Through echolocation and coordination, 270 00:22:58,461 --> 00:23:01,548 they conjure a feast from the mud. 271 00:23:04,509 --> 00:23:06,511 [dramatic music fades] 272 00:23:08,304 --> 00:23:10,306 Out in the big blue, 273 00:23:10,390 --> 00:23:13,810 dolphins must push their super senses to the limits. 274 00:23:18,690 --> 00:23:21,067 [tranquil music plays] 275 00:23:21,151 --> 00:23:23,027 The challenge of hunting in the abyss 276 00:23:23,111 --> 00:23:27,824 has created one of the most extraordinary dolphins of all. 277 00:23:27,907 --> 00:23:29,909 [tranquil music continues] 278 00:23:33,997 --> 00:23:38,001 [dolphin squeaks] 279 00:23:38,084 --> 00:23:40,462 [tranquil music continues] 280 00:23:48,511 --> 00:23:51,097 Pilot whales may look strange, 281 00:23:51,806 --> 00:23:55,935 but their bulbous foreheads hold the secret to their success. 282 00:23:57,187 --> 00:24:01,274 They project long-range sonic beams hundreds of feet. 283 00:24:02,317 --> 00:24:05,820 The most powerful echolocation of any dolphin. 284 00:24:07,071 --> 00:24:09,073 [tranquil music continues] 285 00:24:10,283 --> 00:24:13,036 {\an8}[dolphins click] 286 00:24:13,745 --> 00:24:16,873 {\an8}It enables pilot whales to hunt shoals of squid 287 00:24:16,956 --> 00:24:19,083 over half a mile down. 288 00:24:19,918 --> 00:24:24,589 [dolphins click and squeak] 289 00:24:24,672 --> 00:24:26,674 [tranquil music continues] 290 00:24:29,469 --> 00:24:33,181 But young calves can't hold their breath long enough to follow. 291 00:24:37,560 --> 00:24:40,688 So the family take turns 292 00:24:40,772 --> 00:24:42,732 babysitting at the surface. 293 00:24:44,108 --> 00:24:45,902 [tranquil music continues] 294 00:24:45,985 --> 00:24:48,696 Grandma is over 50 years old. 295 00:24:50,031 --> 00:24:53,368 But she still produces milk to keep the youngsters fed. 296 00:25:02,460 --> 00:25:05,922 These dolphins live up to 70 years 297 00:25:06,923 --> 00:25:09,217 and stay with the family for life. 298 00:25:10,093 --> 00:25:15,014 Possibly the longest, most loyal bonds of any animal. 299 00:25:15,682 --> 00:25:21,229 [dolphins squeak] 300 00:25:22,480 --> 00:25:24,649 When the hunting party surfaces, 301 00:25:24,732 --> 00:25:26,734 it's clear they've had success. 302 00:25:32,824 --> 00:25:34,409 Time to move on. 303 00:25:35,785 --> 00:25:38,913 Grandma has a mental map of their ocean home. 304 00:25:40,039 --> 00:25:43,835 She listens for the sounds of waves crashing on islands 305 00:25:43,918 --> 00:25:46,588 and currents washing around sea mouths. 306 00:25:49,591 --> 00:25:52,385 Acoustic landmarks revealing the route. 307 00:25:53,595 --> 00:25:55,597 [tranquil music plays] 308 00:25:59,392 --> 00:26:00,602 But sometimes, 309 00:26:01,853 --> 00:26:04,355 even these great navigators lose their way. 310 00:26:08,318 --> 00:26:09,736 [somber music plays] 311 00:26:09,819 --> 00:26:10,695 Every year, 312 00:26:11,696 --> 00:26:15,325 hundreds of dolphins strand on beaches around the world. 313 00:26:16,284 --> 00:26:18,828 Pilot whales more often than most. 314 00:26:20,997 --> 00:26:23,958 It only takes one or two to go off course… 315 00:26:26,044 --> 00:26:29,589 and family members feel compelled to swim to their side. 316 00:26:30,882 --> 00:26:33,092 [somber music continues] 317 00:26:33,176 --> 00:26:36,304 Sometimes, their distress calls bring hundreds more. 318 00:26:36,387 --> 00:26:39,766 [dolphins squeak] 319 00:26:44,479 --> 00:26:46,397 Natural disasters, 320 00:26:46,481 --> 00:26:48,858 noise pollution, and ill health 321 00:26:48,941 --> 00:26:51,110 all seem to play a part. 322 00:26:53,613 --> 00:26:57,241 {\an8}But the exact triggers for these events are poorly understood. 323 00:26:57,325 --> 00:26:59,327 {\an8}[somber music continues] 324 00:27:04,666 --> 00:27:08,169 {\an8}People do all they can to keep stranded whales alive 325 00:27:08,252 --> 00:27:10,963 and try to help them back out to sea. 326 00:27:11,047 --> 00:27:12,924 [somber music continues] 327 00:27:20,473 --> 00:27:24,018 The connection between humans and dolphins runs deep. 328 00:27:25,728 --> 00:27:30,149 We share a thrill-seeking side found in few other animals. 329 00:27:31,275 --> 00:27:36,280 And we express ourselves in ways that have no obvious role in survival. 330 00:27:36,364 --> 00:27:38,366 [dramatic music plays] 331 00:27:41,077 --> 00:27:43,871 But it seems there's purpose to all this play. 332 00:27:46,332 --> 00:27:48,710 It produces a rush of hormones 333 00:27:48,793 --> 00:27:51,963 that create feelings of confidence and joy. 334 00:27:53,673 --> 00:27:56,926 Playing together heightens these emotions… 335 00:27:59,095 --> 00:28:03,057 encouraging teamwork and time spent with friends. 336 00:28:03,141 --> 00:28:05,977 [exhilarating music plays] 337 00:28:17,113 --> 00:28:20,408 Perhaps this is why dolphins seek the company of others. 338 00:28:20,491 --> 00:28:22,910 [exhilarating music continues] 339 00:28:34,797 --> 00:28:36,924 Playing with their own kind. 340 00:28:37,008 --> 00:28:40,052 [exhilarating music continues] 341 00:28:41,763 --> 00:28:42,597 With us. 342 00:28:46,601 --> 00:28:48,603 And with other animals. 343 00:28:49,312 --> 00:28:51,314 [exhilarating music continues] 344 00:29:08,623 --> 00:29:10,041 [exhilarating music fades] 345 00:29:15,379 --> 00:29:18,299 Dolphins are famous for their friendly nature. 346 00:29:20,468 --> 00:29:22,887 But they also have a darker side. 347 00:29:36,651 --> 00:29:39,987 When the ocean's top predators go hunting, 348 00:29:40,071 --> 00:29:42,114 nothing is safe. 349 00:29:42,949 --> 00:29:44,867 [dolphins squeaking] 350 00:29:54,001 --> 00:29:56,003 [ominous music plays] 351 00:30:01,634 --> 00:30:04,220 Southern right whales. 352 00:30:06,347 --> 00:30:08,599 Up to 80 tons. 353 00:30:08,683 --> 00:30:10,017 [whale trumpets] 354 00:30:10,101 --> 00:30:12,895 Ten times heavier than an orca. 355 00:30:17,608 --> 00:30:18,776 [whale trumpets] 356 00:30:21,362 --> 00:30:23,155 But working as a team, 357 00:30:24,115 --> 00:30:26,784 orca are almost unstoppable. 358 00:30:32,081 --> 00:30:34,500 The right whales make for the shallows 359 00:30:34,584 --> 00:30:36,586 to avoid attack from below. 360 00:30:36,669 --> 00:30:38,671 [tense music plays] 361 00:30:40,923 --> 00:30:43,801 But orca don't give up easily. 362 00:30:43,885 --> 00:30:46,012 [tense music continues] 363 00:30:48,055 --> 00:30:49,891 Taking turns, 364 00:30:49,974 --> 00:30:52,894 they smash into the whales' flanks, 365 00:30:52,977 --> 00:30:54,687 hitting them where it hurts. 366 00:30:55,938 --> 00:30:57,440 [tense music continues] 367 00:31:05,072 --> 00:31:07,116 The whales strike back. 368 00:31:07,199 --> 00:31:08,409 [squeaking] 369 00:31:08,492 --> 00:31:10,828 [tense music continues] 370 00:31:10,912 --> 00:31:12,121 [whale trumpets] 371 00:31:16,709 --> 00:31:18,085 [tense music crescendos] 372 00:31:18,169 --> 00:31:19,587 [squeaking] 373 00:31:20,504 --> 00:31:21,589 [whale trumpets] 374 00:31:21,672 --> 00:31:23,591 [tense music resumes] 375 00:31:35,061 --> 00:31:39,190 But it's only when the sounds of struggle attract more right whales 376 00:31:40,733 --> 00:31:43,736 that the orca finally back off. 377 00:31:46,072 --> 00:31:48,074 [tense music fades] 378 00:31:50,576 --> 00:31:53,329 Orca's ability to take on such large prey 379 00:31:53,412 --> 00:31:55,957 earned them the nickname "whale killers," 380 00:31:56,624 --> 00:31:57,458 or 381 00:31:58,209 --> 00:31:59,418 "killer whales." 382 00:32:02,922 --> 00:32:05,341 Dolphins are not just ruthless hunters. 383 00:32:06,634 --> 00:32:10,221 They can also be surprisingly aggressive to each other. 384 00:32:21,857 --> 00:32:24,318 [tranquil music plays] 385 00:32:24,402 --> 00:32:25,653 By six years old, 386 00:32:26,237 --> 00:32:28,197 this young spotted dolphin 387 00:32:28,280 --> 00:32:31,409 has finally developed his trademark spots. 388 00:32:31,492 --> 00:32:33,494 [tranquil music continues] 389 00:32:37,373 --> 00:32:39,041 He's seeing less of Mom… 390 00:32:41,085 --> 00:32:44,296 and spending more time hanging out with friends. 391 00:32:48,884 --> 00:32:52,555 Building alliances is crucial in these early years. 392 00:32:52,638 --> 00:32:53,681 [dolphin clicks] 393 00:32:54,932 --> 00:32:56,934 [tranquil music continues] 394 00:33:02,773 --> 00:33:06,610 Dolphins form more numerous, more intense relationships 395 00:33:06,694 --> 00:33:09,864 than any other animal except us. 396 00:33:09,947 --> 00:33:11,949 [tranquil music continues] 397 00:33:14,994 --> 00:33:18,205 As he matures, life will become more complicated. 398 00:33:18,289 --> 00:33:22,043 [dolphins click and squeak] 399 00:33:22,126 --> 00:33:24,628 And he'll need all the friends he can get. 400 00:33:28,215 --> 00:33:30,217 [tranquil music fades] 401 00:33:36,766 --> 00:33:40,352 A community of bottlenose dolphins in Western Australia 402 00:33:40,436 --> 00:33:45,357 is considered the most sophisticated dolphin society of all. 403 00:33:48,319 --> 00:33:50,988 Two thousand live in this one bay. 404 00:33:51,697 --> 00:33:53,699 [upbeat music plays] 405 00:34:02,124 --> 00:34:04,251 During the breeding season, 406 00:34:04,335 --> 00:34:07,713 who you know becomes more important than ever. 407 00:34:09,757 --> 00:34:11,675 Males that are able to team up 408 00:34:11,759 --> 00:34:14,011 have more chance of winning a mate. 409 00:34:14,095 --> 00:34:16,013 [upbeat music continues] 410 00:34:28,359 --> 00:34:31,237 This trio hangs out on the east side of the bay. 411 00:34:31,320 --> 00:34:34,198 [upbeat music continues] 412 00:34:37,535 --> 00:34:41,539 They've been best friends for 20 years. 413 00:34:42,748 --> 00:34:44,750 [upbeat music fades] 414 00:34:44,834 --> 00:34:49,296 Swimming in sync shows just how tight they are. 415 00:34:51,757 --> 00:34:55,845 And choreographed moves help impress the opposite sex. 416 00:34:56,512 --> 00:34:58,514 [jaunty music plays] 417 00:35:02,935 --> 00:35:04,645 There's the crossover. 418 00:35:07,273 --> 00:35:08,482 The butterfly. 419 00:35:12,111 --> 00:35:13,946 The duo tail touch. 420 00:35:16,157 --> 00:35:17,992 Synchronous dives. 421 00:35:20,161 --> 00:35:21,537 Dual leaps. 422 00:35:22,997 --> 00:35:24,582 Tango moves. 423 00:35:25,249 --> 00:35:29,044 And the inverse rooster strut. 424 00:35:32,256 --> 00:35:36,010 The slicker the routine, the more attractive they seem. 425 00:35:36,093 --> 00:35:38,095 [jaunty music continues] 426 00:35:41,557 --> 00:35:42,808 Even so, 427 00:35:42,892 --> 00:35:45,561 it often takes days to win over a female. 428 00:35:51,692 --> 00:35:54,403 And now they have competition. 429 00:35:56,530 --> 00:35:57,907 On the west side, 430 00:35:57,990 --> 00:36:00,117 rival gangs are forming. 431 00:36:00,201 --> 00:36:02,494 [tense music plays] 432 00:36:03,412 --> 00:36:05,706 The east side trio needs backup. 433 00:36:09,001 --> 00:36:11,795 So they call on a wider circle of friends. 434 00:36:11,879 --> 00:36:14,215 [tense music continues] 435 00:36:31,440 --> 00:36:33,234 Weaker gangs usually back down. 436 00:36:35,611 --> 00:36:37,988 But when the sides are equally matched, 437 00:36:39,365 --> 00:36:41,825 fights can cause serious injury. 438 00:36:45,996 --> 00:36:47,998 [tense music plays] 439 00:36:51,377 --> 00:36:53,379 [tense music intensifies] 440 00:37:27,871 --> 00:37:29,999 [tense music fades] 441 00:37:30,082 --> 00:37:31,083 An hour later, 442 00:37:32,167 --> 00:37:33,377 it's all over. 443 00:37:38,299 --> 00:37:41,593 Through strong allegiances and tight teamwork, 444 00:37:41,677 --> 00:37:44,221 the east side friends emerge victorious 445 00:37:44,847 --> 00:37:48,642 {\an8}and win the chance to father the next generation. 446 00:37:48,726 --> 00:37:50,728 {\an8}[tranquil music plays] 447 00:37:52,813 --> 00:37:54,940 Intelligence and collaboration 448 00:37:55,024 --> 00:37:58,986 have enabled dolphins to navigate life in the ocean. 449 00:38:01,405 --> 00:38:03,824 But their home is changing fast. 450 00:38:06,869 --> 00:38:08,537 [dolphins click] 451 00:38:08,620 --> 00:38:12,291 Even these adaptable animals are struggling to cope. 452 00:38:15,044 --> 00:38:16,211 [boat horn blares] 453 00:38:18,630 --> 00:38:20,716 Our seas are becoming noisier. 454 00:38:20,799 --> 00:38:22,051 [boat horn blares] 455 00:38:22,843 --> 00:38:23,719 Warmer. 456 00:38:25,471 --> 00:38:26,847 And more polluted. 457 00:38:34,313 --> 00:38:35,939 Instead of seaweed, 458 00:38:36,023 --> 00:38:39,151 many dolphins now play with plastic bags. 459 00:38:49,661 --> 00:38:55,334 Swallowing trash kills over 100,000 marine mammals every year. 460 00:38:56,377 --> 00:38:58,629 And chemical contamination 461 00:38:58,712 --> 00:39:01,382 threatens their ability to reproduce. 462 00:39:04,718 --> 00:39:09,348 But industrial-scale fishing is the biggest problem dolphins face… 463 00:39:12,017 --> 00:39:14,436 rapidly depleting their vital food 464 00:39:15,062 --> 00:39:19,233 and drowning hundreds of thousands of them each year. 465 00:39:19,316 --> 00:39:21,318 [somber music plays] 466 00:39:28,283 --> 00:39:31,412 However, even small changes in our actions 467 00:39:31,495 --> 00:39:33,747 can make a big difference. 468 00:39:35,207 --> 00:39:37,209 [upbeat music plays] 469 00:39:47,428 --> 00:39:49,346 When fishermen trawl for shrimp… 470 00:39:52,099 --> 00:39:54,601 other animals are caught in their nets. 471 00:39:57,104 --> 00:40:00,607 But these fishermen now incorporate special openings 472 00:40:00,691 --> 00:40:02,901 so larger animals can escape. 473 00:40:06,196 --> 00:40:09,408 And the local bottlenose have learned to seek them out, 474 00:40:10,868 --> 00:40:14,788 {\an8}using the exit holes to pick out a prize of fish. 475 00:40:15,289 --> 00:40:18,083 [upbeat music continues] 476 00:40:31,472 --> 00:40:34,641 Entering these death traps is a risky maneuver. 477 00:40:38,812 --> 00:40:41,732 But these hungry dolphins take their chances. 478 00:40:43,442 --> 00:40:46,487 [upbeat music continues] 479 00:40:56,538 --> 00:40:58,332 And the fishermen tolerate them. 480 00:41:01,251 --> 00:41:03,086 There's no loss to their catch. 481 00:41:06,423 --> 00:41:08,425 [upbeat music fades] 482 00:41:08,509 --> 00:41:11,261 We still have a lot to learn about dolphins. 483 00:41:12,054 --> 00:41:15,432 And while some species are on the brink of extinction, 484 00:41:17,100 --> 00:41:20,354 new ones are still being found. 485 00:41:20,437 --> 00:41:22,439 [jaunty music plays] 486 00:41:26,693 --> 00:41:31,949 It's long been thought there were five species of river dolphin in the world. 487 00:41:32,032 --> 00:41:35,285 Now biologists believe they've discovered a sixth. 488 00:41:37,371 --> 00:41:42,543 Only around 1,000 Araguaian river dolphins are thought to exist. 489 00:41:42,626 --> 00:41:45,337 [jaunty music continues] 490 00:41:46,296 --> 00:41:48,048 But every day 491 00:41:48,131 --> 00:41:50,384 in this Brazilian town, 492 00:41:50,467 --> 00:41:52,803 a small number come to hang out. 493 00:41:54,930 --> 00:41:58,475 The local children can hardly wait. 494 00:42:03,730 --> 00:42:08,151 {\an8}It's easy to understand their affinity with these magical animals. 495 00:42:12,739 --> 00:42:17,035 {\an8}Humans and dolphins may inhabit very different worlds… 496 00:42:19,538 --> 00:42:23,041 but there's much in our nature that we share. 497 00:42:24,042 --> 00:42:26,044 [uplifting music plays] 498 00:42:30,132 --> 00:42:32,843 A deep connection to be cherished 499 00:42:33,719 --> 00:42:36,513 for generations to come. 500 00:42:36,597 --> 00:42:39,766 [uplifting music continues] 501 00:42:44,980 --> 00:42:46,982 [uplifting music fades] 502 00:42:48,233 --> 00:42:50,027 [dramatic music plays]