1 00:00:36,600 --> 00:00:38,800 The coast. 2 00:00:38,800 --> 00:00:41,280 Nature's most demanding hunting ground. 3 00:00:49,640 --> 00:00:53,600 So hazardous that few predators stay here all year. 4 00:01:03,160 --> 00:01:08,640 This frontier between sea and land is continuously changing. 5 00:01:17,800 --> 00:01:20,120 Opportunities never last long. 6 00:01:23,640 --> 00:01:28,240 To hunt at the coast, you have to be in the right place 7 00:01:28,240 --> 00:01:30,000 at just the right time. 8 00:01:46,400 --> 00:01:51,760 On the east coast of America, in the tidal creeks of South Carolina, 9 00:01:51,760 --> 00:01:56,720 a team of hunters is about to leave the safety of their natural habitat. 10 00:02:18,720 --> 00:02:22,640 This group of bottlenose dolphins has perfected 11 00:02:22,640 --> 00:02:24,480 a unique hunting strategy. 12 00:02:27,520 --> 00:02:32,720 It relies on teamwork, intelligence and timing. 13 00:02:42,160 --> 00:02:47,360 But beaching themselves like this is also difficult and dangerous. 14 00:03:06,200 --> 00:03:10,240 Hunting is only possible for three hours around low tide, 15 00:03:10,240 --> 00:03:12,640 when the mud banks are exposed. 16 00:03:17,680 --> 00:03:22,400 Razor-sharp oysters cover much of the shore. 17 00:03:22,400 --> 00:03:24,560 Beaching here could be lethal. 18 00:03:35,000 --> 00:03:37,840 The hunters need to find a stretch of shoreline 19 00:03:37,840 --> 00:03:39,400 with just the right slope. 20 00:03:42,520 --> 00:03:45,520 Too level and the dolphins risk stranding. 21 00:03:50,800 --> 00:03:54,320 Too steep and they can't force their prey from the water. 22 00:04:06,760 --> 00:04:10,120 Working as a team, the dolphins surround the fish, 23 00:04:10,120 --> 00:04:12,200 driving them towards the shore. 24 00:04:35,440 --> 00:04:39,720 Attacking in perfect synchrony, the dolphins create a bow wave. 25 00:04:46,200 --> 00:04:49,200 It carries their prey onto the muddy banks. 26 00:05:03,280 --> 00:05:06,000 Other fish-eaters profit from their daring. 27 00:05:12,520 --> 00:05:15,440 Herons and gulls follow every hunt. 28 00:05:27,840 --> 00:05:29,680 To get to the fish first, 29 00:05:29,680 --> 00:05:32,440 the dolphins drive themselves high up the bank. 30 00:05:33,760 --> 00:05:36,840 But if they go too far, they risk stranding. 31 00:05:50,200 --> 00:05:52,840 To prevent fish escaping between them, 32 00:05:52,840 --> 00:05:56,040 the dolphins all beach themselves on the same side. 33 00:05:59,680 --> 00:06:01,120 Always the right. 34 00:06:03,480 --> 00:06:05,680 But this has a cost - 35 00:06:05,680 --> 00:06:09,960 each time they grab a fish, they also take in a mouthful of mud. 36 00:06:12,320 --> 00:06:15,480 The grit gradually wears down their teeth... 37 00:06:20,120 --> 00:06:21,560 ..but on one side only. 38 00:06:27,800 --> 00:06:32,200 In time, these teeth get so worn down that older dolphins can no 39 00:06:32,200 --> 00:06:36,240 longer hunt like this and must find other ways to catch fish. 40 00:06:51,800 --> 00:06:56,160 Within a few hours, the banks will vanish once again 41 00:06:56,160 --> 00:06:58,240 beneath the muddy water. 42 00:07:04,400 --> 00:07:08,480 The ebb and flow of the tide dominates the lives of all 43 00:07:08,480 --> 00:07:11,360 who try to hunt on the coast. 44 00:07:22,480 --> 00:07:26,600 Northern Australia has the highest tides in the tropics, 45 00:07:26,600 --> 00:07:29,160 which expose vast areas of shoreline. 46 00:07:34,080 --> 00:07:38,920 And here lives a truly extraordinary species of octopus. 47 00:07:50,400 --> 00:07:55,680 Octopuses are marine animals - they live and breathe underwater. 48 00:08:02,120 --> 00:08:07,080 At low tide, most octopuses would be imprisoned in their rocky pools. 49 00:08:13,760 --> 00:08:17,040 But this is no ordinary octopus. 50 00:08:49,360 --> 00:08:54,120 It's the only one specially adapted to walk on land. 51 00:08:56,280 --> 00:08:58,240 It pulls itself along, 52 00:08:58,240 --> 00:09:02,280 using the hundreds of tiny suckers that line its arms. 53 00:09:08,440 --> 00:09:12,320 Hunting for crabs, it walks from pool to pool. 54 00:09:24,120 --> 00:09:26,240 Apart from a rather startled fish... 55 00:09:31,600 --> 00:09:33,560 ..this one is empty. 56 00:09:43,840 --> 00:09:45,920 So the octopus moves on. 57 00:10:03,000 --> 00:10:06,720 A rock pool may seem like a safe refuge. 58 00:10:13,720 --> 00:10:17,080 But the octopus' suckers enable it to move 59 00:10:17,080 --> 00:10:20,320 just as stealthily in water as out of it. 60 00:11:00,160 --> 00:11:04,280 Nowhere is safe when this octopus is around. 61 00:11:09,040 --> 00:11:13,560 Everything living here must march to the rhythm of the coast. 62 00:11:43,120 --> 00:11:47,920 Regiments of soldier crabs, several thousand strong, 63 00:11:47,920 --> 00:11:52,280 march and counter-march across these Australian beaches. 64 00:12:02,600 --> 00:12:05,720 They sift out microscopic food. 65 00:12:05,720 --> 00:12:09,840 But they can only feed for a few hours while the sand remains damp. 66 00:12:15,880 --> 00:12:19,240 And it's not just the tide they're racing against. 67 00:12:24,320 --> 00:12:27,800 Hunting birds follow in their wake. 68 00:12:29,680 --> 00:12:32,160 But the army is undeterred. 69 00:12:41,560 --> 00:12:43,680 They swarm in such huge numbers 70 00:12:43,680 --> 00:12:46,640 that their predators make little impact upon them. 71 00:12:50,840 --> 00:12:54,720 But safety in numbers isn't the only defence on these flats. 72 00:12:58,480 --> 00:13:02,360 Another crab here has a different strategy. 73 00:13:02,360 --> 00:13:05,960 The sand bubbler crab - no bigger than a pea. 74 00:13:08,280 --> 00:13:11,480 They also sift out tiny food particles 75 00:13:11,480 --> 00:13:15,040 and then leave the sand as pellets in their wake. 76 00:13:20,320 --> 00:13:25,600 Sand bubblers are wary and never venture far from their burrows. 77 00:13:30,480 --> 00:13:33,920 The crabs position their sand balls very carefully 78 00:13:33,920 --> 00:13:36,800 to ensure there is a clear path back to safety. 79 00:14:03,160 --> 00:14:06,480 As soon as the coast is clear, they're off again, 80 00:14:06,480 --> 00:14:09,600 racing to feed before the sand dries out. 81 00:14:26,200 --> 00:14:30,320 The industry of thousands transforms the whole beach... 82 00:14:38,680 --> 00:14:40,760 ..until the tide returns once more. 83 00:14:45,880 --> 00:14:49,880 Few hunters make the coast their permanent home - 84 00:14:49,880 --> 00:14:54,320 most only visit to take advantage of short-lived opportunities. 85 00:15:00,320 --> 00:15:02,960 On the coast of Thailand, 86 00:15:02,960 --> 00:15:07,080 a most unlikely visitor waits for the tide to ebb. 87 00:15:21,720 --> 00:15:27,240 Long-tailed macaques feed mostly on fruit and leaves in the forest. 88 00:15:28,960 --> 00:15:33,720 But these have learnt to supplement their vegetarian diet with seafood. 89 00:15:38,080 --> 00:15:41,200 As the tide begins to fall, the macaques make their way 90 00:15:41,200 --> 00:15:45,560 down to the shore - a beach-side restaurant is about to open. 91 00:15:58,600 --> 00:16:02,600 There's plenty of food here, if you know how to get at it. 92 00:16:08,080 --> 00:16:12,160 The macaques have learnt to use heavy rocks as tools 93 00:16:12,160 --> 00:16:14,120 to break open the sea snails. 94 00:16:17,200 --> 00:16:21,880 It takes a great deal of skill to master this technique, 95 00:16:21,880 --> 00:16:25,080 but not everyone has got the hang of it. 96 00:16:56,160 --> 00:17:00,320 You have to be ingenious to make a living at the coast. 97 00:17:02,800 --> 00:17:07,240 As the tide falls still further, it reveals the next course. 98 00:17:12,320 --> 00:17:14,080 To feed on this dish, 99 00:17:14,080 --> 00:17:17,520 they need a stone tool with a very particular shape. 100 00:17:19,760 --> 00:17:21,840 They're after rock oysters. 101 00:17:28,720 --> 00:17:31,680 To crack the shells open, they must strike the oyster 102 00:17:31,680 --> 00:17:34,840 in just the right place with their chosen tool. 103 00:17:51,480 --> 00:17:56,160 The lowest tide reveals a course that is particularly delicious... 104 00:17:59,520 --> 00:18:01,960 ..but also very hard to collect. 105 00:18:14,240 --> 00:18:19,480 Crabs have good eyesight and can move fast. 106 00:18:19,480 --> 00:18:23,040 So catching them requires a special trick. 107 00:18:29,560 --> 00:18:33,960 Before pouncing, the macaques wait for a wave to obscure their attack. 108 00:18:53,080 --> 00:18:56,880 Macaques learn their skills by watching their parents. 109 00:19:04,720 --> 00:19:08,640 But some techniques do take time to perfect. 110 00:19:26,800 --> 00:19:30,560 And time and tide waits for no macaque. 111 00:19:41,560 --> 00:19:46,040 The returning water closes the beach restaurant for another day. 112 00:19:59,920 --> 00:20:02,080 It's not just tides that rule the lives 113 00:20:02,080 --> 00:20:03,880 of those that live on the coast. 114 00:20:09,600 --> 00:20:11,480 The shores of Chile are battered 115 00:20:11,480 --> 00:20:15,240 by some of the wildest and coldest seas. 116 00:20:21,880 --> 00:20:25,800 This coastline is home to a remarkable little hunter... 117 00:20:32,840 --> 00:20:35,680 ..the South American marine otter. 118 00:20:37,760 --> 00:20:40,520 The world's smallest sea mammal. 119 00:20:45,520 --> 00:20:50,520 This rare and elusive otter is half the size of its European cousin. 120 00:21:02,680 --> 00:21:05,920 They live along the Pacific coast of South America, 121 00:21:05,920 --> 00:21:09,800 right down to Cape Horn at the very tip of the continent. 122 00:21:14,800 --> 00:21:16,920 Surprisingly, the pounding breakers 123 00:21:16,920 --> 00:21:20,160 aren't a problem for the little otters... 124 00:21:21,400 --> 00:21:23,000 ..but the cold water is. 125 00:21:27,560 --> 00:21:32,000 A continuous frigid current sweeps up from Antarctica. 126 00:21:41,560 --> 00:21:46,720 A small body loses heat faster than a large one, and so these tiny 127 00:21:46,720 --> 00:21:51,480 otters can only hunt in the chilly water for 20 minutes at a time. 128 00:21:56,400 --> 00:22:00,440 But their small size enables them to reach the fish and crabs 129 00:22:00,440 --> 00:22:02,320 that hide amongst the boulders. 130 00:22:15,960 --> 00:22:20,280 To stay warm, marine otters have to eat a quarter of their body weight 131 00:22:20,280 --> 00:22:23,000 in seafood every single day. 132 00:22:31,000 --> 00:22:33,920 And things are particularly hard for this female 133 00:22:33,920 --> 00:22:38,280 because her cubs aren't yet old enough to hunt for themselves. 134 00:22:50,800 --> 00:22:54,480 Before each fishing trip she rolls in seaweed, 135 00:22:54,480 --> 00:22:56,800 trapping air in her fur, 136 00:22:56,800 --> 00:23:00,240 so insulating herself from the chill of the seas. 137 00:23:08,360 --> 00:23:10,840 The cold isn't her only challenge. 138 00:23:14,200 --> 00:23:17,560 Being so small, these otters can only hold their breath 139 00:23:17,560 --> 00:23:22,640 for about a minute, making every dive a race against time. 140 00:23:31,000 --> 00:23:35,080 This otter lives on a calorific knife-edge, 141 00:23:35,080 --> 00:23:39,400 often only getting enough from one hunting trip to fuel the next. 142 00:24:22,520 --> 00:24:25,760 Success - a meal for the youngsters. 143 00:24:42,200 --> 00:24:46,840 These otters spend their entire lives at the coast, 144 00:24:46,840 --> 00:24:50,880 so they must accept its day-to-day challenges. 145 00:24:50,880 --> 00:24:55,400 But coasts pulse to much more than just the daily rhythms. 146 00:25:20,280 --> 00:25:22,280 On the shores of Alaska, 147 00:25:22,280 --> 00:25:26,880 a spectacular annual event is about to take place. 148 00:25:30,800 --> 00:25:36,280 Each July, predators gather for the biggest feast of the year... 149 00:25:36,280 --> 00:25:39,680 but it will only last a few weeks. 150 00:25:45,600 --> 00:25:48,920 Brown bears come down from the hills. 151 00:25:53,080 --> 00:25:55,640 Wolves appear out of the woods. 152 00:25:57,200 --> 00:25:59,920 And seals assemble in the ocean. 153 00:26:02,120 --> 00:26:05,800 The coast is the only place where hunters from the sea 154 00:26:05,800 --> 00:26:08,040 meet those from land and air. 155 00:26:11,040 --> 00:26:16,240 Bears have a sense of smell 2,000 times better than ours 156 00:26:16,240 --> 00:26:19,520 and can even detect prey out at sea. 157 00:26:22,200 --> 00:26:25,320 They know the salmon are coming. 158 00:26:28,760 --> 00:26:31,240 BARKING 159 00:26:31,240 --> 00:26:34,320 They also know the best fishing spots... 160 00:26:35,760 --> 00:26:38,320 ..and are prepared to fight for them. 161 00:26:44,520 --> 00:26:46,400 GROWLING 162 00:26:56,760 --> 00:26:58,560 GROWLING 163 00:27:09,880 --> 00:27:12,440 After years feeding out in the Pacific, 164 00:27:12,440 --> 00:27:16,000 the salmon are returning to spawn. 165 00:27:16,000 --> 00:27:17,640 But before they head upriver, 166 00:27:17,640 --> 00:27:22,320 they must pause and modify their bodies to function in fresh water. 167 00:27:32,080 --> 00:27:35,480 The young and overeager try to catch the salmon 168 00:27:35,480 --> 00:27:37,400 while they're still in the surf. 169 00:27:39,680 --> 00:27:43,680 Those with experience are more patient. 170 00:27:48,360 --> 00:27:51,920 After six months of starvation in a winter den, 171 00:27:51,920 --> 00:27:55,640 all this food is just too tempting for the youngster. 172 00:28:14,320 --> 00:28:18,640 Wise old bears wait for the salmon to move into the river, 173 00:28:18,640 --> 00:28:21,120 where they know the fishing will be easier. 174 00:28:25,840 --> 00:28:28,960 The incoming tide signals a change. 175 00:28:32,120 --> 00:28:36,400 The experienced bears now take up their prized fishing spots 176 00:28:36,400 --> 00:28:38,080 at the mouth of the river. 177 00:28:40,800 --> 00:28:43,080 The salmon are finally here. 178 00:28:47,320 --> 00:28:50,120 As the fish are funnelled into shallower water, 179 00:28:50,120 --> 00:28:52,480 a seal gets its chance. 180 00:29:22,840 --> 00:29:24,480 The wolves will have to wait. 181 00:29:27,280 --> 00:29:29,960 Bears dominate the river-mouth. 182 00:29:59,120 --> 00:30:01,520 These bears rely on the salmon run 183 00:30:01,520 --> 00:30:05,200 for nearly 90% of their year's food. 184 00:30:11,280 --> 00:30:15,760 Most of the salmon make it upstream past the bears, 185 00:30:15,760 --> 00:30:19,320 but now they must run the gauntlet of wolves. 186 00:30:56,640 --> 00:31:01,160 The salmon will sustain the wolves through the rest of the summer. 187 00:31:04,880 --> 00:31:08,440 The sheer abundance of this seasonal bounty 188 00:31:08,440 --> 00:31:12,480 has made these bears the largest in North America. 189 00:31:21,560 --> 00:31:26,480 Estuaries are the meeting place of rivers and sea, 190 00:31:26,480 --> 00:31:30,440 and they're vital staging points for migrating birds. 191 00:31:33,480 --> 00:31:38,280 In Europe, each autumn, they're visited by millions of waders. 192 00:31:42,040 --> 00:31:45,880 The birds are returning from their breeding grounds in the Arctic 193 00:31:45,880 --> 00:31:50,000 to overwinter in Africa, and are stopping off to refuel. 194 00:31:56,560 --> 00:32:00,560 Knot can only feed when the mudflats are exposed. 195 00:32:02,680 --> 00:32:05,480 At high tide, they're forced onshore 196 00:32:05,480 --> 00:32:09,400 where they must wait for the tide to turn and reopen the larder. 197 00:32:19,480 --> 00:32:21,200 A peregrine falcon. 198 00:32:28,080 --> 00:32:30,480 BIRDS SQUAWK 199 00:32:40,160 --> 00:32:44,240 Young peregrines come to these estuaries in autumn... 200 00:32:44,240 --> 00:32:46,000 to hunt waders. 201 00:32:48,520 --> 00:32:52,320 Peregrines are the world's fastest aerial hunters, 202 00:32:52,320 --> 00:32:56,600 but this is a very challenging environment for a young falcon. 203 00:32:59,840 --> 00:33:03,880 It's one predator faced with thousands of prey. 204 00:33:08,360 --> 00:33:09,880 Flashing black and white, 205 00:33:09,880 --> 00:33:14,840 the swirling mass of wings dazzles the falcon's sensitive eyesight. 206 00:33:39,680 --> 00:33:43,320 An individual target may be a better option. 207 00:33:54,920 --> 00:33:58,160 A peregrine's plumage is not properly waterproof, 208 00:33:58,160 --> 00:34:00,680 so he can't afford to get his feathers wet. 209 00:34:02,920 --> 00:34:05,640 He must flush his prey into the air. 210 00:34:13,000 --> 00:34:14,720 But as soon as he gets close, 211 00:34:14,720 --> 00:34:18,280 the waders ditch into the sea where he can't follow. 212 00:34:47,680 --> 00:34:52,600 Success depends on keeping his prey away from the water. 213 00:34:57,400 --> 00:35:00,320 Now it's a dogfight at close quarters. 214 00:35:33,280 --> 00:35:36,080 Peregrines only stay around estuaries 215 00:35:36,080 --> 00:35:38,960 for the few months the waders are there. 216 00:35:38,960 --> 00:35:42,920 As soon as their prey leaves, they will head back inland. 217 00:35:52,480 --> 00:35:55,880 Some animals come to the coast, not to feed 218 00:35:55,880 --> 00:35:57,280 but to have their young. 219 00:36:10,280 --> 00:36:12,160 SEA LION CALLS 220 00:36:13,720 --> 00:36:15,040 Patagonian sea lions. 221 00:36:17,680 --> 00:36:19,880 These are just a few months old. 222 00:36:28,160 --> 00:36:31,160 Sea lions can't give birth at sea, 223 00:36:31,160 --> 00:36:33,600 they must come to land to have their pups. 224 00:36:40,840 --> 00:36:43,840 Each summer, thousands cluster in colonies 225 00:36:43,840 --> 00:36:46,960 along Argentina's Valdes Peninsula. 226 00:36:53,320 --> 00:36:56,000 The mothers regularly return to sea to hunt... 227 00:36:57,720 --> 00:36:59,720 ..but their young stay on the beach 228 00:36:59,720 --> 00:37:01,840 for they have not yet learnt to swim. 229 00:37:28,920 --> 00:37:31,080 Orca. Killer whales. 230 00:37:34,160 --> 00:37:38,840 They come at exactly the same time each year to hunt the pups. 231 00:37:44,560 --> 00:37:47,600 It's a narrow window of opportunity 232 00:37:47,600 --> 00:37:51,000 and the odds are stacked against the hunters. 233 00:38:00,200 --> 00:38:01,840 Just like the dolphins, 234 00:38:01,840 --> 00:38:05,560 orca take great risks in leaving their natural habitat. 235 00:38:12,480 --> 00:38:15,960 With every attack, there's a real danger of being stranded. 236 00:38:34,320 --> 00:38:37,880 Orca can only hunt for a few hours each day, 237 00:38:37,880 --> 00:38:43,240 because at low tide a rocky reef blocks their access to the beach. 238 00:38:49,360 --> 00:38:54,320 So until the tide is high, the pups are safe. 239 00:39:00,560 --> 00:39:04,560 Early in the season the orca have one big advantage... 240 00:39:06,200 --> 00:39:10,080 ..the pups are naive and don't yet recognise the whales as a threat. 241 00:39:17,360 --> 00:39:20,520 But the young sea lions will learn quickly. 242 00:39:25,280 --> 00:39:29,240 Silently, the killer whales move into position. 243 00:39:51,200 --> 00:39:54,400 Less than half the attacks are successful 244 00:39:54,400 --> 00:39:57,320 and with each attempt, the pups grow wiser. 245 00:40:00,880 --> 00:40:04,280 The orca's advantage is slipping away. 246 00:40:18,800 --> 00:40:20,640 For the next few weeks, 247 00:40:20,640 --> 00:40:25,000 hunter and hunted are locked in a desperate race. 248 00:40:26,680 --> 00:40:29,240 The orca to seize pups, 249 00:40:29,240 --> 00:40:32,840 and the sea lions to learn how to evade their attacks. 250 00:41:29,400 --> 00:41:32,760 These young sea lions have triumphed. 251 00:41:32,760 --> 00:41:37,160 They've learnt to recognise the danger and evade the killers. 252 00:41:45,560 --> 00:41:47,000 For the orca, 253 00:41:47,000 --> 00:41:51,480 the window of opportunity has closed for another season. 254 00:42:01,520 --> 00:42:03,880 Newfoundland, Canada. 255 00:42:09,560 --> 00:42:14,760 A unique seasonal event is about to transform this place. 256 00:42:16,280 --> 00:42:20,760 It is the greatest coastal breeding spectacle on the planet, 257 00:42:20,760 --> 00:42:23,600 but it will only last a week or two. 258 00:42:27,080 --> 00:42:29,200 Capelin. 259 00:42:29,200 --> 00:42:30,720 Billions of them. 260 00:42:34,600 --> 00:42:39,640 In early summer, these tiny fish mass just offshore. 261 00:42:45,080 --> 00:42:47,880 The great shoals inevitably attract predators. 262 00:42:53,960 --> 00:42:55,800 Humpback whales. 263 00:43:07,480 --> 00:43:10,520 They've travelled over 3,000 miles 264 00:43:10,520 --> 00:43:13,200 from their breeding grounds in the Caribbean. 265 00:43:14,600 --> 00:43:16,360 Nowhere else in the world 266 00:43:16,360 --> 00:43:19,880 do humpback whales gather to feed in greater numbers. 267 00:43:29,600 --> 00:43:31,960 But no sooner have the whales arrived 268 00:43:31,960 --> 00:43:35,560 than the capelin do something apparently suicidal. 269 00:43:49,320 --> 00:43:52,920 They deliberately cast themselves ashore, 270 00:43:52,920 --> 00:43:56,560 and, once out of water, they lay their eggs. 271 00:44:03,400 --> 00:44:06,200 They're one of only two species of fish 272 00:44:06,200 --> 00:44:08,720 that leave the ocean to spawn like this. 273 00:44:19,760 --> 00:44:23,040 A fish out of water is an easy meal. 274 00:44:26,480 --> 00:44:29,560 But capelin go to these extreme lengths 275 00:44:29,560 --> 00:44:32,720 to give their offspring the best chance of survival. 276 00:44:34,280 --> 00:44:37,000 For many, it's the ultimate sacrifice. 277 00:44:49,880 --> 00:44:51,440 Cod. 278 00:44:51,440 --> 00:44:54,520 Great numbers of them move in from deeper water 279 00:44:54,520 --> 00:44:57,040 to plunder this brief bounty. 280 00:45:02,600 --> 00:45:05,920 Their impact on the vast shoals is small 281 00:45:05,920 --> 00:45:10,240 but as they hunt, the cod drive capelin off the seabed 282 00:45:10,240 --> 00:45:13,240 and up into the range of the waiting humpbacks. 283 00:45:28,400 --> 00:45:31,360 The whales herd the fish against the cliffs. 284 00:45:46,360 --> 00:45:49,760 Then they unleash a secret weapon. 285 00:45:49,760 --> 00:45:53,240 ERRATIC WHALE SOUNDS 286 00:46:04,560 --> 00:46:08,760 These bizarre calls panic the capelin, 287 00:46:08,760 --> 00:46:12,040 driving the fish ever closer together, 288 00:46:12,040 --> 00:46:14,760 making them a more concentrated target. 289 00:46:17,960 --> 00:46:20,760 ERRATIC WHALE SOUNDS CONTINUE 290 00:46:26,160 --> 00:46:29,200 This bonanza will disperse within days, 291 00:46:29,200 --> 00:46:32,480 so the humpbacks have to make the most of it while they can. 292 00:46:37,920 --> 00:46:43,040 Hunters at the coast are always in a race against time. 293 00:47:38,240 --> 00:47:42,920 The Hunt team came to Chile to film the world's smallest sea mammal... 294 00:47:44,280 --> 00:47:46,600 ..the South American marine otter. 295 00:47:49,200 --> 00:47:50,840 The thing about these otters 296 00:47:50,840 --> 00:47:53,600 is no-one really knows anything about them. 297 00:47:53,600 --> 00:47:58,040 No-one's actually studied them for any length of time at all. 298 00:47:58,040 --> 00:48:00,080 So Mark is going to have to work out 299 00:48:00,080 --> 00:48:02,920 the otters' movements and habits for himself. 300 00:48:06,000 --> 00:48:08,440 These otters have never been filmed before, 301 00:48:08,440 --> 00:48:11,320 but Mark has a lot of experience with British otters 302 00:48:11,320 --> 00:48:13,440 so it should be straightforward. 303 00:48:19,160 --> 00:48:23,120 Filming them underwater, however, is a daunting prospect - 304 00:48:23,120 --> 00:48:25,440 no-one has ever tried to dive with them. 305 00:48:27,360 --> 00:48:31,200 It's not going to be easy. Maybe one shot a day, two shots a day 306 00:48:31,200 --> 00:48:33,440 would be a successful trip. 307 00:48:34,640 --> 00:48:37,640 But the underwater team has a plan. 308 00:48:37,640 --> 00:48:39,800 Now, what we've got are these camouflaged wet suits, 309 00:48:39,800 --> 00:48:41,320 camouflage tape on the camera, 310 00:48:41,320 --> 00:48:44,360 just to try and help us to blend in a little bit more. 311 00:48:44,360 --> 00:48:45,880 And so does Mark. 312 00:48:45,880 --> 00:48:48,560 Well, you probably can't actually see me now, of course, 313 00:48:48,560 --> 00:48:49,960 covered in camo. 314 00:48:49,960 --> 00:48:51,880 But going to work, definitely going to work. 315 00:48:51,880 --> 00:48:54,840 Much better than Pearson's camo wet suit palaver! 316 00:48:55,880 --> 00:48:58,560 Grown men dressed like that, it's ridiculous. 317 00:49:03,240 --> 00:49:05,240 We can't just get into the water and see them 318 00:49:05,240 --> 00:49:06,680 because they move too quickly. 319 00:49:06,680 --> 00:49:09,040 So I've got this little comms unit inside of my mask 320 00:49:09,040 --> 00:49:11,000 and I can listen to it underwater. 321 00:49:11,000 --> 00:49:13,480 Joaquin can talk to me from the search. 322 00:49:15,200 --> 00:49:16,240 Oh, there's one. 323 00:49:21,200 --> 00:49:23,840 - JOAQUIN: - He's going west under rock one. 324 00:49:23,840 --> 00:49:25,720 I repeat, west under rock one. 325 00:49:28,680 --> 00:49:31,560 He's on the surface, swimming really fast to three. 326 00:49:33,520 --> 00:49:36,120 A combination of eyes on the surface... 327 00:49:38,320 --> 00:49:40,000 He's coming back to two. 328 00:49:40,000 --> 00:49:44,000 ..and camouflage below brings early results. 329 00:49:47,160 --> 00:49:52,400 Filming otters underwater is turning out to be easier than Doug expected. 330 00:49:52,400 --> 00:49:53,480 That was cool. 331 00:49:53,480 --> 00:49:56,120 I wasn't sure we were going to see one of these guys underwater 332 00:49:56,120 --> 00:49:57,840 but, yeah, very encouraging. 333 00:49:59,560 --> 00:50:01,640 Success for the underwater team 334 00:50:01,640 --> 00:50:03,840 means the pressure is now on Mark. 335 00:50:06,760 --> 00:50:09,160 I've been here six-and-a-half hours 336 00:50:09,160 --> 00:50:10,600 and I've got one shot. 337 00:50:11,800 --> 00:50:15,040 Not very good shot of it on a rock over there. 338 00:50:15,040 --> 00:50:16,640 It's not going to work. 339 00:50:17,680 --> 00:50:19,560 It's not going to work like that. 340 00:50:23,680 --> 00:50:26,480 I think the only way that we're going to get any more 341 00:50:26,480 --> 00:50:31,840 is to find out a way of getting consistently close to them. 342 00:50:31,840 --> 00:50:34,560 I think the only way of doing that is at a den 343 00:50:34,560 --> 00:50:39,760 where there's cubs and they're coming back to it consistently. 344 00:50:41,480 --> 00:50:46,560 Surprisingly, the most likely den site is in a busy harbour. 345 00:50:48,320 --> 00:50:51,760 So we are just by the den of the otters 346 00:50:51,760 --> 00:50:54,400 and we are going to put the hide on location 347 00:50:54,400 --> 00:50:57,640 to hopefully get some shots of the otter up close. 348 00:51:00,000 --> 00:51:03,960 It's just a very weird mixture of, like, trying to hide from the animal 349 00:51:03,960 --> 00:51:06,640 when in fact it just sees people all the time. 350 00:51:08,480 --> 00:51:09,960 Doesn't quite add up. 351 00:51:11,680 --> 00:51:14,320 Right, well, you can just leave me in here now. I'm quite happy. 352 00:51:14,320 --> 00:51:17,200 Just send me down empanadas every few hours. 353 00:51:17,200 --> 00:51:20,240 See if you can have a word with the otters, 354 00:51:20,240 --> 00:51:21,840 tell them that dinner's up. 355 00:51:31,840 --> 00:51:35,920 I've been sat here now for three hours, looking at a rock. 356 00:51:40,080 --> 00:51:42,480 After a week of surveillance... 357 00:51:44,960 --> 00:51:47,560 Where's it gone, where is it, where is it, where is it? 358 00:51:47,560 --> 00:51:51,040 ..Mark is no closer to figuring out any pattern 359 00:51:51,040 --> 00:51:52,920 in the otters' behaviour. 360 00:51:52,920 --> 00:51:55,120 Oh, don't do that. 361 00:51:55,120 --> 00:51:59,480 He's had only fleeting glimpses of the adults and no cubs. 362 00:52:05,120 --> 00:52:07,520 The weird thing is, I've filmed otters in Scotland 363 00:52:07,520 --> 00:52:10,960 and so I've been equating those otters with these otters. 364 00:52:10,960 --> 00:52:13,000 The more you find out about these otters, 365 00:52:13,000 --> 00:52:16,160 you realise that they're just not similar at all. 366 00:52:16,160 --> 00:52:19,400 All your tactics that you thought would work with otters 367 00:52:19,400 --> 00:52:21,040 are just straight out the window, 368 00:52:21,040 --> 00:52:22,680 so it's like starting again. 369 00:52:24,600 --> 00:52:30,080 News of another otter family nearby raises Mark's hopes. 370 00:52:30,080 --> 00:52:31,480 (It's going to happen.) 371 00:52:32,800 --> 00:52:34,680 The day starts out with promise. 372 00:52:37,800 --> 00:52:40,680 - ON RADIO: - 'I've just seen one of the cubs in the den. 373 00:52:41,840 --> 00:52:44,600 'Just for... It was about half a second.' 374 00:52:44,600 --> 00:52:46,440 That's great news. Over. 375 00:52:48,280 --> 00:52:51,160 But the sun brings out unwelcome visitors. 376 00:52:53,280 --> 00:52:56,400 Ah, yeah, there's been one around. About three hours ago, 377 00:52:56,400 --> 00:53:02,200 but a few people have turned up on the beach 378 00:53:02,200 --> 00:53:03,840 and we haven't seen it since. 379 00:53:08,840 --> 00:53:12,200 The topside shoot is proving to be much more difficult 380 00:53:12,200 --> 00:53:14,120 than anyone could have imagined. 381 00:53:15,880 --> 00:53:17,560 This is rather depressing 382 00:53:17,560 --> 00:53:22,080 because it's the only place that we have been able to actually see cubs. 383 00:53:25,200 --> 00:53:29,400 The big worry, really, is that the cubs are being moved 384 00:53:29,400 --> 00:53:31,520 from den to den. 385 00:53:31,520 --> 00:53:33,480 If they are being moved from den to den, 386 00:53:33,480 --> 00:53:37,480 then staking the dens out is almost impossible. 387 00:53:38,840 --> 00:53:42,000 Such are the challenges of trying to film an animal 388 00:53:42,000 --> 00:53:44,040 about which we know so little. 389 00:53:49,640 --> 00:53:52,080 With all their options exhausted, 390 00:53:52,080 --> 00:53:56,200 Mark and Ignacio dismantle their hide in the harbour. 391 00:53:56,200 --> 00:54:00,160 Wow! Wow! 392 00:54:00,160 --> 00:54:03,760 Oh, my... What the...? 393 00:54:03,760 --> 00:54:07,640 The hide that was supposed to be for Mark has been used by the otters. 394 00:54:07,640 --> 00:54:09,080 Look at his face! 395 00:54:16,400 --> 00:54:17,840 I can't believe it. 396 00:54:17,840 --> 00:54:21,320 They've been using the hide as a larder for their food. 397 00:54:25,760 --> 00:54:28,720 I've never felt so utterly defeated 398 00:54:28,720 --> 00:54:30,800 by an animal that I've tried to film. 399 00:54:32,760 --> 00:54:38,800 After two months, I still have no idea about these animals. 400 00:54:38,800 --> 00:54:40,320 Really no idea. 401 00:54:44,440 --> 00:54:46,360 I thought that was an otter, then! 402 00:54:52,040 --> 00:54:57,080 I just went to see in another cove this early morning, 403 00:54:57,080 --> 00:55:01,880 and I just found two little cubs playing in the water with one adult. 404 00:55:04,320 --> 00:55:05,360 What? 405 00:55:08,600 --> 00:55:12,640 We've finally got within 100 metres of a mother and cubs. 406 00:55:19,880 --> 00:55:21,440 Through sheer persistence, 407 00:55:21,440 --> 00:55:25,080 Mark finally gets his chance to film an otter family. 408 00:55:38,880 --> 00:55:41,000 You know, they don't feel like mammals, 409 00:55:41,000 --> 00:55:42,520 they're almost like little eels, 410 00:55:42,520 --> 00:55:45,360 you know, the way they disappear underneath the boulders. 411 00:55:47,280 --> 00:55:49,840 I think we've genuinely revealed something new about them - 412 00:55:49,840 --> 00:55:51,040 how they hunt. 413 00:55:51,040 --> 00:55:52,760 You know, they go through these rocks 414 00:55:52,760 --> 00:55:54,640 and that's why they're so small. 415 00:55:58,320 --> 00:56:01,720 What makes the otters successful hunters on this coast 416 00:56:01,720 --> 00:56:04,040 is also what makes them so hard to film... 417 00:56:06,520 --> 00:56:10,920 ..they're small, fast and have an affinity for nooks and crannies. 418 00:56:15,440 --> 00:56:16,880 And Mark? 419 00:56:16,880 --> 00:56:18,960 He's finally learnt the secret 420 00:56:18,960 --> 00:56:21,720 to filming the world's smallest marine mammal. 421 00:56:23,240 --> 00:56:24,720 Keep the faith. 422 00:56:26,480 --> 00:56:28,160 Yeah, keep the faith. 423 00:56:32,400 --> 00:56:35,120 Next time, in the final episode, 424 00:56:35,120 --> 00:56:38,400 we examine the health of our planet's top predators. 425 00:56:42,800 --> 00:56:45,800 We meet the pioneers on the front-line, 426 00:56:45,800 --> 00:56:47,840 searching for bold solutions. 427 00:56:50,400 --> 00:56:54,480 Can people make room for the world's most celebrated hunters? 428 00:56:56,680 --> 00:57:00,120 For a free interactive Open University poster, call... 429 00:57:04,520 --> 00:57:05,840 Or go to... 430 00:57:08,680 --> 00:57:11,520 ..and follow the links to the Open University.