1 00:00:18,435 --> 00:00:19,478 The night. 2 00:00:24,441 --> 00:00:30,822 A shadowy world that hides more than half the animals on our planet. 3 00:00:33,534 --> 00:00:38,747 Until now, cameras only offered a glimpse into their lives. 4 00:00:41,750 --> 00:00:44,795 But with next-generation technology, 5 00:00:44,878 --> 00:00:49,800 we can see the night as clear as day. 6 00:00:56,557 --> 00:01:00,727 With cameras a hundred times more sensitive than the human eye... 7 00:01:04,147 --> 00:01:06,859 we can now capture the beauty of night... 8 00:01:09,361 --> 00:01:10,487 in color. 9 00:01:15,367 --> 00:01:17,202 Alien landscapes. 10 00:01:20,289 --> 00:01:24,751 Strange creatures brought to life by the darkness. 11 00:01:27,713 --> 00:01:30,215 Unseen behaviors. 12 00:01:37,222 --> 00:01:40,767 Now we can follow the lives of animals 13 00:01:41,602 --> 00:01:44,104 in Earth's last true wilderness. 14 00:01:46,565 --> 00:01:47,608 The night. 15 00:02:10,672 --> 00:02:13,217 Winter in the Arctic. 16 00:02:17,471 --> 00:02:19,932 By day, the sun barely rises. 17 00:02:23,936 --> 00:02:26,021 And soon it will set. 18 00:02:27,356 --> 00:02:32,361 Plunging this frozen world into darkness for over a month. 19 00:02:38,909 --> 00:02:44,748 And for one arctic resident, it's a time of great change. 20 00:02:49,753 --> 00:02:52,548 This polar bear mother has twins. 21 00:03:00,973 --> 00:03:03,600 She'll look after them for two years, 22 00:03:04,434 --> 00:03:08,105 teaching them all the skills they'll need to survive. 23 00:03:18,615 --> 00:03:20,242 They follow her everywhere. 24 00:03:24,788 --> 00:03:26,415 No easy task. 25 00:03:33,672 --> 00:03:35,883 There's lots to learn. 26 00:03:45,517 --> 00:03:49,354 At the start of winter, there's so little food around, 27 00:03:50,063 --> 00:03:53,901 polar bear moms can lose a kilo of weight each day. 28 00:03:59,323 --> 00:04:00,949 Weak and hungry, 29 00:04:01,450 --> 00:04:05,287 just keeping her cubs safe through the freezing nights ahead 30 00:04:05,370 --> 00:04:07,998 will be her greatest challenge. 31 00:04:13,253 --> 00:04:16,255 And this family is not alone. 32 00:04:19,635 --> 00:04:25,474 Along the Arctic coastline, other hungry bears are gathering. 33 00:04:28,268 --> 00:04:31,271 Waiting for the temperature to drop so low 34 00:04:32,272 --> 00:04:35,984 that even the sea will freeze solid. 35 00:04:38,737 --> 00:04:43,242 Then they'll head out onto the sea ice to hunt for seals, 36 00:04:43,325 --> 00:04:47,329 a vital source of food for these ravenous bears. 37 00:04:53,502 --> 00:04:55,921 But until the big freeze comes, 38 00:04:56,463 --> 00:04:58,549 the mother and her cubs, 39 00:04:59,925 --> 00:05:05,013 and all the other bears, must play a waiting game. 40 00:05:16,483 --> 00:05:18,694 As the arctic winter draws in... 41 00:05:22,239 --> 00:05:23,866 the nights get longer. 42 00:05:29,538 --> 00:05:33,375 And this frozen landscape transforms. 43 00:05:42,342 --> 00:05:44,970 Filming just by the light of the moon... 44 00:05:51,393 --> 00:05:56,231 low light cameras capture this icy world 45 00:05:56,732 --> 00:05:58,567 like never before. 46 00:06:08,869 --> 00:06:10,996 Offering an intimate glimpse 47 00:06:12,289 --> 00:06:16,502 of what polar bears get up to under the stars. 48 00:06:27,179 --> 00:06:32,643 Tonight, the mother's first job is to suckle her hungry cubs. 49 00:06:45,489 --> 00:06:48,617 Her milk is more than 30% fat... 50 00:06:52,329 --> 00:06:57,543 helping the cubs develop the thick blubber they'll need to survive the winter. 51 00:07:02,714 --> 00:07:06,635 Next, it's time for a midnight clean. 52 00:07:10,347 --> 00:07:14,852 Rolling in the snow is how polar bears wash their thick fur. 53 00:07:29,491 --> 00:07:31,660 The cubs copy their mom. 54 00:07:38,000 --> 00:07:42,296 A regular snow bath keeps their coats well insulated. 55 00:07:46,466 --> 00:07:50,637 And tonight, they'll need all the warmth they can get. 56 00:07:53,223 --> 00:07:54,892 In the arctic winter, 57 00:07:56,059 --> 00:07:58,812 storms can strike with little warning. 58 00:08:01,023 --> 00:08:04,651 And for young cubs, these blizzards can prove fatal. 59 00:08:16,038 --> 00:08:18,749 But polar bears aren't the only animals 60 00:08:18,832 --> 00:08:21,960 that are active through the freezing winter nights. 61 00:08:24,463 --> 00:08:27,966 In snowy forests on the edge of the Arctic Circle, 62 00:08:28,509 --> 00:08:33,096 an equally tough little creature emerges in the moonlight. 63 00:08:36,265 --> 00:08:37,808 The mountain hare. 64 00:08:40,520 --> 00:08:44,483 To avoid predators, they only come out after dark. 65 00:08:48,487 --> 00:08:53,158 By the start of winter, their coat has changed from brown to white. 66 00:08:56,537 --> 00:08:58,539 The perfect camouflage. 67 00:09:06,713 --> 00:09:10,342 This young male is having a midnight snack. 68 00:09:14,638 --> 00:09:19,059 With limited food around, he must feed while he can. 69 00:09:21,854 --> 00:09:25,148 But he's not the only hungry hare here. 70 00:09:28,569 --> 00:09:31,572 Rivals must be seen off. 71 00:09:38,954 --> 00:09:42,416 Competition for food and mates can be fierce. 72 00:09:48,046 --> 00:09:52,050 Their chasing can hit speeds of 40 kilometers an hour. 73 00:10:04,313 --> 00:10:06,815 But when his rival won't back down... 74 00:10:09,234 --> 00:10:11,737 the gloves really come off. 75 00:10:19,203 --> 00:10:21,580 Few punches hit the target. 76 00:10:24,791 --> 00:10:27,878 It's all about who looks the toughest. 77 00:10:49,233 --> 00:10:52,361 Tonight, he emerges victorious. 78 00:10:54,571 --> 00:10:56,990 Giving this nocturnal champion 79 00:10:57,074 --> 00:11:00,994 the best chance of getting through the long winter nights ahead. 80 00:11:08,961 --> 00:11:10,921 Back on the coastline, 81 00:11:11,755 --> 00:11:15,342 the polar bear mother and her cubs hunker down 82 00:11:15,425 --> 00:11:17,177 as the temperatures plummet. 83 00:11:20,430 --> 00:11:25,394 During winter nights, polar cyclones blow in off the ocean 84 00:11:25,936 --> 00:11:29,439 with a wind chill of minus 50 degrees Celsius. 85 00:11:48,333 --> 00:11:52,212 Polar bear cubs are vulnerable to the severe cold. 86 00:11:55,007 --> 00:11:58,677 Only one in two make it through their first winter. 87 00:12:04,725 --> 00:12:10,189 But night cameras show the mother has an ingenious solution. 88 00:12:16,361 --> 00:12:17,654 She digs. 89 00:12:19,489 --> 00:12:21,575 Slowly carving out a shelter 90 00:12:23,035 --> 00:12:25,996 for her cubs to take refuge from the storm. 91 00:12:36,965 --> 00:12:40,761 Polar bear families can spend up to four nights 92 00:12:40,844 --> 00:12:42,971 holed up in dens like this. 93 00:12:46,308 --> 00:12:50,187 It's the only way mothers can keep their precious youngsters alive. 94 00:12:57,194 --> 00:12:58,862 The family must lie low... 95 00:13:02,074 --> 00:13:04,201 until the blizzard has passed. 96 00:13:20,384 --> 00:13:22,135 The storm subsides. 97 00:13:25,597 --> 00:13:31,603 And the family emerge to find the winds have brought great change. 98 00:13:40,279 --> 00:13:42,364 Where once there was ocean, 99 00:13:44,157 --> 00:13:46,660 now there's ice. 100 00:13:47,786 --> 00:13:49,997 As far as the eye can see. 101 00:13:55,878 --> 00:14:00,299 The mother leads her cubs towards the sea ice for the first time. 102 00:14:04,553 --> 00:14:09,057 To start the next chapter of their lives. 103 00:14:13,395 --> 00:14:14,855 In the weeks ahead, 104 00:14:14,938 --> 00:14:18,442 she'll teach them how to survive this frozen landscape 105 00:14:19,067 --> 00:14:21,153 through the long arctic winter. 106 00:14:30,162 --> 00:14:32,789 But she's not the only polar bear mother 107 00:14:33,498 --> 00:14:37,377 exploring this frozen landscape in the darkness. 108 00:14:41,798 --> 00:14:43,675 Far out on the sea ice, 109 00:14:44,259 --> 00:14:47,679 another mom has bigger parenting challenges. 110 00:14:56,563 --> 00:15:00,901 At four years old, her youngsters are nearly fully grown. 111 00:15:02,444 --> 00:15:04,029 Mischievous teenagers. 112 00:15:11,328 --> 00:15:14,665 Low light cameras catch something unusual. 113 00:15:15,707 --> 00:15:19,294 The cubs taking a nighttime dip. 114 00:15:35,853 --> 00:15:38,105 They're already excellent swimmers. 115 00:15:39,731 --> 00:15:44,236 But at this age, the hardest part is learning how to get out. 116 00:15:50,450 --> 00:15:53,912 The first cub has got the hang of it. 117 00:16:02,045 --> 00:16:03,380 But for his brother... 118 00:16:08,010 --> 00:16:09,386 it's more of a challenge. 119 00:16:23,233 --> 00:16:24,234 Finally. 120 00:16:26,570 --> 00:16:28,238 At least no one was watching. 121 00:16:31,033 --> 00:16:35,537 Even with such big cubs, the mother must be on her guard. 122 00:16:38,999 --> 00:16:42,002 At four years old, they're testing their boundaries. 123 00:16:46,548 --> 00:16:50,010 And with large males around, that can be dangerous. 124 00:16:51,929 --> 00:16:56,058 She'll have to keep them close in the nights ahead. 125 00:17:06,234 --> 00:17:09,154 Throughout the long, dark winter, 126 00:17:09,238 --> 00:17:12,324 the night skies over this frozen world 127 00:17:12,991 --> 00:17:17,996 become the backdrop for Earth's most magical light display. 128 00:17:21,040 --> 00:17:23,001 The aurora borealis. 129 00:17:30,926 --> 00:17:33,595 Energy from solar storms 130 00:17:34,179 --> 00:17:37,808 colliding with our atmosphere to make ribbons of light... 131 00:17:39,685 --> 00:17:42,312 more than a hundred kilometers high. 132 00:17:56,243 --> 00:17:59,037 They blaze both night and day. 133 00:18:01,081 --> 00:18:05,586 But we can only see them against the dark night sky. 134 00:18:25,814 --> 00:18:27,441 By late winter, 135 00:18:29,151 --> 00:18:31,737 the darkness starts to give up its hold. 136 00:18:35,032 --> 00:18:38,368 And the sun rises briefly above the horizon 137 00:18:39,286 --> 00:18:41,997 for the first time in weeks. 138 00:18:51,715 --> 00:18:54,009 In the first hours of twilight, 139 00:18:54,551 --> 00:19:00,057 the mother and her older cubs arrive in a frozen glacial bay. 140 00:19:02,935 --> 00:19:05,437 Whilst mom heads off to hunt for seals... 141 00:19:09,399 --> 00:19:12,194 the four-year-olds are free to play. 142 00:19:18,992 --> 00:19:20,327 But not for long. 143 00:19:25,832 --> 00:19:29,002 A lone bear is also in the bay. 144 00:19:43,559 --> 00:19:47,062 Solitary polar bears can be highly aggressive. 145 00:19:50,732 --> 00:19:55,028 But the cubs are curious. 146 00:20:10,711 --> 00:20:13,839 Approaching a stranger is risky. 147 00:20:27,603 --> 00:20:30,480 A fight could lead to serious injury. 148 00:20:55,214 --> 00:20:58,634 But then, what seemed like aggression... 149 00:21:01,720 --> 00:21:04,723 suddenly becomes more playful. 150 00:21:14,149 --> 00:21:17,778 It turns out the stranger is a young female. 151 00:21:19,488 --> 00:21:23,242 And this is all a romantic play fight. 152 00:21:30,582 --> 00:21:32,960 Polar bear rough-and-tumble. 153 00:21:35,712 --> 00:21:40,217 Such tender social behavior has rarely been seen before. 154 00:21:52,729 --> 00:21:55,357 With her cubs rapidly growing up, 155 00:21:57,609 --> 00:22:00,571 this mother's work is almost done. 156 00:22:03,740 --> 00:22:09,162 She's devoted the last four years of her life to looking after them. 157 00:22:16,044 --> 00:22:20,174 In the coming days, her boisterous cubs will leave her. 158 00:22:20,841 --> 00:22:23,677 And next year, these young bears 159 00:22:24,261 --> 00:22:29,600 will face the long, dark nights of winter on their own. 160 00:22:48,827 --> 00:22:50,495 -Ready? -Yeah. 161 00:22:52,080 --> 00:22:57,419 Filming polar bears at night would test the crew to their limits. 162 00:22:59,546 --> 00:23:02,841 And when a polar storm struck on night one, 163 00:23:02,925 --> 00:23:05,594 they got a sense of the challenges they'd face 164 00:23:05,677 --> 00:23:07,471 in the dark weeks ahead. 165 00:23:07,554 --> 00:23:09,765 It's about minus 30 out here at the moment. 166 00:23:10,265 --> 00:23:12,518 And I think we're finding the limits 167 00:23:12,601 --> 00:23:15,354 of what the cameras and equipment can put up with. 168 00:23:17,814 --> 00:23:20,234 So, we've got a long ride home in this. 169 00:23:25,531 --> 00:23:27,950 With the storm chasing them all the way, 170 00:23:28,033 --> 00:23:32,871 they had to rely on their GPS to find their way back to shelter. 171 00:23:38,961 --> 00:23:42,172 The next night, and the search for bears was hijacked 172 00:23:42,256 --> 00:23:44,800 by arctic conditions once more. 173 00:23:45,259 --> 00:23:46,301 Ready! 174 00:23:50,389 --> 00:23:54,726 Currently stuck in the ice. All this is surface water. 175 00:23:56,603 --> 00:24:00,315 Where fresh water runs off the land and onto the sea ice, 176 00:24:00,399 --> 00:24:03,235 it can melt, turning it to slush. 177 00:24:05,487 --> 00:24:07,739 The crew became trapped. 178 00:24:09,533 --> 00:24:13,537 Every move sank them deeper, closer to the ocean beneath. 179 00:24:18,792 --> 00:24:21,712 This is definitely the hardest shoot I've been on. 180 00:24:22,880 --> 00:24:25,632 Just bad weather and no polar bears. 181 00:24:31,013 --> 00:24:33,724 And things were about to get worse. 182 00:24:35,601 --> 00:24:39,897 Overnight, the sea ice, which the bears need to hunt on, 183 00:24:39,980 --> 00:24:42,608 suddenly sheared off and disappeared. 184 00:24:44,234 --> 00:24:49,198 Blown away, far from the shore, taking the polar bears with it. 185 00:24:52,910 --> 00:24:55,162 Even in the frozen depths of winter, 186 00:24:56,371 --> 00:24:58,999 the sea ice here is shrinking. 187 00:25:02,544 --> 00:25:07,549 A change in climate is making the future for polar bears uncertain. 188 00:25:14,389 --> 00:25:16,266 Three weeks into filming, 189 00:25:16,808 --> 00:25:19,019 the crew needed a change of luck. 190 00:25:20,437 --> 00:25:25,400 And there was the smallest glimmer of hope in the unlikeliest of places. 191 00:25:27,486 --> 00:25:29,863 Well, we've gone looking for the bears today, 192 00:25:29,947 --> 00:25:32,282 but looks like a bear's come looking for us. 193 00:25:32,366 --> 00:25:36,787 And made a beeline for our toilet. 194 00:25:37,788 --> 00:25:41,208 Wow. You can actually see teeth marks 195 00:25:41,291 --> 00:25:44,253 and the claw marks where the bear's been. 196 00:25:44,837 --> 00:25:47,130 Could be a nasty surprise while you're on the toilet. 197 00:25:52,219 --> 00:25:56,014 The next night, they caught the culprit red-handed. 198 00:26:02,187 --> 00:26:05,732 Luckily, it was unoccupied at the time. 199 00:26:12,114 --> 00:26:16,326 With bears about, things were finally looking up for the crew. 200 00:26:17,160 --> 00:26:21,540 And soon, their immense efforts were rewarded. 201 00:26:22,708 --> 00:26:25,752 Day 20, and we finally got bears. 202 00:26:25,836 --> 00:26:27,546 And not just one bear. 203 00:26:29,214 --> 00:26:32,134 Got a mother and two cubs. 204 00:26:33,135 --> 00:26:34,261 Finally. 205 00:26:45,314 --> 00:26:47,983 Oh, my God. They look beautiful, man. 206 00:26:52,905 --> 00:26:55,365 After many arctic adventures, 207 00:26:55,449 --> 00:26:58,952 the crew were finally able to capture unique footage 208 00:26:59,036 --> 00:27:01,455 of polar bears under moonlight. 209 00:27:06,084 --> 00:27:11,507 And reveal the secrets of the arctic night like never before.