1 00:00:01,600 --> 00:00:04,840 In the natural world, 2 00:00:04,840 --> 00:00:06,920 you need to be smart... 3 00:00:08,360 --> 00:00:09,880 ..to stay alive. 4 00:00:11,760 --> 00:00:16,400 But we're only just discovering that some animals are brighter 5 00:00:16,400 --> 00:00:19,040 than we ever imagined. 6 00:00:19,040 --> 00:00:23,520 I've never failed to be impressed by nature's sheer ingenuity. 7 00:00:25,720 --> 00:00:29,000 Now, brand-new science, using innovative techniques 8 00:00:29,000 --> 00:00:30,640 and the latest technology, 9 00:00:30,640 --> 00:00:33,800 is revealing some surprising brainboxes. 10 00:00:33,800 --> 00:00:38,120 You can get bees to learn almost anything. 11 00:00:38,120 --> 00:00:44,200 Researchers across the globe are uncovering the mind-blowing tricks 12 00:00:44,200 --> 00:00:49,960 and clever strategies that give certain species the upper hand... 13 00:00:49,960 --> 00:00:54,320 It is an animal showcasing its intelligence in front of your eyes. 14 00:00:56,560 --> 00:00:58,840 ..as they build their homes... 15 00:01:01,160 --> 00:01:03,520 ..navigate their world, 16 00:01:03,520 --> 00:01:06,520 and raise their young. 17 00:01:06,520 --> 00:01:12,000 It's time to get inside the minds of nature's savviest species. 18 00:01:12,000 --> 00:01:16,040 But I warn you, there's going to be a few surprises 19 00:01:16,040 --> 00:01:19,240 and some controversial candidates, 20 00:01:19,240 --> 00:01:22,720 but, most importantly, it's going to give us an opportunity 21 00:01:22,720 --> 00:01:25,680 to learn from these animal Einsteins, 22 00:01:25,680 --> 00:01:27,880 and that's really exciting. 23 00:01:30,320 --> 00:01:34,320 In this episode, we'll discover the clever methods that animals 24 00:01:34,320 --> 00:01:36,640 use to travel from A to B, 25 00:01:36,640 --> 00:01:39,080 and how they find their way. 26 00:01:39,080 --> 00:01:43,200 We'll learn blue whales know exactly where to refuel, 27 00:01:43,200 --> 00:01:46,280 as they migrate thousands of miles, 28 00:01:46,280 --> 00:01:50,760 how spiders and snakes can actually fly, 29 00:01:50,760 --> 00:01:55,280 and how dung beetles use the Milky Way to navigate. 30 00:01:55,280 --> 00:01:59,840 In the journey of life, animal travellers need mental agility, 31 00:01:59,840 --> 00:02:03,320 as well as endurance, to reach their destinations safely. 32 00:02:13,200 --> 00:02:17,600 I'm starting with an epic wayfarer, an animal that's enabled us 33 00:02:17,600 --> 00:02:22,240 to cross the harshest of landscapes for thousands of years. 34 00:02:22,240 --> 00:02:26,640 Now, there are a number of very famous long-distance animal travellers, 35 00:02:26,640 --> 00:02:31,200 but there's one that comes with a reputation for being strong, 36 00:02:31,200 --> 00:02:32,920 but also a bit spitty. 37 00:02:32,920 --> 00:02:35,280 I'm talking about the camel. 38 00:02:35,280 --> 00:02:37,760 And they've done a lot of travelling over the years, 39 00:02:37,760 --> 00:02:42,400 because we domesticated them over 4,200 years ago 40 00:02:42,400 --> 00:02:47,720 and they were famed for their caravans along the Silk Road. 41 00:02:47,720 --> 00:02:52,640 Meet Baxter and Bertie and look at them, they are absolutely 42 00:02:52,640 --> 00:02:56,880 magnificent and, having evolved in the Central Asian deserts, 43 00:02:56,880 --> 00:03:00,680 they have all sorts of adaptations for that environment. 44 00:03:00,680 --> 00:03:04,800 Keeping the sand out are their very long eyelashes and, you know, 45 00:03:04,800 --> 00:03:09,200 if they do get sand in their eyes, just like birds, they've got 46 00:03:09,200 --> 00:03:12,120 a nictitating membrane, a third eyelid, 47 00:03:12,120 --> 00:03:15,960 which sweeps across to clear the sand out of their eyes. 48 00:03:15,960 --> 00:03:18,200 Look at their feet. 49 00:03:18,200 --> 00:03:20,880 Broad and wide, for spreading their weight, 50 00:03:20,880 --> 00:03:23,720 as they travel across the sand. 51 00:03:23,720 --> 00:03:26,960 Now, the humps... When I was a kid, many years ago, 52 00:03:26,960 --> 00:03:31,200 my mother mistakenly told me that they were water storage organs. 53 00:03:31,200 --> 00:03:32,640 Not at all. 54 00:03:32,640 --> 00:03:35,840 They're full of fat, but what's interesting is 55 00:03:35,840 --> 00:03:38,200 that when that fat is metabolised, 56 00:03:38,200 --> 00:03:40,880 for every gram that they do metabolise, 57 00:03:40,880 --> 00:03:43,920 they can recover a gram of water, 58 00:03:43,920 --> 00:03:48,360 so, indirectly, they are water storage organs. 59 00:03:50,000 --> 00:03:54,880 They are absolutely remarkable and there's one last thing 60 00:03:54,880 --> 00:03:56,840 I have to tell you, and that is that... 61 00:03:58,160 --> 00:04:01,560 HE SNIFFS ..they smell fantastic! 62 00:04:01,560 --> 00:04:03,880 They really do. I love the smell of a camel. 63 00:04:06,680 --> 00:04:11,440 Bertie and Baxter are two-humped Bactrian camels, well adapted 64 00:04:11,440 --> 00:04:16,520 to their original home in the harsh Gobi Desert of China and Mongolia. 65 00:04:16,520 --> 00:04:20,800 Their equally hardy cousin, the single-humped dromedary, was also 66 00:04:20,800 --> 00:04:24,400 domesticated and used to transport goods and people, 67 00:04:24,400 --> 00:04:28,720 especially in arid parts of Africa and Asia. 68 00:04:28,720 --> 00:04:33,960 These powerful ungulates can cover 25 miles or more daily. 69 00:04:33,960 --> 00:04:35,480 Led by an adult male, 70 00:04:35,480 --> 00:04:39,680 Bactrian camels navigate across featureless terrain in search 71 00:04:39,680 --> 00:04:43,920 of grazing and migrate to avoid extreme winter temperatures. 72 00:04:46,360 --> 00:04:49,200 Without these extraordinary travellers, 73 00:04:49,200 --> 00:04:53,280 we would never have survived our desert explorations. 74 00:04:53,280 --> 00:04:55,240 Human travel has moved on. 75 00:04:56,960 --> 00:04:59,520 The bicycle, forerunner of the automobile, 76 00:04:59,520 --> 00:05:02,800 was a unique means of individual transportation. 77 00:05:06,680 --> 00:05:12,120 But while we now rely on fast machines and savvy tech 78 00:05:12,120 --> 00:05:18,760 to get around, animals have only their fins, wings, 79 00:05:18,760 --> 00:05:22,920 hooves and, of course, their brains to get from A to B. 80 00:05:25,000 --> 00:05:27,000 Whether it's a local trip to find food... 81 00:05:29,040 --> 00:05:32,080 ..or an epic journey to reach a safe place to have young... 82 00:05:33,520 --> 00:05:36,560 ..every traveller must work out where to go 83 00:05:36,560 --> 00:05:39,040 and the most energy efficient way to get there. 84 00:05:41,160 --> 00:05:46,320 The record for the longest migration goes to the Arctic tern, 85 00:05:46,320 --> 00:05:50,960 flying 44,000 miles from their breeding grounds in Greenland... 86 00:05:53,200 --> 00:05:56,840 ..to feed down in Antarctica and then back again. 87 00:05:56,840 --> 00:05:58,280 In their lifetime, 88 00:05:58,280 --> 00:06:02,960 they can fly the equivalent of 60 times round the planet. 89 00:06:02,960 --> 00:06:04,120 Truly mindboggling. 90 00:06:06,000 --> 00:06:09,600 Of course, they're not the only long-distance migrant. 91 00:06:09,600 --> 00:06:16,160 On land, caribou travel the furthest, up to 3,000 miles a year. 92 00:06:16,160 --> 00:06:20,800 That's like walking from Land's End to John o' Groats five times over. 93 00:06:23,280 --> 00:06:27,560 And in the ocean, the current record goes to a loggerhead turtle called 94 00:06:27,560 --> 00:06:29,960 Yoshi, who was recently tracked swimming 95 00:06:29,960 --> 00:06:35,040 nearly 22,000 miles in just two years. 96 00:06:36,480 --> 00:06:38,120 In the endurance stakes, 97 00:06:38,120 --> 00:06:43,360 these travellers are truly world leaders, but what I find even more 98 00:06:43,360 --> 00:06:48,200 remarkable are the mental maps and the route planning that's involved. 99 00:06:48,200 --> 00:06:51,240 What are the challenges that these animals need to overcome 100 00:06:51,240 --> 00:06:54,040 and what's the brain power they need to muster to do it? 101 00:06:59,600 --> 00:07:03,680 One basic requirement for being a long-haul traveller is knowing 102 00:07:03,680 --> 00:07:06,760 where you need to go and, over in Wyoming, 103 00:07:06,760 --> 00:07:12,400 the resident mule deer must cover a lot of ground to find enough food. 104 00:07:12,400 --> 00:07:17,000 Each year, they spend up to four months on the move, 105 00:07:17,000 --> 00:07:19,960 migrating between their summer home range 106 00:07:19,960 --> 00:07:23,240 and their winter hideout further south, 107 00:07:23,240 --> 00:07:26,160 a trek of up to 150 miles. 108 00:07:27,840 --> 00:07:29,960 Mule deer are very fussy eaters 109 00:07:29,960 --> 00:07:34,560 and will munch on only the most nutritious plants. 110 00:07:34,560 --> 00:07:36,400 So, if they don't migrate, 111 00:07:36,400 --> 00:07:40,040 they may run out of the essential nutrients they need to survive. 112 00:07:43,520 --> 00:07:45,080 Until recently, 113 00:07:45,080 --> 00:07:49,440 we knew very little about how they navigate around their landscape, 114 00:07:49,440 --> 00:07:52,880 but, now, a long term study that's collaring and tracking females 115 00:07:52,880 --> 00:07:56,480 and their young is showing that they certainly have a better 116 00:07:56,480 --> 00:08:00,120 sense of direction than most humans. 117 00:08:00,120 --> 00:08:04,200 I've been in these areas for multiple years, in some cases, 118 00:08:04,200 --> 00:08:06,600 and I am always having a GPS with me 119 00:08:06,600 --> 00:08:09,120 and I normally look at the area on a map 120 00:08:09,120 --> 00:08:12,120 and, so, I should have a really good sense of where I'm going 121 00:08:12,120 --> 00:08:15,600 and what's going on and I still get turned around all the time. 122 00:08:15,600 --> 00:08:16,720 And deer don't. 123 00:08:19,680 --> 00:08:24,120 Graduate student Rhiannon Jakopak, from the University of Wyoming, 124 00:08:24,120 --> 00:08:28,400 is part of a research team tracking mule deer across the state. 125 00:08:28,400 --> 00:08:31,440 She's discovered that they don't just have an uncanny 126 00:08:31,440 --> 00:08:35,680 sense of direction, the timing of their migration is key. 127 00:08:35,680 --> 00:08:41,040 The deer smartly stop over in areas just as high quality food 128 00:08:41,040 --> 00:08:46,560 starts to grow, a strategy known as surfing the green wave. 129 00:08:48,520 --> 00:08:53,560 Green wave surfing is when mule deer are moving across a landscape 130 00:08:53,560 --> 00:08:58,320 at the same time that vegetation is growing in the spring. 131 00:08:59,880 --> 00:09:03,760 Plants and vegetation can be really nutritious when it's first starting 132 00:09:03,760 --> 00:09:06,160 to grow, but, when it's first starting to grow, 133 00:09:06,160 --> 00:09:08,400 there's just not a ton of it around. 134 00:09:09,640 --> 00:09:13,640 By timing their migration to coincide with the budding plants, 135 00:09:13,640 --> 00:09:17,560 they ride the crest of the growth wave. 136 00:09:17,560 --> 00:09:19,160 And that's surfing. They surf! 137 00:09:24,440 --> 00:09:28,840 Green wave surfing might help deer work out when to migrate, 138 00:09:28,840 --> 00:09:32,280 but how do they know where to migrate to begin with? 139 00:09:32,280 --> 00:09:35,200 Some of the things we've been finding so far is that mule deer 140 00:09:35,200 --> 00:09:38,680 seem to be learning their migrations from their mom. 141 00:09:38,680 --> 00:09:41,720 Because they are really close to their moms for that first year 142 00:09:41,720 --> 00:09:44,960 of life, that is a really good opportunity for them 143 00:09:44,960 --> 00:09:46,600 to learn a ton of information. 144 00:09:49,720 --> 00:09:51,200 So migration routes 145 00:09:51,200 --> 00:09:56,960 and home ranges get passed down from mums to fawns and a 2019 study found 146 00:09:56,960 --> 00:10:02,240 that deer used mental maps, handed down over multiple generations. 147 00:10:05,320 --> 00:10:09,680 Without this knowledge, migrations simply can't take place 148 00:10:09,680 --> 00:10:14,800 and it's not just deer who follow in their ancestors' footsteps. 149 00:10:14,800 --> 00:10:20,160 Other hoofed mammals, like big horn sheep, also learn migration knowhow 150 00:10:20,160 --> 00:10:22,400 from their predecessors. 151 00:10:22,400 --> 00:10:26,520 But interesting new research by Rhiannon shows that some 152 00:10:26,520 --> 00:10:30,680 individuals break away from these handed-down routes. 153 00:10:30,680 --> 00:10:35,640 They are explorers, leaving Mum to forge their own path. 154 00:10:38,000 --> 00:10:43,040 Today, Rhiannon's on the lookout for one remarkable deer called F210. 155 00:10:43,040 --> 00:10:46,680 F210 is a trailblazer and just one of the coolest deer. 156 00:10:46,680 --> 00:10:48,640 She's really special! 157 00:10:48,640 --> 00:10:52,640 When she was one year old, she actually just kind of took off 158 00:10:52,640 --> 00:10:56,000 and went on this really weird walkabout journey. 159 00:11:00,080 --> 00:11:04,400 So she went 60 miles just away from where she had ever been before 160 00:11:04,400 --> 00:11:07,160 and we know that she never been in this area before, 161 00:11:07,160 --> 00:11:10,720 because we've had her collared since the day she was born. 162 00:11:10,720 --> 00:11:12,840 Her mom didn't lead her there and we know that, 163 00:11:12,840 --> 00:11:14,960 because we have her mom collared. 164 00:11:14,960 --> 00:11:17,040 So she went up and over mountain ranges, 165 00:11:17,040 --> 00:11:20,320 navigated through forests and crossed rivers. 166 00:11:20,320 --> 00:11:23,080 But, after roaming around this unknown territory, 167 00:11:23,080 --> 00:11:27,760 the call for adventure was replaced with the pull of home. 168 00:11:27,760 --> 00:11:30,440 On a Monday morning, she just decided to turn around... 169 00:11:32,440 --> 00:11:36,080 ..and take exactly that same path back to her summer range. 170 00:11:38,520 --> 00:11:40,120 And she didn't get lost. 171 00:11:40,120 --> 00:11:45,040 She was able to just somehow retrace her steps entirely and so that's 172 00:11:45,040 --> 00:11:48,880 really the movement that made us start to think, like, "OK, maybe 173 00:11:48,880 --> 00:11:52,280 "deer do have this ability to gain a bunch of information, 174 00:11:52,280 --> 00:11:54,200 "but do it, like, really, really quickly 175 00:11:54,200 --> 00:11:57,360 "and after only being exposed to it just one time." 176 00:11:57,360 --> 00:12:00,040 Just really got us thinking about how much 177 00:12:00,040 --> 00:12:03,520 we aren't really appreciating the cognitive abilities of mule deer. 178 00:12:07,160 --> 00:12:08,720 That's incredible. 179 00:12:08,720 --> 00:12:12,240 It shows that these deer are constantly collecting details 180 00:12:12,240 --> 00:12:15,280 about their environment and their position in it, 181 00:12:15,280 --> 00:12:20,440 to establish their own new routes, different to those learned from Mum. 182 00:12:20,440 --> 00:12:24,720 This spatial awareness suggests significant brain power. 183 00:12:26,680 --> 00:12:29,680 So I bet you're wondering how they do it? 184 00:12:31,320 --> 00:12:34,360 Well, as they move through a landscape, 185 00:12:34,360 --> 00:12:39,160 landmarks and sensory details, like colours and smells, 186 00:12:39,160 --> 00:12:44,120 are collected and processed as spatial memories by a key area 187 00:12:44,120 --> 00:12:46,360 of the brain, the hippocampus. 188 00:12:49,240 --> 00:12:53,760 When an area is revisited, any combination of these reference 189 00:12:53,760 --> 00:12:57,920 points may help mule deer retrace their steps, 190 00:12:57,920 --> 00:13:01,840 but it's still unclear exactly which cues they use. 191 00:13:01,840 --> 00:13:05,440 We don't really know what it is that they are actually cuing 192 00:13:05,440 --> 00:13:06,880 in on and remembering. 193 00:13:06,880 --> 00:13:09,760 So are they remembering that, "Oh, there's a ridgeline over there," 194 00:13:09,760 --> 00:13:13,560 or are they remembering certain smells of a landscape 195 00:13:13,560 --> 00:13:15,080 and how that changes? 196 00:13:16,840 --> 00:13:18,480 One thing's for sure. 197 00:13:18,480 --> 00:13:22,840 Mule deer are masters of mental maps - and they're not alone. 198 00:13:26,560 --> 00:13:30,840 New research in 2019 has shown there's another North American 199 00:13:30,840 --> 00:13:35,480 migrant that knows how to be in the right place at the right time 200 00:13:39,040 --> 00:13:43,440 Like the deer, their daily challenge is to find enough food. 201 00:13:44,640 --> 00:13:48,400 On land, it may be possible to perpetually graze on your journey... 202 00:13:49,360 --> 00:13:54,200 ..but what about in the ocean, where your food is constantly moving? 203 00:13:55,480 --> 00:13:58,240 I've been studying the blue whale population off the West Coast 204 00:13:58,240 --> 00:14:01,000 for about three to four years now. 205 00:14:01,000 --> 00:14:03,960 They're the largest animal on Earth. 206 00:14:03,960 --> 00:14:06,680 They're larger than any dinosaur that ever existed. 207 00:14:06,680 --> 00:14:11,040 And yet they eat some of the tiniest animals in the ocean. 208 00:14:11,040 --> 00:14:15,360 Dr Briana Abrahms is an assistant professor at the University 209 00:14:15,360 --> 00:14:19,680 of Washington, where her research is revealing how these behemoths 210 00:14:19,680 --> 00:14:23,640 use a smart foraging strategy to avoid going hungry. 211 00:14:25,680 --> 00:14:29,360 She studies blue whales along the West Coast of America, 212 00:14:29,360 --> 00:14:32,800 as they migrate from their breeding grounds in the south 213 00:14:32,800 --> 00:14:35,040 to their feeding grounds in the north. 214 00:14:35,040 --> 00:14:40,320 A round trip that can cover a whopping 4,000 miles. 215 00:14:40,320 --> 00:14:43,800 If you think about if you were to drive 4,000 miles... 216 00:14:45,200 --> 00:14:47,240 ..that's going to take a lot of gas. 217 00:14:48,920 --> 00:14:51,680 And whales, to fuel their migrations, 218 00:14:51,680 --> 00:14:53,520 they rely on a lot of food. 219 00:14:55,520 --> 00:14:59,440 These blue whales can actually eat between four and eight tonnes 220 00:14:59,440 --> 00:15:00,760 of krill per day. 221 00:15:02,520 --> 00:15:07,320 That's the equivalent of guzzling down about four small cars daily. 222 00:15:12,920 --> 00:15:16,320 And yet these giants only eat krill, 223 00:15:16,320 --> 00:15:19,280 tiny shrimp-like creatures. 224 00:15:19,280 --> 00:15:23,600 Krill give them the energy they need not only to migrate, 225 00:15:23,600 --> 00:15:26,840 but also to breed and nourish their calves. 226 00:15:28,320 --> 00:15:32,280 But finding krill in the vast open ocean can be tricky. 227 00:15:33,560 --> 00:15:37,600 Their distribution is patchy, and it's constantly changing. 228 00:15:37,600 --> 00:15:41,080 This led Briana to question whether blue whales might be able 229 00:15:41,080 --> 00:15:43,720 to predict where krill will be, 230 00:15:43,720 --> 00:15:47,960 in a similar way to how migratory deer surfed the green wave 231 00:15:47,960 --> 00:15:49,600 of plant growth on land. 232 00:15:51,640 --> 00:15:56,480 Could blue whales be following a pink wave of krill along the coast 233 00:15:56,480 --> 00:15:57,920 as they're migrating? 234 00:15:57,920 --> 00:16:00,760 And so that's really what sparked the study. 235 00:16:04,720 --> 00:16:09,320 To find out, Briana needed to know the location and times of krill 236 00:16:09,320 --> 00:16:13,400 hot spots, and if the whales' migration coincided 237 00:16:13,400 --> 00:16:15,240 with this glut of food. 238 00:16:15,240 --> 00:16:18,640 We had ten years of satellite tagged data on blue whales, 239 00:16:18,640 --> 00:16:21,480 where we could see where they were migrating. 240 00:16:21,480 --> 00:16:24,520 So this is an animation of the tracking data that we used, 241 00:16:24,520 --> 00:16:26,640 which was for 104 blue whales. 242 00:16:28,720 --> 00:16:32,960 Then Briana matched up this tracking data with satellite maps 243 00:16:32,960 --> 00:16:36,080 of where and when there were blooms of krill. 244 00:16:36,080 --> 00:16:39,960 What we expected to find was that the whales... 245 00:16:41,640 --> 00:16:44,840 ..were hitting these hot spots 246 00:16:44,840 --> 00:16:49,200 at the times that they actually peaked in each year. 247 00:16:49,200 --> 00:16:52,840 So if krill peaked at lower latitudes, say, on May 1st, 248 00:16:52,840 --> 00:16:58,200 in a given year and, in other years, maybe May 30th, 249 00:16:58,200 --> 00:17:02,520 what we found is that, instead of actually hitting the peaks 250 00:17:02,520 --> 00:17:04,760 in each given year, 251 00:17:04,760 --> 00:17:09,600 they were timing their migrations to hit the long-term average. 252 00:17:09,600 --> 00:17:14,280 So, in this location, on average, they would arrive around May 15th. 253 00:17:15,520 --> 00:17:18,960 And we saw that they were doing that all along the coast 254 00:17:18,960 --> 00:17:20,160 as they moved up. 255 00:17:22,200 --> 00:17:25,480 By matching their migrations with the long-term average 256 00:17:25,480 --> 00:17:30,160 of when krill are most abundant, the whales increase their chances 257 00:17:30,160 --> 00:17:33,360 of being able to refuel all along the coast. 258 00:17:36,640 --> 00:17:39,720 This suggests some serious brain power. 259 00:17:39,720 --> 00:17:43,200 Using their memory of past foraging locations, 260 00:17:43,200 --> 00:17:47,200 blue whales predict where and when there'll be a steady supply 261 00:17:47,200 --> 00:17:51,320 of food, and time their migrations to match the krill wave. 262 00:17:52,640 --> 00:17:54,040 Pretty remarkable, 263 00:17:54,040 --> 00:17:56,880 considering their food is constantly on the move. 264 00:17:57,880 --> 00:18:02,480 So they plan their trips cleverly, just like we might do. 265 00:18:03,840 --> 00:18:07,400 Say you go on a fishing trip every single year and you know that, 266 00:18:07,400 --> 00:18:11,160 in general, the river that you like to go to, all the fish 267 00:18:11,160 --> 00:18:14,000 generally come in July, but sometimes it's early July, 268 00:18:14,000 --> 00:18:15,840 sometimes it's late July. 269 00:18:15,840 --> 00:18:19,080 Maybe you would plan your trip for mid-July, to kind 270 00:18:19,080 --> 00:18:20,520 of hedge your bets. 271 00:18:22,760 --> 00:18:24,560 And it seems like whales are doing the same thing, 272 00:18:26,240 --> 00:18:31,880 and that, to us, is what indicated that they must be relying on memory, 273 00:18:31,880 --> 00:18:35,960 in addition to just sensing their environment in real time. 274 00:18:35,960 --> 00:18:37,960 So that was really a eureka moment. 275 00:18:40,440 --> 00:18:43,280 These highly intelligent, long-lived animals 276 00:18:43,280 --> 00:18:45,920 have a migration master plan, 277 00:18:45,920 --> 00:18:50,200 drawing upon knowledge gained over decades to find the best krill 278 00:18:50,200 --> 00:18:53,360 hot spots at the right time, year upon year. 279 00:18:54,720 --> 00:18:59,280 Amazingly, blue whales are the only marine creatures that we know of 280 00:18:59,280 --> 00:19:02,280 who use their memories to migrate. 281 00:19:02,280 --> 00:19:05,320 This has really changed what we thought about whale migration, 282 00:19:05,320 --> 00:19:08,080 that it's not just about getting from point A to point B, 283 00:19:08,080 --> 00:19:11,120 but what happens in the middle is incredibly important. 284 00:19:11,120 --> 00:19:14,560 And the fact that they are relying on their memory to time 285 00:19:14,560 --> 00:19:18,440 their migrations helps us understand how they're making these decisions 286 00:19:18,440 --> 00:19:20,440 as they navigate the ocean. 287 00:19:31,280 --> 00:19:34,760 Some very clever strategies there from the whales, when it comes 288 00:19:34,760 --> 00:19:36,680 to planning their next meal. 289 00:19:36,680 --> 00:19:37,920 Very smart indeed. 290 00:19:37,920 --> 00:19:41,720 But what about our largest land mammals? 291 00:19:41,720 --> 00:19:46,040 African elephants, and water, in terms of a resource. 292 00:19:46,040 --> 00:19:49,080 Well, an African elephant needs to drink 50 gallons - 293 00:19:49,080 --> 00:19:53,360 that's 200 litres of water, every day just to survive. 294 00:19:53,360 --> 00:19:57,160 And, given that they move around in herds of 25 or more, 295 00:19:57,160 --> 00:20:01,680 that would mean that they would need a water hole something like this. 296 00:20:01,680 --> 00:20:04,920 Not something they can leave to chance, just to happen across. 297 00:20:04,920 --> 00:20:09,040 They need to know exactly where those water holes are. 298 00:20:11,440 --> 00:20:15,480 Let's take a trip to the Maasai Mara game reserve in Kenya, 299 00:20:15,480 --> 00:20:18,320 one of the best places to see elephants. 300 00:20:24,440 --> 00:20:27,360 I really love my job, I really love nature. 301 00:20:27,360 --> 00:20:30,280 Really love sitting down, watching the animals' behaviour. 302 00:20:32,400 --> 00:20:37,800 Sophie Sadera is one of only a few female safari guides in the country. 303 00:20:37,800 --> 00:20:41,160 And there's one animal traveller she's spent a lot of time with 304 00:20:41,160 --> 00:20:42,680 over the years. 305 00:20:43,760 --> 00:20:45,680 There are these elephants crossing the road. 306 00:20:47,760 --> 00:20:49,480 Look at that tiny baby. 307 00:20:50,480 --> 00:20:52,440 He's playing with that plant. 308 00:20:53,560 --> 00:20:55,920 This is one of the best things, 309 00:20:55,920 --> 00:20:58,520 to sit and watch, and just enjoy them. 310 00:21:00,160 --> 00:21:03,400 This baby could live until it's 70 years old, 311 00:21:03,400 --> 00:21:06,680 but, for now, it's heavily reliant on the herd. 312 00:21:08,440 --> 00:21:12,360 An elephant group is led by the oldest female. 313 00:21:12,360 --> 00:21:16,840 This is the matriarch, the one closest to us with one long tusk. 314 00:21:16,840 --> 00:21:19,240 So she's the matriarch of this group. 315 00:21:21,600 --> 00:21:24,320 It's her responsibility to keep the group safe, 316 00:21:24,320 --> 00:21:26,760 and guide them on their migrations. 317 00:21:28,520 --> 00:21:31,640 Elephants can really, really travel far, 318 00:21:31,640 --> 00:21:33,120 because, actually, yeah, 319 00:21:33,120 --> 00:21:36,360 I can say maybe all year round they have food, 320 00:21:36,360 --> 00:21:38,200 but they travel for water. 321 00:21:39,760 --> 00:21:41,840 During the dry season, 322 00:21:41,840 --> 00:21:46,040 a herd can cover almost 25 miles a day to find water, 323 00:21:46,040 --> 00:21:50,320 and they rely on the matriarch's spatial memory to locate it. 324 00:21:51,800 --> 00:21:55,960 Researchers have found that older matriarchs with more experience 325 00:21:55,960 --> 00:21:58,840 are better at seeing their family through a drought 326 00:21:58,840 --> 00:22:01,120 than younger matriarchs. 327 00:22:01,120 --> 00:22:03,760 When their usual water sources dry up, 328 00:22:03,760 --> 00:22:07,240 they can remember how to find alternative water holes 329 00:22:07,240 --> 00:22:09,840 that they visited in the past. 330 00:22:09,840 --> 00:22:13,920 And the Mara's elephants offer some insight into how these routes 331 00:22:13,920 --> 00:22:16,960 are passed down the generations. 332 00:22:16,960 --> 00:22:21,240 If you look at that escarpment ahead of us, there is a path. 333 00:22:21,240 --> 00:22:23,520 That's the elephants' path, 334 00:22:23,520 --> 00:22:27,720 and they use that path to go all the way up the hills 335 00:22:27,720 --> 00:22:30,160 and, down, they use the same path. 336 00:22:30,160 --> 00:22:33,800 They'll go for years using the same route. 337 00:22:33,800 --> 00:22:36,800 By using the same paths all the time, 338 00:22:36,800 --> 00:22:41,080 younger members of the herd learn where to go in times of crisis. 339 00:22:44,520 --> 00:22:48,440 When they're within a kilometre of a water source, their incredible 340 00:22:48,440 --> 00:22:51,840 sense of smell takes over to guide them in. 341 00:22:51,840 --> 00:22:54,840 With nearly 2,000 olfactory receptors, 342 00:22:54,840 --> 00:22:58,800 their sense of smell is five times stronger than our own. 343 00:23:01,560 --> 00:23:04,680 Recalling remote, life-sustaining sources of water 344 00:23:04,680 --> 00:23:07,120 is critical to their survival. 345 00:23:09,480 --> 00:23:12,400 But, when times are good and water is abundant, 346 00:23:12,400 --> 00:23:15,160 the elephants know how to take advantage. 347 00:23:22,280 --> 00:23:25,200 Perhaps the notion that an elephant never forgets 348 00:23:25,200 --> 00:23:27,480 is more accurate than we realised. 349 00:23:29,280 --> 00:23:33,320 Travelling from A to B is critical for migrating animals to find 350 00:23:33,320 --> 00:23:38,600 the resources they need to survive and memory helps them do it. 351 00:23:38,600 --> 00:23:42,880 But you don't necessarily need a big brain to have a mental map. 352 00:23:44,320 --> 00:23:47,640 It turns out there's one tiny amphibian that's 353 00:23:47,640 --> 00:23:49,800 a memory mastermind. 354 00:23:49,800 --> 00:23:50,840 Look at this. 355 00:23:51,880 --> 00:23:53,520 Superb. 356 00:23:53,520 --> 00:23:58,520 This is a green and black poison dart frog - Dendrobates. 357 00:23:58,520 --> 00:24:03,200 And it's exquisitely beautiful, but also highly toxic, 358 00:24:03,200 --> 00:24:05,760 hence me wearing the gloves. 359 00:24:05,760 --> 00:24:09,640 But it's the first amphibian that we know of, that can make 360 00:24:09,640 --> 00:24:13,400 a mental map of its environment to look after its young. 361 00:24:13,400 --> 00:24:15,400 What about that? 362 00:24:15,400 --> 00:24:20,000 Now, these creatures live in the rainforests of South America. 363 00:24:21,880 --> 00:24:24,320 A very intricate and complex environment. 364 00:24:25,760 --> 00:24:28,160 This is very much a three-dimensional world, 365 00:24:29,800 --> 00:24:33,120 and it's here that they, along with other poison dart frogs, 366 00:24:33,120 --> 00:24:36,080 like this strawberry poison dart frog, 367 00:24:36,080 --> 00:24:37,840 care for their young. 368 00:24:39,720 --> 00:24:42,600 They lay their eggs in leaf litter, 369 00:24:42,600 --> 00:24:46,920 but, once hatched, the tadpoles must be taken to water without delay. 370 00:24:48,720 --> 00:24:53,160 And that involves a piggyback ride up to the treetops. 371 00:24:55,800 --> 00:25:00,280 They need to find a hole full of water to act as a tadpole nursery. 372 00:25:02,440 --> 00:25:04,880 That can be high up in the canopy. 373 00:25:08,360 --> 00:25:12,600 Now, brand-new science on green and black poison dart frogs 374 00:25:12,600 --> 00:25:15,440 has uncovered just how they find their way around - 375 00:25:15,440 --> 00:25:19,560 up, down and in all directions in these vast forests. 376 00:25:21,680 --> 00:25:27,560 This tiny little amphibian has got the mind to remember the structure 377 00:25:27,560 --> 00:25:30,520 of a rainforest, a dynamic environment 378 00:25:30,520 --> 00:25:32,560 which is constantly changing. 379 00:25:32,560 --> 00:25:35,640 So it doesn't only form a mental map, 380 00:25:35,640 --> 00:25:40,480 it has the capacity to constantly revise and update it. 381 00:25:40,480 --> 00:25:42,520 Incredible! 382 00:25:42,520 --> 00:25:46,400 At the moment, it's the only species we know of that can do this. 383 00:25:46,400 --> 00:25:50,440 But it's likely that other poison dart frogs can do the same. 384 00:25:52,800 --> 00:25:57,160 So mental maps help animals find their way from A to B, 385 00:25:57,160 --> 00:26:01,640 both in their home territory and on their epic migrations. 386 00:26:01,640 --> 00:26:06,480 But what if you constantly have to travel to new places to find food, 387 00:26:06,480 --> 00:26:09,520 and then need to find your way home again safely? 388 00:26:12,720 --> 00:26:17,520 Well, fascinating research into one ocean species is revealing some 389 00:26:17,520 --> 00:26:20,520 surprisingly clever navigation strategies. 390 00:26:23,360 --> 00:26:27,400 Mantis shrimp travel around the sea floor, foraging for food. 391 00:26:28,560 --> 00:26:31,280 They're not shrimp, but stomatopods, 392 00:26:31,280 --> 00:26:34,480 a kind of carnivorous marine crustacean. 393 00:26:35,920 --> 00:26:39,800 When hunting, these little creatures pack a punch, 394 00:26:39,800 --> 00:26:42,240 delivering a lightning fast strike, 395 00:26:42,240 --> 00:26:45,280 as quick as a bullet leaving a gun. 396 00:26:47,720 --> 00:26:50,560 Navigating underwater can be challenging. 397 00:26:50,560 --> 00:26:54,440 In shallow tidal areas, the waves push and pull, 398 00:26:54,440 --> 00:26:57,720 and visibility can be poor, 399 00:26:57,720 --> 00:26:59,760 making it hard to keep track of where you are, 400 00:26:59,760 --> 00:27:02,120 and how far you've gone. 401 00:27:02,120 --> 00:27:06,400 So you'd think a small animal, with an even smaller brain, 402 00:27:06,400 --> 00:27:08,640 would find it tough too. 403 00:27:08,640 --> 00:27:10,960 In fact, it's quite the opposite. 404 00:27:12,720 --> 00:27:15,640 They seem to have a great spatial awareness of their surroundings. 405 00:27:15,640 --> 00:27:16,960 This led me to ask the question, 406 00:27:16,960 --> 00:27:19,280 how are mantis shrimp navigating in their environment? 407 00:27:20,880 --> 00:27:24,680 PhD student Ricky Patel, from the University of Maryland, 408 00:27:24,680 --> 00:27:28,960 has been studying mantis shrimps for the past six years. 409 00:27:28,960 --> 00:27:31,600 By devising a series of ingenious tests, 410 00:27:31,600 --> 00:27:36,080 he started to uncover the impressive skills they use to get around. 411 00:27:37,280 --> 00:27:41,320 To study them, Ricky placed food in a circular arena, 412 00:27:41,320 --> 00:27:44,800 and watched how the shrimp travelled from their burrow to search for it. 413 00:27:47,240 --> 00:27:51,080 So I found they make these twisty paths to the location of food. 414 00:27:52,720 --> 00:27:55,760 And, much to my surprise, I found that they returned in a straight 415 00:27:55,760 --> 00:27:58,480 line back to that their home once more. 416 00:27:58,480 --> 00:28:03,400 This suggested mantis shrimp use a navigation technique known as 417 00:28:03,400 --> 00:28:06,120 path integration, or dead reckoning. 418 00:28:06,120 --> 00:28:10,600 It means they're constantly monitoring the turns they make 419 00:28:10,600 --> 00:28:13,520 and the distance they travel away from a starting location 420 00:28:13,520 --> 00:28:15,480 like their home. 421 00:28:15,480 --> 00:28:19,520 And calculating how to return to it in a straight line 422 00:28:19,520 --> 00:28:21,720 from their current position. 423 00:28:23,880 --> 00:28:29,200 In fact, a similar system monitoring speed, direction and time was used 424 00:28:29,200 --> 00:28:32,560 by ancient mariners to find their way back to port 425 00:28:32,560 --> 00:28:34,200 after travelling at sea. 426 00:28:35,400 --> 00:28:37,040 To path integrate, 427 00:28:37,040 --> 00:28:40,840 mantis shrimp must have some sort of internal compass 428 00:28:40,840 --> 00:28:42,640 to orientate themselves, 429 00:28:42,640 --> 00:28:46,360 but they may also be using cues external to the body, 430 00:28:46,360 --> 00:28:48,160 things like the sun. 431 00:28:50,200 --> 00:28:55,480 This led Ricky to question what exactly they do use to navigate. 432 00:28:55,480 --> 00:28:58,520 So, in the arena, I had an artificial burrow, 433 00:28:58,520 --> 00:29:00,960 set into the base of the arena, so that's this dark rock. 434 00:29:02,200 --> 00:29:04,840 I built a platform that could be rotated, and I placed 435 00:29:04,840 --> 00:29:06,840 that directly centre in the arena. 436 00:29:06,840 --> 00:29:08,640 Now, I placed food on that platform 437 00:29:08,640 --> 00:29:10,920 and waited for mantis shrimp to find their way to the food. 438 00:29:13,920 --> 00:29:16,280 So once they found the food on the platform, 439 00:29:16,280 --> 00:29:18,840 I slowly rotated the mantis shrimp 180 degrees... 440 00:29:21,480 --> 00:29:23,440 ..and observed which way they went. 441 00:29:25,240 --> 00:29:26,360 Cunning! 442 00:29:26,360 --> 00:29:28,880 If they only used internal cues, 443 00:29:28,880 --> 00:29:32,640 Ricky expected the shrimp wouldn't realise they'd been rotated, 444 00:29:32,640 --> 00:29:36,240 and should walk in the opposite direction of their home. 445 00:29:36,240 --> 00:29:40,360 But if they were using external signs, they'd travel directly back 446 00:29:40,360 --> 00:29:42,120 to it, despite being turned. 447 00:29:44,320 --> 00:29:45,840 I found that on clear days, like today, 448 00:29:45,840 --> 00:29:47,680 when the sun is clearly visible, 449 00:29:47,680 --> 00:29:49,320 mantis shrimp oriented correctly home. 450 00:29:50,640 --> 00:29:53,000 However, on heavily overcast days, 451 00:29:53,000 --> 00:29:55,000 when all spatial information was obscured... 452 00:29:56,640 --> 00:29:59,480 ..mantis shrimp oriented in the direction opposite of their homes. 453 00:30:02,560 --> 00:30:06,280 So when it's cloudy, mantis shrimp rely on internal 454 00:30:06,280 --> 00:30:08,640 self-motion cues to navigate. 455 00:30:10,160 --> 00:30:11,480 But, on sunny days, 456 00:30:11,480 --> 00:30:15,320 they appear to use cues outside the body, like the sun. 457 00:30:16,440 --> 00:30:19,800 To check this, Ricky devised a clever twist on the test. 458 00:30:21,040 --> 00:30:24,960 I would shade the arena from the sun using a board, 459 00:30:24,960 --> 00:30:27,320 and then I would use a mirror to reflect the sun 460 00:30:27,320 --> 00:30:28,920 on the opposite side of the arena, 461 00:30:28,920 --> 00:30:31,400 to make it appear to the mantis shrimp that the sun is 462 00:30:31,400 --> 00:30:33,680 on the opposite side of the sky from where it actually was. 463 00:30:36,800 --> 00:30:39,920 And I found that most of the time mantis shrimp would indeed orient 464 00:30:39,920 --> 00:30:43,040 in the wrong direction of their homes, after I'd mirrored the sun. 465 00:30:43,040 --> 00:30:47,000 So this showed that mantis shrimp were using the sun for orientation. 466 00:30:47,000 --> 00:30:48,440 That's not all. 467 00:30:48,440 --> 00:30:52,320 Mantis shrimp have yet another way to avoid getting lost. 468 00:30:52,320 --> 00:30:53,320 Local landmarks. 469 00:30:54,720 --> 00:30:58,480 You know how the local pub signposts you're almost home? 470 00:30:58,480 --> 00:31:01,680 Well, the same appears to be true for mantis shrimps, 471 00:31:01,680 --> 00:31:05,320 as Ricky's latest research in 2020 found, 472 00:31:05,320 --> 00:31:08,720 when he added a landmark to the research arena. 473 00:31:08,720 --> 00:31:11,400 Represented today by this feather. 474 00:31:11,400 --> 00:31:14,440 So in this experiment, mantis shrimp left their homes, 475 00:31:14,440 --> 00:31:16,680 and, like always, 476 00:31:16,680 --> 00:31:18,160 made a twisty path away. 477 00:31:18,160 --> 00:31:20,040 While the mantis shrimp were doing that, 478 00:31:20,040 --> 00:31:22,880 I slid the landmark to a new location in the arena. 479 00:31:24,800 --> 00:31:27,200 Despite being moved, some of the time, 480 00:31:27,200 --> 00:31:29,680 the shrimp still honed in on the landmark. 481 00:31:31,760 --> 00:31:35,160 It seems that path integration isn't perfect, 482 00:31:35,160 --> 00:31:36,760 so, to correct for this, 483 00:31:36,760 --> 00:31:39,840 some shrimp also use landmarks. 484 00:31:39,840 --> 00:31:42,400 Their little bit of coral signposts the way home. 485 00:31:43,880 --> 00:31:48,600 So these smart stomatopods navigated a multitude of ways, 486 00:31:48,600 --> 00:31:51,600 error checking their position and route as they go, 487 00:31:51,600 --> 00:31:56,400 and working out which strategy is more effective at any given time. 488 00:31:57,560 --> 00:32:02,400 But why would a shrimp need such a sophisticated navigation system? 489 00:32:02,400 --> 00:32:06,160 Well, they may not travel far, but their lives depend 490 00:32:06,160 --> 00:32:08,720 on finding their way back to the safety of their burrow. 491 00:32:09,960 --> 00:32:13,960 In the natural world, path integration is a big deal, 492 00:32:13,960 --> 00:32:18,640 and mantis shrimp are the only underwater animal known to use it. 493 00:32:18,640 --> 00:32:22,120 Mantis shrimp are small animals with relatively simple brains. 494 00:32:22,120 --> 00:32:25,000 I was really impressed, and quite surprised, by the sophistication 495 00:32:25,000 --> 00:32:26,560 of their navigational authorities. 496 00:32:31,840 --> 00:32:35,880 Daytime navigation is one thing, but what about at night? 497 00:32:39,040 --> 00:32:41,280 When there's no sun to steer by, 498 00:32:41,280 --> 00:32:42,600 how do you find your way? 499 00:32:45,000 --> 00:32:47,480 Well, there's one insect 500 00:32:47,480 --> 00:32:49,680 whose night-time guidance system... 501 00:32:50,920 --> 00:32:53,640 ..has left me suitably impressed. 502 00:32:53,640 --> 00:32:55,040 The dung beetle. 503 00:32:57,680 --> 00:32:59,840 A very successful group of animals. 504 00:32:59,840 --> 00:33:03,320 You can find thousands of species across every continent, 505 00:33:03,320 --> 00:33:05,720 apart from Antarctica, 506 00:33:05,720 --> 00:33:07,960 and as their name suggests, 507 00:33:07,960 --> 00:33:10,440 they either live on or in dung, 508 00:33:10,440 --> 00:33:13,880 and they, or their larvae, feed upon it. 509 00:33:13,880 --> 00:33:17,320 Imagine you're on the plains of Africa, and an elephant poos. 510 00:33:17,320 --> 00:33:20,320 That's a lot of a very valuable resource. 511 00:33:21,360 --> 00:33:24,640 Competition for that poo is intense. 512 00:33:24,640 --> 00:33:26,680 So as soon as you've rolled your ball of it, 513 00:33:26,680 --> 00:33:29,280 you want to get it out of the way quickly. 514 00:33:31,560 --> 00:33:35,400 And the best way to do that is to roll it in a dead straight line. 515 00:33:39,680 --> 00:33:44,120 Something that's quite difficult to do when you're pushing it backwards 516 00:33:44,120 --> 00:33:46,360 and you can't see where you're going. 517 00:33:51,360 --> 00:33:54,280 So how does a dung beetle make a quick getaway 518 00:33:54,280 --> 00:33:56,120 with its precious dung ball? 519 00:33:56,120 --> 00:33:59,680 To find out, we need to take a trip to the African Savannah. 520 00:34:01,800 --> 00:34:05,920 The dung restaurant on the Savannah is open 24 hours a day. 521 00:34:05,920 --> 00:34:08,480 There are beetles that are there during the day, 522 00:34:08,480 --> 00:34:11,560 and then there are other species that are active during the night. 523 00:34:11,560 --> 00:34:14,440 And that is a way to avoid competition. 524 00:34:14,440 --> 00:34:17,840 It's to make sure that you can get dung. 525 00:34:17,840 --> 00:34:21,480 Marie Dacke is Professor of Sensory Biology 526 00:34:21,480 --> 00:34:23,840 at Lund University in Sweden, 527 00:34:23,840 --> 00:34:27,400 and she's been studying dung beetles for over 20 years. 528 00:34:28,440 --> 00:34:32,360 There can be thousands of beetles on a single dung pile, 529 00:34:32,360 --> 00:34:37,400 and about 10% of the beetles at this pile will roll their ball away. 530 00:34:40,360 --> 00:34:42,440 These are the rollers. 531 00:34:44,280 --> 00:34:46,320 But there are also tunnelers, 532 00:34:46,320 --> 00:34:47,920 who burrow into dung, 533 00:34:47,920 --> 00:34:50,760 and dwellers, who live in it. 534 00:34:50,760 --> 00:34:54,240 Yes, as you might have guessed, dung beetles are grouped 535 00:34:54,240 --> 00:34:55,920 by how they use a poo pile. 536 00:34:57,880 --> 00:34:59,920 But there's a fourth kind. 537 00:34:59,920 --> 00:35:01,360 The stealers, 538 00:35:01,360 --> 00:35:04,680 who will snatch the rollers' balls. 539 00:35:04,680 --> 00:35:08,360 So once the rollers sculpt their prize... 540 00:35:08,360 --> 00:35:10,560 ..they'd better hightail it away. 541 00:35:10,560 --> 00:35:14,320 It's the way to make sure they get their little lunch this day, 542 00:35:14,320 --> 00:35:16,320 because they will eat the dung 543 00:35:16,320 --> 00:35:20,200 and, by rolling straight, they get away from the dung pile, 544 00:35:20,200 --> 00:35:23,680 with maximal efficiency, with every step they take. 545 00:35:25,280 --> 00:35:28,760 Going in a straight line means they cover the most distance 546 00:35:28,760 --> 00:35:31,520 in the shortest time - an efficient way to travel. 547 00:35:33,000 --> 00:35:37,280 What's more, rolling these balls is no small feat. 548 00:35:37,280 --> 00:35:40,440 Sometimes we find dung balls that are this big, 549 00:35:40,440 --> 00:35:45,320 and those they are actually going to use to have their brood in. 550 00:35:45,320 --> 00:35:49,000 They are pushing an object that is many, many times heavier 551 00:35:49,000 --> 00:35:50,560 than themselves. 552 00:35:50,560 --> 00:35:54,160 Relatively, they are the strongest animals on the planet. 553 00:35:54,160 --> 00:35:57,360 Rolling their dung balls is the equivalent of us humans 554 00:35:57,360 --> 00:36:00,440 pulling six double decker buses. 555 00:36:03,080 --> 00:36:06,880 Since a fresh dumping of poo can happen day or night, 556 00:36:06,880 --> 00:36:12,120 different dung beetle species are active at particular times. 557 00:36:12,120 --> 00:36:16,680 Marie and her colleagues wanted to understand what visual cues, 558 00:36:16,680 --> 00:36:18,040 such as the moon, 559 00:36:18,040 --> 00:36:21,960 these tiny beetles use to orientate themselves after dark. 560 00:36:23,800 --> 00:36:26,840 So they focused their studies on nocturnal, 561 00:36:26,840 --> 00:36:30,320 ball-rolling dung beetles in South Africa. 562 00:36:30,320 --> 00:36:33,560 And they made a remarkable discovery. 563 00:36:33,560 --> 00:36:38,240 They confirmed these dung beetles do use the moon to navigate. 564 00:36:38,240 --> 00:36:42,080 But there was another, even more surprising finding. 565 00:36:42,080 --> 00:36:45,680 The last experiment was to have no moon at all in the sky, 566 00:36:45,680 --> 00:36:48,560 and we expected them to now be fully lost. 567 00:36:48,560 --> 00:36:49,800 But they were not. 568 00:36:49,800 --> 00:36:51,440 They kept on orienting, 569 00:36:51,440 --> 00:36:55,880 and we wanted to see if they were actually using things in the sky. 570 00:36:55,880 --> 00:37:00,400 So we gave them a hat, to block everything in the sky. 571 00:37:00,400 --> 00:37:03,760 And they look really, really fantastic in hats! 572 00:37:04,920 --> 00:37:07,320 Dung beetles in hats! 573 00:37:07,320 --> 00:37:09,880 An inspired a bit of research. 574 00:37:09,880 --> 00:37:13,760 And then when they couldn't see the stars any more, they were lost. 575 00:37:13,760 --> 00:37:16,200 They started rolling in circles. 576 00:37:16,200 --> 00:37:19,880 We could then draw the conclusion that there was something 577 00:37:19,880 --> 00:37:23,840 in the starry sky that was important for them to orient by. 578 00:37:25,560 --> 00:37:30,200 On a moonless night, the most obvious landmark is the Milky Way. 579 00:37:32,120 --> 00:37:34,960 If you look into the galaxy, like you do in the Southern Hemisphere, 580 00:37:34,960 --> 00:37:38,360 you have a nice streak of light across the sky. 581 00:37:38,360 --> 00:37:42,480 Then the southern end is brighter than the northern end. 582 00:37:42,480 --> 00:37:46,880 And the theory we have is that they actually ignore the rest 583 00:37:46,880 --> 00:37:50,760 of the Milky Way and concentrate on the southern part. 584 00:37:50,760 --> 00:37:55,000 So, in that way, they would have one bright area to steer by. 585 00:37:56,440 --> 00:38:00,520 And Marie's findings suggest that it's this gradient of light 586 00:38:00,520 --> 00:38:04,360 in the Milky Way that's really important to the beetles. 587 00:38:04,360 --> 00:38:08,360 We know that if you have a light streak that is totally even, 588 00:38:08,360 --> 00:38:10,400 so it's the same across, 589 00:38:10,400 --> 00:38:12,280 they can't orient by that. 590 00:38:12,280 --> 00:38:14,520 It needs to have a gradient, 591 00:38:14,520 --> 00:38:17,760 and they follow the brightest bit of it. 592 00:38:17,760 --> 00:38:21,680 The nocturnal dung beetles that Marie studied are the only 593 00:38:21,680 --> 00:38:26,320 animals on the planet thought to navigate using the Milky Way. 594 00:38:26,320 --> 00:38:31,160 But what's really incredible is that this star compass is only one part 595 00:38:31,160 --> 00:38:34,840 of these tiny travellers' navigation system. 596 00:38:34,840 --> 00:38:38,080 The Milky Way is part of a bigger study when we are trying 597 00:38:38,080 --> 00:38:42,680 to understand how these animals can navigate at all hours of the day, 598 00:38:42,680 --> 00:38:46,800 and then how they can combine the different cues to have a very, 599 00:38:46,800 --> 00:38:49,640 very safe compass to move by. 600 00:38:49,640 --> 00:38:52,160 So the Milky Way is part of this system. 601 00:38:52,160 --> 00:38:55,360 It's a back-up when the moon is not there, for example. 602 00:38:56,760 --> 00:39:00,440 As Marie continues to learn more about their abilities, 603 00:39:00,440 --> 00:39:03,520 her respect for these mini navigators grows. 604 00:39:05,680 --> 00:39:10,160 We have to remember that its brain is smaller than the head 605 00:39:10,160 --> 00:39:15,520 of a needle, and still they can solve so many tasks in ways 606 00:39:15,520 --> 00:39:19,400 that we didn't really imagine with our massive brains. 607 00:39:21,840 --> 00:39:23,160 Incredible. 608 00:39:23,160 --> 00:39:26,200 But being a successful animal traveller is not 609 00:39:26,200 --> 00:39:29,240 just about navigating the best path. 610 00:39:29,240 --> 00:39:33,920 You also need to be smart about how you reach your destination, 611 00:39:33,920 --> 00:39:37,360 making the journey in the most economical way possible. 612 00:39:39,360 --> 00:39:42,040 Generally, moving uses lots of energy. 613 00:39:44,280 --> 00:39:48,160 So what if you want to save your legs, wings and fins... 614 00:39:49,560 --> 00:39:53,400 ..to minimise the precious calories used to move around? 615 00:39:58,000 --> 00:40:01,520 Well, the natural world has some savvy solutions. 616 00:40:04,240 --> 00:40:08,920 Did you know that jellyfish are one of the most energy efficient animals 617 00:40:08,920 --> 00:40:10,360 in the world? 618 00:40:10,360 --> 00:40:13,760 Just look at their swarms - they're mesmeric, aren't they? 619 00:40:13,760 --> 00:40:17,640 You know, for their size, they can travel further 620 00:40:17,640 --> 00:40:23,080 using the least amount of energy than any other ocean-going animal. 621 00:40:23,080 --> 00:40:26,720 And they achieve this with a dual propulsion system, 622 00:40:26,720 --> 00:40:29,640 through opening and closing their bells. 623 00:40:29,640 --> 00:40:30,600 Just look. 624 00:40:33,480 --> 00:40:37,080 They have a ring of muscles around the outside of their bell 625 00:40:37,080 --> 00:40:39,720 and, when they tighten those, the bell contracts, 626 00:40:39,720 --> 00:40:43,560 expelling all of that water that's been stored inside it, 627 00:40:43,560 --> 00:40:45,400 pushing the jellyfish forward. 628 00:40:47,280 --> 00:40:51,360 When the jellyfish relaxes its muscles and the bell reopens 629 00:40:51,360 --> 00:40:55,720 is when the genius behind its efficiency is exposed, 630 00:40:55,720 --> 00:40:59,320 as this produces a second wave of water movement, 631 00:40:59,320 --> 00:41:02,880 a vortex that forms under the jellyfish, 632 00:41:02,880 --> 00:41:05,280 giving it another push forward. 633 00:41:07,800 --> 00:41:12,440 This extra thrust is responsible for 30% of the distance 634 00:41:12,440 --> 00:41:14,960 that the jellyfish travel through the water, 635 00:41:14,960 --> 00:41:19,160 and they achieve it with no extra expenditure of energy. 636 00:41:19,160 --> 00:41:23,000 So whilst they might look like amorphous blobs of tissue, 637 00:41:23,000 --> 00:41:25,640 they are, in fact, brilliant swimmers. 638 00:41:28,480 --> 00:41:30,360 When it comes to moving efficiently, 639 00:41:30,360 --> 00:41:33,160 some large birds, like storks, 640 00:41:33,160 --> 00:41:35,200 have a few tricks of their own. 641 00:41:35,200 --> 00:41:39,280 They use their long broad wings to catch thermals, 642 00:41:39,280 --> 00:41:40,880 hot air rising from the ground. 643 00:41:42,120 --> 00:41:45,440 This is a smart short cut to gain height. 644 00:41:45,440 --> 00:41:50,040 Once up high, they can position their wings to glide on the wind, 645 00:41:50,040 --> 00:41:51,440 just like hang gliders. 646 00:41:53,880 --> 00:41:58,160 No need to waste precious calories on flapping those wings. 647 00:42:00,760 --> 00:42:04,480 But there's another energy efficient way to fly, too. 648 00:42:04,480 --> 00:42:07,280 I'm sure many of you will have seen birds flying 649 00:42:07,280 --> 00:42:09,720 in a distinctive V formation. 650 00:42:09,720 --> 00:42:12,160 Well, it's all about aerodynamics. 651 00:42:14,200 --> 00:42:17,440 When cranes begin their impressive migration from Europe 652 00:42:17,440 --> 00:42:20,360 to Northern Africa, they fall into formation, 653 00:42:20,360 --> 00:42:22,760 with birds flying just behind 654 00:42:22,760 --> 00:42:26,200 and just to the side of their flock mate in front. 655 00:42:28,200 --> 00:42:33,080 Those separated feathers at the tip of each bird's wing create a force 656 00:42:33,080 --> 00:42:34,800 called a wing tip vortex. 657 00:42:37,640 --> 00:42:42,360 Each bird, except for the leader, gets a free lift from this vortex 658 00:42:42,360 --> 00:42:44,880 created by the bird in front. 659 00:42:44,880 --> 00:42:46,160 Reducing effort. 660 00:42:49,120 --> 00:42:51,560 And just like a cycling peloton, 661 00:42:51,560 --> 00:42:55,040 pole position is the most strenuous job. 662 00:42:55,040 --> 00:42:58,280 So whilst the group benefits from the leader's slipstream, 663 00:42:58,280 --> 00:43:00,760 there's plenty of switches up top. 664 00:43:02,560 --> 00:43:08,640 Studies estimate birds use 20 to 30% less energy when flying in a V. 665 00:43:12,800 --> 00:43:15,680 Using thermals and aerodynamics, 666 00:43:15,680 --> 00:43:19,400 these masters of the sky travel for days, 667 00:43:19,400 --> 00:43:21,640 barely flapping their wings. 668 00:43:21,640 --> 00:43:24,480 Now, that's smart efficiency. 669 00:43:26,040 --> 00:43:27,800 Birds will use winds, 670 00:43:27,800 --> 00:43:31,600 they'll use those columns of hot rising air, thermals, 671 00:43:31,600 --> 00:43:34,840 but could there be any other physical forces 672 00:43:34,840 --> 00:43:36,880 that we don't frequently think of, 673 00:43:36,880 --> 00:43:40,720 that might help transport animals around our globe? 674 00:43:40,720 --> 00:43:43,360 Well, it turns out that there are. 675 00:43:43,360 --> 00:43:46,440 If I take this balloon, rub it against my head, 676 00:43:46,440 --> 00:43:48,600 generate some static electricity, 677 00:43:48,600 --> 00:43:50,480 and this small piece of plastic 678 00:43:50,480 --> 00:43:53,200 to represent an organism, and do the same... 679 00:43:55,480 --> 00:43:58,280 ..I can make that organism fly. 680 00:43:58,280 --> 00:44:00,640 But which type of creature 681 00:44:00,640 --> 00:44:03,000 could travel around the world 682 00:44:03,000 --> 00:44:05,720 using static electricity? 683 00:44:07,080 --> 00:44:11,000 Well, brand-new science by the University of Bristol 684 00:44:11,000 --> 00:44:16,080 has uncovered how one surprising animal has conquered the skies. 685 00:44:16,080 --> 00:44:17,760 Would you believe... 686 00:44:17,760 --> 00:44:20,920 ..spiders can fly? 687 00:44:23,080 --> 00:44:26,840 At first, it might seem they just float on the wind. 688 00:44:29,480 --> 00:44:32,520 But these smart spiders are actually tapping 689 00:44:32,520 --> 00:44:34,920 into the earth's electric fields. 690 00:44:36,440 --> 00:44:39,480 There are different levels of electricity in the air, 691 00:44:39,480 --> 00:44:43,080 produced naturally by thunderstorms around the planet. 692 00:44:43,080 --> 00:44:47,920 Amazingly, the tiny hairs on a spider's body can sense these 693 00:44:47,920 --> 00:44:50,320 and use them to get around. 694 00:44:52,920 --> 00:44:56,480 Called ballooning, they'll start by tiptoeing, 695 00:44:56,480 --> 00:44:59,360 sticking up their back legs into the air 696 00:44:59,360 --> 00:45:03,600 and unravelling strings of web, until their spider senses 697 00:45:03,600 --> 00:45:05,560 detect the electrical fields. 698 00:45:09,680 --> 00:45:12,520 As their silk is negatively charged, 699 00:45:12,520 --> 00:45:15,360 it repels negative charges in the air, 700 00:45:15,360 --> 00:45:18,040 generating a force strong enough 701 00:45:18,040 --> 00:45:19,680 to launch them skywards. 702 00:45:23,920 --> 00:45:26,240 Not all spiders can balloon, 703 00:45:26,240 --> 00:45:30,200 but those that can likely use both wind and electricity 704 00:45:30,200 --> 00:45:33,640 sailing along on their silk lines 705 00:45:33,640 --> 00:45:35,720 wherever the wind takes them. 706 00:45:36,720 --> 00:45:39,360 An almost effortless way to travel. 707 00:45:43,640 --> 00:45:47,040 But why would a small spider take to the skies? 708 00:45:48,200 --> 00:45:51,680 Well, flying may be part of a clever strategy, 709 00:45:51,680 --> 00:45:54,400 helping them to avoid competition, 710 00:45:54,400 --> 00:45:55,600 start a new colony 711 00:45:55,600 --> 00:45:57,240 or even find more food. 712 00:45:58,680 --> 00:46:02,680 In fact, their silk superhighway is so successful, 713 00:46:02,680 --> 00:46:05,160 some tiny travellers have been found 714 00:46:05,160 --> 00:46:09,040 an astonishing 1,000 miles out at sea, 715 00:46:09,040 --> 00:46:11,720 and up to two and a half miles high in the air. 716 00:46:12,840 --> 00:46:16,800 So these airborne arachnids certainly do get around. 717 00:46:18,280 --> 00:46:20,600 But whether they can control their altitude 718 00:46:20,600 --> 00:46:22,640 and choose where they're landing 719 00:46:22,640 --> 00:46:25,880 is something scientists are still trying to find out. 720 00:46:30,400 --> 00:46:35,440 Like the spiders, sometimes it's the animals you'd least expect 721 00:46:35,440 --> 00:46:38,880 that get around in the most surprising ways. 722 00:46:38,880 --> 00:46:41,880 To help me explain, let's meet one of my favourites. 723 00:46:44,960 --> 00:46:46,480 Stunning, isn't it? 724 00:46:46,480 --> 00:46:48,640 Absolutely stunning. 725 00:46:48,640 --> 00:46:53,280 This is a rhino ratsnake from Southeast Asia, 726 00:46:53,280 --> 00:46:55,600 and you can see how it got its name. 727 00:46:55,600 --> 00:47:00,440 It's got this extraordinary proboscis of scales sticking out 728 00:47:00,440 --> 00:47:03,240 from the front of its nose, which is actually flexible. 729 00:47:03,240 --> 00:47:07,920 Its green colouration betrays this snake as a type of tree snake. 730 00:47:08,880 --> 00:47:12,760 It clambers up the twigs and branches into the canopy, 731 00:47:12,760 --> 00:47:15,240 where it searches for its prey. 732 00:47:15,240 --> 00:47:19,080 And I've got to say, it's one of the most beautiful snakes 733 00:47:19,080 --> 00:47:20,560 that I've ever seen. 734 00:47:21,880 --> 00:47:23,840 Fantastic. 735 00:47:23,840 --> 00:47:28,120 But perhaps it's trumped by another species of tree snake - 736 00:47:28,120 --> 00:47:30,280 the paradise tree snake, 737 00:47:30,280 --> 00:47:33,080 which doesn't only climb trees, 738 00:47:33,080 --> 00:47:35,120 it flies out of them. 739 00:47:36,000 --> 00:47:40,720 To see one in action, let's head to Borneo in Southeast Asia... 740 00:47:44,680 --> 00:47:48,120 ..where these snakes are fearless flyers, 741 00:47:48,120 --> 00:47:50,560 especially from heights like this. 742 00:47:52,800 --> 00:47:56,640 Travelling in this immense jungle might at first seem tricky. 743 00:47:57,560 --> 00:48:00,760 But the paradise tree snake has an ingenious solution. 744 00:48:02,760 --> 00:48:06,000 It appears to almost swim through the air. 745 00:48:07,200 --> 00:48:09,040 Covering up to 100 metres. 746 00:48:13,760 --> 00:48:18,600 These spectacular glides may help them escape predators, 747 00:48:18,600 --> 00:48:21,240 but, with no wings, how do they do it? 748 00:48:22,800 --> 00:48:28,160 New research conducted in 2020 shows us that there's more to their wiggle 749 00:48:28,160 --> 00:48:29,560 than meets the eye. 750 00:48:32,400 --> 00:48:36,560 The researchers placed them in a study area, high off the ground, 751 00:48:36,560 --> 00:48:39,320 and gave them a fake tree to aim for. 752 00:48:39,320 --> 00:48:42,400 Then, by putting markers onto the snakes, 753 00:48:42,400 --> 00:48:47,000 they used motion capture technology to develop a 3-D model 754 00:48:47,000 --> 00:48:48,040 of snake flight... 755 00:48:50,440 --> 00:48:52,320 ..and create an animation. 756 00:48:53,520 --> 00:48:56,800 The team found the snakes flattened their bodies 757 00:48:56,800 --> 00:49:01,280 and used an undulating horizontal and vertical motion. 758 00:49:01,280 --> 00:49:04,400 Essentially, it's wiggling through the air 759 00:49:04,400 --> 00:49:08,520 and, as its body curves, it acts like a wing, generating lift. 760 00:49:10,400 --> 00:49:14,560 This winding movement also helps the snake stay upright, 761 00:49:14,560 --> 00:49:16,760 and not roll over in mid-air, 762 00:49:16,760 --> 00:49:19,280 gliding and landing safely. 763 00:49:22,640 --> 00:49:25,440 The exciting research being done on flying snakes 764 00:49:25,440 --> 00:49:29,120 is being used to develop innovative technology. 765 00:49:29,120 --> 00:49:32,840 Snake inspired robots are already in the works. 766 00:49:32,840 --> 00:49:35,600 Their adaptable locomotion means they can tackle 767 00:49:35,600 --> 00:49:38,120 a variety of different terrain. 768 00:49:38,120 --> 00:49:42,680 So the mechanics behind how flying snakes move could be used 769 00:49:42,680 --> 00:49:45,960 as a template for dynamic flying snake robots. 770 00:49:54,080 --> 00:49:57,520 The wonders of nature never fail to inspire us. 771 00:49:59,560 --> 00:50:03,640 But some of the most intriguing learning is coming from studying 772 00:50:03,640 --> 00:50:05,640 how animals travel en masse. 773 00:50:07,600 --> 00:50:11,840 When we move together, it requires a high level of coordination - 774 00:50:11,840 --> 00:50:14,920 so much so, almost 100 years ago, 775 00:50:14,920 --> 00:50:18,280 naturalists were so stunned when they saw flocks moving 776 00:50:18,280 --> 00:50:22,320 that they believed that the birds must have been using telepathy 777 00:50:22,320 --> 00:50:23,480 to communicate. 778 00:50:24,560 --> 00:50:29,120 Fast forward to the present day, and we're learning that bird flocks, 779 00:50:29,120 --> 00:50:32,360 along with other collectives like shoals and swarms, 780 00:50:32,360 --> 00:50:35,280 are actually tapping into a group mind. 781 00:50:36,800 --> 00:50:39,400 This influences how they travel, 782 00:50:39,400 --> 00:50:42,840 but it's got nothing to do with any navigating or being efficient. 783 00:50:44,040 --> 00:50:47,600 It's all about smart coordination. 784 00:50:47,600 --> 00:50:50,760 For us humans, there's one particular species 785 00:50:50,760 --> 00:50:54,400 whose collective behaviour can have a devastating impact. 786 00:50:55,840 --> 00:51:00,920 These animals are a specialised type of grasshopper called a locust. 787 00:51:00,920 --> 00:51:03,040 They are boom and bust animals, 788 00:51:03,040 --> 00:51:06,200 and where they're booming, boy, are they booming. 789 00:51:06,200 --> 00:51:11,040 The largest ever recorded swarm was in 1875, 790 00:51:11,040 --> 00:51:17,360 and probably consisted of 12.5 trillion of these insects. 791 00:51:20,000 --> 00:51:23,400 But what instigates the swarming behaviour? 792 00:51:23,400 --> 00:51:25,920 Well, it's their density on the ground, 793 00:51:25,920 --> 00:51:30,360 because these insects can eat their own body weight 794 00:51:30,360 --> 00:51:32,720 a day in vegetation. 795 00:51:32,720 --> 00:51:35,000 And if you've got lots of them eating that vegetation, 796 00:51:35,000 --> 00:51:38,160 then, very soon, there's not much vegetation left. 797 00:51:38,160 --> 00:51:40,440 And that's when things get nasty, 798 00:51:40,440 --> 00:51:43,440 because their little minds turn to cannibalism. 799 00:51:46,480 --> 00:51:50,480 And no locust wants to get eaten by another locust, so it starts 800 00:51:50,480 --> 00:51:54,320 to move on, and then the next one moves on, and the next, 801 00:51:54,320 --> 00:51:57,840 ad infinitum, until you've got a mobile swarm. 802 00:52:00,200 --> 00:52:04,440 For locusts, a swarm is triggered by a massive population boom. 803 00:52:06,120 --> 00:52:08,960 But other animals, like bird flocks and fish shoals, 804 00:52:08,960 --> 00:52:11,000 come together by choice. 805 00:52:11,000 --> 00:52:14,880 So what can they tell us about animal intelligence? 806 00:52:14,880 --> 00:52:18,840 It's almost impossible for us as humans to observe these groups, 807 00:52:18,840 --> 00:52:20,120 and make sense of them. 808 00:52:20,120 --> 00:52:21,520 This now captivated me. 809 00:52:21,520 --> 00:52:23,760 I now wanted to understand. 810 00:52:23,760 --> 00:52:27,680 Dr Iain Couzin, from the Max Planck Institute in Germany, 811 00:52:27,680 --> 00:52:31,800 is one of the world's leading experts in animal behaviour. 812 00:52:31,800 --> 00:52:36,160 Some of his most exciting insights are coming from schooling fish. 813 00:52:38,840 --> 00:52:42,480 Iain and his team studied them in special tanks, 814 00:52:42,480 --> 00:52:45,720 observing their reaction to various simulations. 815 00:52:45,720 --> 00:52:49,360 We project into the background any stimuli we want. 816 00:52:49,360 --> 00:52:53,400 So we can have moving dots, we can have naturalistic environments. 817 00:52:53,400 --> 00:52:56,360 And this allows us to understand how the animals both interact 818 00:52:56,360 --> 00:52:59,080 with each other, and how they interact with the environment 819 00:52:59,080 --> 00:53:01,440 through which they move. 820 00:53:01,440 --> 00:53:04,640 But as Iain adds more fish to the tank, 821 00:53:04,640 --> 00:53:08,080 and their numbers grow into the hundreds, even thousands, 822 00:53:08,080 --> 00:53:12,480 each individual becomes increasingly difficult to monitor. 823 00:53:12,480 --> 00:53:16,200 So what we do is we programme computers to see the world for us, 824 00:53:16,200 --> 00:53:18,240 to track the motion of the individuals, 825 00:53:18,240 --> 00:53:20,080 to calculate where their eyes are, 826 00:53:20,080 --> 00:53:23,680 to reconstruct the visual fields of each individual within the group. 827 00:53:23,680 --> 00:53:26,880 And so these techniques give us a completely new insight 828 00:53:26,880 --> 00:53:29,400 into how they sense, how they communicate 829 00:53:29,400 --> 00:53:31,840 and how collective intelligence has evolved. 830 00:53:35,480 --> 00:53:37,520 Each individual is interacting with his neighbour, 831 00:53:37,520 --> 00:53:39,120 who interact with their neighbours, 832 00:53:39,120 --> 00:53:41,680 who interact with their neighbours, and, together 833 00:53:41,680 --> 00:53:45,320 these social interactions can fuse their brains together 834 00:53:45,320 --> 00:53:48,560 to create a sort of higher level intelligence. 835 00:53:50,920 --> 00:53:54,640 And this actually allows the groups themselves to have an awareness 836 00:53:54,640 --> 00:53:57,720 of the environment that is not present at the individual level. 837 00:54:02,200 --> 00:54:05,960 This means there doesn't need to be a global orchestrating 838 00:54:05,960 --> 00:54:08,000 leader within these groups. 839 00:54:08,000 --> 00:54:12,240 Each individual follows relatively simple local rules. 840 00:54:12,240 --> 00:54:14,720 They will avoid colliding with each other. 841 00:54:14,720 --> 00:54:17,640 They'll be attracted towards each other, and they will tend to move 842 00:54:17,640 --> 00:54:19,920 in the direction of the neighbours around them, 843 00:54:19,920 --> 00:54:22,200 and those simple rules alone, 844 00:54:22,200 --> 00:54:25,640 if all of the individuals follow them, it's sufficient to explain 845 00:54:25,640 --> 00:54:27,480 these large swirling flocks that we see. 846 00:54:29,720 --> 00:54:33,800 Now that we know how individuals in a group respond, the question 847 00:54:33,800 --> 00:54:37,680 is why do they form such large groups to begin with? 848 00:54:37,680 --> 00:54:40,280 One of the main reasons is about information. 849 00:54:40,280 --> 00:54:45,800 So each individual has a local sphere where it can detect what's 850 00:54:45,800 --> 00:54:48,720 going on in its environment, and that's inherently limited. 851 00:54:50,480 --> 00:54:53,080 However, if each individual pays attention to what's 852 00:54:53,080 --> 00:54:55,080 going on within that local environment, 853 00:54:55,080 --> 00:54:58,560 but also pays attention to the others around it, 854 00:54:58,560 --> 00:55:00,800 and each of them is paying attention 855 00:55:00,800 --> 00:55:03,200 to their own part of the environment, 856 00:55:03,200 --> 00:55:05,560 and if information can flow quickly across the group... 857 00:55:07,520 --> 00:55:11,760 ..this effectively means, if I'm a fish at one side of the school, 858 00:55:11,760 --> 00:55:14,840 I can feel what's going on at the other side. 859 00:55:16,440 --> 00:55:20,680 This is all being integrated into the sort of collective mind. 860 00:55:20,680 --> 00:55:25,600 So what Iain is saying is that, by one fish reacting to a predator 861 00:55:25,600 --> 00:55:30,240 and by moving away from it, the fish nearby rapidly respond too, 862 00:55:30,240 --> 00:55:34,400 and their behaviour is copied by the fish around them. 863 00:55:34,400 --> 00:55:38,240 And, in this way, the shoal responds collectively. 864 00:55:38,240 --> 00:55:43,040 There's no leader, but they act together through a collective mind. 865 00:55:43,040 --> 00:55:45,920 That's a very strange way of thinking. 866 00:55:45,920 --> 00:55:47,960 It's a different type of intelligence. 867 00:55:50,480 --> 00:55:54,640 By coming together, these animals boost their brainpower, 868 00:55:54,640 --> 00:55:57,840 forming a more intelligent whole. 869 00:55:57,840 --> 00:56:00,760 And, as it turns out, the mathematical rules 870 00:56:00,760 --> 00:56:04,000 behind collective behaviour in animals may be applied 871 00:56:04,000 --> 00:56:05,400 to our lives too. 872 00:56:07,040 --> 00:56:09,480 Using the same types of technologies, we can also 873 00:56:09,480 --> 00:56:12,720 study how people move and behave within crowds. 874 00:56:12,720 --> 00:56:15,560 And this is very important to improve crowd safety, 875 00:56:15,560 --> 00:56:19,040 because we're not necessarily aware, when we're moving through a crowd, 876 00:56:19,040 --> 00:56:22,280 when there are dangerous conditions emerging. 877 00:56:22,280 --> 00:56:26,720 To stop density building up to dangerous levels can help the flow 878 00:56:26,720 --> 00:56:29,640 of people through crowded environments. 879 00:56:29,640 --> 00:56:33,040 So animal collectives may help keep us safer. 880 00:56:33,040 --> 00:56:34,440 But there's more. 881 00:56:34,440 --> 00:56:38,840 The most exciting part of Iain's work is at the cellular level. 882 00:56:38,840 --> 00:56:42,760 The principles that underlie swarm formation in the animal world 883 00:56:42,760 --> 00:56:46,040 also inform us at how cells form swarms. 884 00:56:48,360 --> 00:56:52,080 So when we look at the movement and the invasion of cancer cells 885 00:56:52,080 --> 00:56:55,760 in the body, we're realising now that almost all tumours actually 886 00:56:55,760 --> 00:56:58,400 invade as a collective, whether it's a raft of cells 887 00:56:58,400 --> 00:57:02,040 going through the bloodstream, or some tendrils of cells spreading 888 00:57:02,040 --> 00:57:03,560 out from a brain tumour. 889 00:57:03,560 --> 00:57:06,080 And so we're realising that collective behaviour 890 00:57:06,080 --> 00:57:08,840 is the fundamental process that we need to understand, 891 00:57:08,840 --> 00:57:13,000 to try to divert them, to try to prevent the tumours from being able 892 00:57:13,000 --> 00:57:16,080 to invade tissue, prevent them from being able to spread 893 00:57:16,080 --> 00:57:17,520 throughout the body. 894 00:57:18,880 --> 00:57:21,320 Now that's an incredible thought. 895 00:57:22,400 --> 00:57:24,840 Understanding how these collectives move... 896 00:57:26,280 --> 00:57:29,480 ..could help us tackle cancer more effectively. 897 00:57:33,360 --> 00:57:37,200 Through developing a better understanding of how animals move 898 00:57:37,200 --> 00:57:40,920 and travel, we're not only learning more about their intelligence, 899 00:57:40,920 --> 00:57:44,200 we're learning how to find more intelligent solutions to help 900 00:57:44,200 --> 00:57:45,320 us humans, too. 901 00:57:47,240 --> 00:57:51,880 We are now beginning to realise just how smart nature's travellers are - 902 00:57:51,880 --> 00:57:54,040 from their impressive spatial memory... 903 00:57:55,360 --> 00:57:59,120 ..to navigating using the sun and stars. 904 00:57:59,120 --> 00:58:02,600 Even making their trips in the most efficient ways possible. 905 00:58:03,840 --> 00:58:06,440 And, throughout this series, what I've discovered 906 00:58:06,440 --> 00:58:09,080 about the complexity of animal minds, 907 00:58:09,080 --> 00:58:13,800 how they communicate, build, con and cooperate, 908 00:58:13,800 --> 00:58:17,040 has completely transformed what I thought I knew 909 00:58:17,040 --> 00:58:18,880 about animal intelligence. 910 00:58:18,880 --> 00:58:22,160 The brains of the natural world are far brighter, 911 00:58:22,160 --> 00:58:26,960 more sophisticated and flexible than I could have ever imagined.