1 00:00:20,145 --> 00:00:23,898 The most powerful predators to walk the Earth. 2 00:00:27,277 --> 00:00:29,821 But it takes more than brute force… 3 00:00:35,076 --> 00:00:36,703 …to reach the top. 4 00:00:38,288 --> 00:00:40,123 With remarkable brain power, 5 00:00:41,291 --> 00:00:44,210 and by making the most of any opportunity, 6 00:00:45,837 --> 00:00:49,883 bears rule some of the planet's most hostile lands. 7 00:00:55,013 --> 00:00:58,641 But cubs aren't born with the skills to survive. 8 00:01:00,894 --> 00:01:02,395 They need to be taught. 9 00:01:04,814 --> 00:01:08,109 So a mother bear has her work cut out 10 00:01:08,193 --> 00:01:09,736 preparing her cubs 11 00:01:09,819 --> 00:01:11,529 to face the world. 12 00:01:32,425 --> 00:01:34,594 Locked in winter's icy grip, 13 00:01:36,471 --> 00:01:37,847 northern forests 14 00:01:38,932 --> 00:01:39,849 are still. 15 00:01:42,143 --> 00:01:43,019 Silent. 16 00:01:44,854 --> 00:01:46,689 No clues to suggest 17 00:01:48,149 --> 00:01:50,068 that hidden beneath the snow, 18 00:01:50,860 --> 00:01:53,404 a giant lies asleep. 19 00:02:02,288 --> 00:02:03,748 Breathing slow. 20 00:02:09,379 --> 00:02:11,798 Heart beating just eight times a minute. 21 00:02:15,301 --> 00:02:17,137 Nothing to eat since fall. 22 00:02:19,973 --> 00:02:21,349 For three months, 23 00:02:21,933 --> 00:02:25,520 this American black bear has been in suspended animation. 24 00:02:29,858 --> 00:02:31,359 Even more miraculous… 25 00:02:34,529 --> 00:02:35,780 three weeks ago, 26 00:02:36,322 --> 00:02:40,118 she woke just long enough to give birth 27 00:02:40,660 --> 00:02:41,911 to three cubs. 28 00:02:48,835 --> 00:02:52,630 Each just the weight of a can of soup. 29 00:03:00,889 --> 00:03:04,267 Though she's surviving on nothing but fat reserves, 30 00:03:05,059 --> 00:03:06,895 her babies won't go hungry. 31 00:03:09,689 --> 00:03:11,191 Her milk so rich, 32 00:03:12,358 --> 00:03:14,319 they've already doubled in size. 33 00:03:19,365 --> 00:03:22,994 This same story is unfolding across North America. 34 00:03:25,496 --> 00:03:28,666 Over half a million hibernating black bears. 35 00:03:29,626 --> 00:03:30,710 Underground. 36 00:03:32,921 --> 00:03:35,340 Or tucked under fallen trees. 37 00:03:38,009 --> 00:03:40,887 Some, incredibly, right out in the open. 38 00:03:46,476 --> 00:03:50,730 Cubs snuggle close, kept alive by their mother's warmth. 39 00:03:56,945 --> 00:03:58,363 But this mom 40 00:03:58,446 --> 00:04:01,199 picked the coziest of dens. 41 00:04:08,790 --> 00:04:10,792 When the spring finally arrives, 42 00:04:11,459 --> 00:04:13,336 her hard work will begin. 43 00:04:16,506 --> 00:04:18,049 A bear's upbringing 44 00:04:18,758 --> 00:04:20,843 shapes the whole of its life. 45 00:04:27,558 --> 00:04:30,228 There are just eight species of bear. 46 00:04:36,693 --> 00:04:39,153 Found from the jungles of Asia 47 00:04:39,904 --> 00:04:42,198 to the ice sheets of the Arctic. 48 00:04:44,450 --> 00:04:46,869 Some are surprisingly small, 49 00:04:46,953 --> 00:04:48,496 just the size of a dog. 50 00:04:49,205 --> 00:04:52,709 Others weigh in at nearly a ton. 51 00:04:55,461 --> 00:04:58,172 Though all are classified as carnivores, 52 00:04:58,256 --> 00:05:01,092 most eat whatever they can get their paws on. 53 00:05:03,970 --> 00:05:07,557 But how to find the right food at the right time 54 00:05:08,182 --> 00:05:10,685 can only be taught by a devoted mother. 55 00:05:13,062 --> 00:05:15,815 Each bear's home comes with its own challenges. 56 00:05:22,113 --> 00:05:24,407 So learning to use brains 57 00:05:24,490 --> 00:05:26,117 as well as brawn 58 00:05:27,493 --> 00:05:29,370 is crucial to survival. 59 00:05:39,213 --> 00:05:40,590 The Arctic winter. 60 00:05:43,926 --> 00:05:44,761 Hostile. 61 00:05:47,221 --> 00:05:48,139 Lifeless. 62 00:05:50,516 --> 00:05:51,351 Well, 63 00:05:51,851 --> 00:05:53,102 not entirely. 64 00:06:13,122 --> 00:06:15,124 Even at 40 below, 65 00:06:15,917 --> 00:06:17,752 a polar bear is well insulated, 66 00:06:18,669 --> 00:06:20,380 with a double layer of fur 67 00:06:20,963 --> 00:06:23,925 and a blanket of fat as thick as a man's arm. 68 00:06:29,722 --> 00:06:32,225 Polar bears never have to hibernate. 69 00:06:33,142 --> 00:06:35,812 Winter is their hunting season. 70 00:06:39,524 --> 00:06:41,651 Seals are their favorite prey, 71 00:06:42,819 --> 00:06:46,697 and polar bears use their astounding sense of smell 72 00:06:46,781 --> 00:06:49,450 to detect them many miles away. 73 00:06:56,916 --> 00:06:59,085 This male has picked up a scent, 74 00:06:59,919 --> 00:07:01,921 but it's not prey. 75 00:07:03,631 --> 00:07:05,425 It's other bears. 76 00:07:10,513 --> 00:07:14,767 Male bears are known to kill cubs that are not their own. 77 00:07:17,478 --> 00:07:22,191 This mom's young, near fully grown, are not so vulnerable. 78 00:07:23,609 --> 00:07:26,446 Still, best to keep their distance. 79 00:07:31,868 --> 00:07:34,078 Before they can strike out alone, 80 00:07:34,162 --> 00:07:36,914 they need to perfect their hunting skills. 81 00:07:41,794 --> 00:07:43,963 And this may be a chance 82 00:07:44,881 --> 00:07:47,717 for Mom to show how it's done. 83 00:08:05,067 --> 00:08:06,569 Approach from downwind. 84 00:08:09,071 --> 00:08:10,656 Use camouflage. 85 00:08:15,661 --> 00:08:17,455 Sneak into striking range. 86 00:08:58,287 --> 00:09:00,206 With each successful hunt, 87 00:09:00,289 --> 00:09:04,001 Mom helps her cubs grow stronger and wiser. 88 00:09:07,380 --> 00:09:11,175 Once they leave her, these lessons will make the difference 89 00:09:11,759 --> 00:09:13,844 between life and death. 90 00:09:27,900 --> 00:09:31,237 Bears start learning from Mom the day they leave the den. 91 00:09:41,872 --> 00:09:45,001 Spring has finally arrived for the black bear family, 92 00:09:46,460 --> 00:09:49,213 and the great outdoors is calling. 93 00:09:55,136 --> 00:09:59,056 Mama bear has lost over 100 pounds of fat since fall, 94 00:09:59,807 --> 00:10:01,350 nearly half her body weight, 95 00:10:02,059 --> 00:10:03,978 so she's ready to get going. 96 00:10:06,564 --> 00:10:08,566 But happily full of milk, 97 00:10:09,108 --> 00:10:12,445 her cubs seem in less of a hurry. 98 00:10:18,993 --> 00:10:21,329 It's a whole new world. 99 00:10:23,914 --> 00:10:26,000 Climbing comes naturally. 100 00:10:27,126 --> 00:10:30,504 Even so, it's a bit of an obstacle course. 101 00:10:48,648 --> 00:10:50,149 Right from the first hurdle… 102 00:10:52,401 --> 00:10:53,736 Mom's got their back. 103 00:10:57,573 --> 00:11:02,203 She alone is provider, teacher, and protector. 104 00:11:04,497 --> 00:11:06,332 It's a huge responsibility. 105 00:11:07,083 --> 00:11:10,294 Around a third of cubs don't survive their first year. 106 00:11:17,093 --> 00:11:19,470 One of the greatest dangers they'll face 107 00:11:20,388 --> 00:11:21,889 is other bears. 108 00:11:30,564 --> 00:11:33,943 Brown bears, sometimes known as grizzlies, 109 00:11:34,026 --> 00:11:36,821 have come down from winter dens in the mountains. 110 00:11:39,156 --> 00:11:42,493 They gather in coastal meadows to feed on sedge grass. 111 00:11:44,412 --> 00:11:48,249 Bears don't defend a territory like cats or dogs, 112 00:11:49,291 --> 00:11:51,544 but they still know who's boss. 113 00:11:56,590 --> 00:11:59,051 This old dominant male 114 00:11:59,135 --> 00:12:02,513 has laid claim to this grazing spot for years. 115 00:12:10,479 --> 00:12:12,440 He needs to pile on the pounds 116 00:12:13,649 --> 00:12:16,444 so he can take on anyone who dares challenge him 117 00:12:16,527 --> 00:12:18,571 when breeding season arrives. 118 00:12:28,831 --> 00:12:32,585 This grass is surprisingly high in muscle-building protein. 119 00:12:37,631 --> 00:12:40,676 But if you're smarter than the average bear, 120 00:12:40,760 --> 00:12:43,429 there's even more nutritious food to be found. 121 00:12:50,311 --> 00:12:52,855 This mom is taking her cub 122 00:12:52,938 --> 00:12:56,150 on an exclusive dining experience. 123 00:13:03,365 --> 00:13:06,827 A muddy beach might look unpromising… 124 00:13:13,042 --> 00:13:16,879 …but a little digging can unearth some treasure. 125 00:13:23,219 --> 00:13:24,970 Once you've found a clam, 126 00:13:25,805 --> 00:13:27,139 it needs shucking. 127 00:13:28,432 --> 00:13:30,726 A surprisingly delicate operation. 128 00:13:36,607 --> 00:13:38,776 Not all bears here can do this. 129 00:13:40,069 --> 00:13:42,029 She picked it up from her mother. 130 00:13:43,155 --> 00:13:44,573 And now she's passing it on. 131 00:13:50,204 --> 00:13:51,455 At low tide, 132 00:13:51,539 --> 00:13:55,000 a talented clammer might get a hundred of these juicy treats. 133 00:14:00,923 --> 00:14:02,925 A much better protein hit 134 00:14:03,008 --> 00:14:05,469 than from the same time spent grazing. 135 00:14:10,766 --> 00:14:14,895 Teaching her daughter will give her a head start in a competitive world. 136 00:14:34,373 --> 00:14:35,416 A stranger. 137 00:14:39,378 --> 00:14:40,671 Time to back off. 138 00:14:43,799 --> 00:14:45,342 Another important lesson. 139 00:14:46,051 --> 00:14:48,637 Avoid confrontation if you can. 140 00:14:51,849 --> 00:14:55,060 An angry bear is a force of nature. 141 00:15:08,741 --> 00:15:10,451 Even when the opponent is bigger, 142 00:15:11,160 --> 00:15:12,870 never bet against a bear. 143 00:15:15,831 --> 00:15:17,791 Or its claws. 144 00:15:19,460 --> 00:15:22,755 Up to four inches long, they're fearsome weapons. 145 00:15:25,758 --> 00:15:28,719 But they're also multi-purpose tools. 146 00:15:30,137 --> 00:15:31,347 Climbing spikes. 147 00:15:33,557 --> 00:15:34,600 Shovels. 148 00:15:35,517 --> 00:15:36,727 Ice hooks. 149 00:15:37,645 --> 00:15:39,271 Even silverware. 150 00:15:41,857 --> 00:15:44,193 And when it's time for a good old scratch… 151 00:15:45,986 --> 00:15:47,279 …there's nothing better. 152 00:15:49,698 --> 00:15:51,533 Some of the longest claws 153 00:15:51,617 --> 00:15:53,953 belong to the smallest of bears. 154 00:15:56,163 --> 00:15:58,916 Just one-tenth the size of a grizzly, 155 00:15:58,999 --> 00:16:03,003 a sun bear is a jungle survival specialist. 156 00:16:10,135 --> 00:16:12,846 Finding food in the tangle of vegetation 157 00:16:12,930 --> 00:16:13,764 isn't easy. 158 00:16:20,604 --> 00:16:23,857 But with an almost unrivaled sense of smell… 159 00:16:27,194 --> 00:16:29,113 he follows his nose. 160 00:16:51,176 --> 00:16:54,179 He's narrowed down the source of the sweet aroma. 161 00:16:55,514 --> 00:16:58,183 Just one problem. 162 00:16:59,977 --> 00:17:01,979 It's all the way up there. 163 00:17:05,649 --> 00:17:07,693 Four stories high. 164 00:17:09,820 --> 00:17:11,655 But sun bears 165 00:17:11,739 --> 00:17:13,282 love honey. 166 00:17:18,579 --> 00:17:21,707 Good thing they're also champion climbers. 167 00:17:28,422 --> 00:17:32,593 Those long, curved claws give excellent grip, 168 00:17:33,635 --> 00:17:37,514 and a dog-sized frame keeps him light and agile. 169 00:17:38,265 --> 00:17:39,099 But 170 00:17:40,267 --> 00:17:42,186 he's barking up the wrong tree. 171 00:17:46,398 --> 00:17:47,733 And now 172 00:17:48,734 --> 00:17:50,486 he's got competition. 173 00:18:01,663 --> 00:18:04,333 Or has he? 174 00:18:08,879 --> 00:18:12,883 Sun bears also love feasting on grubs inside rotten logs. 175 00:18:26,647 --> 00:18:29,024 While the other bear's distracted, 176 00:18:29,108 --> 00:18:31,360 a chance to switch trees. 177 00:18:46,959 --> 00:18:48,085 The bees are angry, 178 00:18:48,627 --> 00:18:50,212 but thankfully stingless. 179 00:18:53,298 --> 00:18:54,299 At last… 180 00:18:56,552 --> 00:18:57,928 he's struck gold. 181 00:19:03,767 --> 00:19:06,645 Those claws also make a handy honey scoop. 182 00:19:13,443 --> 00:19:16,363 And a ten-inch tongue does the rest. 183 00:19:22,995 --> 00:19:25,581 When it comes to finding food in the jungle, 184 00:19:25,664 --> 00:19:28,500 sun bears have it licked. 185 00:19:37,176 --> 00:19:40,637 But as the forests they rely on are cleared for agriculture… 186 00:19:42,890 --> 00:19:45,017 it's leaving sun bears homeless. 187 00:19:48,562 --> 00:19:52,733 And more exposed to poaching for traditional remedies. 188 00:19:55,444 --> 00:19:57,946 They're now the rarest bear on Earth. 189 00:20:01,992 --> 00:20:03,285 Rarer even 190 00:20:03,952 --> 00:20:06,705 than the most enigmatic bear of all. 191 00:20:41,657 --> 00:20:45,118 The giant panda spends most of its life 192 00:20:45,202 --> 00:20:47,204 eating just one thing. 193 00:20:50,123 --> 00:20:50,999 Bamboo. 194 00:20:55,837 --> 00:20:58,632 She can lounge around for 12 hours 195 00:20:58,715 --> 00:21:00,133 gorging on the stuff. 196 00:21:03,345 --> 00:21:06,515 It makes up 99% of her diet. 197 00:21:11,561 --> 00:21:13,480 She's the only bear 198 00:21:13,563 --> 00:21:16,400 with a bony pad on her paw, kind of like a thumb. 199 00:21:18,902 --> 00:21:22,281 Perfect for making a bamboo hot dog. 200 00:21:23,782 --> 00:21:27,327 This veggie diet seems a bizarre choice. 201 00:21:27,411 --> 00:21:29,204 Pandas evolved to eat meat. 202 00:21:33,000 --> 00:21:35,335 But because bamboo's plentiful 203 00:21:35,419 --> 00:21:37,045 and grows year round, 204 00:21:37,129 --> 00:21:41,091 over millions of years, they switched to the easier option. 205 00:21:43,927 --> 00:21:45,220 Trouble is, 206 00:21:45,304 --> 00:21:48,598 their gut hasn't fully adapted to digest it. 207 00:21:51,101 --> 00:21:54,771 So she only survives by doing a lot of eating. 208 00:21:56,690 --> 00:21:58,150 And very little else. 209 00:22:08,327 --> 00:22:12,372 But when humans cut down swathes of Asia's bamboo forests, 210 00:22:13,165 --> 00:22:15,459 pandas had nothing left to eat 211 00:22:16,251 --> 00:22:18,795 and were forced to the brink of extinction. 212 00:22:21,715 --> 00:22:24,217 Such a specialized diet is the exception. 213 00:22:26,053 --> 00:22:29,181 Most bears have more adventurous tastes. 214 00:22:38,732 --> 00:22:41,026 The forests on the Canadian border 215 00:22:41,651 --> 00:22:44,696 are home to tens of thousands of black bears. 216 00:22:46,156 --> 00:22:49,034 It's midsummer, and this mother is leading her cubs 217 00:22:49,117 --> 00:22:50,660 on a feeding foray. 218 00:22:52,120 --> 00:22:55,374 She keeps them on track with soft grunts. 219 00:22:59,544 --> 00:23:02,130 At six months, they're curious. 220 00:23:07,803 --> 00:23:10,263 But still naive. 221 00:23:18,980 --> 00:23:22,401 Mom must be their eyes and ears. 222 00:23:31,868 --> 00:23:33,453 Her low moan tells them 223 00:23:34,454 --> 00:23:35,747 something's not right. 224 00:23:45,340 --> 00:23:46,258 A male. 225 00:23:48,218 --> 00:23:49,719 He could kill her cubs 226 00:23:50,262 --> 00:23:52,139 and force her back into heat. 227 00:23:56,268 --> 00:23:59,271 When Mom growls, it's time to hide. 228 00:24:18,081 --> 00:24:19,374 She's warning the male, 229 00:24:19,958 --> 00:24:22,169 but he's not getting the message. 230 00:24:27,507 --> 00:24:29,801 That cough means "climb." 231 00:24:51,907 --> 00:24:56,745 Now Mom must keep her nerve and stand her ground. 232 00:25:03,502 --> 00:25:05,462 Until he understands 233 00:25:05,545 --> 00:25:07,339 she's not to be messed with. 234 00:25:21,269 --> 00:25:23,021 Ever since leaving the den, 235 00:25:23,688 --> 00:25:26,107 Mom's encouraged her cubs to climb. 236 00:25:29,528 --> 00:25:30,612 It's paid off. 237 00:25:35,158 --> 00:25:37,619 Till she's sure the coast is clear, 238 00:25:37,702 --> 00:25:39,371 they'll stay off the ground. 239 00:25:43,625 --> 00:25:45,919 A chance for some more climbing practice, 240 00:25:47,128 --> 00:25:49,965 while Mom grabs a bit of well-earned shut-eye. 241 00:26:08,858 --> 00:26:09,985 But not too much. 242 00:26:11,820 --> 00:26:13,071 Fall is coming, 243 00:26:13,655 --> 00:26:16,116 and the whole family needs to feed up. 244 00:26:21,788 --> 00:26:23,623 In more hostile lands, 245 00:26:23,707 --> 00:26:25,542 finding food and water 246 00:26:25,625 --> 00:26:27,419 is a year-round struggle. 247 00:26:37,137 --> 00:26:39,639 These peaks may look uninhabitable… 248 00:26:42,267 --> 00:26:44,394 but for a few spectacled bears, 249 00:26:45,353 --> 00:26:46,187 it's home. 250 00:26:47,772 --> 00:26:51,067 The only species of bear in South America. 251 00:26:52,861 --> 00:26:54,696 The real-life Paddington. 252 00:26:57,407 --> 00:27:00,035 But no need for a duffle coat and rain hat here. 253 00:27:01,077 --> 00:27:03,496 The tallest mountains block clouds… 254 00:27:07,917 --> 00:27:10,837 …creating a high-altitude desert. 255 00:27:17,636 --> 00:27:21,139 It can go eight months without rain. 256 00:27:32,025 --> 00:27:36,655 This is the only natural spring for miles. 257 00:27:39,366 --> 00:27:42,035 A lush oasis. 258 00:27:55,799 --> 00:27:57,676 He could chill out here all day. 259 00:28:03,473 --> 00:28:05,308 When a male hogs the bath, 260 00:28:06,393 --> 00:28:08,895 others must be more resourceful. 261 00:28:24,452 --> 00:28:26,538 This mother is showing her cub 262 00:28:26,621 --> 00:28:28,039 how even a tree trunk 263 00:28:28,123 --> 00:28:29,791 can be a survival aid. 264 00:28:30,875 --> 00:28:34,212 With the strongest jaws for her size of any bear, 265 00:28:34,295 --> 00:28:37,924 she easily tears it apart to reach the moisture inside. 266 00:28:47,183 --> 00:28:50,228 Food and water are so scarce, 267 00:28:50,311 --> 00:28:51,855 she must save energy. 268 00:28:52,647 --> 00:28:54,190 Rest often. 269 00:28:57,360 --> 00:28:59,446 It's a lot cooler off the ground, 270 00:28:59,529 --> 00:29:01,865 but spindly trees don't offer much support. 271 00:29:03,575 --> 00:29:07,203 So she does something no other bears do. 272 00:29:14,753 --> 00:29:16,629 She makes her own bed. 273 00:29:25,930 --> 00:29:27,640 It's this ingenuity 274 00:29:28,183 --> 00:29:31,978 that helps see her through till the rains finally return. 275 00:29:36,566 --> 00:29:38,318 Naturally air-conditioned. 276 00:29:40,945 --> 00:29:42,071 Nice and comfy. 277 00:29:44,032 --> 00:29:46,701 The perfect spot for a siesta. 278 00:29:52,582 --> 00:29:53,917 In the far north, 279 00:29:54,501 --> 00:29:56,044 life is less peaceful. 280 00:30:00,924 --> 00:30:02,675 The dominant grizzly. 281 00:30:03,760 --> 00:30:04,969 Since spring, 282 00:30:05,053 --> 00:30:07,347 he's packed on two pounds a day. 283 00:30:08,848 --> 00:30:10,517 He needs the extra weight. 284 00:30:14,062 --> 00:30:17,148 It's being bigger and badder that makes him the boss, 285 00:30:17,941 --> 00:30:19,984 controlling the best feeding spots 286 00:30:20,068 --> 00:30:22,111 and mating with the local females. 287 00:30:29,786 --> 00:30:31,788 But after a decade in charge, 288 00:30:32,956 --> 00:30:35,458 he seems to be losing his charm. 289 00:30:57,272 --> 00:31:00,525 And a bigger problem is coming his way. 290 00:31:15,748 --> 00:31:18,543 A younger male has sensed weakness. 291 00:31:32,307 --> 00:31:35,184 The boss needs to prove himself to the females 292 00:31:36,060 --> 00:31:38,897 and show junior who's in charge around here. 293 00:31:42,025 --> 00:31:43,526 The cowboy swagger. 294 00:31:51,659 --> 00:31:54,203 It's meant to look imposing. 295 00:31:58,708 --> 00:31:59,918 The only thing is, 296 00:32:01,502 --> 00:32:04,422 the youngster is enormous. 297 00:32:13,890 --> 00:32:15,767 But with females watching on… 298 00:32:17,894 --> 00:32:19,562 …no backing out now. 299 00:33:13,074 --> 00:33:15,660 The old boss is down for the count. 300 00:33:27,797 --> 00:33:30,049 The meadow's getting a change in management. 301 00:33:31,801 --> 00:33:33,428 Effective immediately. 302 00:33:42,186 --> 00:33:44,439 The old boss's reign is over. 303 00:33:51,237 --> 00:33:53,698 The female made the smart choice, 304 00:33:53,781 --> 00:33:57,702 holding out for a stronger, fitter bear to father her cubs. 305 00:34:00,788 --> 00:34:02,498 He spends the long, warm days 306 00:34:02,582 --> 00:34:04,000 reaping the rewards. 307 00:34:07,420 --> 00:34:09,047 But even further north, 308 00:34:09,130 --> 00:34:10,715 just getting through the summer 309 00:34:11,466 --> 00:34:12,967 is a serious struggle. 310 00:34:17,638 --> 00:34:20,224 Each year, as the Arctic warms, 311 00:34:20,308 --> 00:34:22,477 the sea ice retreats north. 312 00:34:36,032 --> 00:34:40,411 Polar bears become stranded on land, where there's little to eat. 313 00:34:48,252 --> 00:34:51,172 And now that climate change is making the ice melt earlier, 314 00:34:52,340 --> 00:34:54,425 polar bears go hungry for longer. 315 00:34:57,095 --> 00:34:59,680 A mom must do what it takes 316 00:34:59,764 --> 00:35:01,557 to keep her family alive. 317 00:35:06,521 --> 00:35:10,191 Even if it means leading them towards danger. 318 00:35:13,194 --> 00:35:15,113 On the north Alaskan coast, 319 00:35:15,196 --> 00:35:18,366 subsistence whale hunters leave piles of bones. 320 00:35:20,701 --> 00:35:22,578 Driven by hunger, 321 00:35:22,662 --> 00:35:25,039 bears come together to scavenge. 322 00:35:28,835 --> 00:35:31,879 They tolerate each other… to a point. 323 00:35:37,969 --> 00:35:42,098 Mom knows her cubs are vulnerable among bad-tempered adults. 324 00:35:48,062 --> 00:35:51,566 But the threat of starvation is even worse. 325 00:35:58,406 --> 00:36:02,618 The cubs will have to learn to cope with uncomfortable situations like this 326 00:36:03,161 --> 00:36:06,122 if they're to survive longer, hotter summers ahead. 327 00:36:12,420 --> 00:36:16,966 Even so, polar bear numbers are predicted to fall by a third 328 00:36:17,049 --> 00:36:18,759 over the next few decades. 329 00:36:26,851 --> 00:36:28,936 They're not the only ones under threat. 330 00:36:31,147 --> 00:36:36,194 Six of the eight bear species are vulnerable to extinction. 331 00:36:38,863 --> 00:36:40,239 Their biggest threat 332 00:36:41,199 --> 00:36:42,658 is habitat loss. 333 00:36:48,915 --> 00:36:51,083 Many also face persecution. 334 00:36:54,462 --> 00:36:56,756 But it's not too late to save them, 335 00:36:58,466 --> 00:37:01,302 to protect the wilderness they need to thrive… 336 00:37:04,347 --> 00:37:07,308 and help bears by rescuing, 337 00:37:07,391 --> 00:37:08,851 rehabilitating, 338 00:37:10,019 --> 00:37:11,187 and releasing them. 339 00:37:21,989 --> 00:37:23,699 It's been shown to work. 340 00:37:25,326 --> 00:37:27,787 Breeding projects and forest protection 341 00:37:27,870 --> 00:37:31,165 have almost doubled the number of wild pandas. 342 00:37:33,709 --> 00:37:35,628 If we make room for bears, 343 00:37:36,212 --> 00:37:38,965 their adaptable nature will do the rest. 344 00:37:41,342 --> 00:37:45,179 As long as they have someone to show them the way. 345 00:37:57,775 --> 00:38:00,486 As fall colors sweep across North America… 346 00:38:02,571 --> 00:38:07,076 black bear mothers have one last push to get cubs ready for winter. 347 00:38:08,995 --> 00:38:11,706 They target foods high in calories. 348 00:38:14,292 --> 00:38:18,713 In a good year, the acorn harvest provides plenty of carbs and fat. 349 00:38:24,010 --> 00:38:26,262 But when there's not enough food in the wild, 350 00:38:27,179 --> 00:38:28,889 bears get their dinner to go… 351 00:38:31,726 --> 00:38:32,977 heading downtown 352 00:38:33,602 --> 00:38:37,023 to make the most of the food we throw away. 353 00:38:41,110 --> 00:38:43,070 In the urban jungle 354 00:38:43,154 --> 00:38:44,530 or out in the wild, 355 00:38:44,613 --> 00:38:49,118 bears rely on their resourceful nature to feed up through fall. 356 00:38:53,331 --> 00:38:57,209 And the bigger the bear, the more epic the feast. 357 00:39:04,008 --> 00:39:05,551 Brown bears, 358 00:39:05,634 --> 00:39:08,304 the most widespread of all bears, 359 00:39:08,387 --> 00:39:11,682 found across North America, Europe, and Asia. 360 00:39:18,981 --> 00:39:22,193 The largest live where there's plenty of food. 361 00:39:23,319 --> 00:39:27,406 And there are around 10,000 on this volcanic peninsula. 362 00:39:30,159 --> 00:39:35,081 But this land will soon be snowbound for six months. 363 00:39:36,707 --> 00:39:41,128 To survive a hibernation that long, they'll need to double their weight. 364 00:39:43,589 --> 00:39:45,883 And there's only one way to do it. 365 00:39:46,926 --> 00:39:48,260 Go fishing. 366 00:40:01,982 --> 00:40:03,150 Every year, 367 00:40:03,234 --> 00:40:07,071 millions of breeding salmon provide a bonanza of prey. 368 00:40:15,413 --> 00:40:21,585 A big male can gorge on a staggering 100,000 calories a day. 369 00:40:22,128 --> 00:40:24,922 That's 300 cheeseburgers. 370 00:40:26,674 --> 00:40:28,467 It's called hyperphagia. 371 00:40:29,051 --> 00:40:30,386 They can eat 372 00:40:30,469 --> 00:40:31,679 and eat 373 00:40:32,263 --> 00:40:33,848 and eat 374 00:40:33,931 --> 00:40:35,766 without ever feeling full. 375 00:40:39,395 --> 00:40:41,939 Taking a seasonal feast and storing it as fat, 376 00:40:42,565 --> 00:40:44,608 fuel for the long winter ahead. 377 00:40:54,326 --> 00:40:57,163 Each bear lives life a little differently. 378 00:41:00,124 --> 00:41:02,751 But there's something they all have in common. 379 00:41:06,130 --> 00:41:08,090 The time mothers spend 380 00:41:08,174 --> 00:41:10,551 passing skills down generations… 381 00:41:16,140 --> 00:41:19,393 …and leading their cubs through the seasons 382 00:41:21,145 --> 00:41:23,939 is the real secret to a bear's success… 383 00:41:26,484 --> 00:41:29,195 whether enduring harsh deserts 384 00:41:30,863 --> 00:41:34,700 or heading out once again to face the Arctic winter. 385 00:41:48,172 --> 00:41:51,759 The black bear cubs have made it to the end of their year. 386 00:41:55,387 --> 00:41:56,388 Back in the den, 387 00:41:57,806 --> 00:41:59,600 batteries fully charged… 388 00:42:03,020 --> 00:42:05,022 …they've gone into standby mode. 389 00:42:11,695 --> 00:42:12,988 Safe and warm, 390 00:42:13,656 --> 00:42:16,242 they'll sleep tight till spring returns. 391 00:42:19,078 --> 00:42:21,497 Snuggled up to Mom.