WEBVTT 00:00:08.021 --> 00:00:09.720 Enter a world... 00:00:11.136 --> 00:00:13.096 just beyond your perception. 00:00:19.102 --> 00:00:22.313 A world of extraordinary animals... 00:00:23.189 --> 00:00:26.484 with hidden powers and super senses. 00:00:27.610 --> 00:00:29.446 If you think you know nature... 00:00:32.331 --> 00:00:33.948 think again. 00:00:45.852 --> 00:00:48.088 Deep in the Canadian wilderness... 00:00:52.844 --> 00:00:54.387 ...an animal so secretive... 00:00:58.224 --> 00:01:01.144 she's known as the Phantom of the Forest. 00:01:08.693 --> 00:01:10.271 The goshawk. 00:01:21.839 --> 00:01:24.466 Zero to 40 miles an hour... 00:01:25.752 --> 00:01:27.003 in under a second. 00:01:31.007 --> 00:01:34.803 The fastest acceleration of any bird of prey. 00:01:41.559 --> 00:01:44.485 Short, rounded wings and a foot-long tail, 00:01:44.943 --> 00:01:47.415 steer through dense forests, 00:01:47.440 --> 00:01:49.285 with unparalleled agility. 00:01:54.072 --> 00:01:57.784 Yet even she can be outmaneuvered. 00:02:04.999 --> 00:02:07.710 Other, much smaller creatures here... 00:02:09.129 --> 00:02:12.190 ...possess astonishing abilities 00:02:12.230 --> 00:02:14.941 that can defeat the Phantom of the Forest. 00:02:20.181 --> 00:02:22.851 With specialized eyesight adapted to low light, 00:02:23.309 --> 00:02:27.272 the chickadee is first to spot the airborne threat... 00:02:32.360 --> 00:02:34.691 ...and first to raise the alarm. 00:02:35.852 --> 00:02:37.581 A coded message... 00:02:38.908 --> 00:02:41.512 broadcasting the hawk's position and speed. 00:02:44.293 --> 00:02:47.584 Squirrels not only recognize the chickadees' call... 00:02:50.795 --> 00:02:52.660 ...they've learned to mimic it... 00:02:53.965 --> 00:02:55.300 almost perfectly. 00:02:59.145 --> 00:03:00.963 In seconds 00:03:00.988 --> 00:03:05.810 the warning is retweeted from one animal to another. 00:03:10.113 --> 00:03:14.277 It relays through the forest at over a 100 miles per hour. 00:03:18.615 --> 00:03:21.409 More than twice as fast as the hawk. 00:03:28.583 --> 00:03:31.127 Message received, loud and clear. 00:03:32.128 --> 00:03:36.685 "Enemy approaching, low and fast." 00:03:41.908 --> 00:03:44.529 When the little guys look out for each other... 00:03:47.787 --> 00:03:49.812 it keeps them one step ahead. 00:03:58.071 --> 00:04:00.490 You don't have to be big and tough to survive. 00:04:02.116 --> 00:04:05.379 What you really need are friends. 00:04:06.512 --> 00:04:09.874 Welcome to the world of animal alliances... 00:04:11.542 --> 00:04:14.921 where creatures communicate and collaborate in wonderful ways... 00:04:16.938 --> 00:04:20.808 and form the most unexpected partnerships. 00:04:35.452 --> 00:04:37.735 Even in this punishing world... 00:04:39.737 --> 00:04:42.031 by joining forces... 00:04:42.395 --> 00:04:45.523 ...animals can triumph against extreme odds. 00:04:51.485 --> 00:04:54.621 When the weather turns in this North American forest... 00:04:55.376 --> 00:04:58.388 sticking together can make the difference 00:04:58.412 --> 00:05:01.017 between life and death. 00:05:04.658 --> 00:05:06.656 At just five ounces, 00:05:06.681 --> 00:05:08.630 this little squirrel can't store 00:05:08.654 --> 00:05:10.782 enough bodyfat to hibernate. 00:05:11.251 --> 00:05:14.522 So, he has to find food all winter. 00:05:19.527 --> 00:05:21.279 But once he leaves his friends... 00:05:22.120 --> 00:05:23.493 he could freeze. 00:05:29.704 --> 00:05:32.081 When the temperature falls to minus 30... 00:05:33.583 --> 00:05:36.632 only the most superpowered squirrel 00:05:36.656 --> 00:05:39.276 will make it home alive. 00:05:40.837 --> 00:05:42.752 He needs food... 00:05:43.352 --> 00:05:45.158 and fast. 00:05:52.760 --> 00:05:55.500 Large eyes drink in the faint light. 00:06:01.456 --> 00:06:02.967 He sees in the dark... 00:06:04.906 --> 00:06:06.783 as well as we see in the day. 00:06:10.661 --> 00:06:12.766 And his acute sense of smell helps him 00:06:12.790 --> 00:06:15.124 to locate food on the forest floor. 00:06:21.798 --> 00:06:24.849 But a mushroom is only four calories. 00:06:26.614 --> 00:06:29.847 He needs 20 to survive the night. 00:06:34.560 --> 00:06:37.563 Not easy to come by in deep winter. 00:06:42.110 --> 00:06:44.825 If racing up and down in search of food 00:06:44.849 --> 00:06:47.573 burns more energy than he can find, 00:06:48.227 --> 00:06:51.126 this night will be his last. 00:07:00.795 --> 00:07:03.756 But this little lightweight has a secret. 00:07:11.050 --> 00:07:12.777 He can fly. 00:07:15.935 --> 00:07:17.914 Northern flying squirrels 00:07:17.938 --> 00:07:20.248 have a furry wingsuit, 00:07:20.273 --> 00:07:22.180 stretching from wrist to ankle, 00:07:22.204 --> 00:07:24.488 called a patagium. 00:07:30.032 --> 00:07:32.869 They can glide nearly the length of a football field. 00:07:47.341 --> 00:07:52.013 And to land, he turns his tail into an air brake. 00:08:04.734 --> 00:08:06.462 Sailing between the trees, 00:08:06.486 --> 00:08:09.572 he finds enough food with minimal effort. 00:08:16.954 --> 00:08:20.958 But now, this ninja of the night is far from his friends. 00:08:23.234 --> 00:08:25.300 If he doesn't find them soon... 00:08:26.495 --> 00:08:27.836 ...he will die. 00:08:33.888 --> 00:08:36.641 He sends out an emergency ultrasonic message. 00:08:41.726 --> 00:08:44.037 Most predators can't hear it... 00:08:44.148 --> 00:08:47.276 ...but his friends can. 00:08:49.399 --> 00:08:51.553 And when they reply... 00:08:52.588 --> 00:08:54.774 ...he knows exactly where to go. 00:09:03.584 --> 00:09:06.009 Now, they must head home together... 00:09:07.884 --> 00:09:10.118 to warm up before it's too late. 00:09:12.385 --> 00:09:15.638 With more than 20 different dens scattered through the forest... 00:09:17.400 --> 00:09:20.868 it could be hard to keep track of where everyone's going... 00:09:22.524 --> 00:09:24.497 especially at this speed. 00:09:29.485 --> 00:09:34.407 But a recent discovery has exposed an even more spectacular hidden talent. 00:09:36.865 --> 00:09:38.407 Flying squirrels... 00:09:38.890 --> 00:09:40.517 glow. 00:09:43.040 --> 00:09:46.460 Filming in ultraviolet reveals how they fluoresce... 00:09:48.129 --> 00:09:50.172 absorbing moonlight in one color... 00:09:51.841 --> 00:09:53.301 and emitting it in another. 00:09:56.929 --> 00:09:59.265 It's believed that their glow-in-the-dark bellies 00:09:59.290 --> 00:10:01.113 act like beacons... 00:10:06.689 --> 00:10:09.020 so they can see their friends at night... 00:10:11.110 --> 00:10:13.270 and follow them all the way back... 00:10:14.378 --> 00:10:16.886 to where they're safe and warm. 00:10:20.286 --> 00:10:22.766 Staying close together to make it 00:10:22.790 --> 00:10:25.207 through the coldest nights. 00:10:30.691 --> 00:10:35.176 Some animals take cooperation to another level... 00:10:37.348 --> 00:10:40.191 ...creating a powerful sense of community... 00:10:41.410 --> 00:10:44.621 in which the next generation can safely grow. 00:10:48.840 --> 00:10:53.051 Burrowing owls raise their babies in a perilous world. 00:10:59.395 --> 00:11:01.891 Just ten inches tall, they 00:11:01.915 --> 00:11:06.457 live beneath the feet of giants. 00:11:10.711 --> 00:11:12.755 And in constant fear of predators. 00:11:20.471 --> 00:11:22.807 On the wide-open plains of Montana... 00:11:26.018 --> 00:11:29.480 ...danger comes from every angle. 00:11:42.076 --> 00:11:45.871 Thankfully, burrowing owls are all eyes and ears. 00:11:51.168 --> 00:11:53.754 Binocular vision and acute hearing... 00:11:54.630 --> 00:11:56.841 ...allow them to pinpoint danger. 00:12:01.429 --> 00:12:04.557 Even more impressive, they look out for each other. 00:12:09.770 --> 00:12:13.691 The only owls to live in large groups, up to 100 strong. 00:12:16.819 --> 00:12:19.113 They form the ultimate neighborhood watch. 00:12:23.993 --> 00:12:26.954 A safe environment for their growing owlets... 00:12:32.543 --> 00:12:33.961 ...to perfect their skills. 00:12:46.557 --> 00:12:49.268 At one month old, an owlet's eyesight 00:12:49.351 --> 00:12:50.853 is already fully developed. 00:12:53.564 --> 00:12:56.275 But now, only weeks before they leave home... 00:12:57.524 --> 00:13:00.836 they still need to master their listening skills... 00:13:02.823 --> 00:13:05.659 by learning how to rotate their concave faces... 00:13:06.535 --> 00:13:08.704 to direct sound towards their ears. 00:13:11.040 --> 00:13:13.426 Get it right and it amplifies noises 00:13:13.450 --> 00:13:15.961 up to ten times... 00:13:21.675 --> 00:13:24.929 but it takes practice and coordination. 00:13:37.939 --> 00:13:40.517 All the while, the parents have their backs, 00:13:40.898 --> 00:13:42.087 keeping a lookout... 00:13:43.746 --> 00:13:45.407 and keeping them fed. 00:13:48.035 --> 00:13:50.185 Owls are carnivorous, 00:13:50.209 --> 00:13:51.997 but have no teeth to chew. 00:13:53.499 --> 00:13:55.960 So, even the babies swallow meals whole. 00:13:56.836 --> 00:14:01.090 Claws, fur, bones, and all. 00:14:04.064 --> 00:14:05.907 And what goes in... 00:14:07.263 --> 00:14:08.657 must come out... 00:14:14.699 --> 00:14:15.822 as a pellet. 00:14:21.104 --> 00:14:22.846 Anyway, back to class. 00:14:25.573 --> 00:14:27.116 How to avoid danger... 00:14:28.742 --> 00:14:31.495 by listening to their parents and following their example. 00:14:34.957 --> 00:14:37.182 When the rattlesnake alarm is raised... 00:14:42.756 --> 00:14:45.134 ...the owlets know to keep their distance. 00:14:49.638 --> 00:14:51.845 Its venom is potent enough to kill even 00:14:51.869 --> 00:14:54.602 the largest animals, to roam America. 00:15:00.482 --> 00:15:04.445 But being inquisitive can be a lifesaver. 00:15:12.661 --> 00:15:16.457 As long as they keep a watchful eye and keep their distance... 00:15:17.543 --> 00:15:19.472 they should be safe. 00:15:24.632 --> 00:15:27.927 Some dangers are harder to avoid. 00:15:45.945 --> 00:15:49.156 Bison. 00:15:49.239 --> 00:15:52.785 They target the openings around owl burrows to dust bathe. 00:15:57.539 --> 00:16:00.292 This two-and-a-half-thousand pound giant... 00:16:02.169 --> 00:16:04.388 could easily crush the den, 00:16:04.412 --> 00:16:06.650 and then trap those inside. 00:16:11.303 --> 00:16:15.099 So, the owlets do something truly amazing. 00:16:22.173 --> 00:16:25.462 They've mastered the art of imitation... 00:16:27.236 --> 00:16:31.949 copying that telltale snake-rattle to near perfection. 00:16:34.827 --> 00:16:38.789 They scare off a beast 11,000 times their size. 00:16:49.133 --> 00:16:52.761 These marvelous little mimics are well on their way to becoming 00:16:52.786 --> 00:16:57.433 fully-fledged members of the burrowing owl security force. 00:17:01.603 --> 00:17:05.858 Look up, look around, look closer... 00:17:07.484 --> 00:17:09.378 and you'll see 00:17:09.403 --> 00:17:11.649 strange relationships hidden everywhere 00:17:11.673 --> 00:17:13.991 in this wonderful world. 00:17:16.827 --> 00:17:19.038 On a few special nights each year 00:17:19.725 --> 00:17:23.250 this small patch of forest in the mountains of Mexico... 00:17:24.835 --> 00:17:29.798 stages one of the most mesmerizing displays of cooperation on Earth. 00:17:45.773 --> 00:17:48.734 This male firefly has been waiting 00:17:48.817 --> 00:17:51.070 for two years underground. 00:17:55.365 --> 00:17:58.720 Now is his chance to shine. 00:18:04.833 --> 00:18:07.586 And he has just the right chemistry for the job. 00:18:10.923 --> 00:18:13.342 He drives oxygen into his abdomen. 00:18:15.985 --> 00:18:18.735 It reacts with potent chemical compounds... 00:18:19.329 --> 00:18:22.196 luciferin and luciferase... 00:18:23.477 --> 00:18:27.022 in an explosion of bioluminescence. 00:18:30.400 --> 00:18:33.570 But even this enchanting ability is not enough on its own. 00:18:37.478 --> 00:18:40.203 Females like to be dazzled. 00:18:41.662 --> 00:18:43.330 The brighter, the better. 00:18:46.375 --> 00:18:47.543 So, his only choice... 00:18:51.171 --> 00:18:53.132 is to team up with his rivals. 00:18:56.718 --> 00:18:59.596 When thousands of male fireflies come together... 00:19:00.681 --> 00:19:02.141 it's certainly brighter... 00:19:05.561 --> 00:19:07.104 but far more chaotic. 00:19:10.816 --> 00:19:16.280 Females will only make their move when the males flash in sync. 00:19:21.076 --> 00:19:24.663 So, slowly, they adjust their timing... 00:19:27.833 --> 00:19:32.462 until finally, something magical happens. 00:19:38.218 --> 00:19:41.096 They reach supernatural synchronicity... 00:19:43.599 --> 00:19:47.853 a glowing Mexican wave, rarely filmed before. 00:19:52.608 --> 00:19:54.902 Of 2000 firefly species... 00:19:56.403 --> 00:19:59.281 only around 12 display in unison... 00:20:01.617 --> 00:20:04.077 and this ripple effect is so phenomenal... 00:20:05.120 --> 00:20:08.999 even the pickiest female can't help being turned on. 00:20:10.758 --> 00:20:12.932 She shows her interests... 00:20:15.394 --> 00:20:17.261 but her light is so faint... 00:20:18.300 --> 00:20:21.845 she must make her signal in the gap between the male's flashes. 00:20:29.561 --> 00:20:32.606 There are ten rivals vying for each female. 00:20:34.447 --> 00:20:37.571 So now, it's every male for himself. 00:20:40.364 --> 00:20:42.991 It's this determined fellow who reaches her first... 00:20:47.064 --> 00:20:49.236 and finally gets to mate. 00:21:02.219 --> 00:21:03.220 But ultimately, 00:21:03.887 --> 00:21:08.058 his luck in love is all thanks to this spell-binding display 00:21:08.517 --> 00:21:09.935 of cooperation. 00:21:22.531 --> 00:21:25.534 The deeper we delve into nature's strange relations... 00:21:28.787 --> 00:21:30.580 ...the more surprising they become. 00:21:33.875 --> 00:21:35.168 On the African savanna... 00:21:35.838 --> 00:21:38.139 unlikely allies collaborate to overcome 00:21:38.163 --> 00:21:40.966 a big problem. 00:21:43.468 --> 00:21:45.512 To satisfy its enormous appetite... 00:21:46.555 --> 00:21:50.183 an elephant eats 300 pounds of vegetation in a day. 00:21:54.521 --> 00:22:00.360 Trees can't escape. 00:22:09.202 --> 00:22:13.248 But the whistling acacia has an extraordinary elephant deterrent. 00:22:16.665 --> 00:22:19.503 A low-frequency sonic shield... 00:22:25.677 --> 00:22:29.411 ...that sounds like a swarm of angry, stinging bees. 00:22:33.926 --> 00:22:36.664 It's a noise that even elephants fear. 00:22:48.067 --> 00:22:51.648 The acacia doesn't come with a built-in alarm system... 00:22:52.788 --> 00:22:56.041 it's installed by little helpers. 00:23:02.464 --> 00:23:06.343 Cocktail ants gnaw holes in the swollen thorns. 00:23:11.014 --> 00:23:14.838 It's believed they use their antennae to judge the perfect angle. 00:23:18.459 --> 00:23:21.549 So, when the prevailing wind blows... 00:23:23.347 --> 00:23:26.494 the acacia starts to sing. 00:23:31.243 --> 00:23:33.963 The ant holes not only make the tree whistle... 00:23:34.493 --> 00:23:38.642 they are also portals to a hidden world. 00:23:40.745 --> 00:23:42.822 Secret safe houses... 00:23:44.571 --> 00:23:46.767 where the ants raise their young. 00:23:50.603 --> 00:23:55.367 The tree also supplies highly-addictive, sugary nectar to make sure the ants 00:23:55.392 --> 00:23:57.478 stick around. 00:24:06.987 --> 00:24:11.700 And just one acacia can house a colony 50,000 strong. 00:24:13.767 --> 00:24:16.703 It's a city in the sky... 00:24:23.253 --> 00:24:24.884 ...but it's under attack. 00:24:36.954 --> 00:24:40.700 A six-foot neck can reach the highest leaves. 00:24:42.799 --> 00:24:47.291 A dexterous 21-inch tongue can pick between the thorns. 00:24:56.536 --> 00:24:58.205 And unlike elephants... 00:24:59.289 --> 00:25:02.334 giraffes are immune to an acacia's whistle. 00:25:07.047 --> 00:25:10.509 Time for the ants to earn their keep... 00:25:16.389 --> 00:25:19.768 ...and to mobilize an army to take on an enemy, 00:25:19.935 --> 00:25:23.188 158 million times their size. 00:25:40.121 --> 00:25:42.586 Cocktail ants can't see far, 00:25:42.610 --> 00:25:44.376 so they detect attackers 00:25:44.709 --> 00:25:46.962 using hypersensitive vibration sensors. 00:25:49.907 --> 00:25:52.261 As the giraffe feeds... 00:25:52.547 --> 00:25:55.151 it sends shockwaves through the branches. 00:25:59.972 --> 00:26:02.218 The ants can measure minute differences 00:26:02.242 --> 00:26:05.393 in these tremors with their legs. 00:26:17.325 --> 00:26:19.321 If the front right detects motion, 00:26:19.345 --> 00:26:21.888 a fraction of a second before back left, 00:26:21.913 --> 00:26:24.749 it means enemy ahead, to the right. 00:26:31.744 --> 00:26:34.290 The army attacks... 00:26:35.268 --> 00:26:38.483 inflicting painful bites to the tongue and face. 00:26:47.834 --> 00:26:49.768 It's one for all... 00:26:50.536 --> 00:26:53.566 and all for the tree. 00:26:56.225 --> 00:27:00.412 Raising their abdomens, they blast out noxious acid. 00:27:03.079 --> 00:27:04.831 It's how they earned their name. 00:27:06.295 --> 00:27:08.375 Cocktail ants. 00:27:16.576 --> 00:27:18.833 And it works. 00:27:29.108 --> 00:27:31.599 Losses are inevitable... 00:27:35.654 --> 00:27:38.490 but eventually, the giraffe is forced to move on. 00:27:46.654 --> 00:27:49.010 Despite damage and casualties... 00:27:49.788 --> 00:27:52.379 both acacia and colony live on. 00:27:54.948 --> 00:27:57.450 Thanks to their remarkable partnership. 00:28:02.921 --> 00:28:07.143 It's not only conflict that brings species together. 00:28:12.107 --> 00:28:15.331 Warthogs love a good mud bath. 00:28:18.456 --> 00:28:20.416 It feels great... 00:28:22.075 --> 00:28:23.827 and exfoliates the skin... 00:28:25.704 --> 00:28:28.581 but there are some things mud just can't remove. 00:28:31.209 --> 00:28:35.630 A hog's body plays host to all sorts of parasites, 00:28:36.256 --> 00:28:39.299 blood-sucking ticks and lice... 00:28:40.135 --> 00:28:42.674 hiding in places they simply cannot reach. 00:28:46.012 --> 00:28:48.723 At least, not without a little help. 00:28:52.104 --> 00:28:55.900 This band of mongooses lives close by. 00:28:58.235 --> 00:29:00.296 They're a chatty bunch 00:29:00.321 --> 00:29:02.824 with one of the most sophisticated animal languages. 00:29:09.509 --> 00:29:12.718 Using a wide vocabulary of vowels and syllables... 00:29:13.056 --> 00:29:15.784 they discuss where to find food... 00:29:17.573 --> 00:29:19.549 and everyone's agreed. 00:29:20.291 --> 00:29:23.398 It's time to hit the town. 00:29:26.476 --> 00:29:29.907 Weighing in at 330 pounds... 00:29:32.124 --> 00:29:34.774 ...and armed to the teeth... 00:29:36.062 --> 00:29:39.720 warthogs are usually on the defensive. 00:29:42.156 --> 00:29:44.235 But in this Ugandan village... 00:29:44.758 --> 00:29:48.828 they've learned to be a little more approachable. 00:29:59.922 --> 00:30:05.141 Warthogs and mongooses don't speak the same language... 00:30:06.039 --> 00:30:09.687 but they share something exceedingly rare between mammals... 00:30:11.655 --> 00:30:14.125 a cross-species collaboration... 00:30:18.046 --> 00:30:22.535 initiated... by body language. 00:30:25.008 --> 00:30:27.583 When the hog rolls over, 00:30:27.607 --> 00:30:30.328 the mongooses understand. 00:30:32.235 --> 00:30:35.812 It's an invitation to dine. 00:30:38.920 --> 00:30:43.178 With a sense of smell 1000 times more sensitive than our own... 00:30:46.060 --> 00:30:48.955 they detect the faint smell of blood... 00:30:55.889 --> 00:30:59.451 and pick off protein-packed parasites. 00:31:07.453 --> 00:31:10.170 A nutritious meal for the mongooses... 00:31:13.014 --> 00:31:16.736 and a much-needed deep clean for the warthog. 00:31:22.944 --> 00:31:28.475 This special relationship is only seen in two places on Earth. 00:31:30.499 --> 00:31:33.159 Both, around human settlements 00:31:33.183 --> 00:31:35.538 where there are fewer predators... 00:31:36.226 --> 00:31:39.077 so prey can relax a little... 00:31:39.939 --> 00:31:42.984 in the company of newfound friends. 00:31:48.045 --> 00:31:50.861 As animals adapt to the modern world... 00:31:51.451 --> 00:31:54.162 it's giving rise to some of the most efficient 00:31:54.187 --> 00:31:56.949 and effective partnerships of all. 00:32:07.663 --> 00:32:09.604 Bottlenose dolphins 00:32:09.636 --> 00:32:13.018 use highly sophisticated techniques to catch their prey. 00:32:21.397 --> 00:32:25.306 But some have taken hunting to a whole new level... 00:32:28.189 --> 00:32:32.909 by teaming up... with another intelligent animal. 00:32:45.893 --> 00:32:49.054 Local fishermen in Laguna, 00:32:49.078 --> 00:32:51.861 Brazil know that between May and June, 00:32:51.886 --> 00:32:55.390 these estuarine waters are swimming with mullet... 00:32:58.922 --> 00:33:01.877 but it's too murky to see them... 00:33:07.214 --> 00:33:10.877 unless you see in sound. 00:33:18.987 --> 00:33:22.030 Echolocation is a precision sonar system, 00:33:22.054 --> 00:33:26.434 that can detect the size, speed, and distance of prey. 00:33:38.236 --> 00:33:41.252 The dolphins use it to find the mullet... 00:33:47.624 --> 00:33:50.196 and then they shepherd them together. 00:33:55.867 --> 00:33:58.995 But schooling fish are very hard to target. 00:34:05.888 --> 00:34:08.785 So, with a flick of their flukes... 00:34:09.630 --> 00:34:11.549 they make a distinctive dive... 00:34:12.592 --> 00:34:16.863 providing a signature slap that signals to their fishermen friends... 00:34:17.614 --> 00:34:20.646 "It's time to cast." 00:34:35.607 --> 00:34:39.069 It helps the humans land catch after catch. 00:34:40.157 --> 00:34:43.583 Where otherwise, they would be fishing blind. 00:34:51.366 --> 00:34:53.502 It helps the dolphins too. 00:34:58.221 --> 00:34:59.388 When the nets are cast... 00:35:01.057 --> 00:35:02.391 the mullet panic... 00:35:08.773 --> 00:35:09.816 break formation... 00:35:11.275 --> 00:35:12.360 and scatter... 00:35:13.645 --> 00:35:16.215 straight toward the waiting dolphins. 00:35:28.042 --> 00:35:31.085 Everyone gets a belly full of fish. 00:35:33.832 --> 00:35:36.495 It's the perfect partnership. 00:35:40.676 --> 00:35:42.176 Strategic... 00:35:42.864 --> 00:35:44.358 ingenious... 00:35:44.918 --> 00:35:47.047 with two intelligent species combining 00:35:47.071 --> 00:35:49.115 to succeed. 00:35:55.058 --> 00:35:57.764 There's still much to explore in our world. 00:35:59.764 --> 00:36:02.383 And even stranger relationships 00:36:02.407 --> 00:36:03.886 to discover. 00:36:05.988 --> 00:36:10.988 It turns out, one of the most surprising alliances on Earth... 00:36:11.472 --> 00:36:14.598 has been hiding right under our feet. 00:36:19.473 --> 00:36:23.512 Trees lead a secret social life. 00:36:26.542 --> 00:36:28.348 Deep underground... 00:36:29.729 --> 00:36:32.543 ...there's a lively conversation taking place. 00:36:37.351 --> 00:36:39.926 The trees are talking... 00:36:41.020 --> 00:36:43.667 through a newly-discovered social network... 00:36:45.048 --> 00:36:48.317 known as the wood wide web. 00:36:50.425 --> 00:36:54.340 Fungi, form a matrix of hair-like threads... 00:36:56.529 --> 00:36:58.777 detach sugars from tree roots... 00:37:02.020 --> 00:37:04.054 and in return... 00:37:04.332 --> 00:37:08.184 they provide the tree with minerals, they siphon from the soil. 00:37:12.067 --> 00:37:14.714 And this secret subterranean relationship 00:37:14.738 --> 00:37:17.823 allows something even more unexpected 00:37:17.860 --> 00:37:19.779 to take place. 00:37:21.045 --> 00:37:23.976 Once the trees are connected... 00:37:24.777 --> 00:37:27.698 they can exchange information... 00:37:28.700 --> 00:37:32.667 vital warnings of drought and disease. 00:37:46.675 --> 00:37:50.152 This Douglas fir has stood for decades. 00:37:50.715 --> 00:37:53.437 But now, it's in peril. 00:37:55.856 --> 00:37:59.574 A Douglas fir beetle has a deadly plan... 00:38:00.903 --> 00:38:02.154 to raise an army... 00:38:03.281 --> 00:38:04.532 and kill the tree. 00:38:08.910 --> 00:38:12.495 Broadcasting chemical and electrical signals, 00:38:13.082 --> 00:38:18.379 the fir warns its neighbors to produce defensive poisons. 00:38:20.381 --> 00:38:23.134 But it may be too late to save itself. 00:38:28.131 --> 00:38:31.498 The pea-sized pest emits a pheromone... 00:38:36.552 --> 00:38:39.162 ...that could seal the fir's fate. 00:38:45.466 --> 00:38:47.849 It's calling reinforcements... 00:38:49.076 --> 00:38:51.912 and summoning a mass invasion. 00:38:54.733 --> 00:38:56.557 Beetles... 00:38:56.881 --> 00:38:58.317 arrive... 00:38:59.738 --> 00:39:01.311 mate... 00:39:02.131 --> 00:39:03.507 and burrow in. 00:39:05.801 --> 00:39:10.431 Then their young eat the tree alive. 00:39:13.517 --> 00:39:17.355 This mighty fir will be dead within weeks. 00:39:20.024 --> 00:39:21.859 But in a selfless final act... 00:39:24.653 --> 00:39:29.408 the dying giant diverts sugars to its roots... 00:39:35.539 --> 00:39:37.308 ...so these life-giving supplies 00:39:37.332 --> 00:39:39.835 can be shared through the "woodwide web." 00:39:53.217 --> 00:39:56.951 And in doing so, it helps neighbors and offspring 00:39:57.475 --> 00:39:59.338 to grow stronger. 00:40:03.150 --> 00:40:04.902 As one life ebbs away... 00:40:06.487 --> 00:40:07.655 the rest of the forest 00:40:08.280 --> 00:40:11.742 becomes better prepared to fight for its future. 00:40:17.081 --> 00:40:19.517 We're still discovering the power of the connection 00:40:19.542 --> 00:40:21.335 between trees and fungi. 00:40:22.878 --> 00:40:24.547 But it's already clear... 00:40:25.339 --> 00:40:31.137 this deep-rooted relationship is fundamental to all life on Earth. 00:40:36.558 --> 00:40:40.096 They say in nature that only the strongest survive. 00:40:45.526 --> 00:40:47.153 But when cooperation... 00:40:48.154 --> 00:40:49.196 and communication... 00:40:51.031 --> 00:40:53.409 bring animals and plants together... 00:40:55.494 --> 00:40:57.872 and superpowers combine... 00:41:02.001 --> 00:41:06.797 even the most vulnerable can become unstoppable. 00:41:10.173 --> 00:41:12.157 If you think you know nature... 00:41:17.203 --> 00:41:18.605 ...think again.