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